Theoretical perfection and application of entransy analysis method on absorption systems

Abstract

In thermal energy utilization scenarios, absorption systems have been widely and effectively utilized as heat exchange devices. However, existing thermal research methods on absorption systems for these scenarios have limitations. Therefore, the entransy parameter, which is applicable for analyzing the heat exchange process is chosen to study. The entransy balance relationship of the absorption system is theoretically analyzed, and the entransy analysis method is further perfected to break through the limitations. First, the entransy imbalance of the reversible absorption cycle is proved, and the reason for this imbalance is clarified that two heat-work conversion processes at different temperatures occur inside the cycle. Then, the working fluid’s entransy change during the conversion process is theoretically derived and defined, and a new parameter: conversion entransy is defined based on it. Moreover, the comprehensive entransy balance equation and comprehensive entransy analysis method of absorption systems are further proposed. Finally, a specific case study is carried out, and this method is compared with the existing exergy analysis method and entransy analysis method without considering the conversion entransy respectively. By using this method, the optimal process form of the absorption heat exchanger can be directly obtained without numerical simulation calculations, demonstrating significant advantages.