WO2011081666A1

WO2011081666A1 - Heating cooling and power generation system

Info

Publication number: WO2011081666A1
Application number: PCT/US2010/003255
Authority: WO
Inventors: Rodney Hugelman; Marc Albertin
Original assignee: Ecothermics Corporation
Priority date: 2009-12-28
Filing date: 2010-12-28
Publication date: 2011-07-07
Also published as: US20120255302A1

Abstract

A thermal separator/power generator uses the thermodynamic properties of refrigerant substances to provide supplemental heating, cooling, and power without emitting any additional greenhouse gases to the environment by utilizing waste or unused heat energy. This is accomplished through the combined operation of a Rankine Cycle Generator using a refrigerant, preferably a natural refrigerant such as NH3, as the working fluid, and a CO2 a vapor compression heat pump cycle, also called a Thermal Separator Module. The combined system is called a Thermal Separator/Power Generator. It produces electrical power and simultaneously produces secondary heating and water or air cooling as byproducts. In the combined vapor compression heat pump/Rankine power generator cycle, waste heat from external source(s) are recovered and used for heating in the Rankine power cycle. The CO2 heat pump provides cooling and optional space or process heating in lieu of heat boost efficiency for the Rankine power generator cycle.

Description

TITLE OF INVENTION : HEATING COOLING AND POWER GENERATION

SYSTEM

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UNITED STATES DEPARTMENT OF COMMERCE PATENT AND TRADEMARK OFFICE

I. CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority of United States provisional patent application 61/284,936 filed December 28, 2009. II. FIELD OF THE INVENTION

This invention relates to a more efficient and flexible method of providing Combined Cooling, Heating, and Power (CCHP); so-called Tri-generation. The invention embodies a mechanical/electrical power generation system that also produces selectable heating and cooling outputs in an environmentally clean and energy efficient way. A combined thermal separator/power generator uses the thermodynamic properties of natural working fluids to provide supplemental heating, cooling, and power without emitting any additional greenhouse gasses to the environment by use of waste or unused heat energy. This is accomplished through the combined operation of a Rankine cycle, using a refrigerant such as ammonia (NH₃) as the working fluid for power production; and a carbon dioxide (C0₂) heat pumping cycle. Simultaneous and usable energy output forms from this combined energy efficient cycle are mechanical power and/or electricity, and various options and combinations of usable thermal energy. III. BACKGROUND OF THE INVENTION

Cogeneration, also called combined heat and power (CHP), is the use of a heat engine or a power station to sequentially generate mechanical and/or electrical power as well as useful heat. Conventional Rankine (i.e., water/steam) and Brayton cycle (i.e. gas turbine) assemblies have been combined in various forms to increase efficiencies advantaging heat recovery principles. Practical temperatures for a steam plant span H₂0 boiling point to ~1200°F yielding actual efficiencies well below 50%. A Brayton cycle gas turbine generator utilizes much higher input temperatures and typically yields higher flue gas output temperatures (~ 840°F to ~1220^°F). _{, ,} PAGE 2

Therefore system efficiency may be improved substantially by utilizing recovered heat from the Brayton cycle, typically ~1000°F, as a heat source for a "bottoming" Rankine steam cycle. These scenarios generally use higher quality (i.e. higher temperature) heat sources for operation. A further conventional use for moderate quality heat (~212^°F to ~350°F) that may be recovered from many processes is to drive absorption chillers for cooling. A plant which produces a combination of cooling, heating, and power (CCHP) is sometimes called trigeneration or more generally a polygeneration plant. The efficient use and reclamation of prolifically available lower quality waste heat sources to help meet a facility's electrical, thermal, and mechanical power demands has become a global priority. Methods to apply medium grade waste heat (exampled hereafter 100^°F-400^°F) and much more abundant renewable low grade waste heat (<100°F) to help meet the electrical, thermal, and mechanical power demands of society is a paramount need. Due to increasing carbon emissions, and their contribution to global warming, there exists a parallel demand for low greenhouse gas (GHG) emission processes that rely on integrated, natural solutions. This is specifically evidenced by the high growth of two energy efficient market trends identified as vapor compression heat pump systems exampling those used in HVAC applications, as well as CHP systems. Little has been considered in relation to the combination of these two general systems due to practical considerations which have traditionally limited CHP to large scale, higher temperature operations. Scenarios of CHP improvements for smaller scale, lower temperature (<400°F) utilizations have been considered in recent art, however low temperature (<0°F to 100°F) thermal waste recovery is lesser applied in the capacity of use with CHP, as are small scale fixed or portable systems (<50 kW) using natural working fluids in lieu of water/steam or synthetic refrigerant working fluids. New trends building on this CHP background are integrated thermal use possibilities when a cold stream is provided as a by-product of the power producing cycle. Such CCHP tri-generation methods are exemplified as powered by exhaust heat from a prime mover or generator, etc. and the use of an absorption cycle using a refrigerant/absorbent pair such as ammonia/water. In such a system, a stream of medium to high temperature exhaust (waste) heat is utilized to generate a lower temperature cold stream. However, the known methods of CHP and CCHP have not lent sufficient consideration to other configurations utilizing natural refrigerants such as ammonia solely in the capacity of the power producing working fluid. Applicant's Thermal Separator/Power Generator ("TSPG") invention seeks to effectively exploit the thermodynamic properties of natural substances such as carbon dioxide, ammonia, and/or hydrocarbons to provide supplemental heating, cooling and power without emitting additional greenhouse gases to the environment, and to the extent possible, use available waste or unused heat energy. This is accomplished through the combined operation of an ammonia (NH₃) Rankine cycle, and a carbon dioxide (C0₂) compressor/expander module arranged in a heat pumping cycle. The novel NH₃ refrigerant Rankine cycle power generator is heat assisted by a C0₂ heat pump with the total system supplying supplementary heat/cooling outputs. Simultaneous and usable energy output forms from this combined TSPG cycle are mechanical power and/or electricity, and various options and combinations of usable thermal energy. The TSPG unit is anticipated to conveniently serve the heating and cooling needs of a singular use or facility, or distributed uses. This can be directly and locally supplied, or distributed through a hydronic thermal grid (TG). This TG is a network which conveniently facilitates the transportation, amplification, and conversion of waste heat offering nearly limitless opportunities for the recovery and utilization of useful thermal energy that is typically thrown away. The benefits of the invention are made possible by a combination of two specific and sectional natural refrigerant systems. A Rankine cycle power generator (applicant's RPG) section might use synthetic refrigerant fluids or blends. A preferred embodiment would use a natural refrigerant working fluid such as ammonia (NH₃), which is heat boosted by a choice of options to a superheated vapor state. Secondary temperatures are also produced in the power generation cycle which are sufficient for uses such as heating domestic hot water or moderate space heating. A C0₂ heat pump section thermally separates a hot and cold thermal stream from ambient or unused low temperature heat sources such as ambient air or geo-bodies. This thermal separation module (applicant's TSM) section when combined in a parallel preheat operation with the RPG section, adds a significant efficiency heat boost to the RPG cycle ultimately and optionally providing power, even for the TSM operation itself, as well as providing simultaneous space or process cooling. Applicant's TSM exploits the thermodynamic properties of carbon dioxide to efficiently provide full-time cooling sufficient for cooling applications and optionally (to electricity production) for off-the-electrical grid supplemental heating. There is a need for, and applicant's invention provides a compact, modular product which is a type of natural refrigerant powered thermal and mechanical/electrical generator capable of supplying options of heating, cooling, refrigeration, hydraulic power, mechanical power, and electrical power in an integrated device serving both mobile and fixed off-the-electric grid applications. Applicant's invention will convert thermal energy from waste sources such as ambient air, geothermal or geoexchange, and solar sources into useable thermodynamic energy for mechanical applications such as power generation or for thermal uses. Unlike fixed CHP utilities and/or other renewable and inflexible energy sources; applicant's unit could operate as a portable platform in harsh and variable conditions and be deployed in both fixed and mobile applications. As a "distributed" energy system, it can be brought online faster than central power plants, with increased system-wide reliability. Networked as a distributed node or as clustered arrays in concentrated locations to meet variable power growth capacities and thermal requirements, this concept promises to radically change the landscape of responsible and efficient thermal and electrical energy consumption, and the systems required to supply it. Even alternative heat sources such as solar and geo-exchange conveniently adapts and add even greater efficiency and power output.

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IV. SUMMARY OF THE INVENTION

Applicant's invention embodies a Thermal Separator/Power Generator ("TSPG") for rapid user distribution and deployment as a standalone machine which might efficiently serve multiple simultaneous uses. Conveniently networked as a distributed node expandable with like machines via a thermal/electrical grid via rigid or flexible conduits for thermal/mechanical/electrical end-use applications; or also applied in arrays in concentrated locations, variable power growth capacities and thermal requirements may be met as needed in a modular fashion. Heating and cooling needs are advantaged as coexistent applications with power production. Hydraulic power inputs and/or outputs are options within the scope of mechanical power features. Increased efficiency benefits from boosted thermal gain which may be provided by modular ancillary add-on heat recovery components would directly access available heat sources such as solar, water bodies, and waste heat from vehicles or other processes.

Many studies have been completed comparing different refrigerants for use as working fluids for use in Rankine cycles, some of which have been commercialized. Most of these systems utilize synthetic derivative refrigerants and blends with toxic, flammable, or corrosive characteristics, although flammable hydrocarbon gases have also been considered.

Although natural refrigerant hydrocarbons are cited and studied, it is noteworthy that little work has been accomplished in the art in consideration of ammonia and carbon dioxide natural refrigerants combined in new ways for CCHP systems.

With new and increasing knowledge concerning the detrimental aspects of manmade synthetic refrigerants, natural refrigerants will serve the future in ever increasing energy management capacities. The use of natural refrigerant systems will be preferred for thermal, mechanical, or electrical utilizations if efficiencies of cost and performance can be provided. An object of the invention is to provide an improved efficiency thermodynamic system which provides all of the following attributes in a singular platform: · Full time thermal output suitable for heating applications 100 F to 130 F such as domestic hot water

· Full time temperature output suitable for cooling applications such as air conditioning 35°F to 55°F.

It is also an object to provide the same, single platform with the following options: · Electrical output in full and/or in part made operable by high temperature waste heat sources > 400°F and/or

· Electrical output production assisted by medium temperature waste heat sources 100°F to 399°F and/or

· Electrical output production assisted by low temperature waste heat sources -20^°F to 100°F and/or

· Electrical output in full and/or in part made operable by fueled consumption of sustainable bio fuels and/or

· Electrical output in full and/or in part made operable by fueled consumption of fossil fuel · Selectable priority (in lieu of electrical output) thermal output suitable for heating applications 130° F to 212°F.

The selection of a refrigerant for use of the power producing cycle of the RJPG is a primary need. The unique properties of natural refrigerants must be taken into consideration for practical use. Apart from air and water, natural refrigerants basically divide into hydrocarbons, ammonia, and carbon dioxide. The most challenging characteristic of the hydrocarbon family refrigerants is their high flammability. Propane (R290), propylene (Rl 270), butane (R600) and isobutane (R600a) are examples. Such fluids have proved effective refrigerants, but safety design concerns for flammability may exclude them from practical consideration encompassing the mechanical/electrical complexities necessary for the RPG encompassing electrical output. The dominant characteristics of ammonia are a penetrating odor and toxicity. Despite these downsides, ammonia has been widely used for well over 100 years and has a good safety record. This may be partly due to the pungent smell made evident by even a small leak which helps assure proper maintenance of a sealed system.

Carbon dioxide is present in the soda we drink and the air we breathe and is non- flammable and non-toxic. Despite the high pressures associated with its use, carbon dioxide has been used as a refrigerant since 1862. Its use in an RPG cycle has not been seriously considered given its low critical temperature of <85°F.

The graphs illustrated in Figs. 1 and 2 show C0₂ and NH₃ as potential candidates for use in a combined heat pump/Rankine cycle. Fig. 1 shows a C0₂ Heat Pump Cycle

The carbon dioxide system operates as a trans-critical vapor compression heat pump cycle with the following processes shown on its corresponding Temperature (T) - entropy (s) diagram: Process 1 -2: Compression

Process 2-3: Heat rejection

Process 3-4: High pressure side of the internal heat exchanger

Process 4-5: Refrigerant expansion

Process 5-6: Heat absorption

Process 6-1 : Low pressure side of the internal heat exchanger Fig. 1 shows ammonia Rankine Cycle

The ammonia cycle operates as a conventional power producing Rankine cycle with the following processes shown on its corresponding T-s diagram:

Process 1 -2: Liquid pump

Process 2-3 : Heat input from the C0₂ cycle Process 3-4: Supplemental heat input

Process 4-5: Expansion (power production)

Process 5-1 : Waste heat rejection The cycles are linked to one another because the heat that is rejected in Process 2-3 from the C0₂ cycle is used to provide part (Process 2-3 in the ammonia cycle) of the overall heating that is required for the ammonia Rankine cycle to operate. The benefit is two- fold: 1) The C0₂ heat pump provides useful cooling that may be used to meet air conditioning or refrigeration needs, and 2) the heat that is provided by the C0₂ system to the RPG is provided at a much higher coefficient of performance ("COP") than the simple combustion of a fossil fuel which would normally have met the need. Thermodynamic modeling of the TSPG system indicates that by supplementing a modest heat level input of <400 degrees Fahrenheit the full potential of the proposed features described can be attained. This would be accomplished by waste heat recovered from engine stacks or other on-site sources. However consideration has been given encompassing any condition whereby sufficient waste heat is not available for full power output, and conventional on-board combustion fuel (biodiesel, diesel, natural gas, propane, etc.) might be employed to assure full capabilities under all conditions.

The RPG section of the TSPG will not only produce electrical power, but will also simultaneously produce secondary (water or air) heating ~100°F to ~130°F, which otherwise must be rejected, for use in applications such as domestic water heating. In operation, the TSM section of the TSPG generates hot liquid such as water at (~130°F to ~200°F) while simultaneously providing for (water or air) cooling ~35°F to ~55°F. Combining the RPG and TSM sections together with a heat exchanger common to both sections allows construction of a Thermal Separator Power Generator (TSPG) package whereby thermal energy may extracted by the TSM from low temperature sources (<1 OOF) and used to efficiently boost temperature of the working fluid used in the RPG section which has a higher boiling point temperature. Applicant's TSPG invention results in mechanical/electrical power, heat, and cool at low energy consumed, if any, as additional purchased fuel/electrical energy consumption. This is based on available waste heat resources and priorities selected for the use of the energy reclaimed and used in whatever form.

Applicant's TSM is a modular, lightweight and extremely energy efficient portable packaged platform using environmentally responsible CO, as the refrigerant compound. The TSM provides hot and cold high-pressure C0₂ fluid energy streams from which to transfer thermal temperatures to low pressure, safe, easily handled and low cost hot and cold simultaneously available liquid (such as water) base thermal streams. These low-pressure water- base lines offer unlimited potential for meeting heating, cooling, and refrigeration first responder needs for emergency and disaster relief applications.

The TSM utilizes a C0₂ heat pumping cycle, whereby low quality thermal energy is efficiently elevated to significantly higher heat quality than is possible with conventional vapor compression technology using toxic HFC or other refrigerants.

The proposed technical departure utilizing the proposed methods would serve many thermal/electrical/mechanical processes simultaneously leaving a cold thermal stream for cooling applications. Heat energy generated with the TSM in this manner can recover more than three times the BTU's compared with electrical kW power equivalent BTU's, yielding aheating Coefficient of Performance efficiency >3, which is three or more times the electrical input to obtain it; a COP of 1. This equates to >300% efficiency compared with electricity assumed as 100%. When compared with fueled combustion equipment, the method additionally averts a preponderance of the inherent BTU efficiency stack losses resulting in COP efficiencies <1 and the inevitable, wasteful fuel consumption and supply logistics.

The TSM may integrate an Energy Recovery Module ("ERM") which utilizes the fluid-mechanical expansive properties of high pressure C0₂ gas to increase heat pumping efficiency by as much as one third. The net result would incorporate a C0₂ compressor with an expansion engine or ERM in an efficient TSM system design, which would increase heat pumping efficiency to a COP >3.5 or higher. Combined heating/cooling COP efficiencies may be six (6) or even higher. The outcome is a portable field deployable device, or a fixed heating and cooling unit with myriad applications/utilizations and very high efficiency.

Diverse power applications are available for shaft-coupling machinery such as hydraulic or pneumatic devices as well as electric generators. Potential layered applications are made possible by combining C0₂ transcritical heat pump technology with the power production capabilities of a Rankine Cycle Power Generator.

V. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of a C0₂ heat pump cycle plotting temperature verses entropy.. FIG. 2 is a graph of an ammonia Rankine cycle plotting temperatures verses entropy. FIG. 3 is a schematic depiction of the Thermal Separator Module and the Rankine Power Generator illustrating the orientation and applications of the combined two fluid loops.

FIG. 4 is a schematic diagram showing the fluid flow of the various fluid loops comprising the Thermal Separator Module and the Rankine Power Generator and the various pumps, compressors, condensers, and other components used in the loops.

VI. DETAILED DESCRIPTION OF THE INVENTION

Turning to Figs. 3 and 4, there is illustrated a schematic diagram of applicant's invention. There is a Thermal Separator Module ("TSM") 10 that thermally separates and amplifies low grade or low quality heat sources that are generally less than 100^°F, into individual, dual hot and cold thermal streams. This is conventionally known and practiced in current heat pump technology.

There is a drive motor 38 and compressor 40 to power a C02 vapor compression cycle in the TSM 10 by any of a number of power sources indicated at 12. These can be various forms of hydraulic power such as hydraulic power packs, wind hydraulics, farm implements, or other hydraulic means. The drive motor can also be conventionally powered by means of electrical energy.

As can be seen in Fig. 3, the TSM has both a hot loop 14 and a cold loop 16. The hot loop 14 has various applications 18 that it can satisfy a temperature boost up to ~250^°F for the RPG working fluid in a thermal exchange between TSM 10 and RPG 22. An alternative use for this thermal energy may include hydronic applications such as hot water ~130°F to ~180°F for hydronic distribution, or secondary exchange air delivery/distribution, or secondary heat exchange of other similar singular or combined applications. The cold loop 16 also has various applications that it can satisfy (~25°F to 55°F). These include air conditioning/distribution, air conditioning hydronic delivery, secondary water cooling or chilling and other similar applications illustrated in block 20.

The RPG) section is illustrated in Fig. 3 at 22. In operation, the RPG is arranged combined by heat exchange with the C0₂ heat pumping TSM cycle. Using low temperature sources (<100°F) which are available prolifically and may be amplified to higher temperatures ~200°F for preheat of the working fluid in the RPG This enhances efficiency of the RPG when waste heat sources are insufficient to supply all the thermal capacity requirements of the RPG. One fluid loop at 24 in the RPG is provided to recover waste heat from various heat producing equipment such as vehicles, solar packs, heavy equipment, industrial/commercial processes, etc. If additional heat is further required to boost the temperature of the working fluid to its working state, it can be done at block 26 with a supplemental fuel tank/heater to supply exchanged secondary steam heat, direct fire burner, or other thermal power source providing >300^°F for ammonia superheating. The RPG may generate electrical power at 28 and be a feedback source of power for TSM power source 12

At block 30, unused warm/hot fluid such as water i s diverted at valve 32 for undefined thermal regeneration uses or for heat rejection as and if necessary. However, alternatively and preferably, the warm/hot water may be used at block 34 for warm/hot water applications such as domestic hot water uses, storage, or processes, etc.

Fig. 4 illustrates in detail the components and fluid flow circuits of the TSM and RPG. The TSM heat pump high pressure hot loop 14 has the drive motor 38 that drives the compressor 40. The compressor 40 compresses a refrigerant fluid 41 , preferably C0₂, to high pressures on the order of 1200-2400 psi and temperatures of preferably between 150^°F and 300^°F and discharges it at high pressure discharge 42. This fluid 41 from discharge 42 then enters a segmented high pressure to high pressure heat exchanger Rankine cycle refrigerant boiler 44 which cools the fluid 41 from the inlet to the outlet of the boiler 44. The fluid 41 remains at a high pressure on the order of 1200-2400 psi, with a very small pressure drop through the refrigerant boiler 44, whereby heat from the fluid 41 is transferred from the fluid 41 to a second condensed cold Rankine cycle refrigerant fluid 46 (preferably NH₃), which is in another fluid flow circuit described later.

This process is described as high pressure gas of high temperature exchanging thermal energy to a high pressure Rankine refrigerant fluid of lower temperature. The refrigerant boiler 44 is similar to and more fully described in PCT US2008/006827 filed May 30, 2008 which is incorporated herein by reference. However, in this dual high pressure embodiment, both TSM fluid 41 and the Rankine refrigerant fluid circuit are at high pressures; therefore, the entire heat exchanger shell must also be designed to safely handle these pressures. Other types and styles of heat exchangers can also be configured for use as known to those skilled in the art.

Thus, the high pressure fluid 41 (which is in a gaseous state) passes through a channel tube array in the heat exchanger gas boiler 44 where the fluid 41 is cooled to a warm gas 47 and discharged at the gas boiler 44 discharge 48. As seen in Figure 4, the warm gas 47 may then by-pass through a throttle/expansion valve 50 which lowers the pressure and temperature of the gas 47 to a cold gas 52. In parallel the throttle/expansion valve 50 controls all or a percentage of warm gas 47 which may be directed to be used by an energy recovery machine i.e., expansion engine 54 which is connected to the compressor 40 and assists in driving the compressor. The expansion engine 54 and compressor 40 may be combined into one machine such as disclosed in PCT/US2006/030759 and PCT/US2008/006845. This compressor/expansion engine has both expansion cylinders and compression cylinders disposed in the same engine. When an expansion engine is used, it will result in a drop in the temperature and pressure of the gas 47 to approximately 300-700 psi at 15^°F to 50^°F. For a full description of the compression/expansion engine, see the above referenced applications.

In lieu of temperature boost from fluid 41 exchanged to the second Rankine refrigerant fluid 46, there exists still another alternative, i.e., of hot liquid applications >130°F in block 18. As well known in the art, by diverting the hot gas around gas boiler 44 to a high pressure to low pressure gas cooler heat exchanger as previously described (exchanger, pipe/valving not shown) alternate thermal applications may be attained such as hot water > 130^°F but must be realized at the expense of boost heat (efficiency) for the power generation circuit.

The warm gas 47 is then is routed to the expansion engine 54 and throttle/expansion valve 50 exiting either or both as a cold mixed gas/fluid 52 and into a high pressure to low pressure heat exchanger evaporator 56 where it is evaporated back to gas. In this process the cold gas 52 is warmed (as will be explained below) and exits the evaporator 56 as warmed gas 57. The gas remains at close to the inlet pressure which is a pressure of approximately 300- 700 psi, with a very small pressure drop through the evaporator 56. The warmed gas 57 enters the compressor 40 at a low temperature but at pressure and temperature which assures the fluid is in a gaseous state as the cycle repeats.

In addition to RPG heat boost, when in operation the TSM vapor compression cycle heat extraction function therefore serves to leave a resultant full time supplemental cooling loop exampled and shown, supplied as a water or water/glycol cooling or refrigeration loop but may use other gas or liquid fluids. In this case, the cooling loop 16 provides cooled air 60 to a living or temperature cooled environment. It can also serve other low temperature applications such as previously described at block 20. There is a low pressure liquid circulation pump 62 that pumps a water/glycol or similar solution at a low pressure and low temperature 64. The solution 64 passes through a second stage heat exchanger 66 where ambient warm air forced by a fan 68 is blown over or through the heat exchanger 66. Alternatively, a liquid (i.e., water based) heat exchanger 67 shown supplying block 20 for optional cooling uses. Warmed water/glycol solution 70 leaves the heat exchanger 66 and/or 67 and is pumped to the low pressure section of the evaporator 56. The warmed water glycol solution 70 is cooled in the evaporator 56 and exits at discharge end 72 as a low pressure and low temperature solution 64. The water/glycol solution in the heat exchanger 56 is physically separated from the cold Rankine cycle refrigerant 52 that is passing through the evaporator 56. However, they are in thermal communication with each other so that the heat is removed from the warmed water/glycol solution 70 as it passes through the evaporator 56. The cold water/glycol solution 64 is discharged at 72 and is then recirculated by the pump 62.

The RPG 22 is illustrated in the top half of Figs. 3 and 4. The power producing Rankine cycle loop generally uses a relatively high subcritical boiling point refrigerant. A natural refrigerant such as NH₃ is preferable for use in the RPG 22. At atmospheric pressure NH3 boiling point is -28°F and compares favorably with other natural but flammable refrigerants such as Propane (- 44°F) and Butane at (-3 I T). However CO, boiling point is very low, - 70T at ~5X atmospheric which helps explain why C0₂ is not a suitable candidate for the Rankine cycle working refrigerant. In this example, a high pressure liquid feed pump 76 pumps liquid NH₃ to one end of the gas boiler 44. The liquid NH₃ is physically segregated from the hot high pressure refrigerant fluid 41 that is passing through the gas boiler 44 from the compressor 40. However, the two fluids are in thermal communication so that heat from the high pressure refrigerant fluid 41 is transferred to the liquid NH₃ causing it to "boil" and transition to a gaseous state. The NH₃ gas leaves the gas boiler 44 as the high pressure warm gas 78. As observed, the combined cycle uses the heat exchanged in gas boiler 44 from the C0₂ heat pump refrigerant fluid 41 discharged from the compressor 40 as pre-heat boosting the temperature of the NH₃ before it enters a second pre-heater or waste heat, heat exchanger 80. At waste heat exchanger 80, higher temperature heat from the operations described in block 24 is recovered and transferred to the high pressure preheated yet cooler temperature NH₃ This may be accomplished by means of a hot hydronic loop 81 that circulates a fluid from the waste heat recovery source at 24 to the NH₃ waste heat exchanger 80, and then returns it to the source at 24.

The NH₃ gas 78 exits the pre heater 80 at 82. At this point, and only if necessary, the gas 82 is further heated by means of a heat source 84 to assure full capacity temperature and pressure adequate to power a turbine, piston machine, or other prime mover 86. In this way further heat may be added only as required from conventional processes such as fueled combustion. The heat source 84 can be a standby fueled steam boiler, direct fire to the Rankine circuit, or other appropriate heat generating source and means of generating a topping temperature suitable to reach the superheated vapor heat thresholds desired. The fuel source can be an on-board fuel tank which allows the system to be portable. The benefit of this combined cycle is that approximately one quarter to one third of the heat input requirements of the RPG can be supplied by the C0₂ heat pump, from low temperature waste sources, and the balance required for full power production derived from medium and high temperature waste heat sources with provision for conventional heat topping of the Rankine cycle only as and if necessary/required. The sum waste heat recovery potentials would be anticipated to dramatically reduce or even eliminate the BTU heat input that typically comes from sources such as natural gas or bio or diesel fuel as conventionally supplied.

The prime mover 86 is powered by the NH₃ and drives a generator 88. This generates electrical power 90. Alternatively, the prime mover 86 may be any form of electrical or mechanical power generator that can be powered by the high temperature high pressure NH₃. Thus, mechanical, hydraulic or electric power can be produced. Another form of utilization of the gas 78 may be made by the expansion engine as disclosed in both US2006/030759 and PCT/US2008/006845.

A warm gas 92 exiting prime mover 86 at a mid pressure enters a high pressure side 94 of a high pressure fluid to low pressure fluid heat exchanger 96 which is a NH₃ condenser or gas cooler providing heat rejection of the power cycle. This cools and liquefies the NH₃ and, in this embodiment, discharges it at 98 as a mixed fluid or liquid to enter liquid storage tank receiver 100 for re-circulation by the pump 76.

The last loop to consider is an RPG condenser loop 102. Generally water 104 will be the heat transfer fluid medium. A pump, not illustrated, pumps the water 104 through the loop. Cool water 106 enters the heat exchanger 96 at 98. Heat from the warm gas 92 is transferred to the cool water 106 as it passes through the exchanger 96. When the water is discharged from the heat exchanger 96 at 108, it is warm/hot water that may be heat rejected as described at block 30 but is also suitable for many domestic warm water applications as described at block 34.

Thus there has been provided a Thermal Separator Power Generator that incorporates a thermal separator heat pump cycle and a Rankine power generator cycle. While the invention has been described in conjunction with a specific embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims.

Claims

VII. CLAIMS What is claimed is:

1. A heating, cooling and power generation system comprising:

a thermal separator module for producing two fluid loops, a first high temperature fluid loop at a temperature substantially above ambient temperature and a second low temperature fluid loop at a temperature substantially less than ambient temperature, the thermal separator module comprising a C0₂ compressor, a high pressure heat exchanger Rankine refrigerant boiler a C0₂ gas expansion means, a heat exchanger evaporator means, and carbon dioxide flowing through the compressor, the high pressure heat exchanger Rankine refrigerant boiler, the C0₂ gas expansion means, and the heat exchanger evaporator means in a continuous circuit;

a Rankine cycle power generator system for generating power comprised of a serial flow system with a Rankine refrigerant fluid in the system, a fluid pump, the high pressure heat exchanger Rankine refrigerant boiler, at least one Rankine refrigerant heater, a prime mover for generating power from the expansion of the Rankine refrigerant fluid from a liquid to a gas, a heat rejection means, and means for returning the Rankine refrigerant to the pump;

the high pressure heat exchanger refrigerant boiler having high pressure fluid passageways through which the C0₂ passes and having other high pressure fluid passageways through which the Rankine refrigerant flows, the Rankine refrigerant and C0₂ passing through the high pressure heat exchanger Rankine refrigerant boiler in their separate passageways, but in thermal communication with each other.

2. The heating, cooling and power generation system of claim 1 wherein the Rankine refrigerant fluid is a natural refrigerant.

3. The heating, cooling and power generation system of claim 2 wherein the Rankine refrigerant fluid is ammonia.

4. The heating, cooling and power generation system of claim 1 and further comprising an energy recovery device for receiving energy from the C0₂ during its expansion process and converting it to work..

5. The heating, cooling and power generation system of claim 1 wherein the second heat exchanger evaporator is in serial fluid flow with the compressor and high pressure heat exchanger Rankine refrigerant boiler, the second heat exchanger evaporator providing a heat removal source to apply a cooling refrigeration stream.

6. The heating, cooling and power generation system of claim 1 and further comprising at least a fourth heat gas cooler heat exchanger in serial fluid flow with the prime mover for providing a heat removal means for removing heat from the Rankine refrigerant fluid.

7. The heating, cooling and power generation system of claim 1 wherein the prime mover is a turbine and the Rankine refrigerant fluid vaporizes to provide power to the turbine.

8. The heating, cooling and power generation system of claim 3 wherein the prime mover is a piston driven machine and the ammonia fluid vaporizes to provide power to the piston machine.

9. The heating, cooling and power generation system of claim 1 wherein the C0₂ is pumped from the compressor and enters the high pressure heat exchanger Rankine refrigerant boiler at a pressure of between 200 psi and 2500 psi.

10. The heating, cooling and power generation system of claim 1 and further comprising at least one auxiliary heat source to increase the temperature of the Rankine refrigerant fluid so that said refrigerant fluid has sufficient heat capacity to generate power when it enters the prime mover.

1 1. The heating, cooling and power generation system of claim 10 wherein the auxiliary heat source is a waste heat, heat exchanger system.

12. The heating, cooling and power generation system of claim 1 and further comprising heat exchanger means in the Rankine cycle power generator system for providing heat for a warm water loop.

13. The heating, cooling and power generation system of claim 1 wherein the second heat exchanger evaporator is fluidly connected to a pump for circulating cold fluid through an air conditioner for providing cool air.

14. The heating, cooling and power generation system of claim 1 wherein the Rankine refrigerant heater is a waste heat heat exchanger.

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15. A method of operating an efficient heating, cooling and power generation system comprising:

providing a thermal separator for producing a first high temperature fluid loop and a second high temperature fluid loop by means of a high pressure C0₂ compressor for compressing C0₂ and supplying the highly compressed C0₂ to a high pressure heat exchanger Rankine refrigerant boiler, the compressor forcing the C0₂ through the high pressure heat exchanger, reducing the temperature of the C0₂ in the high pressure heat exchanger and utilizing the C0₂ in a hot water or energy recovery process that reduces the temperature of the C0₂, flowing the reduced temperature C0₂ through a second heat exchanger where the C0₂ removes heat from the second low temperature fluid loop, and returning the C0₂ to the compressor;

providing a Rankine cycle power generator system for generating power from a Rankine refrigerant fluid which converts heat energy from the fluid to mechanical energy, a pump for circulating the Rankine refrigerant fluid in a liquid state through the high pressure heat exchanger Rankine refrigerant boiler where it is warmed, passing the refrigerant fluid through a third heat exchanger, passing the refrigerant to a prime mover where the Rankine refrigerant fluid vaporizes and drives the prime mover, and

returning the Rankine refrigerant fluid the prime mover to the pump for recirculation.

16. The method of operating an efficient heating, cooling and power generation system of claim 15 and further comprising:

providing the high pressure heat exchanger refrigerant boiler with high pressure fluid passageways through which the C0₂ passes and other high pressure fluid passageways through which the Rankine refrigerant flows, the Rankine refrigerant and CO, passing through the high pressure heat exchanger Rankine refrigerant boiler in their separate passageways, but in thermal communication with each other.

17. The method of operating an efficient heating, cooling and power generation system of claim 16 and further comprising using ammonia as the Rankine refrigerant fluid.

18. The method of operating an efficient heating, cooling and power generation system of claim 16 and further comprising providing an energy recovery device for receiving energy from the C0₂ during its expansion process and converting it to work.

19. The method of operating an efficient heating, cooling and power generation system of claim 15 and further comprising providing at least a fourth heat gas cooler heat exchanger in serial fluid flow with the prime mover for providing a heat removal means for removing heat from the Rankine refrigerant fluid.