US3871179A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stirling cycle engine with catalytic regenerator
Assignee: Individual
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Filing: 1974-03-13
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Granted: 1975-03-18
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Expires: 1994-03-13
Abstract
Abstract A modified Stirling engine has a regenerator with catalytic surfaces for inducing reversible chemical reaction in the working fluid. The basic Stirling engine has an expansion space and compression space with one or more pistons for periodically transferring the working fluid therebetween. Heat is added to the working fluid in the expansion space to maintain temperature during expansion and heat is extracted from the compression space to counteract compression heating. A regenerator, which is a temporary heat reservoir, is provided in the fluid flow path between the expansion and compression spaces. In this improvement, the working fluid is subject to a reversible chemical reaction which is endothermic in one direction and exothermic in the other direction, and has less specific volume when driven in the exothermic direction. The volume difference arises since there are more moles of gas in the higher temperature regime than in the lower. Particularly suitable is the endothermic dehydrogenation and exothermic hydrogenation of hydrocarbons. In such a system the quantity of working fluid being compressed is minimized so that there is less cooling required. The volume of working fluid being expanded is maximized thereby enhancing power output. Thermodynamic efficiency is significantly enhanced by such a working fluid and catalytic regenerator.
Inventors
- 👤 Reginald B Bland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:15
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G2244/00; F02G2254/00; F02G2254/10; F02G2254/11; F02G2258/00; F02G2258/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
139 words
In a Stirling engine having an expansion space; a compression space; a working fluid in said spaces; means for periodically transferring working fluid between the expansion space and the compression space; a heat source for adding heat to the working fluid adjacent the expansion space; a heat sink for removing heat from the working fluid adjacent the compression space; and a regenerator in the fluid flow path between the expansion space and the compression space, the improvement comprising: a working fluid having components susceptible to reversible chemical reaction under the temperature and pressure conditions in the engine, said reaction having a greater number of moles of fluid when the reaction proceeds in its higher temperature direction than when it proceeds in its lower temperature direction; and a catalyst in the regenerator for enhancing the rate of the chemical reaction.
Claim 2
Dependent Claim
139 words
In a Stirling engine having an expansion space; a compression space; a working fluid in said spaces; means for periodically transferring working fluid between the expansion space and the compression space; a heat source for adding heat to the working fluid adjacent the expansion space; a heat sink for removing heat from the working fluid adjacent the compression space; and a regenerator in the fluid flow path between the expansion space and the compression space, the improvement comprising: a working fluid having components susceptible to reversible chemical reaction under the temperature and pressure conditions in the engine, said reaction having a greater number of moles of fluid when the reaction proceeds in its higher temperature direction than when it proceeds in its lower temperature direction; and a catalyst in the regenerator for enhancing the rate of the chemical reaction.
Claim 3
Dependent Claim
27 words
In a Stirling cycle engine as defined in claim 1 the further improvement wherein the reaction is exothermic in one direction and endothermic in the other direction.
Claim 4
Dependent Claim
63 words
In a Stirling cycle engine as defined in claim 1 the further improvement wherein the components of the working fluid comprise hydrogen and hydrocarbons subject to reversible hydrogenation and dehydrogenation at temperatures and pressures prevailing in the Stirling cycle engine; and the catalyst in the regenerator enhances the dehydrogenation reaction nearer the expansion space and enhances the hydrogenation reaction nearer the compression space.
Claim 5
Dependent Claim
60 words
In a Stirling cycle engine as defined in claim 3 the further improvement wherein the working fluid is selected from the group consisting of hydrogen, cyclohexane, and benzene paraffins having three or more carbon atoms, and their corresponding olefins, said paraffins and olefins being in the vapor state at temperatures and pressures prevailing during operation of the Stirling cycle engine.
Claim 6
Dependent Claim
22 words
In a Stirling cycle engine as defined in claim 3 the further improvement wherein the working fluid comprises cyclohexane, benzene and hydrogen.
Claim 7
Dependent Claim
47 words
In a Stirling cycle engine as defined in claim 1 the further improvement comprising a second catalyst in the regenerator, the catalyst nearer the expansion space enhancing reaction in the greater molal direction and the catalyst nearer the compression space enhancing reaction in the lesser molal direction.
Claim 8
Dependent Claim
25 words
In a Stirling cycle engine as defined in claim 6 the further improvement comprising a noncatalytic regenerator portion between the expansion space and the catalyst.
Claim 9
Dependent Claim
25 words
In a Stirling cycle engine as defined in claim 1 the further improvement comprising a noncatalytic regenerator portion between the expansion space and the catalyst.
Claim 10
Dependent Claim
140 words
In a Stirling engine having an expansion space; a compression space; a working fluid in said spaces; means for periodically transferring working fluid between the expansion space and the compression space; a heat source for adding heat to the working fluid adjacent the expansion space; a heat sink for removing heat from the working fluid adjacent the compression space; and a regenerator in the fluid flow path between the expansion space and the compression space, the improvement comprising: a working fluid having components susceptible to reversible chemical reaction under the temperature and pressure conditions in the engine, said reaction producing a number of moles of working fluid that is greater in the expansion space than the number of moles of working fluid in the compression space; and a catalyst in the regenerator for enhancing the rate of the chemical reaction.
Claim 11
Dependent Claim
140 words
In a Stirling engine having an expansion space; a compression space; a working fluid in said spaces; means for periodically transferring working fluid between the expansion space and the compression space; a heat source for adding heat to the working fluid adjacent the expansion space; a heat sink for removing heat from the working fluid adjacent the compression space; and a regenerator in the fluid flow path between the expansion space and the compression space, the improvement comprising: a working fluid having components susceptible to reversible chemical reaction under the temperature and pressure conditions in the engine, said reaction producing a number of moles of working fluid that is greater in the expansion space than the number of moles of working fluid in the compression space; and a catalyst in the regenerator for enhancing the rate of the chemical reaction.
Claim 12
Dependent Claim
151 words
In a Stirling engine having an expansion space; a compression space; a working fluid in said space; means for periodically transferring working fluid between the expansion space and the compression space; a heat source for adding heat to the working fluid adjacent the expansion space; a heat sink for removing heat from the working fluid adjacent the compression space; anD a regenerator in the fluid flow path between the expansion space and the compression space, the improvement comprising: a working fluid having components susceptible to reversible chemical reaction under the temperature and pressure conditions in the engine, said reaction having a reactant that is more stable at a relatively lower temperature and reaction products more stable at a relatively higher temperature, the molal volume of the reaction products being greater than the molal volume of the reactant; and a catalyst in the regenerator for enhancing the rate of the chemical reaction.
Claim 13
Dependent Claim
151 words
In a Stirling engine having an expansion space; a compression space; a working fluid in said space; means for periodically transferring working fluid between the expansion space and the compression space; a heat source for adding heat to the working fluid adjacent the expansion space; a heat sink for removing heat from the working fluid adjacent the compression space; anD a regenerator in the fluid flow path between the expansion space and the compression space, the improvement comprising: a working fluid having components susceptible to reversible chemical reaction under the temperature and pressure conditions in the engine, said reaction having a reactant that is more stable at a relatively lower temperature and reaction products more stable at a relatively higher temperature, the molal volume of the reaction products being greater than the molal volume of the reactant; and a catalyst in the regenerator for enhancing the rate of the chemical reaction.
Claim 14
Independent Claim
102 words
A method of operating a Stirling cycle engine comprising the cyclic steps of: compressing a working fluid including a chemically reactive fluid; heating the working fluid to a temperature sufficient for reaction to products having a greater number of moles than the reactive fluid; expanding the reaction products; cooling the expanded reaction products to a sufficiently low temperature for reversing the reaction and producing the original reactive fluid; and temporarily storing the heat from the cooling step for transfer to the reactive fluid in the heating step, said stored heat including sensible heat of the working fluid and any heat of reaction.
Claim 15
Independent Claim
102 words
A method of operating a Stirling cycle engine comprising the cyclic steps of: compressing a working fluid including a chemically reactive fluid; heating the working fluid to a temperature sufficient for reaction to products having a greater number of moles than the reactive fluid; expanding the reaction products; cooling the expanded reaction products to a sufficiently low temperature for reversing the reaction and producing the original reactive fluid; and temporarily storing the heat from the cooling step for transfer to the reactive fluid in the heating step, said stored heat including sensible heat of the working fluid and any heat of reaction.
Claim 16
Dependent Claim
20 words
A method as defined in claim 11 further comprising catalytically promoting the reversible reaction between the compressing and expanding steps.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |