Bland/Ewing Cycles for CHP and CC processes
20250116259 ยท 2025-04-10
Inventors
Cpc classification
International classification
Abstract
Engine systems and methods for performing a new chemical/thermodynamic cycle, termed a Chemo/thermodynamic Closed Combined (CCC) cycle, are proposed herein. The CCC cycle is composed of an Endothermic Chemo/thermodynamic Open cycle (En-C-O) and an Exothermic Chemo/thermodynamic Open cycle (Ex-C-O), which together complete the larger CCC cycle. CCC cycles may operate as a Combined Heat and Power (CHP) cycle. Since the En-C-O and the Ex-C-O cycles are able to operate independently of one another, they can be distanced from one another in time and/or space. To complete the larger CCC cycle, the En-C-O and Ex-C-O chemical working fluids are stored and/or transported between one another. An Exothermic Reactor Exhaust Compressor (EREC), for permitting otherwise-waste CCC heat to convert said chemical working fluids from liquid/frozen pressurized states into pressurized vapors and/or gases, is also proposed herein. Finally, various En-C-O and Ex-C-O cycles are proposed herein.
Claims
1.-32. (canceled)
33. A method for performing a closed thermochemical and thermodynamic (chemo/thermodynamic) work-producing cycle comprising two independent open chemo/thermodynamic work-producing cycles, the two open chemo/thermodynamic work-producing cycles comprising a first cycle that chemically or endothermically absorbs heat in a reactant/reactant mix such that said reactant/reactant mix is converted to a product/product mix, and a second cycle that chemically or exothermically releases heat from said product/product mix to recreate at least part of said reactant/reactant mix, the method comprising: a. increasing, from a first storage, a non-gaseous first reactant/reactant mix to a set pressure; b. preheating, with a first heat source, said pressurized non-gaseous first reactant/reactant mix to its point of conversion to a vapor; c. completely vaporizing, with a second heat source, said preheated and pressurized non-gaseous first reactant/reactant mix to make a pressurized vaporous first reactant/reactant mix; d. increasing, from a second storage, a gaseous second reactant/reactant mix to the pressure of said pressurized vaporous first reactant/reactant mix; e. matching, with a third heat source, the temperature of said pressurized gaseous second reactant/reactant mix to the temperature of said pressurized vaporous first reactant/reactant mix; f. mixing, with a first mixer, said pressurized vaporous first reactant/reactant mix and said pressurized gaseous second reactant/reactant mix together to make a vaporous and gaseous pressurized combined reactant/reactant mix; g. preheating, with a fourth heat source, said pressurized combined reactant/reactant mix to the temperature of an endothermic thermochemical reaction chamber; h. passing said preheated and pressurized combined reactant/reactant mix into said endothermic thermochemical reaction chamber; i. stimulating, with a fifth heat source, said preheated and pressurized combined reactant/reactant mix within said thermochemical reaction chamber to cause the preheated and pressurized combined reactant/reactant mix to chemically absorb heat during a first constant temperature and constant pressure process of changing said preheated and pressurized combined reactant/reactant mix into a vaporous and/or gaseous first product/product mix; j. expanding, with a first work-producing expander, said first product/product mix to lower the pressure and temperature of the first product/product mix; k. cooling, with a first cooler, said expanded first product/product mix to the point where said expanded first product/product mix separates into a gaseous product/product mix portion and a non-gaseous product/product mix portion; l. storing, in a second storage, said gaseous and non-gaseous product/product mix portions; m. physically transferring and/or storing for a set time period said gaseous and non-gaseous product/product mix portions; n. increasing, from said second storage, at least part of the non-gaseous product/product mix portion to a set pressure; o. preheating, with a sixth heat source, said pressurized at least part of the non-gaseous product/product mix portion to its point of conversion to a vapor; p. completely vaporizing, with a seventh heat source, said preheated and pressurized at least part of the non-gaseous product/product mix portion to make a vaporous product/product mix portion; q. increasing, from said second storage, at least part of said gaseous product/product mix portion to the pressure of said vaporous product/product mix portion; r. matching, with an eighth heat source, the temperature of said pressurized at least part of the gaseous product/product mix portion to the temperature of said vaporous product/product mix portion; s. mixing, with a second mixer, said vaporous product/product mix portion and said pressurized at least part of the gaseous product/product mix portion to make a vaporous and gaseous pressurized combined product/product mix; t. preheating, with a ninth heat source, said pressurized combined product/product mix to the temperature of an exothermic thermochemical reaction chamber; u. passing said pressurized and preheated combined product/product mix into said exothermic thermochemical reaction chamber; v. stimulating, with a chemical heat releaser, said pressurized and preheated combined product/product mix to cause said pressurized and preheated combined product/product mix to chemically release heat within said exothermic thermochemical reaction chamber during a second constant temperature and constant pressure process of changing said pressurized and preheated combined product/product mix into a third reactant/reactant mix; w. expanding, with a second work-producing expander, said third reactant/reactant mix to lower the pressure and temperature of said third reactant/reactant mix; x. cooling, with a second cooler, said expanded third reactant/reactant mix to the point where said expanded third reactant/reactant mix separates into a gaseous reactant/reactant mix portion and a non-gaseous reactant/reactant mix portion; y. storing, in a third storage, said gaseous and non-gaseous reactant/reactant mix portions; and z. physically transferring and/or storing for a set time said stored gaseous and non-gaseous reactant/reactant mix portions.
34. The method of claim 33, wherein: at least two of said first storage, second storage, or third storage are the same storage, and/or at least two of said first heat source, second heat source, third heat source, fourth heat source, fifth heat source, sixth heat source, seventh heat source, eighth heat source, or ninth heat source are the same heat source, and/or said first mixer and the second mixer are the same mixer, and/or said first work-producing expander and second work-producing expander are the same work-producing expander, and/or said first cooler and second cooler are the same cooler.
35. An engine system configured to perform a closed thermochemical and thermodynamic (chemo/thermodynamic) work-producing cycle comprising two independent open chemo/thermodynamic work-producing cycles, the two open chemo/thermodynamic work-producing cycles comprising a first cycle that chemically or endothermically absorbs heat in a reactant/reactant mix such that said reactant/reactant mix is converted to a product/product mix, and a second cycle that chemically or exothermically releases the heat from said product/product mix to recreate at least part of said reactant/reactant mix, the engine system comprising: a. a first storage configured to increase a non-gaseous first reactant/reactant mix to a set pressure; b. a first heat source configured to preheat said pressurized non-gaseous first reactant/reactant mix to its point of conversion to a vapor; c. a second heat source configured to completely vaporize said preheated and pressurized non-gaseous first reactant/reactant mix to make a pressurized vaporous first reactant/reactant mix; d. a second storage configured to increase a gaseous second reactant/reactant mix to the pressure of said pressurized vaporous first reactant/reactant mix; e. a third heat source configured to match the temperature of said pressurized gaseous second reactant/reactant mix to the temperature of said pressurized vaporous first reactant/reactant mix; f. a first mixer configured to mix said pressurized vaporous first reactant/reactant mix and said pressurized gaseous second reactant/reactant mix together to make a vaporous and gaseous pressurized combined reactant/reactant mix; g. a fourth heat source configured to preheat said pressurized combined reactant/reactant mix to the temperature of an endothermic thermochemical reaction chamber, the endothermic thermochemical reaction chamber being configured to receive said preheated and pressurized combined reactant/reactant mix; h. a fifth heat source configured to stimulate said preheated and pressurized combined reactant/reactant mix to cause said preheated and pressurized combined reactant/reactant mix to chemically absorb heat during a first constant temperature and constant pressure process of changing said preheated and pressurized combined reactant/reactant mix into a vaporous and gaseous first product/product mix; i. a first work-producing expander configured to expand said first product/product mix to lower the pressure and temperature of said first product/product mix; j. a first cooler configured to cool said expanded first product/product mix to the point where said expanded first product/product mix separates into a gaseous product/product mix portion and a non-gaseous product/product mix portion; k. a second storage configured to store said gaseous and non-gaseous product/product mix portions and to increase at least part of said non-gaseous product/product mix portion to a set pressure; l. a sixth heat source configured to preheat said pressurized at least part of the non-gaseous product/product mix portion to its point of conversion to a vapor; m. a seventh heat source configured to completely vaporize said preheated and pressurized at least part of the non-gaseous product/product mix portion to make a vaporous product/product mix portion, wherein said second storage is configured to increase at least part of said gaseous product/product mix portion to the pressure of said vaporous product/product mix portion; n. an eighth heat source configured to match the temperature of said pressurized at least part of the gaseous product/product mix portion to the temperature of said vaporous product/product mix portion; o. a second mixer configured to mix said vaporous product/product mix portion and said pressurized at least part of the gaseous product/product mix portion to make a vaporous and gaseous pressurized combined product/product mix; p. a ninth heat source configured to preheat said pressurized combined product/product mix to the temperature of an exothermic thermochemical reaction chamber, said exothermic thermochemical reaction chamber being configured to receive said pressurized and preheated combined product/product mix; q. a chemical heat releaser configured to stimulate said pressurized and preheated combined product/product mix to cause said pressurized and preheated combined product/product mix to chemically release heat within said exothermic thermochemical reaction chamber during a second constant temperature and constant pressure process of changing said pressurized and preheated combined product/product mix into a third reactant/reactant mix; r. a second work-producing expander configured to expand said third reactant/reactant mix to lower the pressure and temperature of said third reactant/reactant mix; s. a second cooler configured to cool said third reactant/reactant mix to the point where said third reactant/reactant mix separates into a gaseous reactant/reactant mix portion and a non-gaseous reactant/reactant mix portion, t. a third storage configured to store said gaseous and non-gaseous reactant/reactant mix portions.
36. The engine system of claim 35, wherein: at least two of said first storage, second storage, or third storage are the same storage, and/or at least two of said first heat source, second heat source, third heat source, fourth heat source, fifth heat source, sixth heat source, seventh heat source, eighth heat source, or ninth heat source are the same heat source, and/or said first mixer and the second mixer are the same mixer, and/or said first work-producing expander and second work-producing expander are the same work-producing expander, and/or said first cooler and second cooler are the same cooler.
37. The engine system of claim 35, wherein the chemical heat releaser is in part or in whole a heater within a heat engine.
38. The engine system of claim 35, wherein the chemical heat releaser does not comprise a heater within a heat engine.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be illustrated in greater detail by description in connection with specific examples of the practice of it and by reference to the accompanying drawing, in which:
[0023]
[0024]
[0025] To aid in calculations, at various points the gaseous fuel/air states in
[0026] Note that the proposed B/E Cycle engine's working fluid is chemically changed halfway through a complete cycle. That is, at 100% conversion, the chemically expanded mol count ideally equals 4 the chemically compressed mol count. The comparative volumes and enthalpies can be easily adjusted at those points in
[0027] It was important to keep the cycle elements roughly within the chart's shown boundaries. Thus, for this initial analysis, an endothermic reaction to 90% completion, a maximum endothermic reaction pressure of 5.1 atm (75 psi), and a maximum endothermic temperature of 950 K (1,710 R) is used. Exothermic temperatures and pressures are different in different options, and unless stated the exothermic reaction is assumed to go to 100% completion.
[0028]
[0029]
[0030]
[0031]
[0032] As will become clear, the endothermic and exothermic segments will not necessarily need to be in physical proximity to be fully functional. Indeed, the ability to physically separate the endothermic and exothermic segments is a major advantage of the proposed concepts.
[0033]
[0034] Note: In many of the Figures, an H2 Staged and inter-cooled compression and storage system is shown. H2 is well known to be a very efficient heat transfer medium. In instances where H2 is already being stored, advantage of its presence can be taken to aid in efficient heat transfer, as between a hot fluid and a distant or disconnected cold source or a cold fluid and a distant and disconnected heat source.
[0035] Note that
[0036] A legend for
DETAILED DESCRIPTION
[0037] The underlying improvement to the foundational B/E Cycle invention disclosed in U.S. Pat. Nos. 3,225,538, 3,067,594, and 3,871,179 takes the form of methods and apparatuses for combining various half-cycle endothermic and half-cycle exothermic portions of a complete B/E Cycle, said combinations depending on whether the requirement for said full cycle is to aid in generating stored thermal energy (as for CHP purposes) or to aid in generating work (as for CC purposes). To accomplish this, the B/E Cycle is broken into endothermic portions and exothermic portions, and the half-cyclical nature of each is designed to optimize for either CHP or CC output.
Endothermic Segment
[0038] In the endothermic segment, the products of the endothermic reaction or exothermic fluid are created from the reactant or endothermic fluid. The low temp (low temperature) endothermic half-cycle variant assumes a non-lubricated expander solution is required to avoid impacting the chemistry. One means of avoiding the use of lubrication is to moderate the expander input temperature with a high temperature counterflow heat exchanger between the endothermic reactor and the expander, permitting the use of teflon seals and a zero-to-moderately-cooled expander.
[0039] A high temp (high temperature) endothermic half-cycle variant assumes a high temp solution can be found to the issue of non-lubrication. It is obvious that other expander approaches may permit high temperature C6H6 and H2 exhausting from the endothermic reactor to be expanded at the temperature of the endothermic reaction or higher. Those approaches may include novel forms of positive displacement equipment, rotary expanders such as reaction and impulse turbines, magnetohydrodynamic expanders, or some combination thereof.
Exothermic Segment
[0040] Various exothermic half-cycles will mate with the endothermic segment's low temp and high temp endothermic half cycle variants. These can be divided into two general variants; exothermic-for endothermic variants and exothermic production variants. Note that each exothermic variant itself contains sub-variants.
Exothermic-for-Endothermic Variants
[0041] Two alternative exothermic-for-endothermic half-cycles generate heat from a small fraction of the exothermic fluid product of the low temp endothermic variant and are purposed for direct use within the low temp endothermic variant. The first exothermic-for-endothermic half-cycle is a simple cycle, and the second is a complex cycle, as will be shown below. As mentioned earlier, in order to create a B/E Cycle, both an endothermic element and an exothermic element would be required. However, the exothermic-for-endothermic variants do not serve in that capacity. They are better viewed as essential parts of the endothermic half-cycles. Essentially, a small portion of the exothermic fluid exiting the endothermic element is proposed to be captured and used to assist the endothermic cycle. The remaining large portion of exothermic fluid would then be used to power a complete B/E CHP or CC cycle.
Exothermic Production Variants
[0042] Three exothermic production variants are proposed, one for creating a complete CHP cycle, and two for creating alternative complete CC cycles. Each simple or complex exothermic production variant can be further defined by its approach to combining with either a low or high temperature endothermic variant, as will be shown.
[0043] For the CHP cycle, the goal will be the generation of the maximum amount of total thermal energy delivered, while the two CC cycles will emphasize the production of the maximum amount of total work delivered. Note that, for all three cycles, the total work will be an accumulation of the work out from the endothermic half-cycle plus the work out from the exothermic production half-cycle.
SpecificationDetailed DescriptionFirst EmbodimentB/E-LS Half-Cycle
[0044] A low temperature endothermic half-cycle (
[0045] In a CHP cycle, the primary goal is the generation of a maximum amount of stored and/or transported thermal energy from a given amount of thermal input. That thermal energy is captured in the large remaining portion of exhausted exothermic fluid. That large remaining portion of exothermic fluid may then be run through an exothermic half-cycle at some distant location and/or later time. The total system for generating this thermal energy is referred to as an exothermic production variant. A summary of the thermal efficiencies and the heat source efficiencies under the described temperature, pressure, volume, and mass constraints of the B/E-LS cycle can be found under the heading Thermal Analysis below.
[0046] Note that a novel technique termed an EREC (Exothermic Reactor Exhaust Compressor) is described for use with all exothermic segments, as will be shown. An EREC is a small compressor that sets up a pressure differential between the endothermic fluid exiting the exothermic reactor and the exothermic fluid vaporous component exiting the exothermic liquid component vaporizer. By raising the pressure of vaporous C6H6 prior to raising its temperature to that required by the exothermic reactor, the reaction will yield the C6H12 endothermic fluid at a higher pressure than the (pumped in) C6H6 requiring vaporization. With a sufficient pressure differential, the temperature at which the endothermic fluid will condense can be raised above the temperature that the exothermic fluid requires for vaporization. As a result, a large portion of the required C6H6 exothermic fluid vaporization heat can be supplied by the condensing C6H12 endothermic fluid, greatly increasing the efficiency of the overall exothermic half-cycle.
[0047] Note that no power source for the EREC is shown in
SpecificationOperationFirst EmbodimentB/E-LS Half-Cycle
Endothermic Half-Cycle (Low Temp, See FIG. 3 and FIG. 6):
[0048] 9. 0.454 kg & 586.6 cm3 of liquid reactant (C6H12) at 344 K and 1 atm is pumped from storage and into the half-cycle at 5.1 atm. Note: The pump inlet would start at point 13 in
Exothermic Half-Cycle (Simple, See FIG. 4 and FIG. 8):
[0061] 1. 0.038 kg of liquid C6H6 at 1 atm and 344 K is either pulled from storage or recycled from the endothermic or exothermic segment's 1 atm exhaust and injected into the endothermic segment's exothermic system at 0.68 atm. [0062] 2. The 0.038 kg or (0.038/0.07811=) 0.44 mol of liquid C6H6 at 0.68 atm flows into counterflow heat exchanger #5, where it is preheated to 353 K and vaporized and superheated to 422 K by exchanging heat with (0.038+0.0029=) 0.041 kg of C6H12 exhausting from heat exchanger #6 at 1 atm and 544 K. [0063] 3. The C6H6 vapor is compressed to 1 atm and 456 K within the Exothermic Reactor Exhaust Compressor (EREC) (compressor #2), which is powered by the endothermic segment's expander #1. [0064] 4. Following compression, the 0.038 kg of vaporous C6H6 at 1 atm and 456 K flows into counterflow heat exchanger #6, where it is preheated to 544 K by exchanging heat with 0.041 kg of C6H12 exhausting at 1 atm and 544 K from exothermic reactor #1 (see calculations below). [0065] 5. 0.0029 kg of H2 at 344 K (in the case of a PSR, storage temperature could approach 150 K) and 1 atm is injected into the half-cycle. [0066] 6. The temperature of the 0.0029 kg of H2 is then raised at constant pressure to 544K by partial external cooling of the exothermic reactor in heat exchanger #7. [0067] 7. The 0.0029 kg of preheated H2 at 1 atm and 544 K is then mixed with the 0.038 kg of preheated, vaporized, and superheated C6H6 at 1 atm and 544 K. [0068] 8. The 0.038 kg of C6H6 and 0.0029 kg of H2 product is then passed through exothermic reactor #1 at constant pressure and temperature, which produces (90+8.3)=98.3 kJ at 544 K plus 0.041 kg of C6H12 reactant. [0069] 9. The 0.041 C6H12 reactant at 1 atm exiting exothermic reactor #1 is then passed at constant pressure (1) through counterflow heat exchanger #6, thus superheating the inflowing C6H6 vapor, and (2) through counterflow heat exchanger #5, thus vaporizing the inflowing C6H6 liquid. Simultaneously, the C6H12 is cooled and condensed. [0070] 10. The 1 atm C6H12 (plus any excess H2) is then cooled, separated into liquid and gaseous constituents, and either stored, shipped, or recycled.
SpecificationDetailed DescriptionSecond EmbodimentB/E-LC Half-Cycle
[0071] In the B/E-LC half-cycle, a low temperature endothermic half-cycle (
[0072] Recall that no power source for the EREC is shown in
SpecificationOperationSecond EmbodimentB/E-LC Half-Cycle
Endothermic half-cycle (low temp, same as B/E-LS half-cycle):
Exothermic half-cycle (complex, see
[0073] (Note: An exothermic heat-powered H2 compressor (compressor #3) and expander (expander #3) engine system is added to the exothermic-for-endothermic half-cyclesimple variant to power the EREC.) [0074] 11. See B/E-LS Exothermic half-cycle, Step 1, above. [0075] 12. See B/E-LS Exothermic half-cycle, Step 2, above. [0076] 13. See B/E-LS Exothermic half-cycle, Step 3, above. [0077] 14. See B/E-LS Exothermic half-cycle, Step 4, above. [0078] 15. 0.0129 kg of H2 at 344 K and 1 atm is taken into compressor #3. 16. 0.0129 kg of H2 at 344 K is compressed by compressor #3 to 1.36 atm and 372 K. [0079] 17. 0.0129 kg of H2 at 372 K and 1.36 atm is exhausted from compressor #3 at constant pressure. [0080] 18. 0.0129 kg of H2 at 1.36 atm and 372 K absorbs heat from counterflow heat exchanger #8, raising the temperature of the 0.0129 kg of H2 to 511 K. [0081] 19. 0.0129 kg of H2 at 1.36 atm and 480 K absorbs heat from a heat exchanger attached to exothermic reactor #1, raising the temperature to 544 K. [0082] 20. 0.0129 kg of H2 at 1.36 atm and 544 K is taken into expander #3 at constant pressure. [0083] 21. 0.0129 kg of H2 is adiabatically expanded in expander #3 to 1 atm and 511 K, or a temperature difference of (544-511=) 33 K, producing (330.184=) 6.1 kJ. Per the ideal air calculator, volume would increase to 268 L. [0084] 22. 0.0129 kg of H2 is exhausted from expander #3 at 1 atm and 511 K. [0085] 23. 0.0129 kg of H2 (was 0.0029; see above) at 1 atm and 511 K is separated into two H2 streams of 0.0029 kg and (0.0129-0.0029=) 0.01 kg. [0086] 24. The 0.01 kg of H2 at 511 K and 1 atm is passed through heat exchanger #8, where it exchanges heat with the 0.0129 kg of H2 exhausting from compressor #3 at 372 K. [0087] 25. The 0.0029 kg H2 at 1 atm and 511 K is injected into the C6H6 stream at 1 atm and 456 K. [0088] 26. The 0.038 kg C6H6 and 0.0029 kg H2 mix is raised to 544 K in heat exchanger #6. [0089] 27. The 0.038 kg of C6H6 and 0.0029 kg of H2 at 1 atm and 544 K is then passed through exothermic reactor #1, which produces 103 kJ at 544 K plus 0.041 kg of C6H12 reactant. [0090] 28. See B/E-LS Exothermic half-cycle, Step 9, above. [0091] 29. See B/E-LS Exothermic half-cycle, Step 10, above. [0092] 30. The 0.01 kg and (0.1/0.00202=) 4.95 mols of H2 at 1 atm and 372 K is passed through a cooler where it is cooled to 344 K and either returned to storage or recycled back into the engine.
SpecificationDetailed DescriptionThird EmbodimentB/E-CHP-LC
[0093] In the B/E-CHP-LC cycle, a low temperature endothermic half-cycle (
[0094] In the exothermic production segment, the emphasis is on generating heat recreated by recombining all of the product, not just a small fraction for use in the endothermic segment. In the exothermic-for-endothermic half-cycles above, the exothermic reaction pressure/temperature occurred at atmospheric pressure. However, there is no reason the exothermic reaction pressure/temperature cannot be increased. In this segment, the impact of higher exothermic reactor pressures/temperatures will be explored.
[0095] Note that the question of heat quality (temperature of exothermic generation) is also important. Thus, while one process has been detailed above for generating heat at about 544 K, it is possible to increase the temperature of the thermal output by increasing the pressure of the exothermic reaction. In the system below, the product pressure has been raised from 1 atm to 5.1 atm, increasing the exothermic reaction to 589 K. It is obvious that the process described below can be used to create even higher heat quality.
[0096] Having generated the thermochemical storage product, the question arises how best to store/transport it to where it's needed. The C6H6 component is not a problem, since it can be easily stored, pumped, or shipped as a liquid. However, H2 gas could have a volume issue. Where the distance is not too great, it can be pumped through a pipeline, of course. But the longer the pipeline, the larger the pumping loss, especially at lower pressure. Physically transporting lower pressure H2 long distances could be expensive, but might be made economical using extremely lightweight and streamlined high pressure H2 storage tanks and streamlined, lightweight, low horsepower tractors and trains.
[0097] In other words, transportation and storage would be more economical if the H2 were increased substantially in pressure, reducing the diameter of a pipeline or the volume/diameter of an H2 storage/shipment tank for a given amount of H2 throughput.
SpecificationOperationThird EmbodimentB/E-CHP-LC
Endothermic Half-Cycle (Low Temp, Same as B/E-LS):
Exothermic Half-Cycle (See FIG. 5 and FIG. 10):
[0098] 1. 0.343 kg C6H6 liquid product at 1 atm is pressurized to 1.7 atm. [0099] 2. 0.343 kg C6H6 liquid at 1.7 atm and 344 K is raised at constant pressure in counterflow heat exchanger #5 to approximately the temperature of vapor-liquid equilibrium, estimated at 372 K, and then to approximately 456 K to completely vaporize the C6H6. [0100] 3. The 0.343 kg C6H6 vapor at 456 K and 1.7 atm is taken into the EREC (compressor #2) at constant pressure. [0101] 4. 0.343 kg (4.39 mols) C6H6 vapor is adiabatically compressed to 5.1 atm and 589 K within the EREC (compressor #2). [0102] 5. The 0.343 kg C6H6 vapor at 589 K and 5.1 atm (51.7 N/cm2, 75 psi) is exhausted from the EREC (compressor #2) at constant pressure. [0103] 6. 0.027 kg (13.2 mols) of H2 at 1 atm is compressed to 5.1 atm and 428 K, is injected into the exothermic segment, then heated to 589 K by, for example, heat exchanger #7, which is attached to exothermic reactor #2.) [0104] 7. The C6H6 and H2 product (plus possible excess H2) is then run through exothermic reactor #2, which produces (1062-103=) 959 kJ at 589 K and outputs 0.372 kg of C6H12 reactant (plus any excess H2). [0105] 8. The 0.372 kg of C6H12 reactant at 5.1 atm and 589 K is taken into expander #4 at constant pressure. [0106] 9. The 0.372 kg of C6H12 steam at 589 K is expanded adiabatically to a pressure of 2 atm (20.3 N/cm2) and a temperature of 456 K. [0107] 10. The 0.372 kg of C6H12 is exhausted from expander #4 through heat exchanger #5 at 2 atm (20.3 N/cm2) and 456 K, exchanging heat with the inflowing C6H6 and dropping to about 344 K. [0108] 11. The 1.7 psi liquid C6H12 is then pumped back into storage.
SpecificationDetailed DescriptionFourth EmbodimentB/E-CHP-H
[0109] The fourth embodiment proposes a cycle that is using the high temp endothermic half-cycle (
SpecificationOperationFourth EmbodimentB/E-CHP-H
Endothermic Half-Cycle (High Temp, See FIG. 3 and FIG. 7):
[0110] 14. 0.454 kg & 586.6 cm3 of liquid reactant (C6H12) at 344 K and 1 atm is pumped from storage and into the cycle at 5.1 atm. It will be assumed that the C6H12 is stored as a liquid at 344 K. [0111] 15. The 0.454 kg of liquid reactant (C6H12) is raised to 648 K with product exhausting from expander #2 through heat exchanger #1. [0112] 16. In the preheater (heat exchanger #3), the C6H12 is raised at constant pressure to 950 K. [0113] 17. The C6H12 at 5.1 atm is converted in the endothermic reactor to the product (10% C6H12 and 90% C6H6+3H2 at 950 K), absorbing heat thermo-chemically and storing potential heat energy equal to 1,062 kJ. [0114] 18. The 5.1 atm of C6H6, H2, and remnant C6H12 product at 950 K is then exhausted from the endothermic reactor into high temperature expander #1 and low temperature expander #2 (calculated as a single expander volume below). [0115] 19. The product is expanded adiabatically in expander #1 from 950 K and 5.1 atm to 694 K and 1 atm. [0116] 20. The product is exhausted at constant pressure of 1 atm and 694 K. [0117] 21. The converted working fluid then passes through counterflow heat exchanger #1, where the 1 atm gas/vapor product (C6H6, H2, and remnant C6H12) will be cooled to about 344 K by inflowing vaporized 5.1 atm C6H12 reactant at 344 K. [0118] 22. The 1 atm product stream then flows through cooler (heat exchanger #41, where it is cooled back to 344 K (or lower). [0119] 23. The product is then separated into liquid and gaseous constituents, and the C6H12 is either stored, shipped, or recycled back to add to the new inflowing charge from liquid storage.
Exothermic Half-Cycle (Same as B/E-LC):
SpecificationDetailed DescriptionFifth Embodiment
[0120] The intent in the B/E-CC cycles is to maximize the work output rather than the thermal output. This is accomplished by essentially using the B/E-CHP cycle to power what might be called a bottoming cycle heat engine (called so because it typically makes use of the lower temperature exhaust product of the main heat engine, although the more general term combined cycle engine also applies, since there are multiple heat engines involved).
[0121] For calculation purposes of this specific example, a 100% conversion of C6H6+3H2 to C6H12 and 898 kJ of net exothermic reactor heat per pound of reactant are assumed, permitting exothermic reactor heat to be made available at 589 K and 5.1 atm. Any excess heat energy at 589 K may be used to power a heat engine, for example a stirling engine. In an alternative heat engine approach, which is the approach shown below, excess working fluid may be added to the product components, in some designs permitting the excess fluid to share components like compressors, expanders, and heat exchangers. Note, however, that the additional fluid must beinert to the thermochemical processes (that is, its presence will not negatively react with or impact the processes). One such inert working fluid is H2, since it is already part of the product. Note that it is possible to use this approach with a gas other than H2, such as He (helium).
[0122] As shown in
[0123] For a complete BIE-CC cycle, the excess H2 (or equivalent) working fluid is exhausted from the engine, recompressed, and recycled. As a result, net work out is a function of expansion work minus compressor work. Note that the engine can operate so long as it has a supply of stored product (C6H6 liquid and H2 gas).
[0124] It will be assumed that the excess working fluid equals about 10 times the H2 working fluid required to produce the excess 755 kJ, or about 0.3 kg of H2, equal to about 148.5 mols of additional H2 that can be raised from 344 K to 589 K. Following the preliminary analysis, the amount of heat input required for 0.3 kg will be calculated. The amount of excess H2 required to utilize the available exothermic heat may then be determined.
[0125] In the B/E-CC-LC-1 analysis (
[0126] Note: In order to simplify the B/E-CC-LC-1 cycle, the added excess H2 is analyzed as a separate H2 heat engine. The B/E-CHP cycle is assumed to run in parallel, with the H2 component for the B/E-CHP cycle being separated out and added as described below. That is, in this version of a B/E-CC cycle, all the elements of the B/E-CHP cycle repeat themselves.
SpecificationOperationFifth Embodiment(B/E-CC-LC-1)
Endothermic Half-Cycle (Low Temp, Same as B/E-LS):
Exothermic Half-Cycle (Low Temp, See FIG. 5 and FIG. 11):
[0127] 12. 0.33 kg of H2 at 344 K (in the case of a PSR, storage temperature could approach 150 K) and 2 atm is compressed to 10.9 atm and 422 K by, for example, two-staged and inter-cooled compressor #3 (if located at a distant exothermic segment) or #1 (if located at the endothermic segment). This combined process is shown in
SpecificationDetailed DescriptionSixth Embodiment
[0136] The sixth embodiment proposes a cycle that is using the high temp endothermic half-cycle (
SpecificationOperationSixth Embodiment(B/E-CC-H-1)
Endothermic Half-Cycle (High Temp, Same as B/E-CHP-H):
Exothermic Half-Cycle (High Temp, Same as B/E-CC-LC-1):
SpecificationDetailed DescriptionSeventh Embodiment
[0137] The seventh embodiment, or B/E-CC-LS-2, adds a second approach towards achieving a higher exothermic half-cycle efficiency, in this case using the low temp endothermic half-cycle (
[0138] Due to the lower exothermic reactor heat available, it will be assumed that the excess working fluid equals about 0.125 kg of H2, equal to about 62 mols of additional H2 that can be raised from 344 K to 589 K. The total H2 mass circulated will thus equal 0.152 kg. Following the preliminary analysis, the amount of heat input required for 0.152 kg H2 can be calculated. The amount of excess H2 required to utilize the available exothermic heat may then be determined and the net results recalculated.
[0139] In B/E-CC-LS-2, as in B/E-CC-LS-1, a pump is used to pressurize the C6H6 liquid, starting at 1 atm. However, the C6H6 is pumped to a much higher pressure, in this example to 10.2 atm. After vaporization of the C6H6 by raising the temperature via heat exchange to 780 K, an EREC is used to increase the pressure from 10.2 atm and 780 K to 10.9 atm and 800 K.
SpecificationOperationSeventh Embodiment(B/E-CC-LC-2)
Endothermic Half-Cycle (Low Temp, Same as B/E-CC-LC-1):
Exothermic Half-Cycle (Low Temp, See FIG. 5 and FIG. 12):
[0140] 21. 0.343 kg C6H6 liquid product at 344 K and 1 atm is pressurized via a liquid pump #1 to 10.2 atm. [0141] 22. The 0.343 kg of C6H6 liquid at 10.2 atm and 344 K is raised constant pressure in counterflow heat exchanger #5 to the temperature of vapor-liquid equilibrium, estimated at 465-475 K (see Source B), and partially vaporized. (Note: Source B indicates the vapor-liquid equilibrium for C6H12, which is assumed to approximately equal the vapor-liquid equilibrium for C6H6.) [0142] 23. 0.343 kg C6H6 liquid at 10.2 atm and 475 K continues to be raised at constant pressure in counterflow heat exchanger #5 to approximately 780 K. [0143] 24. 0.343 kg C6H6 liquid at 10.2 atm and 780 K is taken into the EREC (compressor #2) at constant pressure. [0144] 25. 0.343 kg (4.39 mols) C6H6 vapor is adiabatically compressed to 10.9 atm and 800 K within the EREC (compressor #2). [0145] 26. The 0.343 kg C6H6 vapor at 800 K and 10.9 atm (110 N/cm2, 75 psi) is exhausted from the EREC (compressor #2) at constant pressure. [0146] 27. 0.152 kg (75 mols) of H2 at 344 K (in the case of a PSR, storage temperature could approach 150 K) and 1 atm is compressed by multi-staged and inter-cooled compressor #1 (if located at the endothermic segment) or #3 (if located at a distant exothermic segment). [0147] 28. 0.152 kg (75 mols) of H2 at 428 K and 10.9 atm is raised to a temperature of 451 K by 0.125 kg (61.9 mols) of H2 at 456 K exhausting from expander #3. [0148] 29. 0.08 kg of exothermic mix exhausting from exothermic reactor #2 at 800 K is used to preheat, in heat exchanger #10, the 0.152 kg of H2 exhausting from heat exchanger #8 to 465 K. [0149] 30. The 0.152 kg of H2 at 10.9 atm and 465 K is used to partially cool exothermic reactor #2 in heat exchanger #7, raising the temperature to 800 K. [0150] 31. 0.152 kg (75 mols) of compressed and heated H2 at 10.9 atm and 800 K are separated into 0.027 kg (13.4 mols) and 0.125 kg (61.6 mols) of H2. [0151] 32. The 0.125 kg of H2 at 10.9 atm and 800 K are taken into expander #3 at constant pressure. [0152] 33. The 0.125 kg (61.6 mols) of H2 at 10.9 atm and 800 K are expanded adiabatically in expander #3 to a pressure of 1 atm and 456 K. [0153] 34. The 0.125 kg (61.6 mols) of H2 at 1 atm and 456 K are exhausted at constant pressure from expander #3. [0154] 35. The 0.125 kg (61.6 mols) of H2 at 1 atm and 456 K is passed through heat exchanger #8, raising the 0.152 kg of H2 to 451 K and exhausting the 0.125 kg of H2 at 428 K. [0155] 36. The 0.343 kg of C6H6 and 0.027 kg of H2 product at 10.9 atm and 800 K are then mixed and passed through exothermic reactor #2. [0156] 37. The 0.372 kg of exothermic mix at 10.9 psi and 800 K is separated into two streams equal to 0.08 kg and 0.292 kg (see step 23 above). [0157] 38. 0.292 kg of the exothermic mix at 10.9 atm and 800 K will be passed through heat exchanger #6, raising the temperature of the inflowing 0.343 kg of C6H6 at 10.2 atm from 475 K to 780 K and lowering the temperature of the exhausting 0.292 kg of exothermic mix to 480 K (see step 28 above). [0158] 39. 0.08 kg of the exothermic mix at 10.9 atm and 800 K will be passed through heat exchanger #10, raising the temperature of the inflowing 0.152 kg of H2 to 475 K and reducing the temperature of the exothermic mix to 428 K (see step 29 above). [0159] 40. The 0.08 kg of exothermic mix exiting heat exchanger #8 at 10.9 atm and 480 K and the 0.175 kg of exothermic mix exiting heat exchanger #6 at 10.9 atm and 480 K will be rejoined into 0.372 kg of exothermic mix and will be passed through heat exchanger #5, raising the temperature of the 0.343 kg of C6H6 liquid entering the system via liquid pump #1. [0160] 41. The 10.9 atm exothermic mix is passed through cooler/gas-liquid separator system #2 and is separated into a liquid C6H12 and C6H6 stream and a (0.003 kg) H2 stream at 344 K. [0161] 42. The liquid C6H12 and C6H6 stream at 10.9 atm passes through hydraulic motor #1 and drops to 1 atm, creating work that drives pump #1 and pressurizes the 0.343 kg of C6H6 entering the cycle to 10.2 atm (see step 21 above), and then passes through gas-liquid separates system #1 to be either recycled or go to storage. [0162] 43. The 0.003 kg of H2 at 10.9 atm and 344 K is injected back into the 0.152 kg H2 stream exhausting from multi-staged and intercooler compressor #3 (see step 27 above).
SpecificationDetailed DescriptionEighth Embodiment
[0163] As in the previous cycles, the B/E-CC-H-2 cycle utilizes the high temp endothermic half-cycle to boost overall thermal efficiency, thus creating the highest calculated potential thermal efficiency of all the cycles analyzed herein.
SpecificationOperationEighth Embodiment(B/E-CC-H-2)
Endothermic Half-Cycle (High Temp, Same as B/E-CC-H-1):
Exothermic Half-Cycle (High Temp, Same as B/E-CC-LC-2):
SpecificationThermal Analysis of Endothermic and Exothermic Segments
[0164] TE=Thermal Efficiency [0165] TTE=Total Thermal Efficiency [0166] HE=Heat Source Efficiency [0167] THE=Total Heat Source Efficiency
Endothermic Segment
Low Temp Endothermic Half-Cycle (See FIG. 3 and FIG. 6)
High Temp Endothermic Half-Cycle (See FIG. 3 and FIG. 7)
Exothermic Segment
Exothermic-for-Endothermic Variants
Simple Exothermic-for-Endothermic Half-Cycle (See FIG. 4 and FIG. 8)
Complex Exothermic-for-Endothermic Half-CycleComplex (See FIG. 4 and FIG. 9)
Exothermic Production Variants
Exothermic Production Variants for B/E-CHP Cycles (See FIG. 5 and FIG. 10)
Exothermic Production Variants for B/E-CC CyclesApproach #1 (See FIG. 5 and FIG. 11)
Exothermic Production Variants for B/E-CC CyclesApproach #2 (See FIG. 5 and FIG. 12)
SpecificationMiscellaneous Descriptions and Operations
[0168]
[0190] One interesting application of the system detailed in
[0191] Since the same side of the Moon always faces the Earth, Earth's Moon rotates around its axis once per revolution relative to the sun, or approximately one revolution per month. As a result, many PSR's receive solar radiation on their rims for two weeks out of every month.
[0192] Assuming a solar thermal input was a reasonable distance from the depths of the PSR, for example 4 or 5 km, the exothermic fluid products could be produced during the limited period when solar energy is present and pumped through pipelines to the bottom of the PSR. Even though the PSR is at a substantially lower altitude, little net pumping work would be required for the liquid components flowing down as C6H6 and back up as C6H12, since the mass would be essentially the same in both directions. Only the difference in molecular mass and internal pipe friction would require work to overcome. Note that the H2 would only flow down its pipeline, since it will be returned within the C6H12 being pumped back up.
[0193] Importantly, the temperature of the product components, being in a natural vacuum, can likely be maintained to large degree as they traverse the distance. Thus, within the PSR, they can serve to give up useful latent heat to elements within the PSR, which may see temperatures as low as 100 K or lower. Note that H2 remains a gas at even these extreme temperatures.
[0194] Specific to the H2, if compression to higher pressure is made to occur within the PSR, then the heat generated by that compression can also be useful. That is, refraining from compressing the H2 at the endothermic reactor end could have a benefit within the PSR by making low quality thermal energy from compression available for other uses, such as melting water ice.)
[0195] Note that, as shown in
[0196] Note also that high pressure super-cooled H2 recirculated out of and back into a PSR-based reservoir/heat exchange manifold can be used as a coolant for various processes, including cooling heat exchanger #4 and cooling the H2 during the above-described inter-cooling stages.
[0197] Finally, note that, in a PSR, any remaining waste heat from a heat engine may still be useful, for example in processes such as maintaining temperature of equipment and releasing H20 vapor from lunar regolith.