Techno-economic analysis of a novel hybrid heat pump system to recover waste heat and condensate from the low-temperature boiler exhaust gas

作     者：Jamil, Shah Rukh Wang, Limin Che, Defu 

作者机构：Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Sch Energy & Power Engn Xian 710049 Peoples R China 

出 版 物：《INTERNATIONAL JOURNAL OF ENERGY RESEARCH》 (国际能源研究杂志)

年 卷 期：2020年第44卷第5期

页      面：3821-3838页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 0807[工学-动力工程及工程热物理] 0827[工学-核科学与技术] 

基　　金：National Natural Science Foundation of China 

主　　题：flue gas condensation gas boiler hybrid heat pump indirect contact condensing economizer thermo-economic analysis waste heat recovery 

摘      要：This paper is based on the proposal of a new waste heat recovery (WHR) system, which can be utilized to heat the boiler return water, boiler supply air, and building heating air. The system is the combination of an indirect contact condensing unit (IDCCU), a mechanical compression heat pump, and two air preheaters. The system is modeled on the basis of mass and energy balance and then thermodynamically analyzed. Improved performance results were obtained in the form of an increase in the boiler s energy efficiency of about 10.47%, with 4.87% increase in exergy efficiency. The coefficient of performance (COP) of the heat pump was increased from 1.23 to 1.45 by the addition of an air heater in the conventional heat pump. The exergy destruction in each component is calculated. Sensitivity analysis was performed to check the influence of different operating parameters on the performance of the WHR system and boiler. It can be observed from the results that for a specific refrigerant temperature and a calculated amount of mass, flow rate can maximize the condensation efficiency of IDCCU by decreasing the flue gas temperature, while the use of the air heater can further reduce the flue gas temperature, and a stream of hot air can be utilized for space heating. A comparison is made with the other system on a performance basis. The results shows a clear difference in efficiencies and profit earned.