A simple method to determine the optimal gas turbine capacity and operating strategy in building cooling, heating and power system

摘要

The gas turbine capacity and operating strategy of Building Cooling,Heating and Power(BCHP)system play important roles in the system operating performance,leading to different primary energy consumption for the same building loads.However,the relationship between the two factors was not considered for BCHP systems with or without the Thermal Energy Storage(TES).This paper presents a simple method to determine the optimal gas turbine capacity and operating strategy.The grid power efficiency,the Coefficient of Performance(COP)of absorption/electric heat pumps,and the difference between the supply and demand heat/power ratios are found to be the key factors.The results show that the hourly optimal operating strategy is either Following the Thermal Load(FTL)or Following the electrical Load(FEL).And the gas turbine capacity can be obtained according to the operating strategy and building loads.There also exists critical gas turbine efficiency,below which more primary energy will be consumed.Based on this method,some typical cases with or without TES are analyzed.The results agree well with the experienced conclusion.This method gives a new aspect to understand BCHP design,and is convenient to be applied in the engineering area.