JPS63150567A - Refrigeration cycle device for heat pump type air conditioner - 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 Field of Industrial Application The present invention relates to a heat pump type air conditioner that utilizes heat storage.

Conventional technology Conventionally, the majority of defrosting methods for outdoor heat exchangers in air source heat pump air conditioners switch a four-way valve to create a cooling cycle, with the outdoor heat exchanger serving as a condenser and the indoor heat exchanger serving as an evaporator. It uses a reverse cycle defrosting method, and the indoor fan was turned off at this time to prevent cold drafts. With this method, the amount of refrigerant that circulates during the refrigeration cycle is basically small and it is not possible to expect much increase in compressor input, so the defrosting time becomes longer, and the indoor fan stops for several minutes during defrosting, so heating is not possible. Users complain that the temperature of the indoor heat exchanger takes a long time to rise even after the four-way valve is switched and heating operation is resumed after defrosting operation is completed. In recent years, in place of the reverse cycle defrosting system, which has these drawbacks, a bypass circuit has been installed, which allows the four-way valve to remain in the heating cycle even during defrosting operation, reducing indoor heat. A heating continuous defrosting method has been proposed in which both the exchanger and the outdoor heat exchanger function as condensers to defrost while maintaining a certain heating capacity (for example, Japanese Utility Model Application No. 60-59042).

The conventional heat pump air conditioner will be described below with reference to the drawings.

FIG. 3 shows a refrigeration cycle diagram in a first example of a conventional pump type air conditioner.

In the figure, 1 is a capacity-controllable frequency variable compressor (
2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a capillary, 5 is an outdoor heat exchanger, 6 is a hot gas bypass circuit, 7 is a two-way valve, and 8 is a bypass capillary. . In addition, 9 is an outdoor heat exchanger temperature sensor, and 1o receives a signal from this sensor 9 to control the compressor 1, two-way valve 7, indoor/outdoor fan (not shown), etc. to control the temperature of the outdoor heat exchanger 5. It is a defrost control controller. The hot gas bypass circuit 6 connects the discharge pipe of the compressor 1 and the pipe that becomes the inlet side during heating operation of the outdoor heat exchanger 5, and includes a two-way valve 7 and a bypass capillary 8 in the middle. .

During normal heating operation, the two-way valve 7 is closed to form a heating cycle, but when frost is detected on the outdoor heat exchanger 5 by a signal from the outdoor heat exchanger temperature sensor 9 at low outside temperatures, the A command is issued from the frost control controller 10 to increase the frequency of the compressor 10, and the main body temperature of the compressor 1 is increased to "C".
Store heat. After a predetermined period of time has elapsed, a command is issued from the defrosting controller 10 to set the C1 compressor 1 to the maximum frequency, open the two-way valve 7, and direct most of the high temperature discharged gas through the hot gas bypass circuit 6 to the outdoor heat. It is guided to the inlet side of the exchanger 5. At the same time, the remainder of the high-temperature discharged gas is passed through the four-way valve 2, indoor heat exchanger 3, and capillary 4 in the same way as during heating operation to continue heating operation slightly, and hot gas bypass is performed at the inlet of outdoor heat exchanger 5. It is made to merge with the refrigerant that has passed through the circuit 6.

After this combined refrigerant defrosts the outdoor heat exchanger 5 with its own heat of condensation, it returns to the compressor 1 via the four-way valve 2 and completes the defrosting cycle.

In this way, defrosting can be performed while the heating cycle is still in progress, making it possible to improve comfort during defrosting.

Moreover, FIG. 4 shows a refrigeration cycle diagram in a second example of a conventional heat pump type air conditioner. In this example, a bypass circuit 11 that bypasses the capillary 4 is provided in place of the hot gas bypass circuit 6. The bypass circuit 11 is equipped with a two-way valve 12 and a check valve 13. During defrosting, the two-way valve 12 is opened to allow most of the refrigerant to pass through the bypass circuit 11, thereby increasing the refrigerant pressure in the outdoor heat exchanger 5 and reducing both the indoor heat exchanger 3 and the outdoor heat exchanger 5. By acting as a condenser, it is possible to obtain the same effect as described in the first example.

Furthermore, by connecting a heat storage tank filled with heat storage material to a refrigerant circuit for heat exchange, it is possible to store heat in the heat storage tank during heating operation, and use that heat to melt frost in a short time during defrosting operation. Some methods have also been proposed (for example, Japanese Patent Publication No. 54-38737
Publication No.).

Problems to be Solved by the Invention However, the above method has the following problems. FIG. 5 shows the relationship between the amount of restriction of the bypass capillary, the defrosting time, and the heating capacity during defrosting operation in the first example of the conventional heat pump type air conditioner shown in FIG. As is clear from the figure, if the amount of restriction of the bypass capillary 8 is increased, the amount of refrigerant circulated through the indoor heat exchanger 3 during defrosting operation will increase, and the pressure will also rise, so the heating capacity will increase. Since the pressure of the refrigerant passing through the outdoor heat exchanger 5 decreases and the condensing capacity decreases, the defrosting time becomes longer. Therefore, in order to finish defrosting in a short time, it was not possible to increase the heating capacity. For example, in a 1 horsepower class heat pump air conditioner,
Most manufacturers have a control device that keeps the total current below 20A, and in this case, the amount of heat given to the refrigerant out of the compressor input is at most 1300 Kcae, as a result of experiments by the inventors. /h. Assuming that defrosting is completed in 5 minutes, the amount of heat given to the refrigerant from the compressor input during this time is 108 Kcae. Compressor weight is 10k
g, the specific heat is 0.1, and the compressor body temperature is 3 during defrosting operation.
Assuming that the temperature drops to 0°C, 30Kca (1') of heat is given to the refrigerant.The sum of these two heats is 138
KcaeO heat is imparted to the refrigerant.

On the other hand, if the frost amount is 900 g, 72 KcaeO heat is used for defrosting, and the remaining (138-72
) Kcae heat can be used for space heating. This was 792 Kcae/h per unit time, and with this level of heating capacity, it was not possible to sufficiently suppress the decrease in comfort during defrosting operation. Furthermore, the reliability of the compressor was also low because the compressor body was used as a heat storage body and the refrigerant with low dryness was sucked in to remove heat from the compressor body.

The second example shown in FIG. 4 also had a low heating capacity during defrosting operation, and had the same problem as the first example. Furthermore, in the second example, in the case of a separate type heat pump air conditioner that connects the indoor unit and outdoor unit with connecting piping, the frequency of compressor 1 may be increased to increase the amount of refrigerant circulation, or the connecting piping may be made longer. If this occurs, the pressure loss in the connecting pipe connecting the outlet of the indoor heat exchanger 3 and the inlet of the bypass circuit will increase because the completely cooled air will pass through the outdoor heat exchanger 5.
There is a problem in that the pressure of the refrigerant passing through the refrigerant decreases, and the condensing capacity decreases, resulting in a longer defrosting time or inability to defrost.

Furthermore, the method that utilizes heat storage is a reverse cycle defrosting method, in which the indoor heat exchanger acts as an evaporator and instead of absorbing heat from the room, the stored heat is taken. Therefore, although this method can shorten the defrosting time and prevent cold air from being blown into the room during the defrosting operation, there is a problem in that the indoor room cannot be heated during the defrosting operation.

In view of the above problems, the present invention stores heat in a heat storage tank filled with heat storage material during heating operation, and utilizes this heat during defrosting operation, thereby defrosting while maintaining high heating capacity and ensuring compressor reliability. This provides a highly efficient heat pump air conditioner.

Means for Solving the Problems In order to solve the above problems, the refrigeration cycle device for a pump type air conditioner of the present invention includes a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducer, an indoor heat exchanger, etc. A first bypass circuit is provided that bypasses a part of the refrigerant circuit that becomes a high-pressure side during heating operation, and a first bypass circuit that bypasses the pressure reducer and connects the first bypass circuit and the circuit. a second bypass circuit that shares the same portion, a flow path control means that allows refrigerant to flow through only one of the first bypass circuit and the second bypass circuit;
A heat storage tank is provided, which is connected to at least a part of the shared portion of the bypass circuit and the second bypass circuit for heat exchange, and is filled with a heat storage material inside.

For production The present invention has the following effects through the above means.

That is, during heating operation, the refrigerant is flowed through the first bypass circuit to exchange heat with the heat storage material in the heat storage tank to store heat, and during defrosting operation, the refrigerant is flowed through the second bypass circuit to remove heat from the heat storage material. It is possible to perform defrosting operation while maintaining high heating capacity.

Moreover, by integrating the heat exchange parts between the first bypass circuit, the second bypass circuit, and the heat storage tank, it is possible to make the heat storage tank smaller and lighter, and to perform heat exchange efficiently. Furthermore, since the dryness of the refrigerant sucked into the compressor can be kept high, the reliability of the compressor is also high. Furthermore, in the case of separate type heat pump air conditioners, there is a large pressure loss in the connecting piping, and even if the pressure of the refrigerant passing through the outdoor heat exchanger is low, defrosting is possible because the refrigerant in the superheat range can be used. .

EXAMPLE Hereinafter, the present invention will be explained with reference to FIGS. 1 and 2 of the accompanying drawings, which show one example of the invention. In describing this embodiment, parts having the same functions as those of the conventional system shown in FIGS. 3 and 4 are given the same reference numerals and their explanations will be omitted.

In the figure, 14 is a first bypass circuit that pipes the discharge pipe of the compressor 1, and 15 is a second bypass circuit that bypasses the capillary 4. These two bypass circuits share a part of the pipe line. A heat exchanger 17 is provided in this shared portion 16. Further, on-off valves 18 and 19 are provided in the first bypass circuit 14 across the shared portion 16, and on-off valves 20 and 21 are provided in the second bypass circuit 15 and provided on both sides of the shared portion 16. There is.

In addition, 22 is a heat storage tank, inside which is a latent heat storage material (N a C
H3CO2-3H20) 23 is filled, and the heat exchanger 17 is disposed so as to be able to exchange heat with this heat storage material 23.

In this refrigerant circuit [, during heating operation, on-off valve 18.19
is open, and the on-off valves 20 and 21 remain closed. Therefore, a part of the refrigerant discharged from the compressor 1 flows through the main refrigerant circuit, and the rest flows into the first bypass circuit 14, passes through the on-off valve 18, the heat exchanger 17, and the on-off valve 19, and then passes through the main refrigerant circuit. It joins with the refrigerant that has flowed through and flows to the four-way valve 2, and then the indoor heat exchanger a, the capillary 4, the outdoor heat exchanger 5,
It flows through the four-way valve 2 and is sucked into the compressor 1. therefore,
A part of the heat possessed by the refrigerant is transferred to the heat storage material 23 through the heat exchanger 17.
heat is stored.

When the outdoor heat exchanger 5 is frosted, defrosting operation is started. During defrosting operation, the frequency of the compressor 1 is set to the maximum, and the on-off valve 18 is
．． 19 is closed, and on-off valves 20 and 21 are opened. Therefore, the refrigerant discharged from the compressor 1 flows to the four-way valve 2 and the indoor heat exchanger 3, and most of the refrigerant flows to the second bypass circuit 1.
5, passes through the on-off valve 20, the heat exchanger 17, and the on-off valve 21, joins with a small amount of refrigerant that has passed through the capillary 4, flows through the outdoor heat exchanger 5, the four-way valve 2, and enters the compressor 1. Inhaled. Therefore, when the refrigerant passes through the heat exchanger 17, it removes the heat stored in the heat storage material 23 and is used for defrosting.

FIG. 2 is a diagram showing the refrigeration cycle of the heat pump air conditioner shown in FIG. 1 during defrosting operation on a Mollier diagram. Symbols a-'-g in the figure indicate the state of the refrigerant at positions a-g in FIG. First, the refrigerant compressed by the compressor 1 (a → b) is used for heating in the indoor heat exchanger 3 and condenses (c-+d), and the pressure does not decrease due to pressure loss when passing through connecting pipes etc. d-+e), flows into the second bypass circuit 15, removes heat from the heat storage material 23 in the heat exchanger 17 (e-+f), is used for defrosting in the outdoor heat exchanger 5, and is condensed (f-+g) , passes through the four-way valve 2 and is sucked into the compressor 1 (g-+1). In this way, when the condensed refrigerant (dl) is used for heating, the enthalpy is raised to (1) again by taking heat from the heat storage material 23, so the heating capacity can be increased and the defrosting can be done in a short time. It is possible to finish.

Here, to show an example of the inventors' experimental results, the heat storage material 2
When the heat storage tank 22 is filled with 2 kg of 3, the latent heat of fusion is s
o Kca e/Kg, so assuming that all of this can be used, the amount of heat given to the refrigerant is 228 Kcae, which is the compressor manual power of 108 Kca (l plus latent heat and 120 Kcae) explained in the conventional example. Since the amount of heat used is 72 Kcae, the remaining 156 Kcae
of heat can be used for heating. Since this is 1 ayoxcag/h per unit time, sufficient indoor comfort can be maintained.

In addition, the first bypass circuit 14 and the second bypass circuit 15 share a part of the pipe line, and the heat exchanger 17 is disposed in the common part 16, so that heat storage from the refrigerant to the heat storage material 23 is carried out. Both the heat exchanger 17 and the extraction of heat from the heat storage material 23 can be performed through this single heat exchanger 17, and the heat storage tank 22 can be made small and lightweight. Moreover, when the first bypass circuit 14 and the second bypass circuit 15 are made into independent circuits, and a heat exchanger is provided in each circuit, the second bypass circuit 14 during heat storage operation (heating operation)
5 is not used, and during defrosting operation, the heat storage material 23 provided in the first viva Z circuit 14 is
Whereas efficient heat exchange with the heat storage material 23 is not possible, the above-described configuration allows efficient heat exchange with the heat storage material 23.

In addition, since the refrigerant used for defrosting in the outdoor heat exchanger 5 is mostly in the state of superheated gas (f-+g), it is necessary to increase the compressor frequency to increase the amount of refrigerant circulation or to connect By lengthening the piping, the pressure loss of (d-+e) increases, and (
Even if the pressure of the refrigerant in i→g) decreases, defrosting can be performed. Moreover, since the dryness of the refrigerant (a) sucked into the compressor can be maintained high, defrosting operation with high reliability of the compressor can be performed.

Furthermore, if sufficient heat is not stored in the heat storage material 2a during heat storage operation, there is a possibility that the stored heat will be used up during defrosting operation and defrosting will not be possible. After the time has elapsed, open the on-off valve 18.21,
By controlling the on-off valves 19 and 20 to close, a portion of the high-temperature refrigerant discharged from the compressor 1 is passed through the first bypass circuit 14 and a portion of the second bypass circuit 15 to the outdoor heat exchanger 6. Even if the stored heat is used, defrosting can be performed.

In addition, in this embodiment, the on-off valve 18 is always turned on during heating operation.
．． 19 is opened to allow refrigerant to flow through the first bypass circuit 14, but in order to speed up the start-up, the on-off valves 18 and 19 are closed for a predetermined period of time after the start of operation to prevent refrigerant from flowing through the first bypass circuit 14. The control is arbitrary, and it is sufficient that the required amount of heat can be stored in the heat storage tank 22 before the defrosting operation starts. Further, although the flow path control means has been explained using an on-off valve in this embodiment, it is not limited to this, and means having functions such as a three-way valve may be used. Furthermore, a compressor with a constant capacity may be used.

Furthermore, the heat storage material used in this example was NaCH3COO.
Materials other than 3H20 may be used.

Effects of the Invention As described above, the heat pump air conditioner of the present invention can perform defrosting operation while maintaining high heating capacity by flowing the refrigerant through the second bypass circuit to remove heat from the heat storage material during defrosting operation. is possible, and the first bypass circuit and the second
By integrating the heat exchange section between the bypass circuit and the heat storage tank, it is possible to make the heat storage tank smaller and lighter and to perform heat exchange efficiently. In addition, since the dryness of the refrigerant sucked into the compressor can be kept high, the reliability of the compressor is also high. Even if the pressure of the refrigerant passing through the exchanger is low, the refrigerant in the superheated region can be used, so it has advantages such as defrosting.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of a heat pump air conditioner according to an embodiment of the present invention, FIG. 2 is a Mollier diagram showing the refrigeration cycle of the heat pump air conditioner during defrosting operation, and FIG.
The figure shows the refrigeration cycle diagram for the first example of a conventional heat pump type air conditioner, and Figure 4 shows the second example of the same heat pump type air conditioner.
FIG. 5 is a characteristic diagram showing the relationship between the bypass capillary throttle amount, defrosting time, and heating capacity of the heat pump air conditioner. 1... Frequency variable compressor (compressor), 2...
...Four-way valve, a...Indoor heat exchanger, 4...
... Capillary (pressure reducer), 5... Outdoor heat exchanger, 14... First bipanu circuit, 15...
...Second bypass circuit, 16...Shared part,
17... Heat exchanger, 18-21... On-off valve (flow path control means), 22... Heat storage tank, 23
...Heat storage material. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
1 Shuronohiracho Sou 51: Fuo (compressor) 2 - V valve 3 - Indoor P exchange world 4 - O V Pillari (l coercion world) 5 - External P exchange world / 4 - $1 bypass circuit 15- Name 2 Bypass circuit I6- Deep blue part 17- μ exchange field 23- Storage p, material Fig. 2 Eletarby □ Large Fig. 3

Claims (2)

[Claims] (1) The compressor, four-way valve, outdoor heat exchanger, pressure reducer, and indoor heat exchanger are connected to form a main refrigerant circuit, and a part of the main refrigerant circuit that becomes the high pressure side during heating operation is bypassed. 1 bypass circuit is provided to bypass the pressure reducer and
A second bypass circuit that shares a part of the circuit with the bypass circuit is provided, and flow path control means is provided that allows the refrigerant to flow through only one of the first bypass circuit and the second bypass circuit. A refrigeration cycle device for a heat pump air conditioner, comprising a heat storage tank filled with a heat storage material and connected for heat exchange to at least a part of a shared portion of the first bypass circuit and the second bypass circuit. (2) Claim 1, which includes flow path control means that allows at least a portion of the high-pressure refrigerant in the main refrigerant circuit to be guided to the low-pressure side of the main refrigerant circuit via the first bypass circuit and the second bypass circuit. A refrigeration cycle device for a heat pump air conditioner as described in Section 1.