Thermoeconomic Optimization of Steam Pressure of Heat Recovery Steam Generator in Combined Cycle Gas Turbine under Different Operation Strategies

Abstract

The optimization of the steam parameters of the heat recovery steam generators (HRSG) of Combined Cycle Gas Turbines (CCGT) has become one of the important means to reduce the power generation cost of combined cycle units. Based on the structural theory of thermoeconomics, a thermoeconomic optimization model for a triple pressure reheat HRSG is established. Taking the minimization of the power generation cost of the combined cycle system as the optimization objective, an optimization algorithm based on three factors and six levels of orthogonal experimental samples to determine the optimal solution for the high, intermediate and low pressure steam pressures under different gas turbine (GT) operation strategies. The variation law and influencing factors of the system power generation cost with the steam pressure level under all operation strategies are analyzed. The research results show that the system power generation cost decreases as the GT load rate increases, T4 plays a dominant role in the selection of the optimal pressure level for high pressure (HP) steam and, in order to obtain the optimum power generation cost, the IGV T3-650-F mode should be adopted to keep the T4 at a high level under different GT load rates.

Environmental thermoeconomic performance analysis of gas turbine combined cycle under off‐design conditions

“…In the ETC calculation, it is necessary to convert the equipment investment into the investment cost per unit time. The nonenergy cost calculation equations of each component used in this study have been described in detail in the published article 27 . Using the equation in the literature, the nonenergy cost of each piece of equipment in the system can be obtained, as shown in Table 3.…”

“…wThe design parameters of the GTCC system 27,28 are shown in Table 1. The design/off-design operation condition model of the reference GTCC unit is described in detail in, 9 so the calculation method of off-design characteristics of GTCC components will not be repeated in this study.…”

“…27,28 Flowchart of the gas turbine combined cycle system. AC, air compressor; CC, combustion chamber; CND, condenser; GT, gas turbine; HPB, high pressure evaporator; HPE1, high pressure economizer 1; HPE2, high pressure economizer 2; HPFP, high pressure feed water pump; HPS, high pressure superheater; HPT, high pressure turbine; IPB, intermediate pressure evaporator; IPE,…”

Opportunities of waste heat recovery from various sources: Review of technologies and implementation

“…However, in a bottoming cycle, fuel is burnt to provide process heat, and the resulting WH from the processes is used to generate power. Among all the power plants running on fossil fuel, the Combined Cycle Gas Turbine (CCGT) system working in the mode of combined heat and power (CHP) is considered the most effective means of exploiting the fuel's energetic potential, thus making it the main development directions of future thermal power generation [ 103 , 104 ] The main parts of the CCGT power plant are the gas turbine and the Heat Recovery Steam Generator (HRSG). The HRSG which is an efficient WHR steam boiler (heat exchanger) recovers WH from the gas turbine’s exhaust gases and uses it to raise steam.…”

Fault diagnosis analysis of combined cycle based on the structural theory of thermo‐economics

“…Thermo‐economics theory is a comprehensive combination of thermodynamic and economic analysis, widely applied to describe the cost formation process of the thermal system as a whole. It has a strong advantage in dealing with the cost analysis, fault diagnosis, and system optimization of the energy system 1–3 . thermo‐economic diagnosis is a general, methodology that can be used to identify the equipment with faults in energy systems and quantify the additional fuel consumption of the system due to component degradation.…”