Research on Regional Energy Supply System Coupled with Distributed Energy System Based on Natural Gas and Ground Source Heat Pump System

摘要

In order to further improve the energy efficiency,taking energy cascade utilization as principle and basing on the existing conditions of local energy and resources,the regional energy supply system(RESS)coupled with distributed energy system based on natural gas(NG-DES)and ground source heat pump system(GSHP)is proposed in this paper.The coupling mechanism of RESS is described by the equation derivation and the figure.To explain the energy-saving characteristic,the evaluation method and the influence characteristic of RESS,a case system is given,which is simulated and analyzed by the Aspen Plus software.The results show that the utilization efficiency of low-grade waste heat of RESS is 117％by changing the utilization way of low-grade waste heat of NG-DES.The utilization efficiency of low-grade waste heat of “parallel type” energy supply system(PESS)is 117％.So when the reference system is PESS and NG-DES,the relative energy saving rate of RESS is 12.5％and 17％,respectively.The energy efficiency of GSHP is increased from 4.18 to 8.19,and the demand for the power is decreased by 29.6 kW in RESS.The performance characteristics of NG-DES coupled individually with the inlet at ground source side of units,the inlet at demand side of units and the outlet at demand side of units(the three key points)respectively are also discussed.So the proposed RESS coupled with NG-DES and GSHP can provide a new development guideline for energy utilization technology of complementary advantages of fossil energy and renewable energy,namely the “internal and external” coupling with NG-DES and conventional energy systems and renewable energy systems to achieve the high energy efficiency.