Estimation of the efficiency of thermal energy production by heat pump stations on the basis of heat of low-temperature groundwater according to the methodology of full energy costs

Abstract

Heat pump station (HPS) as a source of heat supply for district heating system is considered as an alternative to heating boilers on fossil fuels (mainly on natural gas). One of the promising areas of application of powerful HPS, which currently is being studied actively, is their use as consumers-regulators in the control of electrical load in power systems. In this article, we consider groundwater (deep-well water), which lies at a shallow depth and has stable parameters throughout a year, as a source of low-potential heat. On the territory of Ukraine, there are regions with sufficient groundwater reserves that can be used as a source of low-potential heat for HPS. We carried out calculation of the energy consumption for construction, operation and liquidation of HPS on the example of HPS project with an installed heat capacity of 9 MW, consisting of 3 heat pumps with a capacity of 1.9 MW each and a peak gas boiler with a capacity of 3.2 MW, with regard for a typical schedule of heat loads under conditions of Kyiv. The efficiency of such HPS was determined by the method of estimating the total energy costs by comparing the obtained characteristics with similar characteristics of a gas boiler house of the same capacity. We determined energy consumption for the creation of all elements of HPS and its construction: heat pump and other equipment, station building, drilling and arrangement of wells, pipelines, and peak gas boiler. Energy consumption for the creation and operation of an autonomous gas boiler house of the same capacity was calculated. The reduction of energy consumption for the creation of HPS due to the use of polyethylene-propylene pipes instead of steel is determined. The comparison of energy consumption shows that the creation and operation of HPS on deep-well water with a peak boiler house during the first year of operation compensates the energy consumption for its creation and ensures further energy saving. Operation of such HPS with the use of deep-well water will provide an almost fourfold energy saving as compared with an autonomous boiler house. Keywords: energy consumption, comparative analysis, heat pump systems, groundwater, deep-well water, autonomous boiler house, heat supply