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| Main Authors: | , , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2506.20410 |
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| _version_ | 1866909659948908544 |
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| author | Xia, Xinshu Huang, Hongbo Dong, Hui |
| author_facet | Xia, Xinshu Huang, Hongbo Dong, Hui |
| contents | Conventional heat-engine models typically assume two heat reservoirs at fixed temperatures. In contrast, radioisotope power systems introduce a fundamentally different paradigm in which the hot sources supply heat at a constant generation rate rather than maintaining a constant temperature. We develop a theoretical framework for finite-time heat engines operating between constant heat-generation-rate hot sources and constant-temperature cold reservoirs. A universal proportion between average output power and efficiency is established, independent of the specific cycle configuration or working substance. As a representative case, we analyze a finite-time Stirling cycle employing a tailored control protocol that maintains the working substance at constant temperatures during the quasi-isothermal processes. An intrinsic oscillatory behavior emerges in the temperature dynamics of the hot source, reflecting the interplay between heat accumulation and release. We further quantify the long-term decline in engine performance resulting from radioactive decay and demonstrate its impact over the system's operational lifespan. This work establishes a new theoretical prototype for heat engines and shall provide guidings for the analysis and design of radioisotope power systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2506_20410 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Beyond Constant-Temperature Reservoirs: A Stirling Cycle with Constant Heat-Generation Rate Xia, Xinshu Huang, Hongbo Dong, Hui Statistical Mechanics Conventional heat-engine models typically assume two heat reservoirs at fixed temperatures. In contrast, radioisotope power systems introduce a fundamentally different paradigm in which the hot sources supply heat at a constant generation rate rather than maintaining a constant temperature. We develop a theoretical framework for finite-time heat engines operating between constant heat-generation-rate hot sources and constant-temperature cold reservoirs. A universal proportion between average output power and efficiency is established, independent of the specific cycle configuration or working substance. As a representative case, we analyze a finite-time Stirling cycle employing a tailored control protocol that maintains the working substance at constant temperatures during the quasi-isothermal processes. An intrinsic oscillatory behavior emerges in the temperature dynamics of the hot source, reflecting the interplay between heat accumulation and release. We further quantify the long-term decline in engine performance resulting from radioactive decay and demonstrate its impact over the system's operational lifespan. This work establishes a new theoretical prototype for heat engines and shall provide guidings for the analysis and design of radioisotope power systems. |
| title | Beyond Constant-Temperature Reservoirs: A Stirling Cycle with Constant Heat-Generation Rate |
| topic | Statistical Mechanics |
| url | https://arxiv.org/abs/2506.20410 |