Transcritical CO2 heat pump system based on precooler and water path two-way valve control method of transcritical CO2 heat pump system

Abstract

The invention discloses a transcritical CO2 heat pump system based on a precooler and a water path two-way valve control method. A conventional transcritical CO2 heat pump system is assisted by a precooler system; a circulating water path is divided into two parts in the system through a three-way shunt valve and a three-way water catchment valve, and the two parts are connected through a water path two-way adjusting valve and a water path bypass valve; and meanwhile, in cooperation with an environment temperature sensor, an evaporator fin temperature sensor and an evaporation pressure sensor,a programmable logic controller is adopted as a collecting, operation and control core. By means of the system configuration and a properly constituted temperature, pressure and time combined controlmethod, popularization of the transcritical CO2 heat pump system to the field of heat supply can be achieved, performance degradation caused by high return water temperature to the transcritical CO2heat pump system is made up, and a unit is properly controlled to enter in and quit from defrosting; and the problem that the transcritical CO2 heat pump system stops supplying heat within a relatively long defrosting time, and the average temperature of a circulating water system is fast reduced is solved.

Description

technical field [0001] The invention belongs to the technical field of heating, ventilation, refrigeration and heat pumps, and relates to a transcritical CO 2 heat pump system. Background technique [0002] In recent years, with the rapid development of the national economy, a large number of unhealthy energy supply methods and incomplete environmental friendly technology development have caused increasingly serious environmental problems and energy crises. Effect carrying capacity is the most serious problem facing the eternal contradiction. As the basic direction of national economic development has gradually shifted from industry to tertiary industry and industries supporting residents’ living conditions in the past ten years, the energy output field under the background of industry, commerce and civil use has also undergone subtle changes. According to reports, the energy consumption of the HVAC industry in the context of industrial, commercial and civil use has now oc...

AI Technical Summary

Problems solved by technology

[0005] In summary, existing transcritical CO 2 The heat pump system faces three main technical problems in the practical application of the heating field: high-temperature return water directly enters the CO 2 The gas cooler will reduce the system efficiency, the entry and exit judgment conditions and control logic of defrosting should be more accurate and rigorous, and the temperature fluctuation of the circulating water system should be avoided as far as possible during the long-term defrosting process

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