Heat pump apparatus and method for controlling regulating valve

Abstract

It is aimed to provide a heat pump type hot-water supply outdoor apparatus that can control a temperature of a compressor shell, according to a water temperature of a water circuit and a temperature of the compressor. A heat pump type hot-water supply outdoor apparatus includes a refrigeration cycle including a compressor, a water-refrigerant heat exchanger, an expansion valve, and an air heat exchanger, a water jacket that is arranged on the shell of the compressor and connected in the middle of a branch water circuit branching in parallel to a main water circuit which starts from a hot water storage tank and returns to the hot water storage tank through a water-refrigerant heat exchanger, a water flow valve that is connected between a branch and the water jacket and regulates the quantity of water flow, according to a control signal, a shell temperature detection sensor that senses a temperature of the shell of the compressor, a water temperature sensor that is installed in the vicinity of the branch and senses a temperature of the water flowing out of the hot water storage tank, and a control apparatus that generates a control signal for controlling the water flow valve, based on the temperature sensed by the shell temperature detection sensor and the temperature sensed by the water temperature sensor, and outputs it to the water flow valve.

1 . A heat pump apparatus comprising:
 a refrigeration cycle that includes a compressor, a condenser, an expansion valve, and an evaporator;   a water jacket that is arranged on a shell of the compressor and connected in a middle of a branch path branching in parallel to a main circuit which starts flowing from a hot water storage tank to the condenser and returns to the hot water storage tank from the condenser and branching at a branch located at an inlet side of the condenser and at a branch located at an outlet side of the condenser in the main circuit, and that lets water flowing out from the hot water storage tank pass through the water jacket itself;   a regulating valve that is connected in a middle of the branch path between the branch at the inlet side and the water jacket, and regulates, according to a control signal having been input, a water flow quantity;   a first temperature sensor that senses a temperature of the shell of the compressor;   a second temperature sensor that is installed upstream of the regulating valve and senses a temperature of water flowing out from the hot water storage tank; and   a control apparatus that generates the control signal for controlling the regulating valve, based on the temperature sensed by the first temperature sensor and the temperature sensed by the second temperature sensor, and outputs the control signal having been generated to the regulating valve.   
     
     
         2 . The heat pump apparatus according to  claim 1 ,
 wherein the second temperature sensor is installed at one of positions in a vicinity of the branch at the inlet side, in a vicinity of the branch path between the branch at the inlet side and the regulating valve, and in a vicinity and upstream of the regulating valve.   
     
     
         3 . The heat pump apparatus according to  claim 1 , further comprising
 a third temperature sensor that senses a temperature of an ambient air,   wherein the control apparatus generates the control signal, based on the temperature sensed by the first temperature sensor, the temperature sensed by the second temperature sensor, and the temperature sensed by the third temperature sensor, and outputs the control signal having been generated to the regulating valve.   
     
     
         4 . The heat pump apparatus according to  claim 3 ,
 wherein the control apparatus calculates an ambient air temperature increase rate, which indicates an increase rate of an ambient air temperature, based on the temperature sensed by the third temperature sensor, and a shell temperature increase rate, which indicates an increase rate of a temperature of the shell of the compressor, based on the temperature sensed by the first temperature sensor, and generates a temperature increase rate dependent control signal, which is a second control signal for controlling the regulating valve, based on a high-low relation between the ambient air temperature increase rate and the shell temperature increase rate.   
     
     
         5 . A method for controlling a regulating valve in a heat pump apparatus provided with a refrigeration cycle that includes a compressor, a condenser, an expansion valve, and an evaporator; a water jacket that is arranged on a shell of the compressor and connected in a middle of a branch path branching in parallel to a main circuit which starts flowing from a hot water storage tank to the condenser and returns to the hot water storage tank from the condenser and branching at a branch located at an inlet side of the condenser and at a branch located at an outlet side of the condenser in the main circuit, and that lets water flowing out from the hot water storage tank pass through the water jacket itself, the regulating valve that is connected in a middle of the branch path between the branch at the inlet side and the water jacket, and, by being controlled, regulates a water flow quantity, a first temperature sensor that senses a temperature of the shell of the compressor, and a second temperature sensor that is installed upstream of the regulating valve and senses a temperature of water flowing out from the hot water storage tank, the method comprising:
 controlling, by a control apparatus, the regulating valve based on the temperature sensed by the first temperature sensor and the temperature sensed by the second temperature sensor.   
     
     
         6 . The heat pump apparatus according to  claim 2 , further comprising
 a third temperature sensor that senses a temperature of an ambient air,   wherein the control apparatus generates the control signal, based on the temperature sensed by the first temperature sensor, the temperature sensed by the second temperature sensor, and the temperature sensed by the third temperature sensor, and outputs the control signal having been generated to the regulating valve.   
     
     
         7 . The heat pump apparatus according to  claim 6 ,
 wherein the control apparatus calculates an ambient air temperature increase rate, which indicates an increase rate of an ambient air temperature, based on the temperature sensed by the third temperature sensor, and a shell temperature increase rate, which indicates an increase rate of a temperature of the shell of the compressor, based on the temperature sensed by the first temperature sensor, and generates a temperature increase rate dependent control signal, which is a second control signal for controlling the regulating valve, based on a high-low relation between the ambient air temperature increase rate and the shell temperature increase rate.