Power Generation Technology ›› 2022, Vol. 43 ›› Issue (1): 131-138.DOI: 10.12096/j.2096-4528.pgt.21017

• Power Generation and Environmental Protection • Previous Articles     Next Articles

Thermodynamic Analysis of a New Combined Cooling, Heating and Power System Using CO2 Working Fluid

Yaonan GAO, Haifeng CHEN, Jianyong WANG   

  1. School of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Xi’an 710021, Shaanxi Province, China
  • Received:2021-07-03 Published:2022-02-28 Online:2022-03-18
  • Supported by:
    Natural Science Foundation of China(51906131);Natural Science Fundamental Research Program of Shaanxi Province(2020JQ-723);China Postdoctoral Science Foundation(2020M673604XB)

Abstract:

In order to develop and utilize low-grade thermal energy such as solar energy, geothermal energy, industrial waste heat, etc, this paper proposed a combined cooling, heating and power system using CO2 as the working fluid. The system, coupling the supercritical CO2 Brayton power generation cycle and the transcritical CO2 compression refrigeration cycle by sharing the condenser, can provide users with electricity, refrigerant water and domestic hot water at the same time. This paper established the thermodynamic mathematical models of the proposed system in detail, and conducted numerical simulation of its operating conditions. The simulation results showed that the net output power of the simulated system is 140.34 kW, cooling capacity is 340.50 kW, heating capacity is 5 ?332.75 kW, thermal efficiency is 113.27%, and exergy efficiency is 41.24%. Then, on this basis, the sensitivity analysis of thermodynamic parameters of the system was carried out, and the effects of five thermodynamic parameters, including turbine inlet pressure, turbine outlet pressure, turbine inlet temperature, evaporator pressure and CO2 flow ratio of top cycle and bottom cycle, on the performance of the system were obtained.

Key words: carbon dioxide, combined cooling, heating and power, numerical simulation, parameter analysis

CLC Number: