Heat pump apparatus

Abstract

A heat pump apparatus includes: a refrigerant circuit, which is configured to circulate refrigerant, and includes a compressor, a heat source heat exchanger, an expansion mechanism, and an intermediate heat exchanger which are sequentially connected through a pipe; and a fluid circuit, which is configured to circulate a fluid, and includes the intermediate heat exchanger, a load heat exchanger, and a check valve which are sequentially connected through a pipe. A pressure regulating valve is provided to the heat pump apparatus. The pressure regulating valve is connected to a pipe connecting an outlet of the intermediate heat exchanger and an inlet of the load heat exchanger, and is configured to interrupt a flow passage of the fluid when the refrigerant leaks to the fluid, and pressure of the fluid is increased.

1 . A heat pump apparatus comprising:
 a refrigerant circuit in which refrigerant circulates, the refrigerant circuit being formed by connecting in order, by pipes, a compressor, a heat source heat exchanger, an expansion mechanism, and an intermediate heat exchanger;   a fluid circuit in which a fluid circulates, the fluid circuit being formed by connecting in order, by pipes, the intermediate heat exchanger, a load heat exchanger, and a check valve; and   a pressure regulating valve arranged in the fluid circuit and connected to a pipe connecting an outlet of the intermediate heat exchanger and an inlet of the load heat exchanger,   the pressure regulating valve being configured to interrupt a flow passage of the fluid when the refrigerant leaks to the fluid and pressure of the fluid is increased.   
     
     
         2 . The heat pump apparatus of  claim 1 ,
 wherein the pressure regulating valve includes
 a flow part through which the fluid flows, and 
 a space that the fluid is prevented from flowing into, 
 an inner wall configured to partition an inflow side of the flow part and an outflow side of the flow part, 
 a diaphragm arranged on the inflow side and configured to partition the space and the flow passage, and to be deformed in accordance with the pressure, 
 a closing mechanism configured to be moved in association with the deformation of the diaphragm to open and close an opening portion formed in the inner wall; and 
 a spring configured to deform the diaphragm by applying a force to the diaphragm to move the closing mechanism to a position at which the closing mechanism is prevented from closing the opening portion, and 
   wherein the spring is configured to have a force set such that, under a state in which the refrigerant is not leaking, the diaphragm is deformed against the pressure of the fluid by the force, to prevent the opening portion from being closed by the closing mechanism, and that, under a state in which the refrigerant is leaking, the diaphragm is deformed against the force, by the pressure of the fluid increased due to leakage of the refrigerant so that the opening portion is closed by the closing mechanism.   
     
     
         3 . The heat pump apparatus of  claim 2 ,
 wherein the closing mechanism includes
 a shaft being a longitudinal member, inserted through the opening portion while being supported by the diaphragm, and arranged so that one distal end of the shaft is located on the outflow side and an other distal end of the shaft is located in the space; and 
 a closing plate arranged on the one distal end of the shaft, 
   wherein the spring is wound around the shaft in the space,   wherein, under the state in which the refrigerant is not leaking, the diaphragm is deformed in a direction toward the opening portion by the force of the spring against the pressure of the fluid, and the shaft is moved in association with the deformation of the diaphragm so that the closing plate is located at a position away from the opening portion, and   wherein, under the state in which the refrigerant is leaking, the diaphragm is deformed in a direction to be away from the opening portion by the pressure of the fluid increased due to the leakage of the refrigerant against the force of the spring, and the shaft is moved in association with the deformation of the diaphragm so that the closing plate is located at a position at which the closing plate closes the opening portion.   
     
     
         4 . The heat pump apparatus of  claim 1 , further comprising an air purge valve configured to exhaust air inside the fluid circuit to an outside of the fluid circuit, and connected to a pipe branching from the pipe connecting the outlet of the intermediate heat exchanger and the inlet of the load heat exchanger,
 wherein the pressure regulating valve is interposed between the outlet of the intermediate heat exchanger and the air purge valve.   
     
     
         5 . The heat pump apparatus of  claim 1 , further comprising a safety valve configured to be opened when the pressure in the fluid circuit is increased, and to exhaust the fluid to the outside of the fluid circuit to prevent the increase of the pressure in the fluid circuit,
 wherein the safety valve is connected to a pipe branching from a portion between the check valve and the pressure regulating valve in a circulating direction of the fluid which flows from the check valve into an inlet of the intermediate heat exchanger and reaches the pressure regulating valve through the outlet of the intermediate heat exchanger, and   wherein the safety valve is configured to, when the refrigerant leaks to the fluid and the pressure in the fluid circuit is increased, exhaust the fluid including the refrigerant through the safety valve.   
     
     
         6 . The heat pump apparatus of  claim 5 , wherein fluid interruption pressure of the pressure regulating valve is set equal to or lower than operating pressure of the safety valve. 
     
     
         7 . The heat pump apparatus of  claim 1 , wherein the refrigerant circulating through the refrigerant circuit is flammable, and the fluid circulating through the fluid circuit is non-flammable.