Bivalent Carbon Dioxide Heat Pump for Heating Multi-Storey Buildings

Abstract

The aim of the work is to analyze the operation of a hybrid heat pump that simultaneously uses the heat of the return network water and outdoor air for heating multi-storey buildings. To achieve this goal, the following tasks are solved: the influence of influences on the temperature of the return network water, air temperature and their compensation on the operation of the product is considered, intermediate circuits at the evaporator and gas cooler are considered for transferring a variable heat load to the heat pump and from the heat pump. The most significant results are the hydraulic-aerodynamic scheme of the heat pump, the schemes of the intermediate circuits before the evaporator and the gas cooler. The significance of the results obtained lies in the establishment of such technical solutions for the CHP - heat pumps system, which allow sav-ing gas consumption at the CHP, the cost of heat consumers to pay bills. The use of a working fluid cooler before the gas cooler of the heat pump to control the temperature of the direct net-work water of the heating system of the building allows you to select such a compressor pres-sure at which the amount of heat given off by the heat pump to the building will correspond to the temperature curve. In this case, it is desirable to install an air-to-refrigerant heat exchanger after the compressor before the gas cooler. It has been established that a PI controller can be used to control the temperature at the outlet of the gas cooler through the inlet air channel.of var-ious parameters, including solar radiation, ambient temperature, compressor speed and initial water temperature, have been simulated and analyzed on the thermal performance of the system.

Keywords

• heat exchanger
• variable heat transfer surface
• control system
• mathematic model