JPS6217570A - Method of controlling chilling unit - 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 method of controlling a cooling device equipped with a regenerator to compensate for a temporary increase in cooling load.

(Prior art) As such a cooling device, for example, Japanese Patent Application Laid-Open No. 58-644
There is one disclosed in Publication No. 60.

This cooling device has a compressor, a condenser, a pressure reducing device, and an evaporator connected by piping, and these constitute a refrigeration cycle, and a heat capacity body is provided in the piping from the compressor to the condenser. This heat capacity body here functions as a cold storage device that is cooled by outside air and stores cold when the air conditioner is not in operation, and releases the cool to lower the temperature of the refrigerant when the air conditioner with a large cooling load is started, that is, during so-called cool-down. do.

However, in this cooling system, heat exchange is always performed between the heat capacity body and the refrigerant, so when the heat capacity body finishes cooling, it becomes the same temperature as the refrigerant. Since there is no means to actively cool down the heat capacity, the heat capacity body is not cooled sufficiently when the cooling system is inactive for a short period of time after continuous operation. There was a problem that the function as a cold storage device could not be expected.

As a cooling device that solves this problem, the applicant has proposed, for example, the one shown in FIG.

In the figure, 1 is a compressor, and here, the compressor 1 is connected to a condenser 2, a liquid receiver 8, an expansion valve 4 for cold storage as an example of pressure reduction means for cold storage, a cold storage 5, and this cold storage 6. A check valve 6 whose inlet side is the inlet side, a cooling expansion valve 7 as an example of a cooling pressure reducing means, and an evaporator 8 are connected in this order, and the evaporator 8 is further connected to the compressor 1 . In addition, here, a first bypass path 9 that bypasses the cold storage expansion valve 4, a first two-way valve 10 that opens and closes this, and a first bypass path 9 that bypasses the cold storage expansion valve 4, and a first two-way valve 10 that opens and closes this, and the cold storage expansion valve 4.
A second bypass path 11 that detours from to the check valve 6 and a second two-way valve 1z that opens and closes it, and a third bypass path 18 that detours from the check valve 6 to the evaporator 8 and this. A third two-way valve 14 that opens and closes is provided. The fluid circuit configured in this way is filled with refrigerant to form a vapor compression refrigeration cycle. In addition, the above-mentioned regenerator 5 is a conventional heat exchanger that is covered with a heat insulating material,
It has a structure in which a latent heat storage material such as water is filled between these heat exchangers and the heat insulating material.

This cooling device having such a configuration has a two-way valve 10.
12.14 are selectively opened and closed in eight different combinations as shown below, and the operation is controlled to provide cold storage, cooling release, and normal functions as described below.

For example, when there is a surplus of cooling capacity, the refrigerant does not need to continue to flow through the evaporator 8, so the cold storage mode in which only the third two-way valve is opened is selected intermittently for short periods of time. Because of the flow path resistance of the stop valve 6, the cooling expansion valve 7, and the evaporator 8, a fluid circuit is configured that bypasses these and flows through the third bypass path 18.

According to this fluid circuit, the high-temperature, high-pressure liquid refrigerant that has exited the liquid receiver 8 is depressurized by flowing through the cold storage expansion valve 4, expands adiabatically, and becomes a low-temperature, low-pressure mist. flow through,
It vaporizes, cools or solidifies the latent heat storage material therein, and then returns to the compressor 1 through the third bypass path 18, thereby providing a cold storage effect to the regenerator 5.

Furthermore, when a large cooling load is temporarily applied, such as during cool-down, a cooling mode is selected in which only the first two-way valve 10 is opened. A fluid circuit that detours and flows through the first bypass path 9 is configured.

According to this fluid circuit, the high-temperature, high-pressure liquid refrigerant that exits the liquid receiver 8 passes through the regenerator 5 via the first bypass path 9, is cooled by the latent heat storage material therein, and is supercooled. Expansion valve for cooling through check valve 6? The pressure is reduced in the evaporator 8 to form a low-temperature, low-pressure mist, which passes through the evaporator 8 and is vaporized, providing increased cooling capacity to the evaporator 8, and then returns to the compressor 1. A cooling effect and an effect of increasing the cooling capacity based on the cooling effect are brought about.

Furthermore, during a normal cooling load, the normal mode in which only the second two-way valve 12 is opened is selected, thereby bypassing the cold storage expansion valve 4, the cold storage device 5, and the check valve 6 due to their flow path resistance. A fluid circuit that flows through the second bypass path 1z is configured.

According to this fluid circuit, the high-temperature, high-pressure liquid refrigerant that exits the liquid receiver 8 directly passes through the bypass path 1z and reaches the cooling expansion valve.
The air is depressurized and becomes a low-temperature, low-pressure mist, which passes through the evaporator 8 and then returns to the compressor 1, providing a normal cooling effect.

(Problems to be Solved by the Invention) However, according to the applicant's experiments, when the cooling release mode is selected, the high-pressure refrigerant flows into the cooling expansion valve 7 as described above.
Point A, which is the branching point to the third bypass path 18 between the regenerator 5 and the check valve 6, shown in FIG.
Then, as shown in FIG. 3, high pressure was applied, and it was confirmed that this high pressure was also brought to the upstream side of the third two-way valve 14 that closes the third bypass path, that is, to the point A side. Even when the normal mode is selected after this cooling mode is selected, the third two-way valve 14 is closed and high pressure is brought to the upstream side of the cooling expansion valve 7, so as shown in FIG. High pressure at point A is maintained.

On the other hand, between the evaporator 8 and the compressor 1 shown in FIG.
Since the point B, which is the branching point to the third bypass path, is always kept at a low pressure, the downstream side of the third two-way valve 14, that is, the point B side, is always at a low pressure due to the third bypass path 18. Therefore, when the cooling mode is selected and then when the normal mode is selected as the cooling load decreases, the pressure difference ΔP on both sides of the third two-way valve 14, which is closed, is as shown in FIG. The big one is K.

Therefore, when the cold storage mode is subsequently selected due to excess cooling capacity, the third two-way valve 14 becomes low pressure under the action of the cold storage expansion valve 4 when the cold storage mode is selected.
In order to minimize the flow resistance of the bypass passage 18, the bypass passage 18 has a large diameter of, for example, 10mm, and when it is opened as shown by point C in the figure, for example, 81Jf-
A very large valve opening force of about 12 kyf is required, which necessitates the use of a large solenoid to drive the third two-way valve 14, which creates restrictions on valve arrangement and also increases the valve opening force. Therefore, the power consumption required for this process inevitably increases.

(Means for Solving Problems) A method for controlling a cooling device according to the present invention includes a compressor, a condenser, a pressure reducing means for cold storage, a cold storage, a check valve whose inlet side is the cold storage, and a cooling device. a first two-way valve that opens and closes a first bypass passage that bypasses the pressure reduction means for cold storage and the pressure reduction means for cold storage; a second two-way valve that opens and closes a second bypass path that bypasses the regenerator and the check valve; and a third bypass path that bypasses the check valve, the cooling pressure reducing means, and the evaporator. In an air conditioner equipped with a third two-way valve that opens and closes, the fluid flows through the third two-way valve from a fluid flow state that brings about high pressure upstream of the closed third two-way valve. In bringing about the flow state, the third two-way valve is opened after the first and second two-way valves are closed.

(Operation) According to the method of the present invention, when the fluid on the upstream side of the closed third two-way valve, that is, on the inlet side of the check valve connected thereto via the third bypass path, is at high pressure. First, when the first and second two-way valves are closed, all the two-way valves are closed, and the cold storage pressure reducing means, the cold storage,
A fluid circuit is configured to flow through a check valve, a pressure reducing means for cooling, and an evaporator, and the fluid is stored after its pressure is lowered by flowing through the pressure reducing means for cold storage. It becomes K as it passes through the @ container and reaches the check valve. Therefore, this low pressure is brought to the upstream side of the third two-way valve, while the downstream side of the third two-way valve is connected to the compressor via the third bypass path and has a low pressure. The pressure difference on both sides of the third two-way valve becomes extremely small. Thereafter, when the third two-way valve is opened, due to the small pressure difference mentioned above, opening can be carried out with very little force, resulting in a flow condition through the third two-way valve.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Here, a case will be described in which an embodiment of the method for controlling a cooling device of the present invention is applied to the cooling device shown in FIG. 1, which has already been submitted by the applicant.

In this example, first, a buffer mode is set in addition to the cold storage, cold release, and normal modes. The first in these modes
, the opening and closing combinations of the second and third two-way valves 10°la and 14 are as shown in the following table.

Incidentally, since the combination of opening and closing of these two valves when selecting the cold storage, cooling radiation, and normal modes is the same as in the conventional example, the effects brought about when these modes are selected are the same as in the conventional example.

In this example, as shown in Figure 2, when the normal mode is selected after the sum and cooling modes are selected, the buffer mode is intermittently selected due to excess cooling capacity. Prior to selecting the cold storage mode for the first time, it shall be selected for a very short time.

This, the first. Second and third two-way valve 10°12.14
When the buffer mode is selected in which all of the The high-temperature, high-pressure liquid refrigerant that has exited the liquid receiver 8 is depressurized by flowing through the cold storage expansion valve 4, expands adiabatically, and becomes a mist.
After passing through the regenerator 5 to cool the latent heat storage material therein, the latent heat storage material therein is further passed through the cooling expansion valve 7 via the check valve 6, where it is once again brought under regional pressure and adiabatically expanded. This refrigerant will then flow through the evaporator 8 and return to the compressor 1 after providing it with a reduced cooling capacity.

Therefore, when the cooling mode is selected and then when the normal mode is selected, the pressure at point A in FIG. As shown in Figure 2, the pressure at AB is low as described above, so the pressure at point A and point B
The pressure difference ΔP between the upstream side and the downstream side of the third two-way valve 14 that closes the third bypass passage 18 connecting the two is extremely small.

Then, at the subsequent point indicated by the dot in the middle of FIG. 2, when the third two-way valve 14 is opened to select the cold storage mode,
Owing to the small pressure difference mentioned above, its opening takes place with very little force, resulting in a flow condition through the third two-way valve, i.e. a cold storage mode.

As described above, according to the method of this embodiment, the pressure difference on both sides of the third two-way valve 14 can be made extremely small by selecting the buffer mode, and the force required to open the valve can be made extremely small. This third two-way valve 14
It becomes possible to use a small solenoid for driving the valve, which has the effect of eliminating restrictions on valve arrangement and significantly reducing the power consumption required to open the valve.

In the above embodiment, the buffer mode is selected when switching from the normal mode to the cold storage mode, but the same effect can be achieved even if the buffer mode is selected when switching from the cooling mode to the normal mode. effect is brought about. In addition, the buffer mode is selected prior to the first cold storage mode selection. In this way, when the upstream side of the third two-way valve has a high pressure, an appropriate selection may be made prior to the subsequent cold storage mode selection.

(Effect of the invention) Thus, according to the control method of this invention, the closed third
The pressure difference on both sides of the two-way valve can be made extremely small,
Since the force required to subsequently open the third two-way valve can be made extremely small, it is possible to use a small solenoid for driving the third two-way valve, As a result, restrictions on valve arrangement can be eliminated and power consumption required for opening the valves can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a fluid circuit diagram of a cooling device to which an embodiment of the control method of the present invention is applied; FIG. 2 is a time chart showing the method of the embodiment; FIG. 3 is a time chart showing a conventional method of controlling a cooling device. It's Chiard. 1...Compressor 2...Condenser 4...Expansion valve for cold storage (pressure reducing means for cold storage) 5...Regenerator
6...Check valve? ... Cooling expansion valve (cooling pressure reducing means) 8... Evaporator 9... First bypass path 10... First two-way valve 11... Second bypass path 1z... -Second two-way valve 18...Third bypass passage 14...Third two-way valve

Claims (1)

[Claims] 1. A fluid circuit leading from the compressor to the compressor through a condenser, a pressure reducing means for cold storage, a cold storage, a check valve whose inlet side is the cold storage side, a pressure reducing means for cooling, and an evaporator; a first two-way valve that opens and closes a first bypass passage that bypasses the pressure reduction means for cold storage; and a second two-way valve that opens and closes a second bypass passage that bypasses the pressure reduction means for cold storage, the regenerator, and the check valve. a third two-way valve that opens and closes a third bypass path that bypasses the check valve, the cooling pressure reducing means, and the evaporator; After closing the first and second two-way valves when bringing about a fluid flow state through the third two-way valve from a fluid flow state that brings high pressure on the upstream side of the third two-way valve; A method for controlling an air conditioner, comprising opening the third two-way valve.