JPH0517578Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cooling case such as an open-shoulder case that has a simultaneous cooling mode and a one-sided defrosting mode.

(Prior Art) Conventionally, this type of cooling case, for example, the one disclosed in Japanese Utility Model Application Publication No. 151075/1988 is known as an open-side cooling case.

This open show case has a refrigerant circuit that is arranged in a cold air circulation path of the case body and has two evaporators having refrigerant pipes extending vertically, a compressor, a condenser, and first and second expansion valves. The refrigerant circuit has a simultaneous cooling mode in which the evaporators are cooled simultaneously, and a one-sided defrosting mode in which the one evaporator is defrosted and the other evaporator is cooled.

In this case, in the one-sided defrosting mode, the refrigerant flowing out of the condenser once flows to the lower end side of one evaporator, and then flows to the other evaporator via the second expansion valve.

As a result, one evaporator is defrosted,
Cooling operation is performed in the other evaporator. Note that when defrosting the other evaporator and cooling one evaporator, the refrigerant flowing out from the condenser is first flowed to the lower end of the other evaporator, and then passed through the first expansion valve to the one evaporator. Just pour it into a container.

On the other hand, in the simultaneous cooling mode, a portion of the refrigerant flowing out of the condenser once flows to the lower end side of one evaporator, and then flows to the other evaporator via the second expansion valve. Further, another refrigerant once flows to the lower end side of the other evaporator, and then flows to one evaporator via the first expansion valve. Thereby, cooling operation is performed in each evaporator.

However, in this simultaneous cooling mode,
As mentioned above, since the refrigerant flowing out of the condenser once flows to the lower end of each evaporator, a defrosting action also occurs in the evaporator, which has the disadvantage of reducing the cooling action of each evaporator.

In order to solve these drawbacks, JP-A-59-
The cooling case disclosed in Publication No. 81459 (for example,
Refrigerator) is proposed.

In the simultaneous cooling mode of this refrigerator, the refrigerant flowing out from the condenser flows through the first and second expansion valves to two evaporators, respectively. On the other hand, in the one-sided defrosting mode, a part of the refrigerant discharged from the compressor passes through one evaporator and flows to the other evaporator via the third expansion valve, and the defrosting action is performed in one evaporator. However, the other evaporator exerts a cooling effect.

In this way, in the latter cooling case, the disadvantages of the former are solved, since in the simultaneous cooling mode, the refrigerant is separately supplied to the evaporators in which each cooling action takes place.

(Problem to be solved by the invention) However, in order to solve the drawbacks of the former cooling case, the latter cooling case uses three expansion valves, resulting in an increase in the number of parts. It had

In addition, in both the former and latter cooling cases, the evaporator that performs the defrosting action is open to the inside of the refrigerator, so the heat generated due to the defrosting action leaks into the case body. The problem was that the cooling effect was reduced.

In view of the above-mentioned conventional problems, the purpose of the present invention is to not only prevent the cooling effect from decreasing in the simultaneous cooling mode, but also to prevent the heat associated with the defrosting action from leaking into the case body in the one-sided defrosting mode. There is no cooling case to be provided.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention includes first and second evaporators arranged in the cold air circulation path of the case body and through which refrigerant flows vertically, and a compressor. a condenser;
a refrigerant circuit having a first and a second expansion valve; the refrigerant circuit supplies the refrigerant discharged from the compressor to the condenser, the first expansion valve, and the first and second evaporators; A simultaneous cooling mode in which the refrigerant is sequentially circulated and returned to the compressor to simultaneously cool the first and second evaporators; a first one-sided defrost mode in which the first evaporator is defrosted and the second evaporator is cooled; , circulating the refrigerant discharged from the compressor through the condenser, the second evaporator, the second expansion valve, and the first evaporator and returning it to the compressor; The cooling case is installed in the cold air circulation path and has a second one-sided defrosting mode in which the first evaporator defrosts the air and cools the first evaporator in the first one-sided defrosting mode. regulating the circulation of air flowing through the evaporator, and regulating the circulation of air flowing through the second evaporator when in the second one-sided defrosting mode;
A damper that releases the restriction on air flow to the first and second evaporators when in the simultaneous cooling mode; a first switching valve that switches the refrigerant to flow toward the lower end of the evaporator; and a second switching valve that switches the refrigerant discharged from the condenser to flow toward the lower end of the second evaporator when in the second one-sided defrosting mode. and restricting the refrigerant discharged from the condenser from flowing into the first and second evaporators via the first expansion valve when in the first and second one-sided defrosting modes; a first on-off valve that releases the inflow restriction when in the cooling mode and allows the refrigerant discharged from the condenser to flow into the first and second evaporators via the first expansion valve; and when in the simultaneous cooling mode. The flow of the refrigerant discharged from the condenser is regulated, and when in the first one-sided defrosting mode, this regulation is released and the refrigerant discharged from the upper end side of the first evaporator is passed through the second expansion valve. When in the second one-sided defrosting mode, this restriction is released and the refrigerant discharged from the upper end of the second evaporator is passed through the second expansion valve. and a second on-off valve that allows the flow to flow to the upper end side of the first evaporator through the evaporator.

(Function) According to the present invention, in the simultaneous cooling mode,
The refrigerant in the compressor is circulated in sequence through the condenser, the first on-off valve, the first expansion valve, each evaporator, the first and second switching valves, and the compressor.

In the first one-sided defrosting mode, the refrigerant of the compressor is transferred from the condenser to the first switching valve to the first evaporator to the second on-off valve to the second expansion valve to the second evaporator to the second
It circulates sequentially from the switching valve to the compressor.

In the second one-sided defrosting mode, the refrigerant of the compressor is transferred from the condenser to the second switching valve to the second evaporator to the second on-off valve to the second expansion valve to the first evaporator to the first
It circulates sequentially from the switching valve to the compressor.

In addition, in this one-sided defrosting mode, the evaporator that performs defrosting is closed by a damper and air circulation is restricted, so the flow of heat from the evaporator being defrosted into the case body is restricted. .

(Embodiment) FIGS. 1 to 5 a, b, and c show an embodiment of the present invention, and the same components as in the conventional example are denoted by the same reference numerals. That is, 1 is a compressor, 2 is a condenser, 3a and 3b are first and second evaporators each having refrigerant pipes (not shown) arranged in the vertical direction, and 4a, 4b, 4
c is a normally closed solenoid valve (here, the first on-off valve 4b,
The second on-off valves 4c), 5a and 5b are the first and second on-off valves.
expansion valves, 6a, 6b, 6c, 6d are check valves, 7
a, 7b are first and second four-way valves (switching valves);
10 is a cooling case body, for example, an open case body (hereinafter referred to as the case body), and an outer box 10
A cold air circulation path 11 is formed between a and the inner box 10b, and a product storage 12 is formed inside the inner box 10b. A partition plate 1 is provided in the cold air circulation path 11.
Each of the evaporators 3a and 3b is disposed through the evaporator 3, and a damper 15 connected to a reversibly driven motor 14 is provided at the upper end of the partition plate 13, and a damper 15 is provided at the upper end of the partition plate 13, and a damper 15 is provided at the upper end of the partition plate 13. Air circulation is now regulated.

Each of the four-way valves 7a and 7b has its refrigerant flow port A connected to the discharge side of the condenser 2 via the electromagnetic valve 4a, and its refrigerant flow port B connected to the lower end of the refrigerant pipe of the evaporator 3a and 3b. The ports C are respectively connected to the suction side of the compressor 1, and the refrigerant flow port D is closed. Furthermore, when the four-way valves 7a and 7b are turned on, the refrigerant flow port A and the refrigerant flow port D are turned on.
and the refrigerant flow port B and the refrigerant flow port C are communicated with each other, and when turned off, the refrigerant flow port A and the refrigerant flow port B and the refrigerant flow port C and the refrigerant flow port D are communicated with each other. It's summery.

The upper ends of the refrigerant pipes of the evaporators 3a and 3b are connected to the check valves 6a and 6b connected in series and the check valves 6c and 6d connected in series, respectively. The middle point of connection and the middle point of connection of each of the refrigerant flow ports A are connected via the first expansion valve 5a and the solenoid valve 4b, and the middle point of connection of each of the check valves 6a, 6b and each of the reverse The connection midpoints of the stop valves 6c and 6d are connected via the electromagnetic valve 4c and the second expansion valve 5b, respectively. Note that the check valve 6a regulates the flow of refrigerant to the first evaporator 3a side, and
The check valve 6b regulates the flow of refrigerant toward the second evaporator 3b, and the check valves 6c and 6d regulate the flow of refrigerant toward the expansion valves 5a and 5b. It's summery.

FIG. 3 shows the electric circuit of the open show case according to this embodiment. 20 is a computer-configured controller with a timer function;
Each of the solenoid valves 4a to 4c, each of the four-way valves 7a,
7b and the motor 14 of the damper 15 are connected, and the solenoid valves 4a to 4c and the four-way valves 7a and 7b are connected to each other.
And the motor 14 is driven and controlled as shown in the time chart of FIG.

That is, the solenoid valves 4a, 4b and the four-way valve 7
a, 7b are turned on, the motor 14 is driven, and the damper 15 is positioned between the evaporators 3a, 3b, the refrigerant of the compressor 1 {solid line arrow in FIG. 5a} is condensed. 2, each solenoid valve 4
a, 4b, the first expansion valve 5a, and the check valves 6c, 6d. The inflow refrigerant flows through each four-way valve 7.
It is returned to the compressor 1 via a and 7b. This creates a simultaneous cooling mode, in which the evaporator 3
An endothermic action occurs in a and 3b, and the cold air circulation path 11
The air inside is cooled and fed into the product storage 12.

After the operation in the simultaneous cooling mode continues for a predetermined period of time, the solenoid valve 4c is turned on, the solenoid valve 4b and the four-way valve 7a are turned off, and the motor 14 is driven and the damper is turned on. 15 closes the first evaporator 3a side.
At this time, the refrigerant of the compressor 1 {solid line arrow in FIG. do. The inflow refrigerant flows through the check valve 6
a, the refrigerant flows into the upper end of the refrigerant pipe of the second evaporator 3b via the electromagnetic valve 4c, the second expansion valve 5b and the check valve 6d, and furthermore, the inflow refrigerant flows through the four-way valve 7b. The air is returned to the compressor 1 through the compressor 1. As a result, the first one-sided defrosting mode is formed, an endothermic action occurs in the second evaporator 3b, and the air cooled by the second evaporator 3b is passed through the cold air circulation path 11 to the second evaporator 3b. The products are fed to the product storage 12. On the other hand, in the first evaporator 3a, defrosting is performed from the lower side of the first evaporator 3a, thereby warming the surrounding air at the lower side. The heated air gradually rises and also flows to the upper side of the first evaporator 3a, defrosting the entire first evaporator 3a in a short time.

In this way, the first evaporator 3a on the side to be defrosted
is closed by the damper 15, the inflow of air to the evaporator 3a side is regulated, and the product storage 1
2. Heat generated during defrosting does not leak into the interior.

Further, since the defrosting air is cooled as it rises to the upper side of the evaporator, the airtightness or insulation of the damper 15 is not sufficient, and the defrosting air leaks into the cold air circulation path 11. However, the temperature inside the product storage 12 is not significantly affected.

Furthermore, since the first expansion valve 5a is used in the simultaneous cooling mode described above, and the second expansion valve 5b is used in the first one-sided defrosting mode, The capacity of the first expansion valve 5a can be set to match the simultaneous cooling mode, and the capacity of the second expansion valve 5b can be set to match the first one-sided defrosting mode, thereby applying an excessive load to the compressor 1. Not at all.

Furthermore, after the operation in the first one-sided defrosting mode continues for a predetermined period of time, the solenoid valve 4b is turned on, and the solenoid valves 4a and 4c are turned off. At this time, the refrigerant in the first evaporator 3a (solid arrow in FIG. 5c) flows through the four-way valve 7a, the solenoid valve 4b, the first expansion valve 5a, and the check valve 6d. The refrigerant flows into the second evaporator 3b, and further, the inflow refrigerant flows into the four-way valve 7b and the compressor 1.
And it stays on the electromagnetic valve 4a side via the condenser 2. As a result, the second evaporator 3b continues to absorb heat, and the refrigerant on the first evaporator 3a side is recovered.

Furthermore, after continuing the operation in the first refrigerant recovery mode for a predetermined time, the solenoid valve 4a and the four-way valve 7a are turned on, and the damper 15 is positioned between the evaporators 3a and 3b. let me,
The above-mentioned simultaneous cooling mode is formed.

Furthermore, after the simultaneous cooling mode continues for a predetermined time, the solenoid valve 4c is turned on, and
The electromagnetic valve 4b and the four-way valve 7b are turned off, the motor 14 is driven, and the damper 15 closes the second evaporator 3b.
At this time, the refrigerant of the compressor 1 {dotted chain arrow in FIG. Inflow. The inflow refrigerant flows through the check valve 6b, the electromagnetic valve 4c, the first expansion valve 5b, and the check valve 6c to the first evaporator 3a.
The refrigerant flows into the upper end of the refrigerant pipe, and further, the inflow refrigerant flows back to the compressor 1 via the four-way valve 7a. As a result, a second one-sided defrosting mode is formed, and the first evaporator 3a performs an endothermic action while the second one-side defrosting mode
A defrosting effect occurs in the evaporator 3b. This defrosting action also operates in the same manner as the first one-sided defrosting mode described above, shortens the defrosting time, and has a small effect on the temperature inside the refrigerator.

Furthermore, after the second one-sided defrosting mode is finished, the solenoid valve 4b is turned on, and the solenoid valves 4a and 4c are turned off. At this time, the refrigerant in the second evaporator 3b {dotted chain arrow in FIG. 5c} flows through the four-way valve 7b, the solenoid valve 4b, the first expansion valve 5a, and the check valve 6c The refrigerant flows into the first evaporator 3a, and further passes through the four-way valve 7a, the compressor 1, and the condenser 2, and stays on the electromagnetic valve 4a side. This forms the second refrigerant recovery mode.

In this way, by sequentially repeating the simultaneous cooling mode, the first one-sided defrosting mode, the first refrigerant recovery mode, the simultaneous cooling mode, the second one-sided defrosting mode, and the second refrigerant recovery mode, the case body 1
Refrigeration operation of the product storage 12 of No. 0 is performed.

(Effects of the invention) As explained above, according to the invention, in the one-sided defrosting mode, the evaporator side that performs defrosting is closed by the damper and air circulation is regulated.
The flow of heat from the evaporator to be defrosted into the case body is regulated, and a temperature rise within the case body is suppressed during defrosting.

Further, unlike in the past, the defrosting action is not performed simultaneously in the simultaneous cooling mode, and the defrosting action can be performed without any trouble using the two expansion valves.

[Brief explanation of the drawing]

Figures 1 to 5 a, b, and c show one embodiment of the present invention, in which Figure 1 is a sectional view showing an open shower case, Figure 2 is a refrigerant circuit diagram of the open shower case, and Figure 3 is a refrigerant circuit diagram of the open shower case. The figure shows the electric circuit diagram of the open case. Figure 4 is a time chart showing controller control. Figure 5 a is a refrigerant circuit diagram showing simultaneous cooling mode. Figure 5 b is a refrigerant circuit diagram showing one-sided defrosting mode. , FIG. 5c is a refrigerant circuit diagram showing the refrigerant recovery mode. In the figure, 1... Compressor, 2... Condenser, 3a, 3
b...Evaporator, 4b...First on-off valve, 4c...
Second on-off valve, 5a...First expansion valve, 5b...
Second expansion valve, 7a, 7b...Switching valve, 10...
...Case body, 11...Cold air circulation path, 15...Damper.

Claims (1)

[Claims for Utility Model Registration] First and second evaporators 3a disposed in the cold air circulation path 11 of the case body 10 and through which refrigerant flows upward and downward;
3b, compressor 1, condenser 2, first and second
The refrigerant circuit includes expansion valves 5a and 5b, and the refrigerant circuit transfers the refrigerant discharged from the compressor 1 to the condenser 2, the first expansion valve 5a, and the first and second evaporators. A simultaneous cooling mode in which the refrigerant is sequentially circulated to the compressor 3 and returned to the compressor 1 to simultaneously cool the first and second evaporators 3 a and 3 b; , the first evaporator 3a, the second expansion valve 5
b, a first one-sided defrosting mode in which the circuit is circulated to the second evaporator 3b and returned to the compressor 1, the first evaporator 3a is defrosted, and the second evaporator 3b is cooled; and the refrigerant discharged from the compressor 1 is passed through the condenser 2, the second evaporator 3b, and the second expansion valve 5.
b, a second one-sided defrosting mode in which the circuit is circulated to the first evaporator 3a and returned to the compressor 1, defrosted in the second evaporator 3b, and cooled in the first evaporator 3a; In the cooling case, the cooling case is installed in the cold air circulation path 11, and when in the first one-sided defrosting mode, regulates the circulation of air flowing to the first evaporator 3a, and in the second one-sided defrosting mode. When in frost mode, the circulation of air flowing to the second evaporator 3b is regulated, and when in the simultaneous cooling mode, the circulation of air to the first and second evaporators 3a and 3b is released. a damper 15; and the condenser 2 when in the first one-sided defrosting mode.
a first switching valve 7a that switches the refrigerant discharged from the first evaporator 3a to the lower end side of the first evaporator 3a, and when in the second one-sided defrosting mode, the condenser 2
a second switching valve 7b that switches the refrigerant discharged from the condenser 2 to the lower end side of the second evaporator 3b to flow the refrigerant discharged from the condenser 2 to the lower end side of the second evaporator 3b; The flow into the first and second evaporators 3a, 3b through the expansion valve 5a is regulated, and when in the simultaneous cooling mode, this inflow regulation is canceled and the flow into the first and second evaporators 3a, 3b is regulated.
a first opening/closing valve 4b that allows the refrigerant discharged from the condenser 2 to flow into the first expansion valve 3b through the first expansion valve 5a; When in the one-sided defrosting mode of No. 1, this restriction is canceled and the first evaporator 3
The refrigerant discharged from the upper end side of a is transferred to the second expansion valve 5.
b to the upper end side of the second evaporator 3b, and when in the second one-sided defrosting mode, this restriction is released and the refrigerant discharged from the upper end of the second evaporator 3b is allowed to flow to the upper end side of the second evaporator 3b. A cooling case characterized in that it has a second on-off valve 4c that allows the flow to flow to the upper end side of the first evaporator 3a via the second expansion valve 5b.