JPH04236075A - Air-conditioning machine - Google Patents

Abstract

PURPOSE:To effect heating operation and defrosting operation simultaneously with a big capacity by a method wherein the discharging side of a compressor is branched and one side is connected to an indoor heat exchanger through a four-way switching valve while the other side is connected to an outdoor side heat exchanger to utilize the accumulated heat of a heat accumulating tank. CONSTITUTION:Upon heating operation, an opening and closing valve 18 is closed and high- temperature refrigerant from a compressor 13 heats heat accumulating material by a heat exchanger 14 and, thereafter, all of the refrigerant flows into the compressor 13 through a four-way valve 15, an indoor side heat exchanger 16, an expansion valve 20, an outdoor side heat exchanger 19 and the four-way valve 15. Upon defrosting operation, the four-way valve 15 maintains the heating operation, the expansion valve 20 is fully opened, the opening and closing valve 18 is opened and the refrigerant absorbs heat from the heat accumulating material in the heat exchanger 14 while the refrigerant is branched into a first flow, passing through a pressure reducing device 17, and a second flow, passing through the four-way valve 15. The second flow passes through the four-way valve 15, the indoor side heat exchanger 16 and the pressure reducing device 21 and absorbs heat from the heat accumulating material in the heat exchanger 22, then, passes through a non-return valve 23 so as to be joined with the first flow and, thereafter, flows into the outdoor side heat exchanger 19 through the opening and closing valve 18. According to the inflow of the refrigerant, the outdoor side heat exchanger 19 is defrosted.

Description

[Detailed description of the invention]

0001

[Technical Field] The present invention relates to a heat pump type air conditioner that uses air as a heat source. In particular, the present invention relates to a heat pump type air conditioner that uses air as a heat source. In particular, the present invention relates to a heat pump type air conditioner that uses heat stored in a heat storage material to remove frost that adheres to an outdoor heat exchanger at low outside temperatures. This relates to an air conditioner that melts continuously.

0002

[Prior art] In an air heat source heat pump type air conditioner,
If the heating operation is performed when the outside temperature is low, frost will adhere to the surface of the outdoor heat exchanger, reducing the heating capacity. Therefore, it is necessary to remove frost (defrost) as appropriate. This defrosting has changed from the reverse cycle defrosting method, which is performed by switching a four-way valve, to the continuation heating method, which defrosts while maintaining heating operation without switching the four-way valve, to improve comfort during defrosting operation. Defrosting methods are becoming mainstream. Furthermore, there is a method of shortening defrosting time and increasing heating capacity during defrosting by using a heat storage mechanism.

[0003] The above-mentioned conventional heat pump type air conditioner will be explained below with reference to the drawings.

FIG. 3 is a refrigerant circuit diagram of a conventional heat pump type air conditioner.

In the figure, 1 is a compressor, 2 is a heat storage device,
3 is a heat exchanger for heat storage, 4 is a heat exchanger for heat radiation, 5 is a four-way valve, 6 is an indoor heat exchanger, 7 is an expansion valve, 8 is a first bypass solenoid valve, 9 is an outdoor heat exchanger, 10 1 is a second bypass solenoid valve, 11 is a capillary tube for pressure reduction, and 12 is a heat storage tank containing a heat storage material, and the heat storage heat exchanger 3 and the heat radiation heat exchanger 4 are housed in this heat storage tank 12 ing. To explain the operation, during heating operation, the first bypass solenoid valve 8 is closed and the second bypass solenoid valve 10 is open. Therefore, when the high temperature refrigerant discharged from the compressor 1 passes through the heat storage heat exchanger 3, the heat storage material 12 is heated and heat storage is performed. The refrigerant that has passed through the heat storage tank 12 flows in the following order: the four-way valve 5, the indoor heat exchanger 6, the expansion valve 7, the outdoor heat exchanger 9, the four-way valve 5, the second bypass solenoid valve 10, and the suction side of the compressor 1. Heat the room.

During defrosting operation, the first bypass solenoid valve 8
opens, the second bypass solenoid valve closes, and the four-way switching valve 5 maintains the state of the heating circuit. Therefore, compressor 1
The refrigerant discharged from the heat storage heat exchanger 3, the four-way valve 5,
It passes through the indoor heat exchanger 6, the first bypass solenoid valve 8, the outdoor heat exchanger 9, and the four-way valve 5, and since the second bypass solenoid valve 10 is closed, the decompression capillary tube 11 and the heat radiation heat exchange It flows in the order of container 4 and compressor 1. At this time, the refrigerant is condensed in the indoor heat exchanger 6 and the outdoor heat exchanger 9, so that the outdoor heat exchanger is defrosted while heating the room. The heat exchanger 4 for heat radiation absorbs heat from the heat storage material 12 and evaporates it, thereby recovering the heat stored in the heat storage material 12.

[0007]

[Problems to be Solved by the Invention] The air conditioner configured as described above has the following problems.

That is, during heating operation, the outdoor heat exchanger 9
When frost forms on the outdoor heat exchanger 9, since frost of 0°C or less is attached to the outdoor heat exchanger 9, the pressure when the refrigerant condenses in the outdoor heat exchanger 9 (condensation pressure) is equal to the temperature of the frost. The saturation pressure corresponds to .

Therefore, if the refrigerant pressure loss at the first bypass solenoid valve 8 is sufficiently small, the indoor heat exchanger 6
The internal refrigerant also has the same pressure. For this reason, only a very small heating capacity can be obtained during defrosting.

Furthermore, in order to increase the heating capacity, if the pressure loss at the first bypass solenoid valve 8 is increased and the pressure inside the indoor heat exchanger 6 is increased, the refrigerant is transferred to the indoor heat exchanger 6.
All of the refrigerant is condensed in the outdoor heat exchanger heat exchanger 9, and a gas-liquid two-phase refrigerant with a high liquid ratio flows into the outdoor heat exchanger heat exchanger 9. Therefore, the defrosting ability, which depends on the condensation of the refrigerant, becomes extremely small, and it is inevitable that the defrosting time will be prolonged.

[0011] As described above, with the conventional configuration, it is difficult to perform an operation that harmonizes the heating capacity and the defrosting capacity during defrosting.

0012

[Means for Solving the Problems] In order to solve the above problems, in the heat pump type air conditioner according to the present invention, a first heat exchanger is connected to the discharge side of the compressor. The discharge side of the is branched, one side is connected to the indoor heat exchanger via the four-way switching valve, and the other side is connected to a first pressure reducing device set to a predetermined pressure reduction value and an on-off valve for opening and closing the passage. The indoor heat exchanger is connected to the outdoor heat exchanger through
A discharge side is connected to the outdoor heat exchanger via the expansion valve, and the outdoor heat exchanger has a discharge side connected to the suction side of the compressor via the four-way switching valve, and the outdoor heat exchanger has a discharge side connected to the suction side of the compressor via the four-way switching valve. has a discharge side connected between the discharge side of the on-off valve and the outdoor heat exchanger, and a passage between the indoor heat exchanger and the expansion valve, the first pressure reducing device and the above. A second pressure reducing device set to a predetermined pressure reducing value and a second heat exchanger are provided between the passageway between the on-off valve and the second heat exchanger, and a reverse passageway that allows refrigerant to flow from the second heat exchanger side. A circuit is provided in which a stop valve is connected in series, the first heat exchanger and the second heat exchanger are housed in a heat storage tank containing a heat storage material, and the on-off valve is closed during heating operation to perform defrosting operation. In addition to providing an opening/closing valve control means that opens the expansion valve at certain times, the expansion valve control means controls the opening degree of the expansion valve appropriately during heating operation and fully closes the expansion valve during defrosting operation.

[0013]

[Operation] Since the present invention is constructed as described above, during heating operation, the opening/closing valve is closed and the expansion valve is controlled to an appropriate opening degree.

If heating operation is performed in this state, the high-temperature, high-pressure refrigerant discharged from the compressor passes through the first heat exchanger and stores heat in the heat storage material of the heat storage tank. It flows into the indoor heat exchanger via the valve. This provides heating. The refrigerant that has passed through the indoor heat exchanger is condensed, and the pressure is appropriately reduced by passing through the expansion valve. The depressurized refrigerant evaporates by passing through the outdoor heat exchanger, and flows into the suction side of the compressor via the four-way switching valve.

[0015] When the heating operation is performed in this way and it is detected that frost has formed on the outdoor heat exchanger, the defrosting operation is performed.

During this defrosting operation, the on-off valve is opened. Therefore, if defrosting operation is performed in this state, the high temperature and high pressure refrigerant discharged from the compressor passes through the first heat exchanger, and then
One branch flows into the indoor heat exchanger via a four-way switching valve. The other pressure is reduced by the first pressure reducing device and flows into the outdoor heat exchanger through the on-off valve. As a result, while heating is performed in the indoor heat exchanger, defrosting is performed by the refrigerant discharged from the compressor flowing into the outdoor heat exchanger.

Since the expansion valve is fully closed, the refrigerant that has passed through one of the branched indoor heat exchangers passes through the second heat exchanger via the second pressure reducing device, and is then transferred to the first heat exchanger. It joins the refrigerant passing through the pressure reducing device. When this refrigerant passes through the second heat exchanger, it absorbs the heat of the heat storage material, becomes high in temperature, and merges with the refrigerant. By flowing the combined high-temperature refrigerant into the outdoor heat exchanger as described above, defrosting is efficiently performed. The ratio of the refrigerant for heating and the refrigerant for defrosting is appropriately determined by the pressure reduction ratio of the first pressure reduction device and the second pressure reduction device.

As described above, by utilizing the heat stored in the heat storage material during heating operation, the refrigerant discharged from the compressor is divided into the indoor heat exchanger and the outdoor heat exchanger and allowed to flow into each of them. , defrost while maintaining heating operation.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the heat pump air conditioner according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a refrigerant circuit representing an embodiment of a heat pump type air conditioner according to the present invention. In the same figure,
13 is a compressor, 14 is a first heat exchanger, and the first heat exchanger 14 is connected to the discharge side of the compressor 13. The discharge side of this first heat exchanger 14 is branched into two directions. One branched end is connected to an indoor heat exchanger 16 via a four-way switching valve 15 . The other branch is a first pressure reducing device 1 set to a predetermined pressure reducing value.
7 and an on-off valve 18 that opens and closes the passage, it is connected to an outdoor heat exchanger 19.

The indoor heat exchanger 16 has its discharge side connected to the outdoor heat exchanger 19 via an expansion valve 20. The outdoor heat exchanger 19 has a discharge side connected to the suction side of the compressor 13 via the four-way switching valve 15 . The expansion valve 20 has a discharge side connected between the discharge side of the on-off valve 18 and the outdoor heat exchanger 19.

The indoor heat exchanger 16 and the expansion valve 20
and a passage between the first pressure reducing device 17 and the on-off valve 18, a second pressure reducing device 21 set to a predetermined pressure reducing value and a second heat exchanger are provided. A check valve 23 that allows refrigerant to flow from the heat exchanger 22 and the second heat exchanger 22 side.
A circuit 24 is provided in which these are connected in series.

The first heat exchanger 14 and the second heat exchanger 22 are housed in a heat storage tank 25 containing a heat storage material. As the heat storage material accommodated in this heat storage tank, polyethylene glycol, paraffin, sodium acetate trihydrate, etc. can be used. The first heat exchanger 14 and the second heat exchanger 22 are installed in a heat storage tank 25 so that they can exchange heat, respectively.

Although not shown, the on-off valve 18 is provided with on-off valve control means that closes the on-off valve 18 during heating operation and opens it during defrosting operation. Further, the expansion valve 20 is provided with an expansion valve control means that appropriately controls the opening degree of the expansion valve 20 during the heating operation and fully closes the expansion valve 20 during the defrosting operation.

[0025] The operation of the air conditioner having the above configuration will be explained.

First, during heating operation, the on-off valve 18 is closed. Therefore, after the high-temperature refrigerant discharged from the compressor 13 heats the heat storage material in the first heat exchanger 14, it all passes through the indoor heat exchanger 24 via the four-way valve 15, and performs heating by heat radiation. . The refrigerant that has passed through the indoor heat exchanger 24 passes through the expansion valve 20 and flows into the outdoor heat exchanger 19, where it evaporates and absorbs heat from the outside air. The evaporated refrigerant is transferred to the compressor 13 via the four-way switching valve 15.
flows into the suction side of the The refrigerant that has absorbed heat from the outside air is compressed again by the compressor 13, and a part of the heat absorbed is stored in the heat storage material.

[0027] During this heating operation, the on-off valve 1
Since the circuit 8 is closed, no refrigerant flows into the circuit 24.

In this way, when it is detected that frost has formed on the outdoor heat exchanger 19 during heating operation, or when it becomes time to perform defrosting, the system switches to defrosting operation. It will be done.

During the defrosting operation, the four-way switching valve 15 maintains the heating operation state, and the expansion valve 20 is fully closed and the on-off valve 18 is opened.

Therefore, the refrigerant discharged from the compressor 13 passes through the first heat exchanger 14 and becomes high temperature by absorbing heat from the heat storage material stored during heating operation, and then passes through the first pressure reducing device 17. The first flow passes through the four-way switching valve 15, and the second flow passes through the four-way switching valve 15.

The second flow passes through the four-way switching valve 15, radiates heat and condenses in the indoor heat exchanger 16, and then passes through the second pressure reducing device 2.
1, the second heat exchanger 22 absorbs heat from the heat storage material 32, and the temperature becomes high. This high-temperature refrigerant passes through the check valve 29, joins with the first flow that has passed through the first pressure reducing device 17, passes through the on-off valve 18, and flows into the outdoor heat exchanger 19. As this high-temperature refrigerant flows into the outdoor heat exchanger 19, the frost formed on the outdoor heat exchanger 19 is melted, and defrosting is performed.

The refrigerant that has passed through the outdoor heat exchanger 19 returns to the compressor 21 through the four-way switching valve 15. In this way, by branching the refrigerant discharged from the compressor 13 into heating and defrosting, defrosting is performed while continuing the heating operation.

Note that the ratio of the heating refrigerant to the defrosting refrigerant is the same as that of the first pressure reducing device 17 and the second pressure reducing device 2.
1, and this ratio is appropriately designed and selected depending on the air conditioner.

[0034] Also, the check valve 23 closes the compressor 1 during heating operation.
This is provided to prevent the refrigerant discharged from 3 from flowing into the second heat exchanger 22 through the first pressure reducing device 17.

FIG. 2 is a Mollier diagram showing the state of the refrigerant during the defrosting operation of this embodiment, and the symbols A to H in the figure are
correspond to the positions with the same symbols shown in FIG. The refrigerant (A) discharged from the compressor 13 is transferred to the first heat exchanger 1
4 and becomes the state B, and the first pressure reducing device 17
, a first flow for defrosting that flows into the outdoor heat exchanger 19 via the on-off valve 18, and a second flow for heating that flows into the indoor heat exchanger 16 via the four-way switching valve 15. Branch out.

The first flow Q for defrosting passes through the first pressure reducing device 17 and reaches the state C.

The second flow q for heating passes through the indoor heat exchanger 16, condenses and radiates heat, reaches state D, passes through the second pressure reducing device 21, becomes state E, and enters the second heat exchanger. Vessel 22
is heated and passes through the check valve 23 to reach the F state. The refrigerant in state F that has passed through the check valve 23 is mixed with the first flow Q in state C, further increasing its enthalpy, and becomes in state G. The refrigerant in this state G flows into the outdoor heat exchanger 19 through the on-off valve 18, where a portion of the refrigerant condenses and radiates heat to melt the frost and return to the state H, to the compressor 13.

The ratio of the first flow Q and the second flow q at this time is determined by the ratio of the flow path resistances of the first pressure reducing device 17 and the second pressure reducing device 21. Therefore, the total flow rate (
Q+q) is determined by the value of the flow path resistance of both, so when increasing the defrosting capacity, the flow path resistance of the first pressure reducing device 17 should be made smaller, and when increasing the heating capacity, the second pressure reducing device 17 should be made smaller. The flow path resistance of the pressure reducing device 21 may be set to be smaller. In order to adjust the overall refrigerant flow rate, in addition to setting the flow path resistance of the first and second pressure reducing devices 17 and 21, the flow path resistance of the on-off valve 18 can also be set to a required value.

With the circuit configuration as described above, the low pressure side is 4 kg/cm2G or more, and the refrigerant sucked by the compressor 13 is wet, so its density is high, and therefore the amount of refrigerant circulation is also large. Therefore, the pressure on the high pressure side is 13 to 15
Kg/cm2G, the temperature of the refrigerant flowing into the indoor heat exchanger 16 is high (35 to 38°C), and the amount of refrigerant circulation is large, so a large heating capacity can be obtained. In addition, heat absorption from the heat storage material in the first heat exchanger 14 and the second heat exchanger 22 also
Since the amount of refrigerant circulated is large, the amount of heat absorbed per unit time is large, and a large amount of heat can be absorbed in a short period of time. Outdoor heat exchanger 1
Since some of the refrigerant flowing into the refrigerant 9 flows from the first heat exchanger 14, the enthalpy is higher than that of the conventional one, and the amount of circulation is large, so that a large defrosting ability can be obtained.

As described above, according to this embodiment, it is possible to defrost in a short time while maintaining heating operation with high capacity.
It is possible to achieve harmony between heating capacity and defrosting capacity.

[0041] In the above embodiment, the first heat exchanger 14
Although the configuration has been described in which the refrigerant discharged from the compressor 13 always flows, the configuration is not limited to this. For example, a second on-off valve may be provided in parallel with the first heat exchanger 14, and the second on-off valve may The heat storage by the discharged refrigerant may be controlled by appropriately switching the valve. Furthermore, in the above embodiment, when defrosting, the expansion valve 20
is fully closed, but a combination of a capillary tube and a solenoid valve may be used instead.

[0042]

As is clear from the above description, according to the air conditioner of the present invention, heating operation and defrosting operation can be performed simultaneously while harmonizing each other. In this case, the heat stored in the heat storage material during heating operation is used to heat the refrigerant discharged from the compressor while allowing the refrigerant to flow into the outdoor heat exchanger and the indoor heat exchanger, respectively. Not only can heating operation be performed with a large capacity, but also defrosting can be performed in a short time.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram according to an embodiment of the present invention;

[Fig. 2] Mollier diagram showing the refrigerant state during defrosting in this embodiment,

FIG. 3 is a conventional refrigerant circuit diagram.

[Explanation of symbols]

13 Compressor, 14 First heat exchanger, 15 Four-way switching valve, 16 Indoor heat exchanger, 20 Expansion valve, 19 Outdoor heat exchanger 17 First pressure reducing device, 22 Second heat exchanger 23 Check valve, 18 On-off valve, 21 Second pressure reducing device, 25 Heat storage tank,

Claims (1)

[Claims] Claim 1: A heat pump cycle equipped with a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expansion valve, and a four-way switching valve, wherein a first heat exchanger is provided on the discharge side of the compressor. and the discharge side of this first heat exchanger is branched, one side is connected to the indoor heat exchanger via the four-way switching valve, and the other side is connected to the first heat exchanger set to a predetermined pressure reduction value. The indoor heat exchanger is connected to the outdoor heat exchanger via the pressure reducing device and the on-off valve that opens and closes the passage, and the indoor heat exchanger has its discharge side connected to the outdoor heat exchanger via the expansion valve. The outdoor heat exchanger has a discharge side connected to the suction side of the compressor via the four-way switching valve, and the expansion valve has a discharge side connected to the outlet side of the on-off valve and the outdoor heat exchanger. connected between the passageway between the indoor heat exchanger and the expansion valve, and the passageway between the first pressure reduction device and the opening/closing valve, the pressure reduction value being set to a predetermined pressure reduction value. A circuit is provided in which a second pressure reducing device, a second heat exchanger, and a check valve that allows refrigerant to flow from the second heat exchanger side are connected in series, and the first heat exchanger and the second heat exchanger are connected in series. The second heat exchanger is housed in a heat storage tank containing a heat storage material, and an on-off valve control means is provided to close the on-off valve during heating operation and open it during defrosting operation, and to open the expansion valve as appropriate during heating operation. An air conditioner characterized in that it is provided with an expansion valve control means that is fully closed during defrosting operation.