Multi-objective optimization of an innovative power-cooling integrated system based on gas turbine cycle with compressor inlet air precooling, Kalina cycle and ejector refrigeration cycle

In this paper, an innovative power-cooling integrated system based on gas turbine, Kalina cycle system, ejector refrigeration cycle (GT-KCS-ERC) is proposed. The ERC driven by GT flue gas and KCS low concentration liquid waste heat is utilized to precool GT inlet air for producing extra power from GT and provide some cooling capacity for users, simultaneously. The comprehensive thermodynamic and thermo-economic analyses are conducted to demonstrate the feasibility of novel GT-KCS-ERC hybrid system by comparing with standalone GT-KCS system. Furthermore, the effects of seven key operation parameters on the system performances are investigated. The multi-objective optimization of GT-KCS-ERC hybrid system and standalone GT-KCS system is carried out through Non-dominated Sorting Genetic Algorithm-II, in which the objectives are maximum total energy efficiency and minimum levelized cost of energy (LCOE). The results show that the total energy efficiency of GTKCS-ERC increases with increasing pinch point temperature difference of boiler Delta TKCS,boi and decreasing ammonia concentration of working solution in KCS, while that of standalone GT-KCS shows opposite trends. The LCOE of GT-KCS-ERC is lower than that of standalone GT-KCS as Delta TKCS,boi is larger than 21 degrees C or turbine inlet pressure of KCS is higher than 6.6 MPa. The optimal saturated evaporator temperature and pressure ratio of vapor generator to condenser in ERC with optimal refrigerant of R290 are 0 degrees C and 4, respectively. Under the optimal condition, the GT-KCS-ERC with an ERC secondary flow split ratio of 0.162 for precooling GT inlet air presents 219.4 kW more net power and 764.2 kW more cooling capacity than standalone GT-KCS system. The LCOE decreases by 0.802% and total energy efficiency increases by 5.347% in novel GT-KCS-ERC system comparing with standalone GT-KCS system.