Overview of low grade heat sources for heat pump plants in district heating systems

The use of low grade heat sources by heat pump plants in heat supply systems in developed European countries is considered. It is established that process waters, natural reservoirs, ventilation emissions of buildings, sea water, heat of refrigeration units, groundwater, flue gases of boilers and thermal power plants, wastewater, heat of solar energy batteries, geothermal heat are used as low grade heat sources for heat pump plants. It is shown that for heat pump plants of district heating systems in Ukraine it is most expedient to use the heat of: ventilation emissions of buildings connected to these systems, wastewater, soils and groundwater, air, flue gases of boilers and CHP, rivers, process water, emissions and discharges of industrial enterprises. Exhaust ventilation heat of supermarkets, shopping malls and subways will be used not for district heating systems, but for the own needs of these organizations. The use of the heat of soils and groundwater will not be widely used in district heating systems due to the density of urban buildings Keywords: low grade heat source, district heating systems, thermal energy, heat pump