CN104407073B

CN104407073B - A kind of control system of gas chromatograph and control method

Info

Publication number: CN104407073B
Application number: CN201410723149.2A
Authority: CN
Inventors: 时迎国; 秦高梧; 杜明娟
Original assignee: SHENYANG NORTHEAST INSTITUTE OF METAL MATERIALS Co Ltd
Current assignee: SHENYANG NORTHEAST INSTITUTE OF METAL MATERIALS Co Ltd
Priority date: 2014-12-02
Filing date: 2014-12-02
Publication date: 2016-03-02
Anticipated expiration: 2034-12-02
Also published as: CN104407073A

Abstract

The control system of a kind of gas chromatograph of the present invention and control method, belong to field of analytic instrument, the present invention does the control system of gas chromatograph advantage with Programmable Logic Controller is good stability, and antijamming capability is strong, without the need to welding main circuit board, easy-to-connect, be easy to Function Extension, self-checking function wherein facilitates maintenance and the use of instrument, and temperature control precision is high, the exponent number of intensification temperature control is more, and the control accuracy of gas pressure intensity and gas mass flow is higher.

Description

A kind of control system of gas chromatograph and control method

Technical field

The invention belongs to field of analytic instrument, be specifically related to a kind of control system and control method of gas chromatograph.

Background technology

Gas chromatography (gaschromatography is called for short GC) is the great science and technology achievement occurred nineteen fifties, this is a kind of new separation, analytical technology, it is obtained for widespread use in industry, agricultural, national defence, construction, scientific research, and in petro chemical industry, most raw material and product all can adopt vapor-phase chromatography to analyze; The Hidden fault checking transformer is can be used in power department; The quality of monitoring urban atmosphere and water is can be used in environmental protection work; Agriculturally can be used to monitor agricultural chemicals residual in crops; The quality checking and identify food quality is can be used in commercial department; Medically can be used to researching human body metabolism, physiological function; Clinically for differentiating drug poisoning or disease type; Can be used to automatically monitor gas in airship gas-tight silo etc. in cabin, universe.

The principle of work of GC mainly utilizes the difference of the boiling point of material, polarity and adsorption property to realize the separation of potpourri; Sample to be analyzed vaporizer vaporization after by inert gas (i.e. carrier gas, also mobile phase is) bring chromatographic column into, containing liquid or solid Stationary liquid in post, because the boiling point of component each in sample, polarity or absorption property are different, often kind of component is all tended to be formed between mobile phase and Stationary liquid distribute or adsorption equilibrium; But because carrier gas is flowing, in fact this balance is difficult to set up; Also just because of the flowing of carrier gas, make sample component carry out repeated multiple times distribution at the volley or adsorption/desorption attached, result is that the component that concentration is large in carrier gas first flows out chromatographic column, and flows out distribute the large component of concentration in Stationary liquid after; After component flows out chromatographic column, enter detecting device immediately; Detecting device can change sample component into electric signal, and the amount of the size of electric signal and tested component or concentration are directly proportional.When these signals are amplified and record, it has been exactly gas chromatogram.

GC is structurally made up of six Iarge-scale system: air-channel system, sampling system, piece-rate system, temperature control system, detection record system and control system, wherein control system cans be compared to the brain of GC, other five system coordination work are controlled, to reach optimal separation Detection results by it.

Control system many employings one chip microcomputer (single-chip microcomputer) technology of current gas chromatograph, the shortcoming of this technology is the impact that master control board is subject to the factors such as mask-making technology, layout structure, device quality, thus cause with the poor anti jamming capability of the gas chromatography control system of microcomputer development, failure rate is high, not easily expand, strong to the dependence of environment.

Summary of the invention

For the shortcoming of prior art, the present invention proposes a kind of control system and control method of gas chromatograph, and improve stability and antijamming capability to reach, without the need to welding main circuit board, easy-to-connect, is easy to the object of Function Extension.

A control system for gas chromatograph, this system comprises Programmable Logic Controller, thermal module, analog input and output module and touch-screen or computing machine, wherein,

First output terminal of described Programmable Logic Controller connects the 220V power supply relay input end of gas chromatograph, second output terminal of Programmable Logic Controller connects the column compartment relay input end of gas chromatograph, 3rd output terminal of Programmable Logic Controller connects the vaporizer relay input end of gas chromatograph, 4th output terminal of Programmable Logic Controller connects the detecting device relay input end of gas chromatograph, 5th output terminal of Programmable Logic Controller connects the back pullout (BPO) motor driver input end of gas chromatograph, 6th output terminal of Programmable Logic Controller connects the input end of touch-screen, the back pullout (BPO) limit sensors output terminal of gas chromatograph connects the first input end of Programmable Logic Controller, the output terminal of thermal module connects the second input end of Programmable Logic Controller, the gas pressure switch output terminal of gas circuit connects the 3rd input end of Programmable Logic Controller, first output terminal of analog input and output module connects the first input end of thermal module, the vaporizer temperature sensor output terminal of gas chromatograph connects the second input end of thermal module, the detector temperature sensor output of gas chromatograph connects the 3rd input end of thermal module, the column compartment temperature sensor output terminal of gas chromatograph connects the four-input terminal of thermal module, the input end of the output terminal connection mode analog quantity input/output module of the air pressure sensor in the gas circuit of gas chromatograph or gas mass flow rate sensors, second output terminal of the gas circuit proportion magnetic valve door input end connection mode analog quantity input/output module of gas chromatograph.

The control method adopting the control system of gas chromatograph to carry out, comprises the following steps:

Step 1, startup gas chromatograph;

Step 2, to the temperature sensor in the vaporizer of gas chromatograph, heating resistor in vaporizer, temperature sensor in column compartment, thermal resistance in column compartment, temperature sensor in detecting device, heating resistor in detecting device, column compartment back pullout (BPO) alignment sensor, drive the motor that back pullout (BPO) is rotated, back pullout (BPO) motor driver, gas pressure switch in gas circuit, in gas circuit, in air pressure sensor or gas mass flow rate sensors and gas circuit, proportion magnetic valve is tested, if there is fault, then by touch-screen or computer prompted user, if normal, then perform step 3,

Specifically comprise the steps:

Step 2-1, the temperature sensor in the vaporizer of gas chromatograph and the indoor heating resistor of gasification to be tested;

Step 2-2, the temperature sensor in the column compartment of gas chromatograph and the heating resistor in column compartment to be tested;

Step 2-3, the temperature sensor in the detecting device of gas chromatograph and the heating resistor in detecting device to be tested;

Step 2-4, the column compartment back pullout (BPO) alignment sensor to gas chromatograph, the motor driving back pullout (BPO) to rotate and back pullout (BPO) motor driver are tested;

Step 2-5, proportion magnetic valve in air pressure sensor in gas pressure switch, gas circuit in the gas circuit of gas chromatograph or gas mass flow rate sensors and gas circuit to be tested;

Step 3, adopt pid control algorithm to control in real time temperature and post indoor temperature in the gasification indoor temperature of gas chromatograph, detecting device, comprise the steps:

Step 3-1, vaporizer temperature sensor is adopted to gather the actual temperature value of vaporizer inside, and actual temperature value is sent in thermal module, actual temperature value after analog to digital conversion is sent to Programmable Logic Controller by thermal module, Programmable Logic Controller is according to vaporizer desired temperature and actual temperature value, adopt pid control algorithm to obtain in cooler cycle time and export high level signal, namely pulse signal is obtained, and pulse signal is sent to vaporizer relay, thus control vaporizer heating resistor heats, gasification indoor temperature is made to reach in setting value error range,

The actual temperature value of step 3-2, employing detector temperature sensor acquisition testing device inside, and actual temperature value is sent in thermal module, temperature value after analog to digital conversion is sent to Programmable Logic Controller by thermal module, Programmable Logic Controller is according to detector temperature setting value and actual temperature value, adopt pid control algorithm to obtain in cooler cycle time and export high level signal, namely pulse signal is obtained, and pulse signal is sent to detecting device relay, thus control detecting device heating resistor heats, and makes temperature in detecting device reach in setting value error range;

Step 3-3, selection control model coupled columns indoor temperature control in real time, and described temp-controled mode comprises thermostatic control pattern and intensification control model;

Concrete steps are as follows:

The temp-controled mode that step 3-3-1, judgement adopt, according to thermostatic control pattern, then performs step 3-3-3; According to intensification control model, then perform step 3-3-2;

Step 3-3-2, multiple warm up period is set in Programmable Logic Controller, and the retention time of the starting point column compartment desired temperature of the first period, the heating rate of Different periods, the retention time of period initial temperature setting value and period end temp setting value is set, namely build the desired temperature of Different periods and the linear relationship of time, realize the automatic setting of desired temperature;

Step 3-3-3, employing column compartment temperature sensor gather the actual temperature value of column compartment inside, and are sent in thermal module by actual temperature value, and the actual temperature value after analog to digital conversion is sent in Programmable Logic Controller by thermal module;

Step 3-3-4, employing Programmable Logic Controller judge whether column compartment desired temperature is greater than actual temperature value, and if so, then Programmable Logic Controller sends pulse signal to back pullout (BPO) motor driver, and drive motor drives back pullout (BPO) to close, and performs step 3-3-5; Otherwise, perform step 3-3-6;

Step 3-3-5, employing pid control algorithm obtain the signal exporting high level in cooler cycle time, namely pulse signal is obtained, and pulse signal is sent to column compartment relay, thus control column compartment heating resistor heats, and makes post indoor temperature reach in setting value error range;

Step 3-3-6, judge whether column compartment desired temperature is less than actual temperature value, and whether the difference between observed temperature value and column compartment desired temperature is greater than G value, if, then Programmable Logic Controller sends pulse signal to back pullout (BPO) motor driver, drive motor drives back pullout (BPO) to open, and when column compartment desired temperature is equal with actual temperature value, Programmable Logic Controller sends pulse signal to back pullout (BPO) motor driver, drive motor drives back pullout (BPO) to close; Otherwise, return and perform step 3-3-4;

Step 4, gas pressure intensity or gas mass flow in the gas circuit of gas chromatograph to be controlled;

When adopting air pressure sensor to gather pressure values in gas circuit, concrete steps are as follows:

Gas pressure intensity value is changed into electric signal transmission to Analog input mModule by step 4-1, air pressure sensor, and the transform electrical signals of gas pressure intensity is become gas pressure intensity numerical value by Analog input mModule, and is sent in Programmable Logic Controller;

Gas pressure intensity setting value and gas pressure intensity measured value compare by step 4-2, Programmable Logic Controller, and send analog quantity voltage and control signal to proportion magnetic valve in gas circuit;

If the difference of gas pressure intensity setting value and gas pressure intensity measured value is greater than dMpa, then Programmable Logic Controller is to increase progressively proportion magnetic valve in output m millivolt electric signal to gas circuit second at interval of n; If the difference of gas pressure intensity setting value and gas pressure intensity measured value is greater than 0Mpa and is less than dMpa, then Programmable Logic Controller is to increase progressively proportion magnetic valve in output 1 millivolt of electric signal to gas circuit second at interval of n, when the difference of gas pressure intensity setting value and gas pressure intensity measured value is less than 0.0001Mpa, Programmable Logic Controller stops increasing progressively of above-said current signal;

If the difference of gas pressure intensity setting value and gas pressure intensity measured value is less than-dMpa, then Programmable Logic Controller is to successively decrease output m millivolt electric signal to gas circuit proportion magnetic valve second at interval of n; If the difference of gas pressure intensity setting value and gas pressure intensity measured value is greater than-dMpa and is less than 0Mpa, then Programmable Logic Controller is to successively decrease output 1 millivolt of electric signal to gas circuit proportion magnetic valve second at interval of n, when the difference of gas pressure intensity setting value and gas pressure intensity measured value is greater than-0.0001Mpa, Programmable Logic Controller stops successively decreasing of above-said current signal;

When adopting gas mass flow rate sensors to gather gas mass flow value in gas circuit, concrete steps are as follows:

Gas mass flow value is changed into electric signal transmission to Analog input mModule by step 4-a, gas mass flow rate sensors, the transform electrical signals of gas mass flow is become corresponding gas mass flow numerical quantities by Analog input mModule, and is sent in Programmable Logic Controller;

Gas mass flow setting value compares with gas mass flow measured value by step 4-b, Programmable Logic Controller, and the value gas circuit proportion magnetic valve that transmits control signal;

If the difference of gas mass flow setting value and gas mass flow measured value is greater than Dml/min, then Programmable Logic Controller is to increase progressively output m millivolt electric signal to gas circuit proportion magnetic valve second at interval of n; If the difference of gas mass flow setting value and gas mass flow measured value is greater than 0ml/min and is less than Dml/min, then Programmable Logic Controller is to increase progressively output 1 millivolt of electric signal to gas circuit proportion magnetic valve second at interval of n, when the difference of gas mass flow setting value and gas mass flow measured value is less than 0.01ml/min, Programmable Logic Controller stops increasing progressively of above-said current signal;

If the difference of gas mass flow setting value and gas mass flow measured value is less than-Dml/min, then Programmable Logic Controller is to successively decrease output m millivolt electric signal to gas circuit proportion magnetic valve second at interval of n; If the difference of gas mass flow setting value and gas mass flow measured value is greater than-Dml/min and is less than 0Mpa, then Programmable Logic Controller is to successively decrease output 1 millivolt of electric signal to gas circuit proportion magnetic valve second at interval of n, when the difference of gas mass flow setting value and gas mass flow measured value is greater than-0.01ml/min, Programmable Logic Controller stops successively decreasing of above-said current signal;

Step 5, when the analysis of the complete paired samples of gas chromatograph, closing control system.

The heating resistor of the temperature sensor in the vaporizer of gas chromatograph and gasification indoor is tested described in step 2-1, specific as follows:

Step 2-1-1, adopt the temperature sensor in vaporizer to gather the inner actual temperature of vaporizer, and actual temperature value is changed into electric signal be sent to thermal module, data are carried out analog to digital conversion and are sent to Programmable Logic Controller by thermal module;

Step 2-1-2, Programmable Logic Controller is adopted to judge scope belonging to the actual temperature value that gathers, if actual temperature value is greater than 1000 DEG C, then by touch-screen or the temperature sensor open circuit of computer prompted vaporizer or damage, and send low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is less than 0 DEG C, then by touch-screen or the temperature sensor short circuit of computer prompted vaporizer or damage, and sends low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is more than or equal to 0 DEG C and be less than or equal to 1000 DEG C, then vaporizer temperature sensor is in normal condition, and performs step 2-1-3;

Step 2-1-3, the temperature value setting vaporizer increase by 0.5 ~ 5 DEG C as actual temperature value before start, and adopt temperature sensor Real-time Collection vaporizer internal temperature, if the inner actual temperature value of vaporizer reaches desired temperature in 5 ~ 60 seconds, then heating resistor is in normal condition, and performs step 2-2; Otherwise, by touch-screen or the heating resistor open circuit of computer prompted vaporizer or vaporizer relay damaged, and send low level signal to 220V power supply relay, cut off the electricity supply;

The temperature sensor in the column compartment of gas chromatograph and the heating resistor in column compartment are tested described in step 2-2, specific as follows:

Step 2-2-1, adopt the temperature sensor in column compartment to gather the inner actual temperature of column compartment, and actual temperature value is changed into electric signal be sent to thermal module, data are carried out analog to digital conversion and are sent to Programmable Logic Controller by thermal module;

Step 2-2-2, Programmable Logic Controller is adopted to judge scope belonging to the actual temperature value that gathers, if actual temperature value is greater than 1000 DEG C, then by touch-screen or the temperature sensor open circuit of computer prompted column compartment or damage, and send low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is less than 0 DEG C, then by touch-screen or the temperature sensor short circuit of computer prompted column compartment or damage, and sends low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is more than or equal to 0 DEG C and be less than or equal to 1000 DEG C, then the temperature sensor in column compartment is in normal condition, and performs step 2-2-3;

Step 2-2-3, the temperature value setting column compartment increase by 0.5 ~ 5 DEG C as actual temperature value before start, and adopt temperature sensor Real-time Collection column compartment internal temperature, if reach desired temperature 5 ~ 60 seconds inner prop chamber interior temperature, then in column compartment, heating resistor is in normal condition, and performs step 2-3; Otherwise, by touch-screen or the heating resistor open circuit of computer prompted column compartment or column compartment relay damaged, and send low level signal to 220V power supply relay, cut off the electricity supply;

The temperature sensor in the detecting device of gas chromatograph and the heating resistor in detecting device are tested described in step 2-3, specific as follows:

Step 2-3-1, adopt the inner actual temperature of the temperature sensor acquisition testing device in detecting device, and actual temperature value is changed into electric signal be sent to thermal module, data are carried out analog to digital conversion and are sent to Programmable Logic Controller by thermal module;

Step 2-3-2, Programmable Logic Controller is adopted to judge scope belonging to the actual temperature value that gathers, if actual temperature value is greater than 1000 DEG C, then by touch-screen or the sensor open circuit of computer prompted detector temperature or damage, and send low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is less than 0 DEG C, then by touch-screen or computer prompted detector temperature short circuit sensor or damage, and sends low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is more than or equal to 0 DEG C and be less than or equal to 1000 DEG C, then the temperature sensor in detecting device is in normal condition, and performs step 2-3-3;

Step 2-3-3, the target temperature value setting detecting device increase by 0.5 ~ 5 DEG C as actual temperature value before start, and adopt temperature sensor Real-time Collection detecting device internal temperature, if reach desired temperature at 5 ~ 60 seconds internal detector internal temperatures, heating resistor then in detecting device is in normal condition, and performs step 2-4; Otherwise, by touch-screen or the heating resistor open circuit of computer prompted detecting device or detecting device relay damaged, and send low level signal to 220V power supply relay, cut off the electricity supply;

The column compartment back pullout (BPO) alignment sensor to gas chromatograph described in step 2-4, the motor driving back pullout (BPO) to rotate and back pullout (BPO) motor driver are tested, specific as follows:

Step 2-4-1, employing Programmable Logic Controller send pulse signal to back pullout (BPO) motor driver, and the back pullout (BPO) of driver drives driven by motor column compartment is first opened and closed;

Step 2-4-2, back pullout (BPO) touches the time of back pullout (BPO) limit sensors whether in 3 ~ 10 seconds to adopt Programmable Logic Controller to judge, if, the motor that then column compartment back pullout (BPO) alignment sensor and driving back pullout (BPO) are rotated is in normal condition, and perform step 2-5, otherwise, damaged by touch-screen or computer prompted column compartment back pullout (BPO) alignment sensor or the motor driving back pullout (BPO) to rotate or back pullout (BPO) motor driver, and send low level signal to 220V power supply relay, cut off the electricity supply;

Proportion magnetic valve in air pressure sensor in gas pressure switch, gas circuit in the gas circuit of gas chromatograph or gas mass flow rate sensors and gas circuit is tested described in step 2-5, specific as follows:

Step 2-5-1, employing Programmable Logic Controller judge whether the signal that gas pressure switch sends is low level signal, if, then not enough by gaseous tension in touch-screen or computer prompted gas circuit, and send low level signal to 220V power supply relay, cut off the electricity supply; Otherwise gaseous tension is in normal condition in gas circuit, and perform step 2-5-2;

In step 2-5-2, employing gas circuit, air pressure sensor gathers gas pressure intensity value, or adopt gas mass flow rate sensors to gather gas mass flow numerical quantity, if gas pressure intensity numerical value is greater than 20MPa or gas mass flow numerical quantity is greater than 1000ml/min, then by touch-screen or computer prompted air pressure sensor or gas mass flow rate sensors open circuit or damage, and send low level signal to 220V power supply relay, cut off the electricity supply; Otherwise air pressure sensor or gas mass flow rate sensors are in normal condition in gas circuit;

If step 2-5-3 air pressure sensor is in normal condition, then the object gas pressure settings set in gas circuit is PMpa, Programmable Logic Controller sends Signal Regulation ratio solenoid valve, and adopt the gas pressure intensity value in air pressure sensor collection gas circuit, if the gas pressure intensity value gathered reaches setting value within the time of 5 ~ 60 seconds, then in gas circuit, proportion magnetic valve is in normal condition, and performs step 3; Otherwise, damaged or open circuit by touch-screen or computer prompted proportion magnetic valve, and send low level signal to 220V power supply relay, cut off the electricity supply.

P span described in step 2-5-3 is 0.005 ~ 0.1.

Cooler cycle time span described in step 3-1, step 3-2, step 3-3-5 is 0.1 ~ 10 second, and observed temperature and the approximately equalised error range of design temperature are ± 0.01 DEG C.

G value span described in step 3-3-6 is 5 ~ 15 DEG C.

N span described in step 4-2 is the span of 1 ~ 10, m is 10 ~ 100; The span of d is 0.001 ~ 0.01.

The span of the D described in step 4-b is 1 ~ 10.

Advantage of the present invention:

The control system of a kind of gas chromatograph of the present invention and control method, the advantage doing the control system of gas chromatograph with Programmable Logic Controller is good stability, antijamming capability is strong, without the need to welding main circuit board, easy-to-connect, is easy to Function Extension, self-checking function wherein facilitates maintenance and the use of instrument, temperature control precision is high, and the exponent number of intensification temperature control is more, and the control accuracy of gas pressure intensity and gas mass flow is higher.

Accompanying drawing explanation

Fig. 1 is the Programmable connection diagram of an embodiment of the present invention;

Fig. 2 is gas chromatograph vaporizer, column compartment, the detecting device schematic diagram of an embodiment of the present invention;

Fig. 3 is the column compartment back pullout (BPO) schematic diagram of an embodiment of the present invention;

Fig. 4 is the gas chromatography gas circuit schematic diagram of an embodiment of the present invention;

Fig. 5 is the control method process flow diagram of the employing gas chromatograph of an embodiment of the present invention;

Fig. 6 is testing process flow diagram to the temperature sensor in the vaporizer of gas chromatograph and the indoor heating resistor of gasification of an embodiment of the present invention;

Fig. 7 is that the selection control model coupled columns indoor temperature of an embodiment of the present invention carries out real-time control method process flow diagram;

Fig. 8 is that the employing air pressure sensor of an embodiment of the present invention carries out control method process flow diagram to gas pressure intensity in the gas circuit of gas chromatograph.

Embodiment

Below in conjunction with accompanying drawing, an embodiment of the present invention is described further.

As shown in Figure 1, in the embodiment of the present invention, the control system of gas chromatograph comprises Programmable Logic Controller, thermal module and analog input and output module, also comprises human-computer interaction interface (display screen of touch-screen, band button or computing machine); Described Programmable Logic Controller adopts Siemens s7-200 series: main frame model C PU224; Thermal module adopts EM231 model, analog input RTD, 4 tunnel inputs; Analog input and output module adopts EM235 model, and analog quantity combines, and 4 tunnel inputs 1 export, the GC-8890 that Liaoning Dong Ke Analytical Instrument Co., Ltd produces; On Programmable Logic Controller main frame, A communication port connects touch-screen; B communication port connects microcomputer; The digital output terminal Q0.0 ~ Q1.5 of Programmable Logic Controller; Digital-quantity input terminal I0.0 ~ the I1.3 of Programmable Logic Controller; Connection terminal A+, A-, B+, B-, C+, C-of thermal module; Analog input/output module, analog quantity voltage output wiring terminal V0.3, M0.3, analog quantity voltage input wires terminal V0.0, M0.0, V0.1, M0.1.

As shown in Figure 2, wherein, 5 is vaporizer; 6 is vaporizer heating resistor, and vaporizer heating resistor 6 lead-in wires meet the N (zero line) of AC power 220V, and another root lead-in wire connects the alternating current 220V connection terminal of solid-state relay 8; 8 is vaporizer heating solid-state relay, another alternating current 220V connection terminal of vaporizer heating solid-state relay 8 meets the L (live wire) of AC power 220V, higher electric potential terminal of the DC low-voltage of vaporizer heating solid-state relay 8 meets the Q0.1 (as shown in Figure 1) of Programmable Logic Controller, and lower electric potential terminal meets 24V power cathode M; 7 is vaporizer temperature sensor, and go between A+, A-of vaporizer temperature sensor 7 is connected to Programmable Logic Controller thermal module A+, A-terminal by wire; 9 is column compartment; 10 is column compartment heating resistor; Column compartment heating resistor 10 lead-in wires meet the N (zero line) of AC power 220V, and another root lead-in wire connects the alternating current 220V connection terminal of solid-state relay 14; 14 is vaporizer heating solid-state relay, another alternating current 220V connection terminal of vaporizer heating solid-state relay 14 meets the L (live wire) of AC power 220V, the vaporizer heating Q0.2 (as shown in Figure 1) of the high potential termination Programmable Logic Controller of the DC low-voltage of solid-state relay 14, low potential termination 24V power cathode M; 11 is column compartment temperature sensor, and go between C+, C-of column compartment temperature sensor 11 is connected to Programmable Logic Controller thermal module C+, C-terminal by wire; 12 is column compartment internal fan; 13 is gas chromatographic column; 15 is detecting device; 17 is detecting device heating resistor, and detecting device heating resistor 17 lead-in wires meet the N (zero line) of AC power 220V, and another root lead-in wire connects the alternating current 220V connection terminal of detecting device heating solid-state relay 18; 18 is detecting device heating solid-state relay, another alternating current 220V connection terminal of detecting device heating solid-state relay 18 meets the L (live wire) of AC power 220V, the DC low-voltage high potential terminal of detecting device heating solid-state relay 18 meets the Q0.3 (as shown in Figure 1) of Programmable Logic Controller, and low potential terminal meets 24V power cathode M; 16 is detector temperature sensor, and go between B+, B-of detector temperature sensor 16 is connected to Programmable Logic Controller thermal module B+, B-terminal by wire; 23 for controlling the relay of alternating current 220V power supply switching.

As shown in Figure 3,1 be wherein column compartment back pullout (BPO); 2 for driving the stepper motor of back pullout (BPO) rotation, and stepping motor rotating shaft coaxially connects with column compartment back pullout (BPO); 3 is stepper motor driver, stepper motor driver 3 connects stepper motor 2 by four wires, the pulse connection terminal of stepper motor driver 3 connects Programmable Logic Controller lead-out terminal Q0.4 (as shown in Figure 1), direction connection terminal connects Programmable Logic Controller lead-out terminal Q0.5 (as shown in Figure 1), and off line connection terminal connects Programmable Logic Controller lead-out terminal Q0.6 (as shown in Figure 1); 4 is back pullout (BPO) alignment sensor, and two lead-in wires of alignment sensor, a lead-in wire meets Programmable Logic Controller input terminal I0.0 (as shown in Figure 1), and another lead-in wire meets 24V power cathode M.

As shown in Figure 4, wherein 19 is pressure switch, and pressure switch 19 has two lead-in wires, and a lead-in wire connects Programmable Logic Controller input terminal 10.1 (as shown in Figure 1), and another lead-in wire meets 24V power cathode M; 20 is gaseous tension pressure maintaining valve; 21 is proportion magnetic valve, proportion magnetic valve 21 has two lead-in wires, lead-in wire meets the analog output terminal V0.3 (as shown in Figure 1) in programmable controller analog quantity module, another analog output terminal M0.3 (as shown in Figure 1) connect in programmable controller analog quantity module that goes between; 22 is pressure transducer (or gas mass flow rate sensors), pressure transducer have two lead-in wires, lead-in wire meets the analog input terminal V0.1 (as shown in Figure 1) in programmable controller analog quantity module, another analog input terminal M0.1 (as shown in Figure 1) connect in programmable controller analog quantity module that goes between;

In the embodiment of the present invention, the control system of gas chromatograph comprises the self-checking system (hereinafter referred to as self-checking system) of the gas chromatograph based on Programmable, the temperature control system (hereinafter referred to as temperature control system) based on the gas chromatograph of Programmable Logic Controller and the air-path control system (hereinafter referred to as air-path control system) based on Programmable Logic Controller, after gas chromatograph energising start, first gas chromatograph enters self-inspection state, whether self-checking system will detect each parts of gas chromatograph and damage in 10 ~ 60 seconds, if gas chromatograph has damage parts, self-checking system is by damage component names relevant for the human-computer interaction interface report by programmable control system and possible reason, if all are normal for gas chromatograph, gas chromatograph passes through self-inspection, enter the setting interface of human-computer interaction interface, the temperature of the vaporizer of gas chromatograph can be set at this setting interface, the temp-controled mode (constant temperature mode or temperature programme pattern) of column compartment and temperature, the temperature of detecting device, the gas pressure intensity in gas chromatographic device gas circuit or gas mass flow can be set, temperature control system will control the vaporizer of gas chromatograph within the time of 1 ~ 6 minute, the temperature of column compartment and detecting device reaches setting value, the error range of actual temperature value and set temperature value is ± 0.01 DEG C, air-path control system will control the gas circuit (carrier gas of gas chromatograph within the time of 1 ~ 6 minute, hydrogen and air) in gas pressure intensity or gas mass flow reach setting value, error range that gas pressure intensity value and error range set gas pressure intensity value survey gas mass flow value and set gas mass flow value in ± 0.0001MPa or gas circuit is surveyed as ± 0.01ml/min in gas circuit.

Adopt the control method that the control system of gas chromatograph is carried out, method flow diagram as shown in Figure 5, comprises the following steps:

Step 1, startup gas chromatograph;

Specifically comprise the steps:

Step 2-1, test to the temperature sensor in the vaporizer of gas chromatograph and the indoor heating resistor of gasification, method flow diagram is as shown in Figure 6, specific as follows:

Step 2-1-1, the inner actual temperature of temperature sensor collection vaporizer adopted in vaporizer, and actual temperature value is changed into electric signal be sent to thermal module, it is the Temperature numerical that Programmable Logic Controller main frame can identify that data are carried out analog to digital conversion by thermal module, and is sent to Programmable Logic Controller;

In the embodiment of the present invention, the temperature sensor phenomenon that breaks down has two kinds: a, when the Temperature numerical in self-inspection in vaporizer is greater than 1000 DEG C, is temperature sensor open circuit or damage; B; when Temperature numerical in self-inspection in vaporizer is less than 0 DEG C; for temperature sensor short circuit or damage; when there is a or b phenomenon; the Programmable control system of gas chromatograph will provide by human-computer interaction interface that text prompt is concurrently spoken, visual alarm; and pass through the digital output terminal output low level signal of Programmable Logic Controller; this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire; relay disconnects; whole instrument quits work, and can reach the object of protection instrument and operating personnel.When there is not the situation of a or b, show that the temperature sensor in vaporizer is normal, the human-computer interaction interface of Programmable control system does not provide cue.

Step 2-1-3, in the normal situation of vaporizer temperature sensor, set the temperature value of vaporizer as the front actual temperature value increase by 0.5 ~ 5 DEG C of start, and adopt temperature sensor Real-time Collection vaporizer internal temperature, if the inner actual temperature value of vaporizer reaches desired temperature in 5 ~ 60 seconds, then heating resistor is in normal condition, stop the heating to vaporizer in self-inspection, and perform step 2-2; Otherwise, provided by human-computer interaction interface that text prompt is concurrently spoken, visual alarm, and pass through the digital output terminal output low level signal of Programmable Logic Controller, this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire, relay disconnects, whole instrument quits work, and can reach the object of protection instrument and operating personnel;

Step 2-2, the temperature sensor in the column compartment of gas chromatograph and the heating resistor in column compartment to be tested, specific as follows:

Step 2-2-1, the inner actual temperature of temperature sensor collection column compartment adopted in column compartment, and actual temperature value is changed into electric signal be sent to thermal module, data are carried out analog to digital conversion by thermal module, are converted to Temperature numerical that Programmable Logic Controller main frame can identify and are sent to Programmable Logic Controller;

In the embodiment of the present invention, the temperature sensor phenomenon that breaks down has two kinds: a, when the Temperature numerical of self-inspection center pillar indoor is greater than 1000 DEG C, is temperature sensor open circuit or damage; B; when the Temperature numerical of self-inspection center pillar indoor is less than 0 DEG C; for temperature sensor short circuit or damage; when there is a or b phenomenon; the Programmable control system of gas chromatograph will provide by human-computer interaction interface that text prompt is concurrently spoken, visual alarm; and pass through the digital output terminal output low level signal of Programmable Logic Controller; this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire; relay disconnects; whole instrument quits work, and can reach the object of protection instrument and operating personnel.When there is not the situation of a or b, show that the temperature sensor in column compartment is normal, the human-computer interaction interface of Programmable control system does not provide cue.

Step 2-2-3, the temperature value setting column compartment increase by 0.5 ~ 5 DEG C as actual temperature value before start, and adopt temperature sensor Real-time Collection column compartment internal temperature, if reach desired temperature 5 ~ 60 seconds inner prop chamber interior temperature, then in column compartment, heating resistor is in normal condition, to stop in self-inspection the heating of column compartment and performs step 2-3; Otherwise, show the open circuit of column compartment heating resistor or control vaporizer heating resistor relay damaged, the Programmable control system of gas chromatograph will provide text prompt by human-computer interaction interface, concurrent visual alarm of speaking, and pass through the digital output terminal output low level signal of Programmable Logic Controller, this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire, relay disconnects, whole instrument quits work, and can reach the object of protection instrument and operating personnel;

Step 2-3, the temperature sensor in the detecting device of gas chromatograph and the heating resistor in detecting device to be tested, specific as follows:

Step 2-3-1, the temperature sensor acquisition testing device inside actual temperature adopted in detecting device, and actual temperature value is changed into electric signal be sent to thermal module, data are carried out analog to digital conversion by thermal module, are converted to Temperature numerical that Programmable Logic Controller main frame can identify and are sent to Programmable Logic Controller;

In the embodiment of the present invention, the temperature sensor phenomenon that breaks down has two kinds: a, when the Temperature numerical in self-inspection in detecting device is greater than 1000 DEG C, is temperature sensor open circuit or damage; B; when Temperature numerical in self-inspection in detecting device is less than 0 DEG C; for temperature sensor short circuit or damage; when there is a or b phenomenon; the Programmable control system of gas chromatograph will provide by human-computer interaction interface that text prompt is concurrently spoken, visual alarm; and pass through the digital output terminal output low level signal of Programmable Logic Controller; this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire; relay disconnects; whole instrument quits work, and can reach the object of protection instrument and operating personnel.When there is not the situation of a or b, show that the temperature sensor in detecting device is normal, the human-computer interaction interface of Programmable control system does not provide cue.

Step 2-3-3, the target temperature value setting detecting device increase by 0.5 ~ 5 DEG C as actual temperature value before start, and adopt temperature sensor Real-time Collection detecting device internal temperature, if reach desired temperature at 5 ~ 60 seconds internal detector internal temperatures, heating resistor then in detecting device is in normal condition, to stop in self-inspection the heating of detecting device and performs step 2-4; Otherwise; show the open circuit of detecting device heating resistor or control detecting device heating resistor relay damaged; the Programmable control system of gas chromatograph will provide text prompt by human-computer interaction interface; concurrently to speak, visual alarm; and pass through the digital output terminal output low level signal of Programmable Logic Controller; this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire; relay disconnects; whole instrument quits work, and can reach the object of protection instrument and operating personnel.

Step 2-4, the column compartment back pullout (BPO) alignment sensor to gas chromatograph, the motor driving back pullout (BPO) to rotate and back pullout (BPO) motor driver are tested, specific as follows:

In the embodiment of the present invention, column compartment back pullout (BPO) alignment sensor is connected to Programmable Logic Controller main frame digital-quantity input terminal by wire, Programmable Logic Controller main frame digital quantity lead-out terminal is connected to the driver of stepper motor by wire, stepper motor driver is connected to the stepper motor driving back pullout (BPO) to rotate by wire.Gas chromatography is opened rear self-checking system and is automatically sent pulse signal by the digital output terminal of the Programmable Logic Controller connecting driver (driver for Driving Stepping Motor back pullout (BPO)), Driving Stepping Motor drives column compartment back pullout (BPO) outwards to open 1 ~ 5 degree by driver, and then closes column compartment back pullout (BPO);

Step 2-4-2, back pullout (BPO) touches the time of back pullout (BPO) limit sensors whether in 3 ~ 10 seconds to adopt Programmable Logic Controller to judge, if, the motor that then column compartment back pullout (BPO) alignment sensor and driving back pullout (BPO) are rotated is in normal condition, and perform step 2-5, otherwise, text prompt is provided by human-computer interaction interface, concurrently to speak, visual alarm, and pass through the digital output terminal output low level signal of Programmable Logic Controller, this low level signal is connected to control alternating current 220V power supply by wire and leads to, disconnected relay, relay disconnects, whole instrument quits work, the object of protection instrument and operating personnel can be reached,

Step 2-5, proportion magnetic valve in air pressure sensor in gas pressure switch, gas circuit in the gas circuit of gas chromatograph or gas mass flow rate sensors and gas circuit to be tested, specific as follows:

In the embodiment of the present invention, before gas pressure maintaining valve, gas pressure switch is housed in gas circuit, two lead-in wires of gas pressure switch are connected to the digital-quantity input terminal of Programmable Logic Controller, when gaseous tension is less than XMpa (X is a numerical value in 0.2 ~ 0.5 scope), pressure switch is in normally open, the input end of Programmable Logic Controller detects low level signal, show that in gas circuit, gaseous tension is not enough, the Programmable control system of gas chromatograph will provide text prompt by human-computer interaction interface, concurrently to speak, visual alarm, and pass through the digital output terminal output low level signal of Programmable Logic Controller, this low level signal is connected to control alternating current 220V power supply by wire and leads to, disconnected relay, relay disconnects, whole instrument quits work, the object of protection instrument and operating personnel can be reached.Otherwise show that in gas circuit, gaseous tension is normal, the human-computer interaction interface of Programmable control system does not provide cue.

Step 2-5-2, air pressure sensor in gas circuit is adopted to gather gas pressure intensity value, or adopt gas mass flow rate sensors to gather gas mass flow numerical quantity, if gas pressure intensity numerical value is greater than 20MPa or gas mass flow numerical quantity is greater than 1000ml/min, then provide text prompt by human-computer interaction interface, concurrently to speak, visual alarm, and pass through the digital output terminal output low level signal of Programmable Logic Controller, this low level signal is connected to control alternating current 220V power supply by wire and leads to, disconnected relay, relay disconnects, whole instrument quits work, the object of protection instrument and operating personnel can be reached, otherwise air pressure sensor or gas mass flow rate sensors are in normal condition in gas circuit, the human-computer interaction interface of Programmable control system does not provide cue,

In the embodiment of the present invention, air pressure sensor in gas chromatography gas circuit, gas pressure intensity in gas circuit becomes electric signal to be connected to the analog input terminal of the analog input expansion module of PLC technology by wire by gas mass flow rate sensors with gaseous mass traffic transformation, change into through analog input expansion module the gas pressure intensity numerical value and gaseous mass flow number that Programmable Logic Controller main frame can identify;

If step 2-5-3 air pressure sensor is in normal condition, then the object gas pressure settings set in gas circuit is PMpa, P span is 0.005 ~ 0.1, Programmable Logic Controller sends Signal Regulation ratio solenoid valve, and adopt the gas pressure intensity value in air pressure sensor collection gas circuit, if the gas pressure intensity value gathered reaches setting value within the time of 5 ~ 60 seconds, then in gas circuit, proportion magnetic valve is in normal condition, and performs step 3; Otherwise; the Programmable control system of gas chromatograph will provide text prompt by human-computer interaction interface; concurrently to speak, visual alarm; and pass through the digital output terminal output low level signal of Programmable Logic Controller; this low level signal is connected to the relay controlling the switching of alternating current 220V power supply by wire; relay disconnects, and whole instrument quits work, and can reach the object of protection instrument and operating personnel.

Step 3-1, the temperature sensor of vaporizer is connected to the input terminal of the thermal module of Programmable Logic Controller by wire, the temperature inversion of vaporizer becomes electric signal transmission to thermal module by the temperature sensor of vaporizer, the electric signal that the transmission of vaporizer temperature sensor comes is changed into Temperature numerical and vaporizer observed temperature by thermal module, thermal module by vaporizer observed temperature data transfer to Programmable Logic Controller main frame, Programmable Logic Controller is by the vaporizer set temperature value that set by human-computer interaction interface according to user and vaporizer observed temperature value, adopt pid algorithm, calculate the time and gating pulse that export high level in cooler cycle time (0.1 ~ 10 second), this gating pulse is exported by the digital output terminal of Programmable Logic Controller, this gating pulse is led to controlling heating resistor in vaporizer by wire transmission, disconnected relay, thus control the logical of this relay, break time, leading to of relay, break time just determines the time of 220V alternating current by heating resistor in vaporizer, thus the thermal value of heating resistor in control vaporizer, the set temperature value of the observed temperature value and vaporizer that finally realize vaporizer is close to equal, error range is ± 0.01 DEG C,

Step 3-2, the temperature sensor of detecting device is connected to the input terminal of the thermal module of Programmable Logic Controller by wire, the temperature inversion of detecting device becomes electric signal transmission to thermal module by the temperature sensor of detecting device, the electric signal that the transmission of the temperature sensor of detecting device comes is changed into Temperature numerical and detecting device observed temperature by thermal module, thermal module by detecting device observed temperature data transfer to Programmable Logic Controller main frame, Programmable Logic Controller is by the detecting device set temperature value that set by human-computer interaction interface according to user and detecting device observed temperature value, adopt pid algorithm, calculate the time and gating pulse that export high level in cooler cycle time (0.1 ~ 10 second), this gating pulse is exported by the digital output terminal of Programmable Logic Controller, this gating pulse is led to controlling heating resistor in detecting device by wire transmission, disconnected relay, thus control the logical of this relay, break time, leading to of relay, break time just determines the time of 220V alternating current by heating resistor in detecting device, thus the thermal value of heating resistor in control detecting device, the set temperature value of the observed temperature value and detecting device that finally realize detecting device is close to equal, error range is ± 0.01 DEG C,

As shown in Figure 7, concrete steps are as follows for method flow diagram:

In the embodiment of the present invention, temperature-controlling system is to the temperature controlled processes of column compartment, and the temperature in column compartment controls to comprise thermostatic control and intensification control two kinds of patterns; Gas chromatograph by after startup self-detection, the fan in column compartment by the rotational speed of maintenance 800 ~ 2400 turns/min, to ensure homogeneous temperature distribution in column compartment.

In the embodiment of the present invention, the intensification of column compartment can in the initial temperature of the human-computer interaction interface setting column compartment of gas chromatography, and setting value is Z ₀dEG C (Z ₀be the numerical value in 30 ~ 500 scopes), then set initial temperature retention time T ₀second (T ₀be a numerical value in 0 ~ 600 scope), then set the heating rate K that first segment heats up ₀dEG C/min (K ₀be a numerical value in 0 ~ 60 scope), then set the end temp Z that first segment heats up ₁dEG C (Z ₁be the numerical value in 30 ~ 500 scopes), the end temp Z of then first segment intensification ₁retention time T ₁second (T ₁be a numerical value in 0 ~ 600 scope); Set the heating rate K that second section heats up as required ₁dEG C/min (K ₁be a numerical value in 0 ~ 60 scope), then set the end temp Z that second section heats up ₂dEG C (Z ₂be the numerical value in 30 ~ 500 scopes), the end temp Z of then second section intensification ₂retention time T ₂second (T ₂be a numerical value in 0 ~ 600 scope); Set the 3rd rank intensification, quadravalence intensification by that analogy, 64 rank can be set at most and heat up; Such as: heated up in the n-th rank, the initial temperature Z on the n-th rank _n, Z _nretention time be T _n, the heating rate on the n-th rank is K _n, the time of the initial time heated up on relatively whole finally n-th rank of temperature rise period is T _e, the temperature Z finally on the n-th rank _n+1, Z _n+1retention time be T _n+1.The initial time heated up with the n-th rank is for 0, and the n-th rank heat up 0 to T _n, desired temperature is Z _n; At T _nto T _einterior any time T, desired temperature is Z _n+ (T-T _n) K _n; At T _eto T _e+ T _nmoment desired temperature is Z _n+1.

In the embodiment of the present invention, in intensification controls, the temperature sensor of column compartment is connected to the thermal module input terminal of Programmable Logic Controller by wire, the temperature inversion of column compartment becomes electric signal transmission to thermal module by the temperature sensor of column compartment, the electric signal that the transmission of the temperature sensor of column compartment comes is changed into Temperature numerical and column compartment observed temperature by thermal module, thermal module by column compartment observed temperature data transfer to Programmable Logic Controller main frame, Programmable Logic Controller by according to user by human-computer interaction interface not column compartment set temperature value in the same time and column compartment observed temperature value in heating up in the n-th rank, adopt pid algorithm, calculate the time and gating pulse that export high level in cooler cycle time (0.1 ~ 10 second), this gating pulse is exported by the digital output terminal of Programmable Logic Controller, the relay of this gating pulse heating resistor break-make in wire transmission to control column compartment, thus control the logical of this relay, break time, leading to of relay, break time just determines the time of 220V alternating current by heating resistor in column compartment, thus the thermal value of heating resistor in control column compartment, finally realize column compartment in heating up in the n-th rank not the set temperature value of column compartment observed temperature value in the same time and column compartment close to equal.

In the embodiment of the present invention, in thermostatic control, the temperature sensor of column compartment is connected to the thermal module input terminal of Programmable Logic Controller by wire, the temperature inversion of column compartment becomes electric signal transmission to thermal module by the temperature sensor of column compartment, the electric signal that the transmission of the temperature sensor of column compartment comes is changed into Temperature numerical and column compartment observed temperature by thermal module, thermal module by column compartment observed temperature data transfer to Programmable Logic Controller main frame, Programmable Logic Controller is by the column compartment set temperature value that set by human-computer interaction interface according to user and column compartment observed temperature value, adopt pid algorithm, calculate the time and gating pulse that export high level in cooler cycle time (0.1 ~ 10 second), this gating pulse is exported by the digital output terminal of Programmable Logic Controller, the relay of this gating pulse heating resistor break-make in wire transmission to control column compartment, thus control the logical of this relay, break time, leading to of relay, break time just determines the time of 220V alternating current by heating resistor in column compartment, thus the thermal value of heating resistor in control column compartment, the set temperature value of the observed temperature value and column compartment that finally realize column compartment is close to equal, error range is ± 0.01 DEG C.

Step 3-3-6, judge whether column compartment desired temperature is less than actual temperature value, and whether the difference between observed temperature value and column compartment desired temperature is greater than G value, G value span is 5 ~ 15 DEG C; If, then Programmable Logic Controller sends pulse signal to back pullout (BPO) motor driver, and drive motor drives back pullout (BPO) to open, and when column compartment desired temperature is equal with actual temperature value, Programmable Logic Controller sends pulse signal to back pullout (BPO) motor driver, and drive motor drives back pullout (BPO) to close; Otherwise, return and perform step 3-3-4;

In the embodiment of the present invention, if column compartment set temperature value is greater than column compartment observed temperature value, Programmable Logic Controller main frame will export pulse by digital output terminal, this output pulse through wire transmission to the driver of column compartment back pullout (BPO) stepper motor, the driver of column compartment back pullout (BPO) stepper motor sends Pulse Width Control back pullout (BPO) stepper motor and rotates, and closes column compartment and opens the door; If column compartment set temperature value is less than column compartment observed temperature value, temperature gap is greater than T DEG C (T is a numerical value in 5 ~ 15 scopes), Programmable Logic Controller main frame will export pulse by digital output terminal, this output pulse through wire transmission to the driver of column compartment back pullout (BPO) stepper motor, the driver of column compartment back pullout (BPO) stepper motor sends Pulse Width Control back pullout (BPO) stepper motor and rotates, open column compartment back pullout (BPO), when column compartment observed temperature is equal with column compartment design temperature, Programmable Logic Controller sends pulse and closes column compartment enabling.

In the embodiment of the present invention, gas in air-path control system is connected to gas chromatograph by gas chromatograph outside by gas pipeline, gas pressure switch is connected to by gas pipeline in gas chromatograph inside, out gas pressure maintaining valve is connected to by gas pipeline by gas pressure switch, out proportion magnetic valve is connected to by gas pipeline by gas pressure maintaining valve, out pressure transducer or gas mass flow rate sensors is connected to by gas pipeline by proportion magnetic valve, out be connected to vaporizer by gas pipeline by pressure transducer or gas mass flow rate sensors and do carrier gas, or be connected to detecting device.

When adopting air pressure sensor to gather pressure values in gas circuit (comprising carrier gas, air and hydrogen), as shown in Figure 8, concrete steps are as follows for method flow diagram:

In the embodiment of the present invention, described n span is the span of 1 ~ 10, m is 10 ~ 100; The span of d is 0.001 ~ 0.01;

In the embodiment of the present invention, the span of D is 1 ~ 10.

When the vaporizer of gas chromatograph, column compartment, the temperature of detecting device reaches setting value, after gas pressure intensity in gas circuit or gas mass flow reach setting value, sample to be analyzed injects vaporizer by syringe, after chromatographic column is separated, the compound of different component arrives the time difference of detecting device, the amount of compound is changed into electric signal and obtains chromatogram through chromatographic work station by detecting device, the content of often kind of compound can be analyzed by chromatogram, when the analysis of the complete paired samples of gas chromatograph, closing control system.

Claims

1. the control method of a gas chromatograph, the method adopts the control system of gas chromatograph, this system comprises Programmable Logic Controller, thermal module, analog input and output module and touch-screen or computing machine, wherein, first output terminal of described Programmable Logic Controller connects the 220V power supply relay input end of gas chromatograph, second output terminal of Programmable Logic Controller connects the column compartment relay input end of gas chromatograph, 3rd output terminal of Programmable Logic Controller connects the vaporizer relay input end of gas chromatograph, 4th output terminal of Programmable Logic Controller connects the detecting device relay input end of gas chromatograph, 5th output terminal of Programmable Logic Controller connects the back pullout (BPO) motor driver input end of gas chromatograph, 6th output terminal of Programmable Logic Controller connects the input end of touch-screen, the back pullout (BPO) limit sensors output terminal of gas chromatograph connects the first input end of Programmable Logic Controller, the output terminal of thermal module connects the second input end of Programmable Logic Controller, the gas pressure switch output terminal of gas circuit connects the 3rd input end of Programmable Logic Controller, first output terminal of analog input and output module connects the first input end of thermal module, the vaporizer temperature sensor output terminal of gas chromatograph connects the second input end of thermal module, the detector temperature sensor output of gas chromatograph connects the 3rd input end of thermal module, the column compartment temperature sensor output terminal of gas chromatograph connects the four-input terminal of thermal module, the input end of the output terminal connection mode analog quantity input/output module of the air pressure sensor in the gas circuit of gas chromatograph or gas mass flow rate sensors, second output terminal of the gas circuit proportion magnetic valve door input end connection mode analog quantity input/output module of gas chromatograph, it is characterized in that, comprise the following steps:

Step 1, startup gas chromatograph;

Specifically comprise the steps:

Concrete steps are as follows:

2. control method according to claim 1, is characterized in that:

Step 2-3-2, Programmable Logic Controller is adopted to judge scope belonging to the actual temperature value that gathers, if actual temperature value is greater than 1000 DEG C, then by touch-screen or the sensor open circuit of computer prompted detector temperature or damage, and send low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is less than 0 DEG C, then by touch-screen or computer prompted detector temperature short circuit sensor or damage, and sends low level signal to 220V power supply relay, cut off the electricity supply; If actual temperature value is more than or equal to 0 DEG C and be less than or equal to 1000 DEG C, then the temperature sensor in detecting device is in normal condition, and performs step 2-3-3:

3. control method according to claim 2, is characterized in that: the P span described in step 2-5-3 is 0.005 ~ 0.1.

4. control method according to claim 1, is characterized in that: the cooler cycle time span described in step 3-1, step 3-2, step 3-3-5 is 0.1 ~ 10 second, and observed temperature and the approximately equalised error range of design temperature are ± 0.01 DEG C.

5. control method according to claim 1, is characterized in that: the G value span described in step 3-3-6 is 5 ~ 15 DEG C.

6. control method according to claim 1, is characterized in that: the n span described in step 4-2 is the span of 1 ~ 10, m is 10 ~ 100; The span of d is 0.001 ~ 0.01.

7. control method according to claim 1, is characterized in that: the span of the D described in step 4-b is 1 ~ 10.