REFRIGERANT TRANSFER CONTROL IN MULTI MODE AIR CONDITIONER WITH HOT WATER GENERATOR
FIG4 is a schematic diagram of a system for heating water and conditioning an interior space in hot water heating mode accordance with an embodiment
FIG4 depicts a configuration for the multi-purpose system 10 for heating water and conditioning an interior space in a water heating only mode. In this embodiment, the system 10 operates as a conventional vapor compression cycle to provide water heating via the water heating module 12, particularly when cooling or heating for the building interior space is not provided. In an embodiment, refrigerant is compressed in the compressor 20, exiting the compressor 20 as high pressure, high temperature refrigerant vapor and passes through the heat exchanger 60 of the water heating module 12. Notably, heat is dissipated in the water heater module 12 at this point because based on a call for heated water as described herein, the controller 50 has commanded flow control valve 62, to open. In addition, in this mode, flow control valve 40 denoted SVd is opened in this mode as needed to pass refrigerant as will be discussed later herein. The cooled refrigerant leaving the heat exchanger 60 of the water heating module 12 is directed to the third port 33 of the four-way valve 30, which is in its inactive position. The refrigerant exits the four-way valve 30 at the second port 32 and then passes through the thermal expansion valve 26. Flow control valves 27 and 28 are commanded by controller 50 to an inactive state in this operating mode for the system 10 in order to direct the flow of refrigerant through the thermal expansion valve 26. The thermal expansion valve 26 meters the flow of refrigerant, which is then expanded and directed to the heat exchanger 18 of the outdoor unit 14 to evaporate the refrigerant. Controller 50 provides commands to the fan 25 to operate and provide ambient heat (typically from atmosphere (or the ground for heat pump applications)) to evaporate the refrigerant. The refrigerant evaporated refrigerant is then transmitted to via flow control valve 36, which is now commanded to the open state by the controller 50, to the suction side of the compressor 20 to repeat the refrigerant thermal cycle. It is noteworthy that flow control valve 82 and flow control valve 38 are closed in this mode, so that branch in the circuit passes no refrigerant.
schematic diagram
19
temperature sensor
40
flow control valve
76
heat exchanger
16
indoor unit assembly
21
suction pressure sensor temperature sensors
82
flow control valve
70
water return connector
['1. A method (100) for controlling an operating discharge pressure in a multi-purpose HVAC system (10) including an outdoor unit assembly (14), and an indoor unit assembly (16), the HVAC system including a plurality of flow control valves configured to isolate the indoor unit assembly from the multi-purpose HVAC system, a compressor (20), and a controller (50) operably coupled to a water heater module (12), the water heater module including at least one valve (62), the controller executing a method comprising: operating (110) the multi-purpose HVAC system in a water heating mode; operating (120) the controller to monitor at least an operating discharge pressure from the compressor; and operating (130) the controller to produce a signal commanding at least one of the plurality of flow control valves to isolate the indoor unit assembly from the outdoor unit assembly and water heater module and direct high pressure refrigerant to the indoor unit assembly when the operating discharge pressure is greater than or equal to a predetermined pressure value.', '5. The method (100) of any preceding claim, wherein the at least one of the plurality of flow control valves comprises: a first valve (62) coupled to an inlet of a heat exchanger (60) configured to transfer heat to water; a second valve having a first side coupled to a heat exchanger (18) of the outdoor unit assembly (14), and a second side coupled to the indoor unit assembly (16) in fluid communication with an outlet of a heat exchanger (76) of the indoor unit assembly; a third valve having a first side coupled to an inlet to the heat exchanger of the indoor unit assembly and a second side coupled to a fourth port of a four way valve; a fourth valve having an inlet coupled to a discharge port on the compressor (20) and an outlet coupled to the inlet to the heat exchanger of the indoor unit assembly; and wherein the operating the controller to produce a signal comprises opening the first and fourth valves and closing the second and third and fourth valves.', '8. The method (100) of any preceding claim, further including controlling a superheat value of the HVAC system with an electronic expansion valve (78), the electronic expansion valve in fluid communication with a heat exchanger (76) of the indoor unit assembly (16); and/or the method further including maintaining a desired refrigerant level in the HVAC system with a flow restriction in fluid communication with a suction port of the compressor (20) and a fifth flow control valve, in fluid communication with an inlet to the heat exchanger of the indoor unit assembly (16).']