Supercritical carbon dioxide generalized generality Carnot cycle system

Abstract

The invention provides a supercritical carbon dioxide generalized generality Carnot cycle system. By adoption of the supercritical carbon dioxide generalized generality Carnot cycle system, higher cyclic power generation efficiency can be achieved at a lower heat absorption temperature. According to the supercritical carbon dioxide generalized generality Carnot cycle system, supercritical carbon dioxide is used as a working medium, an approximately-isothermic compression process is achieved through the measures such as multi-stage indirect cooling, and thus compression power is reduced; the heat capacity difference between a cold side and a heat side is balanced through the measures such as multi-stage distribution, so that an extreme backheating process, approximately with a zero temperature difference, of fluid on the cold side and the heat side is achieved in the whole backheating process, and the irreversible loss, caused by a large temperature difference, of available energy is reduced; an isothermic heat absorption process approximate to the temperature of a high-temperature heat source is achieved through multi-stage reheating and an expansion measure, so that the average heat absorption temperature is increased; and since a precooler operates near the critical point of the carbon dioxide, both specific heat and the density are large, the whole heat release process is approximate to isothermic heat release, and the irreversible loss of available energy at the cold end is reduced.

Description

technical field [0001] The invention belongs to the technical field of high-efficiency power cycles, and in particular relates to a generalized Carnot cycle system of supercritical carbon dioxide. Background technique [0002] According to the second law of thermodynamics, the Carnot cycle, or generalized Carnot cycle, is the theoretically most efficient cycle of all power cycles between two isothermal heat sources. The Carnot cycle consists of two isothermal processes and two adiabatic processes, and the generalized Carnot cycle consists of two isothermal processes and two extreme regenerating processes. Its cycle efficiency depends only on the temperature of two isothermal heat sources, that is, the high temperature heat source T 1 The higher the temperature, the lower temperature heat source T 2 The lower the temperature, the higher the cycle efficiency. Therefore, the way to optimize the cycle is to make the actual cycle as close as possible to the Carnot cycle with t...

AI Technical Summary

Problems solved by technology

However, at the heat-absorbing end of the high-temperature heat source, due to the existence of supercooled water and superheated steam to absorb heat, the heat-absorbing temperature range is large. Although the highest temperature of the most advanced steam unit has reached 600-620°C, its average heat-absorbing temperature is not high. High, the average endothermic temperature of the most advanced double reheat unit is only about 450°C, which is determined by the inherent characteristics of the steam Rankine cycle, it is difficult to further increase the average endothermic temperature through cycle optimization

Therefore, in order to improve the cycle efficiency, the only way to further increase the maximum endothermic temperature of the working fluid is to use expensive nickel-based superalloys, which will lead to a significant increase in unit costs, and the economy cannot meet the current market demand.

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