Thermodynamic Analysis of a Novel Heat Pipe Based Regenerative Combined System

Abstract

A comprehensive thermodynamic analysis is presented of a new solar system for heating and power generation. Energy and exergy analyses are used to characterize the exergy destruction rate in any component and investigate solar system performance. The system composed of a solar heat pipe evaporator, an auxiliary pump, a condenser, a turbine, an electrical generator, a domestic water heater, a regenerator, a water preheater and a pump. The solar system provides heating and electricity during the summer and spring in Tabriz, Iran. The analysis involves the specification of effects of varying solar heat pipe evaporator condenser pinch point temperature, varying solar radiation intensity and varying solar heat pipe evaporator heat removal factor on the energetic and exergetic performance of the system. The performance parameters calculated are energy flow, exergy destruction rate, energetic and exergetic efficiencies. The results also showed that the main source of the exergy destruction rate is the solar heat pipe evaporator. In the solar heat pipe evaporator, 291.1 kW of the input exergy was destroyed. Other main sources of exergy destruction rate are the solar heat pipe evaporator condenser, at 6.655 kW; then the turbine, at 6.228 kW; and the water preheater, at 0.907 kW. The overall energetic and exergetic efficiencies of the combined solar system was 69.57% and 12.41%, respectively. A comprehensive thermodynamic analysis is presented of a new solar system for heatingand power generation. Energy and exergy analyses are used to characterize the exergy destruction ratein any component and investigate solar system performance. The system composed of a solar heat pipeevaporator, an auxiliary pump, a condenser, a turbine, an electrical generator, a domestic water heater,a regenerator, a water preheater and a pump. The solar system provides heating and electricity duringthe summer and spring in Tabriz, Iran. The analysis involves the specification of effects of varying solarheat pipe evaporator condenser pinch point temperature, varying solar radiation intensity and varyingsolar heat pipe evaporator heat removal factor on the energetic and exergetic performance of the system.The performance parameters calculated are energy flow, exergy destruction rate, energetic and exergeticefficiencies. The results also showed that the main source of the exergy destruction rate is the solar heatpipe evaporator. In the solar heat pipe evaporator, 291.1 kW of the input exergy was destroyed. Othermain sources of exergy destruction rate are the solar heat pipe evaporator condenser, at 6.655 kW; thenthe turbine, at 6.228 kW; and the water preheater, at 0.907 kW. The overall energetic and exergeticefficiencies of the combined solar system was 69.57% and 12.41%, respectively.