Liquid circulation heating system

Abstract

A liquid circulation heating system includes a heat pump for producing a heated liquid and a heating radiator. The heat pump has a heat pump circuit for circulating a refrigerant to heat a liquid. The refrigerant contains tetrafluoropropene and difluoromethane as main components. According to the liquid circulation heating system having such a configuration, a negative impact on global warming can be reduced.

1 . A liquid circulation heating system for performing air-heating by heating a liquid to produce a heated liquid and releasing heat of the heated liquid from a heating radiator, the system comprising a heat pump circuit for circulating a refrigerant to heat the liquid,
 wherein the refrigerant contains tetrafluoropropene and difluoromethane as main components.   
     
     
         2 . The liquid circulation heating system according to  claim 1 , wherein the content of difluoromethane in the refrigerant is at least 20% by mass. 
     
     
         3 . The liquid circulation heating system according to  claim 1 , wherein the content of difluoromethane in the refrigerant is at most 80% by mass. 
     
     
         4 . The liquid circulation heating system according to  claim 1 , wherein the refrigerant further contains pentafluoroethane. 
     
     
         5 . The liquid circulation heating system according to  claim 4 , wherein the content of pentafluoroethane in the refrigerant is at most 10% by mass. 
     
     
         6 . The liquid circulation heating system according to  claim 1 , wherein
 the heat pump circuit is filled with the refrigerant and a refrigerating machine oil, and   the refrigerating machine oil is a synthetic oil containing, as a main component, an oxygen-containing compound selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of polyvinyl ethers and polyoxyalkylene glycols or monoethers thereof, polyol esters, and polycarbonates; or a synthetic oil containing, as a main component, a compound selected from alkylbenzenes and α-olefines.   
     
     
         7 . The liquid circulation heating system according to  claim 1 , wherein
 the heat pump circuit has a refrigerant radiator for radiating heat from the refrigerant and heating the liquid to produce the heated liquid, and   the liquid circulation heating system further comprises:   a supply pipe for guiding the liquid from the heating radiator to the refrigerant radiator; and   a recovery pipe for guiding the heated liquid from the refrigerant radiator to the heating radiator.   
     
     
         8 . The liquid circulation heating system according to  claim 1 , wherein
 the heat pump circuit has a refrigerant radiator for radiating heat from the refrigerant and heating the liquid to produce the heated liquid, and   the liquid circulation heating system further comprises:   a tank for storing the produced heated liquid;   a supply pipe for guiding the liquid from a lower portion of the tank to the refrigerant radiator;   a recovery pipe for guiding the heated liquid from the refrigerant radiator to an upper portion of the tank;   a feed pipe for feeding the heated liquid stored in the tank to the heating radiator; and   a return pipe for returning the heated liquid to the tank after the heated liquid radiates heat in the heating radiator.   
     
     
         9 . The liquid circulation heating system according to  claim 1 , wherein
 the heat pump circuit has a refrigerant radiator for radiating heat from the refrigerant and heating the liquid to produce the heated liquid, and   the liquid circulation heating system further comprises:   a tank for storing the produced heated liquid;   a supply pipe for guiding the liquid from a lower portion of the tank to the refrigerant radiator;   a recovery pipe for guiding the heated liquid from the refrigerant radiator to an upper portion of the tank;   a heat exchanger, disposed in the tank, for exchanging heat between the heated liquid stored in the tank and a heat transfer liquid;   a feed pipe for feeding the heat transfer liquid to the heating radiator after the heat transfer liquid is heated in the heat exchanger; and   a return pipe for returning the heat transfer liquid to the heat exchanger after the heat transfer liquid radiates heat in the heating radiator.   
     
     
         10 . The liquid circulation heating system according to  claim 1 , wherein the liquid is water, and the heated liquid is hot water.