JPS5981465A - Heat pump type refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump type refrigeration cycle.

In a conventional heat pump type refrigeration cycle, as shown in Fig. 1, a compressor 1. Four-way switching valve 3. Outdoor heat exchanger4. The expansion device 5 and the indoor heat exchanger 6 are sequentially connected in an annular manner, and during cooling operation, high-temperature, high-pressure refrigerant gas is sent from the compressor 1 to the outdoor heat exchanger 4 as shown by the solid arrow, and is condensed there. The refrigerant gas is evaporated in an indoor heat exchanger 6 via a post-expansion device 5, and during heating operation, high-temperature, high-pressure refrigerant gas from the compressor 1 is reversely circulated as shown by the broken line arrow to perform heating.

Generally, in this type of refrigeration cycle, when defrosting is performed during heating operation, the four-way switching valve 3 is switched to flow high-temperature, high-pressure refrigerant gas to the outdoor heat exchanger 4, and the heat exchanger B
4 is designed to melt and remove the frost by exchanging heat with the frost that has adhered to the compressor 1. However, when the four-way switching valve 3 is switched, the high-pressure liquid refrigerant that was in the indoor heat exchanger 6 is transferred to the compressor 1. backflow,
The refrigerant accumulates in two widths of the accumulator used to prevent liquid compression, and the amount of refrigerant circulating in the refrigeration cycle is insufficient, making it impossible to defrost sufficiently. However, the heating operation cannot be performed during this time, which causes a drop in the room temperature and impairs comfort.

The present invention has been made with the aim of eliminating the above-mentioned drawbacks, and is a heat pump type refrigerator that prevents fluid from returning to the compressor during defrosting, performs effective defrosting, and shortens defrosting time. It provides a cycle.

Hereinafter, one embodiment of the present invention will be explained based on the drawings. Fig. 2 is a refrigerant circuit diagram of a heat pump type refrigeration cycle according to the present invention, and Fig. 3 is a heat pump type refrigeration cycle showing another embodiment of the present invention. The refrigerant circuit diagram is shown.

Note that solid arrows indicate the flow of refrigerant during cooling operation, broken arrows indicate the flow of refrigerant during heating operation, and thin arrows indicate the flow of refrigerant during refrigeration cycle switching.

In Fig. 2, 11 is a compressor, 12 is an accumulator, 13 is a switching valve for switching between cooling operation and heating operation, and 14 is an outdoor heat source that acts as a condenser during cooling operation and as an evaporator during heating operation. Exchanger, 15 is an expansion device consisting of an expansion valve or capillary tube, etc., 16 is an indoor heat exchanger that acts as an evaporator during cooling operation and a condenser during heating operation, and 17 is a four-way switch with the suction side of compressor 11. A solenoid valve 18 is provided in a flow path connecting the valve 13 and the flow path between the solenoid valve 17 and the four-way switching valve 13 and the outdoor heat exchanger 14.
A first bypass flow path 19 connects the flow path between the solenoid valve 17 and the four-way switching valve 13, and a first bypass flow path 19 connects the flow path between the solenoid valve 17 and the four-way switching valve 13, and the indoor heat exchanger 16 and the four-way switching valve 13. 20 is a first check valve provided in the first bypass flow path; 21 is a second check valve provided in the second bypass flow path; It is a valve.

Next, the operation of the refrigeration cycle of the present invention will be explained. During normal operation, this refrigeration cycle opens 17 solenoid valves.
Furthermore, the first and second check valves 20 and 21 are not closed, resulting in an operating state similar to that of the conventional refrigeration cycle shown in FIG.

During heating operation, the refrigeration cycle is switched from heating operation to cooling operation in order to start defrosting in response to a signal from a timer de-izer or an interest detection device (not shown). In this case, first, the solenoid valve 17 After closing +-1, the four-way switching valve 13 is switched. The high-temperature, high-pressure refrigerant that had accumulated in the indoor heat exchanger 16 is now removed from the four-way switching valve 1.
3. It flows into the low temperature, low pressure outdoor heat exchanger 14 through the first bypass passage 18 and the first check valve 20. At this time, since the solenoid valve 17 is closed, liquid refrigerant can be prevented from being sucked into the suction side of the compressor 11.

The high-temperature, high-pressure refrigerant flowing into the indoor heat exchanger 14 causes the sheath attached to the outdoor heat exchanger 14 to begin to melt. Next, the indoor heat exchanger 16 and the outdoor heat exchanger 1
When the pressure of 4 is balanced and refrigerant no longer flows from the indoor heat exchanger 16 to the outdoor heat exchanger 14, the solenoid valve 1
7 will be opened.

At time B, the pressure in the outdoor heat exchanger 14 becomes higher than the pressure in the flow path between the four-way switching valve 13 and the solenoid valve 17 due to the gas discharged from the compressor 11, and the first check valve 20 closes. This results in the same operating state as in the conventional cycle shown in FIG.

In this way, the sheath attached to the outdoor heat exchanger 14 is melted and removed by the high temperature and high pressure discharged gas from the compressor 11.

When defrosting is completed and the heating operation is to be switched again, the solenoid valve 17 is first closed, and then the four-way switching valve 13 is switched. The high-pressure refrigerant remaining in the outdoor heat exchanger 14 is now transferred to the low-pressure indoor heat exchanger 16 through the four-way switching valve 13, the second bypass passage 19, and the second check valve 21. flow inside. Since the solenoid valve 17 is closed at this time,
The liquid refrigerant can be prevented from being sucked into the suction side of the compressor 11.Next, the outdoor heat exchanger 14 and the indoor heat exchanger 16 are pressure balanced, and the outdoor heat exchanger 14 performs indoor heat exchange. Vessel 1
When the refrigerant stops flowing to 6, the solenoid valve 17 is opened.

At this time, due to the discharge gas from the compressor 11, the pressure in the indoor heat exchanger 16 is higher than the pressure in the flow path between the four-way switching valve 13 and the solenoid valve 17, and the second check valve 21 becomes closed and resumes heating operation.

FIG. 3 shows another embodiment of the present invention, in which the first bypass passage 18 is connected to the passage between the solenoid valve 17 and the four-way switching valve 13, the outdoor heat exchanger 14, and the expansion device 15. In addition, the second bypass flow path 19 is provided to connect the flow path between the solenoid valve 17 and the four-way switching valve 13, and the flow path between the indoor heat exchanger 16 and the expansion device 15. It is provided so as to connect the flow paths between the two, and performs the same control and operation as the embodiment shown in FIG. 2 above.

In addition, in implementing the present invention, the first bypass flow path 1
8 may be a bypass flow path connecting the flow path between the electromagnetic valve 17 and the four-way switching valve 13 and the flow path between the four-way switching valve 13 including the outdoor heat exchanger 14 and the expansion device 15, Also second
The bypass flow path 19 is a bypass flow path that connects the flow path between the solenoid valve 17 and the four-way switching valve 130 and the flow path between the four-way switching valve 13 including the indoor heat exchanger 16 and the expansion device 15. Bye.

As described above, according to the present invention, when switching the refrigeration cycle for defrosting during room operation, the suction side of the compressor -\,
Liquid refrigerant flows into the indoor heat exchanger or the outdoor heat exchanger and prevents it from accumulating in the accumulator, allowing efficient defrosting in a short time and reducing the drop in room temperature during defrosting. can.

Even after returning from defrosting operation to heating operation, operation can be performed immediately with a refrigerant distribution close to a steady state, so the room temperature can be recovered quickly and heating can be performed with excellent comfort.

Moreover, since the outdoor heat exchanger can always be used in an efficient state with little frost, efficient heating operation is possible.

Furthermore, since liquid can be prevented from returning to the compressor, the reliability of the compressor is also improved.

[Brief explanation of the drawing]

Figure 1 is a refrigerant circuit diagram of a conventional heat pump type refrigeration cycle, Figure 2 is a refrigerant circuit diagram of a heat pump type refrigeration cycle according to the present invention, and Figure 3 is a refrigerant circuit diagram of a heat pump type refrigeration cycle showing another embodiment of the present invention. This is a schematic diagram of a refrigerant. 11 is a compressor, 12 is an accumulator, 13 is a four-way switching valve, 14 is an outdoor heat exchanger, 15 is an expansion device, 16 is an indoor heat exchanger, 17 is a solenoid valve, 18 is a first bypass channel , 19 is a second bypass flow path, 20d is a first check valve, and 21 is a second check valve.

Claims (1)

[Claims] A compressor, a four-way switching valve, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger are sequentially connected in an annular manner, and a solenoid valve is provided in a flow path connecting the suction side of the compressor and the four-way switching valve, A first bypass flow path connecting any point in the flow path between the four-way switching valve and the expansion device, including the outdoor heat exchanger, from the flow path between the solenoid valve and the two-way switching valve, and the outdoor heat exchanger. A second bypass flow path connecting any point in the flow path between the four-way switching valve containing the expansion device and the expansion device is provided, and first and second check valves are provided in the first and second bypass flow paths, respectively. A beat pump type refrigeration cycle characterized in that a solenoid valve is closed for a predetermined period of time when a four-way switching valve is switched.