中深层地埋管地源热泵系统优化配置研究

Optimizing configuration of middle-deep buried pipe ground source heat pump systems

中深层地埋管地源热泵系统作为建筑热源,具有能效高、污染小等特点。本文针对中深层地埋管地源热泵系统的优化配置进行研究,基于建筑实际用能需求,利用中深层地埋管换热模型仿真结果,与实测数据进行“反算”拟合,得到地下岩土体综合热物性参数。进一步采用理论计算、动态仿真手段,进行不同运行策略下的中深层地埋管换热动态仿真计算,开展中深层地埋管地下岩土体温度变化、地埋管进口和出口温度数据分析,实现中深层地埋管地源热泵系统配置方案优化。在本文计算条件下,当中深层地埋管地源热泵系统承担项目设计热负荷时,需要配置65个2500m深的地埋管换热器;当充分发挥中深层地埋管地源热泵系统供热能力,承担最大恒定热负荷时,24个地埋管换热器即可满足建筑累计热负荷需求。因此,为兼顾系统初投资及运行性能,本文建议热源采用中深层地埋管地源热泵+辅助热源的复合式系统形式,由中深层地埋管地源热泵系统承担基础负荷,充分发挥系统供热能力,提高系统经济性。

As a building heat source,middle-deep buried pipe ground source heat pump systems have the characteristics of high energy efficiency and low pollution.Aiming at the research on the optimizing configuration of middle-deep buried pipe ground source heat pump systems,based on the actual energy demand of buildings,the simulation results of the heat transfer model of middle-deep buried pipes are fit by the measured data through reverse calculation,so as to obtain the comprehensive thermal properties of underground rock and soil.Furthermore,the theoretical calculations and dynamic simulation methods are used to conduct dynamic simulation calculations of heat transfer in middle-deep buried pipes under different operating strategies.By analyzing the temperature changes of underground rock and soil,inlet and outlet temperature data of buried pipes,the optimizing configuration scheme of middle-deep buried pipe ground source heat pump systems is achieved.Under the calculation conditions in this article,when the middle-deep buried pipe ground source heat pump system bears the design heating load of the project,sixty-five buried pipe heat exchangers with 2500 m depth need to be configured.To fully utilize the heating capacity of the middle-deep buried pipe ground source heat pump systems under the maximum constant heating load,only twenty-four buried pipe heat exchangers are needed to meet the cumulative heat load demand of the building.Therefore,to balance the initial investment and operational performance of the system,the heat source should adopt a composite system form of middle-deep buried pipe ground source heat pump and auxiliary heat source,with the middle-deep buried pipe ground source heat pump system bearing the basic load,to fully utilize the heating capacity of the system and improve system economy.