Synergetic cascade-evaporation mechanism of a novel building distributed energy supply system with cogeneration and temperature and humidity independent control characteristics

Abstract

Low and medium grade heat sources, such as geothermal energy, solar energy, and various waste heat sources, can only usually meet the independent demand of electricity, cooling or heating in the building. However, the demand for different forms of energy exists simultaneously. Therefore, a novel distributed building energy supply system is presented and cascade evaporation is used for combined cooling, heating and power. Two-stage evaporation is adopted to realize the temperature and humidity independent control. The coupling effect of the cascade evaporation and the building energy supply ability is illustrated through the multi-parameter optimization of system power generation and refrigeration performance as well as the simulation analysis of cooling and power control strategies. The results show that the organic Rankine cycle (ORC) as the power source of the vapor compression cycle (VCC) eliminates the mechanical work and electrical energy conversion process between the ORC and VCC. The low-temperature stage of VCC dehumidifies the outdoor fresh air, while the high-temperature stage cools the indoor return air, realizing the independent control of temperature and humidity and increasing the equivalent evaporation temperature of VCC. The proposed energy supply system can simultaneously meet the cooling, heating and electricity demand of the building, so it can be promoted in practical engineering applications.