Patent Application
20250216110
The present disclosure relates to an air conditioning device.
An air conditioning system including a heat pump unit that performs indoor heating through a vapor-compression refrigeration cycle and a gas furnace unit that is a heat source other than the heat pump unit and performs indoor heating using, for example, heat of gas, is known (for example, Patent Document 1). In such an air conditioning system, a heating operation using the heat pump unit (hereinafter referred to as an “HP heating operation”) is switched to a heating operation using the gas furnace unit (hereinafter referred to as a “GF heating operation”) when the outside air temperature falls, and the GF heating operation is switched to the HP heating operation when the outside air temperature rises.
For example, in a case of a configuration in which a utilization-side heat exchanger of the heat pump unit (a utilization-side heat exchanger) is disposed downstream in an air flow from a heat exchanger of the gas furnace unit as in the air conditioning system described in Patent Document 1, the utilization-side heat exchanger (utilization-side heat exchanger) is exposed to hot air having passed through the heat exchanger of the gas furnace unit during the GF heating operation. Accordingly, the temperature of the utilization-side heat exchanger (utilization-side heat exchanger) becomes higher, and a refrigerant therein is vaporized. Since the GF heating operation is performed under the condition in which the outside air temperature is low, most of the vaporized refrigerant moves to an outdoor unit of the heat pump unit of which the temperature is low. The outdoor unit falls into a refrigerant-excess state, and when the operation is switched to the HP heating operation in the refrigerant-excess state, a liquid backflow phenomenon in which a liquid refrigerant flows back occurs at the time of starting of a compressor of the heat pump unit, which may cause a problem in that the compressor breaks.
The present disclosure has been made in consideration of the aforementioned circumstances, and an objective thereof is to provide an air conditioning device that can prevent liquid backflow at the time of starting of a compressor of a heat pump unit after a GF heating operation has been performed.
According to the present disclosure, there is provided an air conditioning device including: a gas furnace unit including a gas heat source using gas; a heat-pump heat source unit of a heat pump type; and one or more utilization units connected to the heat-pump heat source unit via a refrigerant pipe, wherein the gas furnace unit includes an air blower provided on an inlet side of air of the gas furnace unit and a first heat exchanger provided on an outlet side of air taken in by the air blower, wherein the utilization unit includes a second heat exchanger provided on an outlet side of air after the air taken in by the air blower has passed through the first heat exchanger, wherein the air blower is commonly used by both the first heat exchanger and the second heat exchanger, and an air flow of air taken in by the air blower flows in the order of the first heat exchanger and the second heat exchanger, and wherein the air conditioning device has a first operation mode in which a heating operation is performed using the gas furnace unit, a second operation mode in which a heating operation is performed using the heat-pump heat source unit, and a third operation mode in which a cooling operation is performed using the heat-pump heat source unit as operation modes, and includes a control unit configured to perform refrigerant discharge control for temporarily moving a refrigerant on the heat-pump heat source unit side to the second heat exchanger side of the utilization unit at the time of starting of a compressor provided in the heat-pump heat source unit when the first operation mode is switched to the second operation mode.
According to the present disclosure, there is also provided an air conditioning device including: a gas furnace unit including a gas heat source using gas; a heat-pump heat source unit of a heat pump type; and one or more utilization units connected to the heat-pump heat source unit via a refrigerant pipe, wherein the gas furnace unit includes an air blower provided on an inlet side of air of the gas furnace unit and a first heat exchanger provided on an outlet side of air taken in by the air blower, wherein the utilization unit includes a second heat exchanger provided on an outlet side of air after the air taken in by the air blower has passed through the first heat exchanger and a temperature sensor provided for the second heat exchanger, wherein the air blower is commonly used by both the first heat exchanger and the second heat exchanger, and an air flow of air taken in by the air blower flows in the order of the first heat exchanger and the second heat exchanger, and wherein the air conditioning device has a first operation mode in which a heating operation is performed using the gas furnace unit, a second operation mode in which a heating operation is performed using the heat-pump heat source unit, and a third operation mode in which a cooling operation is performed using the heat-pump heat source unit as operation modes, and includes a control unit configured to perform refrigerant discharge control for temporarily moving a refrigerant on the heat-pump heat source unit side to the second heat exchanger side of the utilization unit when the temperature measured by the temperature sensor at the time of starting of a compressor provided in the heat-pump heat source unit is equal to or higher than a predetermined threshold value when the second operation mode is performed.
According to the present disclosure, it is possible to prevent liquid backflow at the time of starting of a compressor of a heat pump unit after a GF heating operation has been performed.
Hereinafter, embodiments will be described with reference to the accompanying drawings.
First, a first embodiment will be described.
The heat-pump heat source unit 301 and the air utilization units 303a and 303b are connected to each other via pipes 4a and 4b and pipes 7a and 7b which are refrigerant pipes and are configured as a heat pump unit for performing a vapor-compression refrigeration cycle operation. The air utilization units 303a and 303b are indoor units that are installed in a room to be air-conditioned. On the other hand, the heat-pump heat source unit 301 is an outdoor unit. Here, a type of a refrigerant to be used may be, for example, a natural refrigerant such as R410A, R32, HFO-1234yf, or a hydrocarbon and is not particularly limited.
In a heat-pump air conditioning system using the heat-pump heat source unit 301 and the air utilization units 303a and 303b, a heating operation using the heat-pump heat source unit 301 (hereinafter referred to as an “HP heating operation”) or a cooling operation (hereinafter referred to as an “HP cooling operation”) is performed in response to a heating request or a cooling request selected in the air utilization units 303a and 303b (for example, using a remote controller which is not illustrated).
The air utilization unit 303a is connected to the gas furnace unit 304 and performs a heating operation using the gas furnace unit 304 (hereinafter referred to as a “GF heating operation”) in addition to the HP heating operation as a heating operation.
In this way, the air utilization unit 303a can perform the HP heating operation using the heat-pump heat source unit 301 alone (without using the gas furnace unit 304) and the GF heating operation using the gas furnace unit 304 alone (without using the heat-pump heat source unit 301). In the air utilization unit 303a, the HP heating operation and the GF heating operation are exclusive and are not performed at the same time. For example, the heating operation is switched between the HP heating operation and the GF heating operation according to the outside air temperature.
On the other hand, the air utilization unit 303b is configured to perform only the HP heating operation as a heating operation. In addition, both the air utilization units 303a and 303b perform the HP cooling operation as a cooling operation.
Here, an example in which the number of air utilization units is two is illustrated, but the number of air utilization units is not limited to two. For example, the air conditioning device 300 may have a configuration in which one air utilization unit 303a is provided as an air utilization unit. Alternatively, the air conditioning device 300 may have a configuration in which three or more air utilization units are provided. In this case, the air conditioning device 300 may have a configuration in which one air utilization unit 303a that supports switching between the HP heating operation and the GF heating operation is provided or a configuration in which two or more of such air utilization units 303a are provided.
The heat-pump heat source unit 301 includes a compressor 1, a four-way valve 2, an expansion valve 8, a heat-source-side heat exchanger 14, a heat-source-side air blower 15, and an accumulator 16. The HP heating operation or the HP cooling operation is performed by activating the compressor 1. Further, a direction in which a refrigerant flows is switched by switching the four-way valve 2, and the HP heating operation and the HP cooling operation are selectively performed.
Further, temperature sensors 202 to 206 are provided in the heat-pump heat source unit 301. The temperature sensors 202 to 206 measure the temperatures at respective installation positions thereof. Specifically, the temperature sensors 202, 203, and 204 are provided on the four-way valve 2 side of the compressor 1 and a central side and the expansion valve 8 side of the heat-source-side heat exchanger 14 and measure the temperatures of the refrigerant at the respective installation positions. The temperature sensor 205 is provided in an air inlet of the heat-pump heat source unit 301 and measures the air temperature of the heat source. The temperature sensor 206 is provided inside or outside of a housing surface of the heat-pump heat source unit 301 and measures the outside air temperature.
The expansion valve 8 includes four expansion valves including expansion valves 8a, 8b, 8c, and 8d, and a maximum of four air utilization units are connectable thereto. Here, the expansion valve 8a is connected to the air utilization unit 303a via a pipe 7a. Further, the expansion valve 8b is connected to the air utilization unit 303b via a pipe 7b. The expansion valves 8c and 8d are not used. Here, the number of expansion valves 8 is determined according to the specification of the number of air utilization units connectable to the heat-pump heat source unit 301.
The air utilization unit 303b includes a utilization-side heat exchanger 9b and a utilization-side air blower 6b that sends air to the utilization-side heat exchanger 9b. An amount of air sent by the utilization-side air blower 6b can be adjusted. Further, in the air utilization unit 303b, a temperature sensor 207b and a temperature sensor 208b are provided respectively on a central side and the expansion valve 8b side of the utilization-side heat exchanger 9b and measure the temperatures of a refrigerant at the respective installation positions thereof. As described above, the air utilization unit 303b can selectively perform the HP heating operation and the HP cooling operation using the heat-pump heat source unit 301.
The air utilization unit 303a includes a utilization-side heat exchanger 9a. Here, an air blower 19 that sends air to the utilization-side heat exchanger 9a is provided in the gas furnace unit 304. Details thereof will be described later. Further, in the air utilization unit 303a, a temperature sensor 207a and a temperature sensor 208a are provided respectively on a central side and the expansion valve 8a side of the utilization-side heat exchanger 9a and measure the temperatures of a refrigerant at the respective installation positions thereof. As described above, the air utilization unit 303a can selectively perform the HP heating operation using the heat-pump heat source unit 301 and the GF heating operation using the gas furnace unit 304 as a heating operation. Further, the air utilization unit 303a can perform the HP cooling operation using the heat-pump heat source unit 301 as a cooling operation.
The gas furnace unit 304 mainly includes an air intake unit 20a, a gas intake pipe 20b, a combustor 20c, a gas-furnace heat exchanger 18, a gas exhaust pipe 20d, and the air blower 19. The gas furnace unit 304 performs heating by causing the combustor 20c to combust gas and the gas-furnace heat exchanger 18 to exchange heat between combustion gas and air.
The configurations of the air utilization unit 303a and the gas furnace unit 304 will be described below in detail with reference to
Air supplied via the air intake unit 20a and fuel gas supplied via the gas intake pipe 20b are mixed into a gas mixture in the combustor 20c. In the combustor 20c, the gas mixture is combusted with ignition based on discharge and becomes combusted gas. One end of the gas exhaust pipe 20d is connected to the combustor 20c. The combusted gas moves in the gas-furnace heat exchanger 18 via the gas exhaust pipe 20d, exits the gas-furnace heat exchanger 18, and is discharged from the other end of the gas exhaust pipe 20d outdoors via an exhaust duct.
Further, an air intake port 401 for taking in air is provided on the bottom and a side surface near the bottom of the main housing 305. The air blower 19 is a unit for generating an air flow AF1. The air blower 19 is, for example, a blower such as a propeller fan or a sirocco fan.
In the illustrated example, the air blower 19 is a sirocco fan. When a fan of the air blower 19 rotates, air flows in from the air intake port 401 to generate an air flow AF1. The air flow AF1 flows into the main housing 305 from the air intake port 401 and passes through the gas-furnace heat exchanger 18. The air flow AF1 is heated by exchanging heat with the combusted gas in the gas-furnace heat exchanger 18 at the time of passing through the gas-furnace heat exchanger 18. After passing through the gas-furnace heat exchanger 18, the heated air flow AF1 exits the main housing 305, flows into the air utilization unit 303a, passes through the utilization-side heat exchanger 9a, and is discharged to a space (room) to be air-conditioned.
That is, the air blower 19 of the gas furnace unit 304 is an air blower that is commonly used by both the gas-furnace heat exchanger 18 and the utilization-side heat exchanger 9a of the air utilization unit 303a. The utilization-side heat exchanger 9a of the air utilization unit 303a is provided on an outlet side after air taken in by the air blower 19 has passed through the gas-furnace heat exchanger 18. Further, the air flow AF1 of air taken in by the air blower 19 flows in the order of the gas-furnace heat exchanger 18 and the utilization-side heat exchanger 9a and then is discharged to the space (room) to be air-conditioned.
In this way, in the GF heating operation, a beating operation is performed through heat exchange which is performed when the air flow AF1 generated by the air blower 19 passes through the gas-furnace heat exchanger 18. On the other hand, in the HP heating operation, generation of combusted gas in the combustor 20c is stopped, the compressor 1 of the heat-pump heat source unit 301 operates, and a heating operation is performed through heat exchange which is performed when the air flow AF1 generated by the air blower 19 passes through the utilization-side heat exchanger 9a.
Referring back to
The electric unit 310 controls the constituents of the heat-pump heat source unit 301. For example, the electric unit 310 performs control of operations of the compressor 1 and the heat-source-side air blower 15 in the heat-pump heat source unit 301, switching control of the four-way valve 2, acquisition of measurement results of the temperatures from the temperature sensors 202, 203, 204, 205, and 206, and the like.
The electric unit 330a controls the constituents of the air utilization unit 303a. For example, the electric unit 330a performs acquisition of measurement results of the temperatures from the temperature sensors 207a and 208a in the air utilization unit 303a and the like.
The electric unit 330b controls the constituents of the air utilization unit 303b. For example, the electric unit 330b performs control of the operation of the utilization-side air blower 6b in the air utilization unit 303b, acquisition of measurement results of the temperatures from the temperature sensors 207a and 208a, and the like.
The electric unit 340 controls the constituents of the gas furnace unit 304. For example, the electric unit 340 performs control of ignition and combustion stop of the combustor 20c in the gas furnace unit 304, control of the operation of the air blower 19, and the like.
The control box 350 is connected to the electric unit 310, the electric unit 330a, the electric unit 330b, and the electric unit 340 and performs reception and relay of various types of information and control signals. Further, the control box 350 performs control of turning-on and turning-off of the gas furnace unit 304 and the like according to the outside air temperature.
Next, control when the air conditioning device 300 according to this embodiment switches between the GF heating operation and the HP heating operation will be described below. Note that in the following description, an operation mode in which the GF heating operation is performed is referred to as a “GF heating operation mode,” and an operation mode in which the HP heating operation is performed is referred to as an “HP heating operation mode.” Further, an operation mode in which an HP cooling operation is performed is referred to as an “HP cooling operation mode.”
For example, the air conditioning device 300 switches the heating operation mode of the air utilization unit 303a to one of the GF heating operation mode and the HP heating operation mode according to the outside air temperature. Specifically, the air conditioning device 300 switches the HP heating operation mode to the GF heating operation mode when the outside air temperature falls and is equal to or lower than a predetermined threshold value (for example, −20° C.). Further, the air conditioning device 300 switches the GF heating operation mode to the HP heating operation mode when the outside air temperature rises and is higher than the predetermined threshold value (for example, −20° C.).
In the following description, the predetermined threshold value (for example, −20° C.) for the outside air temperature used to switch between the GF heating operation mode and the HP heating operation mode is referred to as “Y° C.” Here, the heating operation mode is described to switch between the GF heating operation mode and the HP heating operation mode according to whether the outside air temperature is equal to or lower than Y° C., and hysteresis may be provided in the threshold value for the outside air temperature for switching the HP heating operation mode to the GF heating operation mode and the threshold value for the outside air temperature for switching the GF heating operation mode to the HP heating operation mode.
Here, as described above with reference to
For this reason, the air conditioning device 300 according to this embodiment performs refrigerant discharge control for temporarily moving a refrigerant on the heat-pump heat source unit 301 side to the utilization-side heat exchanger 9a side of the air utilization unit 303a when the GF heating operation mode is switched to the HP heating operation mode. Here, in the refrigerant discharge control, the air conditioning device 300 may temporarily move the refrigerant on the heat-pump heat source unit 301 side to the utilization-side heat exchanger 9a side of the air utilization unit 303a and the utilization-side heat exchanger 9b side of the air utilization unit 303b.
For example, in the refrigerant discharge control, the air conditioning device 300 moves the refrigerant staying in the heat-source-side heat exchanger 14 to the utilization-side heat exchanger 9a side of the air utilization unit 303a (or the utilization-side heat exchanger 9b side of the air utilization unit 303b) via the expansion valve 8 by switching the four-way valve 2 to the direction in which the refrigerant flows during the cooling operation. That is, the refrigerant discharge control can be said to be control for switching the GF heating operation mode to the HP heating operation mode after having temporarily switched the GF heating operation mode to the HP cooling operation mode when the GF heating operation mode is switched to the HP heating operation mode.
For example, when the GF heating operation mode is switched to the HP heating operation mode, the air conditioning device 300 moves the refrigerant on the heat-pump heat source unit 301 side to the utilization-side heat exchanger 9a side of the air utilization unit 303a (or the utilization-side heat exchanger 9b side of the air utilization unit 303b) by performing the cooling operation in the HP cooling operation mode for a predetermined time and disperses the refrigerant in the refrigerant circuit. After the predetermined time has elapsed, the air conditioning device 300 starts the heating operation in the HP heating operation mode by switching the four-way valve 2 of the heat-pump heat source unit 301.
The electric unit 310 of the beat-pump heat source unit 301 acquires measurement results of the temperature sensors 207a and 208a from the electric unit 330a of the air utilization unit 303a via the control box 350. Further, the electric unit 310 receives a signal indicating an operating state of the gas furnace unit 304 from the electric unit 340 of the gas furnace unit 304 via the control box 350. Further, the electric unit 310 transmits a signal indicating the outside air temperature (the measurement result of the temperature sensor 206) to the control box 350.
The control box 350 transmits a signal for instructing to turn on or off the gas furnace unit 304 to the electric unit 340 of the gas furnace unit 304 on the basis of the signal indicating the outside air temperature received from the electric unit 310. In response to this instruction from the control box 350, the electric unit 340 turns on or off the gas furnace unit 304.
For example, when a signal indicating that the outside air temperature is equal to or lower than Y° C. is received from the electric unit 310, the control box 350 instructs to switch the HP heating operation mode to the GF heating operation mode. At this time, the control box 350 transits a signal for instructing to turn on the gas furnace unit 304 to the electric unit 340 of the gas furnace unit 304 and the electric unit 310 of the heat-pump heat source unit 301.
Further, when a signal indicating that the outside air temperature is higher than Y° C. is received from the electric unit 310, the control box 350 instructs to switch the GF heating operation mode to the HP heating operation mode. At this time, the control box 350 transmits a signal for instructing to turn off (stop) the gas furnace unit 304 to the electric unit 340 of the gas furnace unit 304 and the electric unit 310 of the heat-pump heat source unit 301.
The gas furnace unit 304 controls operation starting or operation stopping of the gas furnace unit 304, that is, starting or stopping of the GF heating operation in accordance with the signal for instructing to turn on or off the gas furnace unit 304 transmitted from the control box 350.
The heat-pump heat source unit 301 controls starting or stopping of the HP heating operation in accordance with the signal for instructing to turn on or off the gas furnace unit 304 transmitted from the control box 350.
Further, the electric unit 310 of the heat-pump heat source unit 301 includes a determination processing unit 311A. The determination processing unit 311A determines whether or not refrigerant discharge control is to be performed at the time of starting of the HP heating operation. The determination processing unit 311A ascertains a prior operating state of the gas furnace unit 304 at the time of starting of the compressor 1 (Step S10). When the HP heating operation is performed after the GF heating operation has been performed, the determination processing unit 311A determines that the GF heating operation has been performed (Step S11) and temporarily performs the refrigerant discharge control (Step S12) because there is a history of the signal for controlling the gas furnace unit 304 to be turned on just before. Then, the HP heating operation mode is started. Accordingly, it is possible to prevent a liquid backflow at the time of starting of the compressor 1.
Here, “just before” is a predetermined period before the HP beating operation is performed, for example, a period in which the heat-pump beat source unit 301 side is likely to be in a refrigerant-excess state because the GF heating operation has been performed.
On the other hand, when there is no history of the signal for controlling the gas furnace unit 304 to be turned on just before, the determination processing unit 311A determines that the GF heating operation has not been performed (Step S13), normally starts the compressor 1 without performing the refrigerant discharge control (Step S14), and starts the HP heating operation mode.
Next, a flow of a process of starting the GF heating operation and the HP heating operation will be described below.
The process flow of starting the GF heating operation will be first described.
First, the electric unit 310 of the heat-pump heat source unit 301 transmits a signal indicating the outside air temperature to the control box 350 on the basis of the measurement result of the temperature sensor 206. For example, the electric unit 310 transmits a signal indicating that the outside air temperature is equal to or lower than Y° C. (outside air temperature≤Y° C.) to the control box 350 (Step S111).
Then, when the signal indicating the outside air temperature is received from the electric unit 310, the control box 350 determines whether or not to tum on the gas furnace unit 304 on the basis of the outside air temperature. For example, when the signal indicating that the outside air temperature is equal to or lower than Y° C. is received from the electric unit 310 (Step S112), the control box 350 transmits a signal for instructing to turn on the gas furnace unit 304 to the gas furnace unit 304 (the electric unit 340) and the electric unit 310 of the heat-pump heat source unit 301 (Step S113).
When the signal for instructing to turn on the gas furnace unit 304 is received from the control box 350, the gas furnace unit 304 (the electric unit 340) starts its operation (Step S114). Specifically, the gas furnace unit 304 (the electric unit 340) generates combusted gas through ignition in the combustor 20c.
Further, when the signal for instructing to turn on the gas furnace unit 304 is received from the control box 350 (Step S115), the electric unit 310 of the heat-pump heat source unit 301 transmits a signal for instructing to stop the air utilization unit 303a to the control box 350 (Step S116). Further, the electric unit 310 stops the operation of the compressor 1.
When the signal for instructing to stop the air utilization unit 303a is received from the electric unit 310, the control box 350 transmits a signal for instructing to stop the air utilization unit 303a to the air utilization unit 303a (the electric unit 330a) (Step S117).
When the signal for instructing to stop the air utilization unit 303a is received from the control box 350, the air utilization unit 303a (the electric unit 330a) stops its operation (Step S118). Accordingly, for example, the HP heating operation mode is switched to the GF heating operation mode.
Next, the process flow of starting the HP heating operation will be described below.
First, the electric unit 310 of the heat-pump heat source unit 301 transmits a signal indicating the outside air temperature to the control box 350 on the basis of the measurement result of the temperature sensor 206. For example, the electric unit 310 transmits a signal indicating that the outside air temperature is equal to or lower than Y° C. (outside air temperature>Y° C.) to the control box 350 (Step S121).
Then, when the signal indicating the outside air temperature is received from the electric unit 310 (Step S122), the control box 350 determines whether or not to stop (turn off) the gas furnace unit 304 on the basis of the outside air temperature. For example, when a signal indicating that the outside air temperature is higher than Y° C. is received from the electric unit 310, the control box 350 transmits a signal for instructing to stop the gas furnace unit 304 to the gas furnace unit 304 (the electric unit 340) and the electric unit 310 of the heat-pump heat source unit 301 (Step S123).
When the signal for instructing to stop the gas furnace unit 304 is received from the control box 350, the gas furnace unit 304 (the electric unit 340) stops its operation (Step S124). Specifically, the gas furnace unit 304 (the electric unit 340) stops generation of combusted gas in the combustor 20c.
Further, when the signal for instructing to stop the gas furnace unit 304 is received from the control box 350 (Step S125), the electric unit 310 of the heat-pump heat source unit 301 transmits a signal for instructing to turn on the air utilization unit 303a to the control box 350 (Step S126).
When the signal for instructing to turn on the air utilization unit 303a is received from the electric unit 310, the control box 350 transmits a signal for instructing to tum on the air utilization unit 303a to the air utilization unit 303a (the electric unit 330a) (Step S127).
When the signal for instructing to turn on the air utilization unit 303a is received from the control box 350, the air utilization unit 303a (the electric unit 330a) starts its operation (Step S128).
Further, after having transmitted the signal for instructing to turn on the air utilization unit 303a in Step S126, the electric unit 310 of the heat-pump heat source unit 301 ascertains the prior operating state of the gas furnace unit 304 and determines whether or not the GF heating operation has been performed (Step S130). When it is determined that the GF heating operation has been performed, the electric unit 310 temporarily performs the refrigerant discharge control (Step S131) and then performs the HP heating operation (Step S132). Accordingly, the GF heating operation mode is switched to the HP heating operation mode.
When it is determined in Step S130 that the GF heating operation has not been performed, the electric unit 310 performs the HP heating operation without performing the refrigerant discharge control (Step S132).
As described above, the air conditioning device 300 according to the present embodiment includes: the gas furnace unit 304 including the combustor 20c (a gas heat source) using gas; the heat-pump heat source unit 301 of a heat pump type; and one or more air utilization units 303a (which is an example of a utilization unit) connected to the heat-pump heat source unit 301 via a refrigerant pipe. The gas furnace unit 304 includes the air blower 19 provided on an inlet side of air (the air intake port 401) of the gas furnace unit 304 and the gas-furnace heat exchanger 18 (which is an example of a first heat exchanger) provided on an outlet side of air taken in by the air blower 19. The air utilization unit 303a includes the utilization-side heat exchanger 9a provided on an outlet side of air after the air taken in by the air blower 19 has passed through the gas-furnace heat exchanger 18. The air blower 19 is commonly used by both the gas-furnace heat exchanger 18 and the utilization-side heat exchanger 9a. An air flow AF1 of the air taken in by the air blower 19 flows in the order of the gas-furnace heat exchanger 18 and the utilization-side heat exchanger 9a.
Further, the air conditioning device 300 has the GF heating operation mode (a first operation mode) in which a heating operation is performed using the gas furnace unit 304, the HP heating operation mode (a second operation mode) in which a heating operation is performed using the heat-pump heat source unit 301, and the HP cooling operation mode (a third operation mode) in which a cooling operation is performed using the heat-pump heat source unit 301 as operation modes. Further, the air conditioning device 300 performs refrigerant discharge control for temporarily moving a refrigerant on the heat-pump heat source unit 301 side to the utilization-side heat exchanger 9a side of the air utilization unit 303a at the time of starting of the compressor 1 provided in the heat-pump heat source unit 301 when the GF heating operation mode is switched to the HP heating operation mode.
Accordingly, since the air conditioning device 300 moves the refrigerant to the utilization-side heat exchanger 9a side of the air utilization unit 303a at the time of starting of the compressor 1 of the heat-pump heat source unit 301 even when the refrigerant vaporized because the temperature of the utilization-side heat exchanger 9a rises during the GF heating operation moves to the heat-pump heat source unit 301 side, it is possible to prevent a liquid backflow at the time of starting of the compressor 1 of the heat-pump heat source unit 301 after the GF heating operation has been performed.
Further, when the temperature of the utilization-side heat exchanger 9a rises due to the GF heating operation, the refrigerant in the utilization-side heat exchanger 9a is vaporized. Accordingly, the refrigerant and a refrigerator oil in the utilization-side heat exchanger 9a are fully separated, only the refrigerator oil stays in the utilization-side heat exchanger 9a, and the refrigerator oil is not recovered. When the refrigerator oil is not recovered, a shortage of a lubricant occurs during starting of the compressor 1, and the reliability of the compressor 1 decreases. However, since the air conditioning device 300 temporarily performs the refrigerant discharge control at the time of starting of the compressor 1 of the heat-pump heat source unit 301, the refrigerant on the heat-pump heat source unit 301 side is returned to the utilization-side heat exchanger 9a side, the refrigerator oil is recovered, and thus it is possible to curb the shortage of a lubricant during starting of the compressor 1.
For example, the air conditioning device 300 ascertains the operating state of the gas furnace unit 304 before the HP heating operation mode is performed when the HP heating operation mode is performed, and proceeds to the HP heating operation mode after the refrigerant discharge control has been temporarily performed when the gas furnace unit 304 has operated in the GF heating operation mode.
Accordingly, when the air conditioning device 300 has operated in the GF heating operation mode before the HP heating operation mode is performed, the refrigerant is moved to the utilization-side heat exchanger 9a side of the air utilization unit 303a at the time of starting of the compressor 1 of the heat-pump heat source unit 301, and thus it is possible to prevent a liquid backflow at the time of starting of the compressor 1 of the heat-pump heat source unit 301 after the GF heating operation has been performed.
Further, when the air conditioning device 300 operates in the HP heating operation mode, the air conditioning device 300 ascertains the operating state of the gas furnace unit 304 before the HP heating operation mode is performed, and proceeds to the HP heating operation mode without performing the refrigerant discharge control when the gas furnace unit 304 has not operated.
Accordingly, when the air conditioning device 300 bas not operated in the GF heating operation mode before operating in the HP heating operation mode, it is possible to immediately operate in the HP heating operation mode.
For example, the air conditioning device 300 operates in the HP cooling operation mode as the refrigerant discharge control.
Accordingly, when the air conditioning device 300 has operated in the GF heating operation mode before operating in the HP heating operation mode, the refrigerant is moved to the utilization-side heat exchanger 9a side of the air utilization unit 303a at the time of starting of the compressor 1 of the heat-pump heat source unit 301 by temporarily operating in the HP cooling operation mode, and thus it is possible to prevent a liquid backflow at the time of starting of the compressor 1 of the heat-pump heat source unit 301 after the GF heating operation has been performed.
Further, the four-way valve 2 for switching the direction in which a refrigerant flows in the refrigerant pipe between during the cooling operation and during the heating operation is provided in the middle of the refrigerant pipe in the heat-pump heat source unit 301. As the refrigerant discharge control, the air conditioning device 300 controls the four-way valve 2 such that the direction in which the refrigerant flows in the refrigerant pipe becomes the direction during the cooling operation.
Accordingly, when the air conditioning device 300 has operated in the GF heating operation mode before operating in the HP heating operation mode, the refrigerant is moved to the utilization-side heat exchanger 9a side of the air utilization unit 303a at the time of starting of the compressor 1 of the heat-pump heat source unit 301 by performing control such that the direction in which the refrigerant flows in the refrigerant pipe temporarily becomes the direction during the cooling operation, and thus it is possible to prevent a liquid backflow at the time of starting of the compressor 1 of the heat-pump heat source unit 301 after the GF heating operation has been performed.
Further, the air conditioning device 300 switches the GF heating operation mode to the HP heating operation mode according to the outside air temperature.
Accordingly, the air conditioning device 300 can perform an appropriate heating operation according to the outside air temperature.
Next, a second embodiment will be described below.
In the present embodiment, control for switching the heating operation mode when the heat-pump heat source unit 301 cannot identify a signal for instructing to turn on or off the gas furnace unit 304, that is, when the heat-pump heat source unit 301 cannot identify a prior operating state of the gas furnace unit 304 will be described.
When a signal indicating the outside air temperature is received from the electric unit 310, the control box 350 transmits a signal for instructing to tum on or off the gas furnace unit 304 to the electric unit 340 of the gas furnace unit 304 as an instruction to switch between the HP heating operation mode and the GF heating operation mode according to the outside air temperature, but cannot transmit the signal to (cannot notify) the electric unit 310 of the heat-pump heat source unit 301 in the present embodiment.
For this reason, when the signal indicating the outside air temperature is received from the electric unit 310, the control box 350 receives information of a remote-controller set temperature Z° C. from the electric unit 330a of the air utilization unit 303a and transmits a signal indicating the remote-controller set temperature Z° C. to the electric unit 310 of the heat-pump heat source unit 301. The remote-controller set temperature is a temperature which is set by a remote controller (not illustrated) for allowing a user to set a heating request, a cooling request, a temperature, or the like to the air utilization unit 303a.
For example, when the outside air temperature is equal to or lower than Y° C. and the remote-controller set temperature Z° C. is high (a heating operation), the electric unit 310 of the heat-pump heat source unit 301 instructs to stop the operation of the air utilization unit 303a, that is, to stop the HP heating operation. On the other hand, when the outside air temperature is higher than Y° C. and the remote-controller set temperature Z° C. is high (a heating operation), the electric unit 310 of the heat-pump heat source unit 301 instructs to start the operation of the air utilization unit 303a, that is, to start the HP heating operation.
Further, the electric unit 310 of the beat-pump heat source unit 301 includes a determination processing unit 311B. The determination processing unit 311B determines whether or not to perform refrigerant discharge control at the time of starting of the HP heating operation. The determination processing unit 311B ascertains the temperature of the utilization-side heat exchanger 9a of the air utilization unit 303a at the time of starting of the compressor 1 (Step S20). The determination processing unit 311B can ascertain the temperature of the utilization-side heat exchanger 9a, for example, by acquiring the measurement results of the temperature sensors 207a and 208a of the air utilization unit 303a via the electric unit 330a and the control box 350.
When the HP heating operation is performed after the GF heating operation has been performed, the temperature of the utilization-side heat exchanger 9a rises due to the gas furnace unit 304 just before. Here, a threshold value for the temperature of the utilization-side heat exchanger 9a for determining that the GF heating operation has been performed is defined as X° C. When the determination processing unit 311B determines that the temperature of the utilization-side heat exchanger 9a is equal to or higher than X° C. (Step S21), the refrigerant discharge control is temporarily performed (Step S22). Then, the HP heating operation mode is started. Accordingly, it is possible to prevent a liquid backflow at the time of starting of the compressor 1.
On the other hand, when it is determined that the temperature of the utilization-side heat exchanger 9a is lower than X° C. (Step S23), the compressor 1 is normally started without performing the refrigerant discharge control (Step S24) and the HP heating operation mode is started.
First, the electric unit 310 of the heat-pump heat source unit 301 transmits a signal indicating the outside air temperature to the control box 350 on the basis of the measurement result from the temperature sensor 206. For example, the electric unit 310 transmits a signal indicating that the outside air temperature is equal to or lower than Y° C. (outside air temperature≤Y° C.) to the control box 350 (Step S211).
Then, when the signal indicating the outside air temperature is received from the electric unit 310, the control box 350 acquires information of the remote-controller set temperature Z° C. from the air utilization unit 303a. For example, when a signal indicating that the outside air temperature is equal to or lower than Y° C. is received from the electric unit 310 (Step S212), the control box 350 acquires information of the remote-controller set temperature Z° C. and transmits a signal indicating the remote-controller set temperature Z° C. to the electric unit 310 of the heat-pump heat source unit 301 (Step S213).
Further, when the signal indicating that the outside air temperature is equal to or lower than Y° C. is received from the electric unit 310 in Step S212, the control box 350 transmits a signal for instructing to turn on the gas furnace unit 304 to the gas furnace unit 304 (the electric unit 340) (Step S214). Here, the processes of Steps S213 and S214 may be performed reversely or simultaneously.
When the signal for instructing to turn on the gas furnace unit 304 is received from the control box 350, the gas furnace unit 304 (the electric unit 340) starts its operation (Step S215). Specifically, the gas furnace unit 304 (the electric unit 340) generates combusted gas through ignition in the combustor 20c.
Further, when the signal indicating the remote-controller set temperature Z° C. is received from the control box 350 (Step S216), the electric unit 310 of the heat-pump heat source unit 301 transmits a signal for instructing to stop the air utilization unit 303a to the control box 350 (Step S217). Further, the electric unit 310 stops the operation of the compressor 1.
When the signal for instructing to stop the air utilization unit 303a is received from the electric unit 310, the control box 350 transmits the signal for instructing to stop the air utilization unit 303a to the air utilization unit 303a (the electric unit 330a) (Step S218).
When the signal for instructing to stop the air utilization unit 303a is received from the control box 350, the air utilization unit 303a (the electric unit 330a) stops its operation (Step S219). Accordingly, for example, the HP heating operation mode is switched to the GF heating operation mode.
First, the electric unit 310 of the heat-pump heat source unit 301 transmits a signal indicating the outside air temperature to the control box 350 on the basis of the measurement result from the temperature sensor 206. For example, the electric unit 310 transmits a signal indicating that the outside air temperature is higher than Y° C. (outside air temperature>Y° C.) to the control box 350 (Step S221).
Then, when a signal indicting the outside air temperature is received from the electric unit 310, the control box 350 acquires information of the remote-controller set temperature Z° C. from the air utilization unit 303a. For example, when the signal indicating that the outside air temperature is higher than Y° C. is received from the electric unit 310 (Step S222), the control box 350 acquires the information of the remote-controller set temperature Z° C. and transmits a signal indicating the remote-controller set temperature Z° C. to the electric unit 310 of the heat-pump heat source unit 301 (Step S223).
Further, when the signal indicating that the outside air temperature is higher than Y° C. is received from the electric unit 310 in Step S222, the control box 350 transmits a signal for instructing to stop (turn off) the gas furnace unit 304 to the gas furnace unit 304 (the electric unit 340) (Step S224). Here, the processes of Steps S223 and S224 may be performed reversely or simultaneously.
When the signal for instructing to stop the gas furnace unit 304 is received from the control box 350, the gas furnace unit 304 (the electric unit 340) stops its operation (Step S225). Specifically, the gas furnace unit 304 (the electric unit 340) stops generation of combusted gas in the combustor 20c.
Further, when the signal indicating the remote-controller set temperature Z° C. is received from the control box 350 (Step S226), the electric unit 310 of the heat-pump heat source unit 301 transmits a signal for instructing to tum on the air utilization unit 303a to the control box 350 (Step S227).
When the signal for instructing to turn on the air utilization unit 303a is received from the electric unit 310, the control box 350 transmits the signal for instructing to turn on the air utilization unit 303a to the air utilization unit 303a (the electric unit 330a) (Step S228).
When the signal for instructing to turn on the air utilization unit 303a is received from the control box 350, the air utilization unit 303a (the electric unit 330a) starts its operation (Step S229).
Further, after having transmitted the signal for instructing to turn on the air utilization unit 303a in Step S227, the electric unit 310 of the heat-pump heat source unit 301 receives the temperature of the utilization-side heat exchanger 9a measured by the temperature sensors 207a and 208a from the air utilization unit 303a (the electric unit 330a) via the control box 350 (Step S230).
The electric unit 310 determines whether the temperature of the utilization-side heat exchanger 9a received in Step S230 is equal to or higher than X° C. (Step S231), When it is determined that the temperature of the utilization-side heat exchanger 9a is equal to or higher than X° C. (YES), the electric unit 310 temporarily performs the refrigerant discharge control (Step S232) and then performs the HP heating operation (Step S233). Accordingly, the GF heating operation mode is switched to the HP heating operation mode.
When it is determined in Step S231 that the temperature of the utilization-side heat exchanger 9a is lower than X° C. (NO), the electric unit 310 performs the HP heating operation without performing the refrigerant discharge control (Step S233),
As described above, similarly to the first embodiment, the air conditioning device 300 according to this embodiment includes the gas furnace unit 304, the heat-pump heat source unit 301, and the air utilization units 303a. The gas furnace unit 304 includes the air blower 19 provided on the inlet side of air (the air intake port 401) of the gas furnace unit 304 and the gas-furnace heat exchanger 18 (which is an example of a first heat exchanger) provided on an outlet side of air taken in by the air blower 19. The air utilization unit 303a includes the utilization-side heat exchanger 9a provided on an outlet side of air after the air taken in by the air blower 19 has passed through the gas-furnace heat exchanger 18 and the temperature sensors 207a and 208a (which are examples of a temperature sensor) provided for the utilization-side heat exchanger 9a. The air blower 19 is commonly used by both the gas-furnace heat exchanger 18 and the utilization-side heat exchanger 9a. An air flow AF1 of the air taken in by the air blower 19 flows in the order of the gas-furnace heat exchanger 18 and the utilization-side heat exchanger 9a.
Further, the air conditioning device 300 has the GF heating operation mode (a first operation mode) in which a heating operation is performed using the gas furnace unit 304, the HP heating operation mode (a second operation mode) in which a heating operation is performed using the heat-pump heat source unit 301, and the HP cooling operation mode (a third operation mode) in which a cooling operation is performed using the heat-pump heat source unit 301 as operation modes. Further, the air conditioning device 300 performs refrigerant discharge control for temporarily moving a refrigerant on the heat-pump heat source unit 301 side to the utilization-side heat exchanger 9a side of the air utilization unit 303a when the temperature measured by the temperature sensors 207a and 208a at the time of starting of the compressor 1 provided in the heat-pump heat source unit 301 is equal to or higher than X° C. (the predetermined threshold value) when the HP heating operation mode is performed.
Accordingly, since the air conditioning device 300 recognizes that the GF heating operation has been performed on the basis of the temperature of the utilization-side heat exchanger 9a and moves the refrigerant to the utilization-side heat exchanger 9a side of the air utilization unit 303a at the time of starting of the compressor 1 of the heat-pump heat source unit 301 even when the refrigerant vaporized because the temperature of the utilization-side heat exchanger 9a rises during the GF heating operation moves to the heat-pump heat source unit 301 side, it is possible to prevent a liquid backflow at the time of starting of the compressor 1 of the heat-pump heat source unit 301 after the GF heating operation has been performed. Further, it is possible to curb a shortage of a lubricant at the time of starting of the compressor 1.
For example, when the heat-pump heat source unit 301 side cannot ascertain the operating state of the gas furnace unit 304, the air conditioning device 300 performs the refrigerant discharge control when the temperature measured by the temperature sensors 207a and 208a at the time of starting of the compressor 1 is equal to or higher than X° C. when the HP heating operation mode is performed.
Accordingly, even when the heat-pump heat source unit 301 side cannot ascertain the operating state of the gas furnace unit 304, the air conditioning device 300 can prevent a liquid backflow at the time of starting of the compressor 1 of the heat-pump heat source unit 301 after the GF heating operation has been performed. Further, it is possible to curb the shortage of a lubricant at the time of starting of the compressor 1.
Further, the air conditioning device 300 does not perform the refrigerant discharge control when the temperature measured by the temperature sensors 207a and 208 is lower than X° C. when the HP heating operation mode is performed.
Accordingly, the air conditioning device 300 can immediately operate in the HP heating operation mode when the GF heating operation mode has not been performed before the HP heating operation mode is performed.
While the embodiments have been described above in detail with reference to the drawings, any specific configuration is not limited to the embodiments. Each embodiment can be combined or each embodiment can be appropriately modified or omitted.
Here, in the aforementioned embodiments, the example in which the air conditioning device 300 switches between the GF heating operation mode and the HP heating operation mode according to the outside air temperature has been described, but the present disclosure is not limited to the outside temperature. For example, the air conditioning device 300 may switch between the GF heating operation mode and the HP heating operation mode according to a user's operation.
Further, the temperatures in the aforementioned embodiments are expressed in the Celsius scales, but may be expressed in the Fahrenheit scales.
Further, in the aforementioned embodiments, the example in which the electric unit 310, the electric unit 330a, the electric unit 330b, and the electric unit 340 are connected to each other via the control box 350 has been described, but some of the electric unit 310, the electric unit 330a, the electric unit 330b, and the electric unit 340 may be directly connected in addition to the connection or instead of a part of the connection.
Further, at least some functions of the electric unit 310, the electric unit 330a, the electric unit 330b, and the control box 350 may be provided in one of the electric unit 310, the electric unit 330a, the electric unit 330b, and the control box 350.
Further, the processes of the control box 350, the electric units 310, 330a, and 330b, and the like may be performed by recording a program for realizing the functions of the control box 350, the electric units 310, 330a, and 330b, and the like on a computer-readable recording medium and causing a computer system to read and execute the program recorded on the recording medium. Here, the “computer system” mentioned herein includes an OS and hardware such as peripherals.
Further, the “computer-readable recording medium” means a portable medium such as a flexible disk, a magneto-optical disc, a ROM, or a CD-ROM, or a storage device such as a hard disk incorporated into the computer system. Further, the “computer-readable recording medium” includes: a medium that dynamically holds a program for a short time such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line; and a medium that holds a program for a predetermined time such as a volatile memory in a computer system serving as a server or a client in that case. Further, the program may be for realizing some of the aforementioned functions, or may be for realizing the aforementioned functions in combination with a program stored in advance in the computer system. Further, the program may be stored in a predetermined server, and the program may be delivered (downloaded or the like) via a communication line in response to a request from another device.
Further, some or all functions of the control box 350, the electric units 310, 330a, and 330b, and the like may be realized as an integrated circuit such as a large scale integration (LSI) circuit. The functions may be implemented as individual processors, or some or all thereof may be integrated and implemented as a processor, Further, the integration method is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. Further, when a technique for integrated circuit in place of LSI appears with advancement in semiconductor technology, an integrated circuit based on the technique may be used.
This application is a U.S. National Stage Application of International Application No. PCT/JP2022/017222 filed Apr. 7, 2022, the contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/017222 | 4/7/2022 | WO |
