Energy Reports (Jun 2023)
Investigation of new combined cooling, heating and power system based on solar thermal power and single-double-effect refrigeration cycle
Abstract
This investigation analyzed a newly developed combined energy system consisting of a solar collector employing CO2 as the heat transfer medium, thermodynamic cycle for power (TCP), and a single-double-effect absorption chiller. Proposed system simultaneously generates electricity, process heating, and refrigeration and while utilizing the concept of special generator temperature it maximizes the utilization of solar radiations despite of solar collector limitations. A model was developed to examine an effect of absorber tube’s internal diameter and solar rays on the temperature at which heat transfer medium leaves the collector (TSHTF, o). The influence of variation in TSHTF,o, TPC pump entry, and evaporator temperature of absorption chiller on generation of power, refrigeration effect, cooling exergy, efficiencies of CCHP is analyzed. Simulation results yield a first law efficiency between 64% and 72%, and the second law efficiency from 19% to 25% with the rise of solar irradiation from 400 to 1000 W/m2. Electrical power and process heating are found increasing and refrigeration effect is seen unchanged with the rise of TSHTF, o. System energetic and exergetic outputs declines considerably with the elevation of TPC pump entry temperature. Exergy evaluation reveals that solar collector accounts for the highest irreversibility of 1359.23 kW in the system and HRVG to follow where it is found to be 692.54 kW. Significant amount of irreversibility is also attributable to the process heater and it is determined to be 262.31 kW. Insights in absorption chiller reveals STG as the component of maximum irreversibility followed by LTG and EVAP and it observed that rise in the temperature of refrigeration led to an increase in the irreversibility of STG and same is reduced considerably in the EVAP. Computational results are placed in comparison with the data reported theoretically and a suitable match is observed between them.
