Heat pump device and hot water supply device
Provided is a main refrigerant circuit in which a compressor having an injection port, a condenser, a main circuit expansion device unit, and an evaporator are connected by pipes to allow refrigerant to circulate in the main refrigerant circuit; an injection pipe an injection expansion device; an outside-air temperature detection device; a suction pressure detection device; and a controller, wherein the main circuit expansion device unit includes a plurality of main circuit expansion devices with different capacities and in a parallel-connected relationship, and during operation, when the controller determines that the temperature of the outside air is equal to or lower than a set temperature, the controller is configured to open the injection expansion device to control an opening degree to select the main circuit expansion device based on the suction pressure to control an opening degree of the selected main circuit expansion device.
1 . A heat pump device comprising:
a main refrigerant circuit in which a compressor, a condenser, a main circuit expansion device unit, and an evaporator are connected by pipes to allow refrigerant to circulate in the main refrigerant circuit, the compressor having an injection port and being configured to compress and discharge the refrigerant, the refrigerant exchanging heat with a load through the condenser, the main circuit expansion device unit being configured to reduce a pressure of the refrigerant, the refrigerant exchanging heat with outside air through the evaporator;
an injection pipe connected at one end to a pipe between the condenser and the main circuit expansion device unit, and connected at an other end to the injection port;
an injection expansion valve configured to regulate an opening degree to regulate an amount of the refrigerant flowing through the injection pipe;
an outside-air temperature sensor configured to detect a temperature of the outside air;
a suction pressure sensor configured to detect a suction pressure of the refrigerant to be suctioned into the compressor; and
a controller, wherein
the main circuit expansion device unit includes a plurality of main circuit expansion valves with different maximum opening areas and different capacities and in a parallel-connected relationship, and
during operation, when the controller determines that the temperature of the outside air is equal to or lower than a set operational temperature that is set in advance based on the temperature of the outside air, the controller is configured to open the injection expansion valve to control an opening degree thereof, and is configured to select, from among the plurality of main circuit expansion valves of the main circuit expansion device unit, a selected main circuit expansion valve based on the suction pressure to control an opening degree of the selected main circuit expansion valve.
2 . The heat pump device of claim 1 , wherein when the controller determines, at a time of activating the compressor, that the temperature of the outside air is equal to or lower than a set activation temperature that is set in advance based on the temperature of the outside air, the controller is configured to open the injection expansion valve to activate the compressor.
3 . The heat pump device of claim 2 , comprising:
a load temperature detection device configured to detect a temperature of the load exchanging heat at the condenser as a load temperature; and
a storage configured to store therein driving-frequency upper limit data in which the temperature of the outside air and the load temperature are associated with an upper limit of a driving frequency of the compressor, wherein
the controller is configured to control driving of the compressor within a range of the driving-frequency upper limit data defined based on the temperature of the outside air and a condition of the load.
4 . The heat pump device of claim 2 , comprising an auxiliary heat exchanger through which the refrigerant flowing from the condenser to the main circuit expansion valve exchanges heat with the refrigerant passing through the injection expansion valve and flowing through the injection pipe.
5 . A hot water supply device comprising the heat pump device of claim 2 , and supplying hot water.
6 . The heat pump device of claim 1 , comprising:
a load temperature detection device configured to detect a temperature of the load exchanging heat at the condenser as a load temperature; and
a storage configured to store therein driving-frequency upper limit data in which the temperature of the outside air and the load temperature are associated with an upper limit of a driving frequency of the compressor, wherein
the controller is configured to control driving of the compressor within a range of the driving-frequency upper limit data defined based on the temperature of the outside air and a condition of the load.
7 . The heat pump device of claim 1 , comprising an auxiliary heat exchanger through which the refrigerant flowing from the condenser to the main circuit expansion valve exchanges heat with the refrigerant passing through the injection expansion valve and flowing through the injection pipe.
8 . A hot water supply device comprising the heat pump device of claim 1 , and supplying hot water.
9 . The heat pump device of claim 1 , wherein the injection pipe is connected at the one end to a portion of the pipe between the condenser and the main circuit expansion device unit feeding into the main circuit expansion device unit.
10 . A heat pump device comprising:
a main refrigerant circuit in which a compressor, a condenser, a main circuit expansion device unit, and an evaporator are connected by pipes to allow refrigerant to circulate in the main refrigerant circuit, the compressor having an injection port and being configured to compress and discharge the refrigerant, the refrigerant exchanging heat with a load through the condenser, the main circuit expansion device unit being configured to reduce a pressure of the refrigerant, the refrigerant exchanging heat with outside air through the evaporator;
an injection pipe connected at one end to a pipe between the condenser and the main circuit expansion device unit, and connected at an other end to the injection port;
an injection expansion valve configured to regulate an opening degree to regulate an amount of the refrigerant flowing through the injection pipe;
an outside-air temperature sensor configured to detect a temperature of the outside air;
a suction pressure sensor configured to detect a suction pressure of the refrigerant to be suctioned into the compressor; and
a controller, wherein
the main circuit expansion device unit includes a plurality of main circuit expansion valves with different capacities and in a parallel-connected relationship, and
during operation, when the controller determines that the temperature of the outside air is equal to or lower than a set operational temperature that is set in advance based on the temperature of the outside air, the controller is configured to open the injection expansion valve to control an opening degree thereof, and is configured to select, from among the plurality of main circuit expansion valves of the main circuit expansion device unit, a selected main circuit expansion valve based on the suction pressure to control an opening degree of the selected main circuit expansion valve,
wherein when the controller determines that the injection expansion valve is open and the suction pressure is equal to or lower than a set pressure that is set in advance, the controller is configured to perform control to drive the compressor with a driving frequency of the compressor being reduced.
11 . The heat pump device of claim 10 , wherein when the controller determines, at a time of activating the compressor, that the temperature of the outside air is equal to or lower than a set activation temperature that is set in advance based on the temperature of the outside air, the controller is configured to open the injection expansion valve to activate the compressor.
12 . The heat pump device of claim 11 , comprising:
a load temperature detection device configured to detect a temperature of the load exchanging heat at the condenser as a load temperature; and
a storage configured to store therein driving-frequency upper limit data in which the temperature of the outside air and the load temperature are associated with an upper limit of a driving frequency of the compressor, wherein
the controller is configured to control driving of the compressor within a range of the driving-frequency upper limit data defined based on the temperature of the outside air and a condition of the load.
13 . The heat pump device of claim 11 , comprising an auxiliary heat exchanger through which the refrigerant flowing from the condenser to the main circuit expansion valve exchanges heat with the refrigerant passing through the injection expansion valve and flowing through the injection pipe.
14 . A hot water supply device comprising the heat pump device of claim 11 , and supplying hot water.
15 . The heat pump device of claim 10 , comprising:
a load temperature detection device configured to detect a temperature of the load exchanging heat at the condenser as a load temperature; and
a storage configured to store therein driving-frequency upper limit data in which the temperature of the outside air and the load temperature are associated with an upper limit of a driving frequency of the compressor, wherein
the controller is configured to control driving of the compressor within a range of the driving-frequency upper limit data defined based on the temperature of the outside air and a condition of the load.
16 . The heat pump device of claim 10 , comprising an auxiliary heat exchanger through which the refrigerant flowing from the condenser to the main circuit expansion valve exchanges heat with the refrigerant passing through the injection expansion valve and flowing through the injection pipe.
17 . A hot water supply device comprising the heat pump device of claim 10 , and supplying hot water.
18 . The heat pump device of claim 10 , wherein the injection pipe is connected at the one end to a portion of the pipe between the condenser and the main circuit expansion device unit feeding into the main circuit expansion device unit.