JPS5888562A - Cooling device - 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 cooling device such as a refrigerator having a plurality of cold storage chambers with different temperatures, and its purpose is to improve the coefficient of performance of a compressor and improve the operating efficiency of the cooling device. At the point.

Conventionally, a typical cooling system for cooling multiple cold storage compartments with different temperatures using a single refrigeration unit is the cooling system of a household refrigerator-freezer, which basically uses a cooling system as shown in Figure 1. are doing.

In Fig. 1, (1) is a compressor, and the refrigerant liquid discharged from this compressor (21) and liquefied in a condenser (21) is
The pressure is reduced in the capillary tube (31), and a portion is evaporated in the refrigerating evaporator (6) disposed in the refrigerating compartment (4), at which time a cooling effect in the refrigerating compartment (41) is performed. The gas-liquid two-phase refrigerant that exits the refrigerant is depressurized again in the second capillary tube (6), and then transferred to the freezing evaporator (81) disposed in the freezing chamber (7).
The residue evaporates, and at that time the freezer compartment (7) is cooled. The refrigerant gas exiting the freezing evaporator (81) is sucked into the compressor (11) via the accumulator (9).The temperature inside each refrigerator is controlled.

This is done by starting and stopping the compressor (1) using a temperature controller (not shown) K disposed in either the refrigerator compartment (41) or the freezer compartment (γ).

In the refrigerator-freezer configured as above.

The compressor (11 suction pressure is a very low pressure refrigeration evaporator (
Since it is determined by the evaporation pressure of 81, the refrigerating evaporator (
No matter how high the evaporation pressure of the compressor (11) was, the coefficient of performance of the compressor (11) was very poor, and the cooling system was forced to operate inefficiently. Because it has to depend on the internal temperature of one or the other.

There is a drawback that the temperature inside the other refrigerator will vary.
o - In order to enable independent control of the internal temperature in each case, one evaporator (8) is installed in the freezer compartment a), so that the refrigerator compartment (4) can control the internal temperature by damper control. The temperature t+ of the freezer compartment (7) is controlled by the compressor (11
Cooling systems that operate by turning on and off have become common in recent years. Although this method allows independent control of the temperature inside the compartment, the evaporation temperature of the evaporator (8) is dependent on the temperature of the freezing compartment (7), so the compressor (1)
The fact remains that the suction pressure of No. 1 is low and the efficiency of the cooling system is very poor. Furthermore, when using this method, the refrigerator compartment (4) is communicated with the freezer compartment (7) via the damper l, which causes the problem of excessive dryness in the refrigerator compartment (4).

Furthermore, the amount of dew on the evaporator (8) increases, making frequent defrosting necessary! 60 The present invention has been designed to improve the various drawbacks of the conventional Queen's system, and includes a plurality of cooling chambers with different cooling temperatures, each of which is provided with an evaporator to cool the respective cooling chambers. By connecting these evaporators in parallel and setting the time for flowing refrigerant to each evaporator separately so that they do not flow at the same time, the coefficient of performance of the compressor is improved, and the refrigerant liquid that is not fully evaporated in the low-temperature side evaporator is improved. The refrigerant gas is completely evaporated in the high-temperature side evaporator, and the refrigerant gas from the low-temperature side evaporator is superheated in the high-temperature side evaporator.The heat of the refrigerant that has passed through the low-temperature evaporator is recovered, increasing the operating efficiency of the entire cooling system. It is something.

The details of the present invention will be explained below using a household refrigerator-freezer as an example.

FIG. 2 is a cooling system diagram showing an embodiment of the present invention, in which (1) a compressor, (21 a condenser, (4 a refrigerator compartment,
(5Hj Refrigerating evaporator installed in this refrigerator compartment (4), (7) is a freezing compartment, (81 is a freezing evaporator installed in this freezing compartment (7), (91 is an accumulator) It is.

(31 is a first capillary tube as a first pressure reducer disposed upstream of the refrigerant passage of the refrigeration evaporator (5), and (6) is disposed upstream of the refrigerant passage of the refrigeration evaporator (8). A second capillary tube as a second pressure reducer is provided.

ao is a first on-off valve disposed on the refrigerant passage am of the first capillary tube (8), αD is a three-way valve as a refrigerant control valve provided downstream of the freezing evaporator (8); a.

One of the three-way valves an communicates with the refrigerant suction passage of the compressor (1) (as shown in FIG. 2 a-4b), and the other is the check valve Q.
2 (indicated by a-40 in FIG. 2) with the upstream side of the refrigeration evaporator (5).

The first on-off valve (++1. First capillary tube C31, the series refrigerant circuit of the refrigeration evaporator (5) and the second capillary tube (6), the refrigeration evaporator (8), the three-way valve (111 series refrigerant circuit) The above condenser is connected in parallel: and the above accumulator (
9).

The embodiment shown in FIG. 2 resembles a conventional refrigeration system with two evaporators connected in parallel, but is fundamentally different.

First, the present invention eliminates the need for a pressure adjustment section that was located after the high-temperature side evaporator in larger conventional devices that match the evaporation pressures of evaporators at different temperature levels to the same suction pressure. The characteristic operation of the present invention is that both evaporators (5) and (81K i
The point is that the refrigerant does not flow at the same time. For more details, please refer to the second
The low temperature side, that is, the refrigeration refrigerant circuit, consisting of a capillary tube (61, refrigeration evaporator C8) and a three-way valve circle, and the first on-off valve a
t1. ．． ．． 1st. ．． ．． (3) and a refrigeration evaporator (5).

That is, the refrigerant liquid from the condenser (21) is distributed to the freezing refrigerant circuit and the refrigerator compartment (21) in chronological order according to the temperature changes in both compartments.
By maintaining the evaporation pressure of the refrigeration evaporator (5) high when cooling the refrigerant (4), the coefficient of performance of the compressor (1) is improved, and the refrigerant that is not fully evaporated in the refrigeration evaporator (8) is improved. Completely evaporate the liquid in the refrigerating evaporator (6), fc,
By superheating the refrigerant gas coming out of the refrigeration evaporator (8) in the refrigeration evaporator (5),
) is used to recover heat from the refrigerant that has passed through the refrigerant evaporator (5i), which together with the former improves the operating efficiency of the entire cooling system.

Figure 3 is an operation control block diagram of the domestic refrigerator-freezer shown in Figure 2, where a3 is a temperature detection sensor installed in the refrigerator compartment (41), and αa is a temperature detection sensor installed in the freezer compartment (]). Sensor a5 is a temperature controller for the refrigerator compartment, and when the detected value from temperature detection sensor 0 is above a predetermined upper limit value of the refrigerator compartment (4), it outputs an ON signal, and when it is below a predetermined lower limit value, it outputs a first OFF signal. , and outputs a second OFF signal at a temperature value slightly higher than this predetermined lower limit value, that is, a second predetermined lower limit value. (7) When the predetermined upper limit value is exceeded, an ON signal is output, and when it is below the predetermined lower limit value, an OFF signal is output. (2) Pito 9
The ON signal of the temperature controller αe and the first
An AND circuit such as an AND gate that outputs an OFF signal and a KYON signal, and an OR gate that outputs a QN signal depending on either the ON signal of this AND gate or the ON signal of the temperature controller. ), (11 Keko's OR gate as
The compressor is driven by the ON signal of
The first on-off valve opens with the ON signal of the above AND gate (2) and closes with the second OFF signal, α11 changes the flow path from a to b with the ON signal of the AND gate (2), otherwise a - + c k It is a three-way switching valve.

With the above configuration, when t is O, if the temperature of the refrigerator compartment (4) is higher than the predetermined upper limit temperature, the temperature detection sensor (to)
In response to the signal from the temperature controller, an ON signal is output from the temperature controller, so open the first on-off valve shaft and turn the three-way valve a
The compressor (1+) is driven through the KL and OR gates. Therefore, the refrigerant passes through the first capillary through the tube (31), passes only through the refrigerating evaporator (5), and cools the inside of the refrigerating compartment (4). When the refrigerator compartment (41) is cooled and the temperature is lower than the predetermined upper limit temperature, and when the temperature is slightly higher than the lower limit temperature, that is, the temperature is lower than the second predetermined lower limit value, the temperature of the freezer compartment (7) is higher than the predetermined upper limit temperature. When the detection value from the temperature detection sensor Ql is detected, the three-way valve holder moves the flow path to a-40K L according to the ° signal from the temperature controller (to).
.

Close the first on-off valve shaft. Then, the refrigerant flows into the second capillary (
61. Pass through the refrigerator evaporator (8) to cool the inside of the freezer (7). Furthermore, it passes through the three-way valve an from a to C and the check valve α, and enters the refrigeration evaporator (5), where the heat of the low-temperature refrigerant is recovered, and at the same time, the refrigerant that evaporated at low temperature is superheated to the refrigerator compartment. (4) is slightly cooled. At this time, the refrigerator room (
The inside of the freezer compartment (7
) is higher than the predetermined lower limit temperature, the temperature detection sensor (2)
AND with the signal from the temperature controller (2)
Switch to the three-way valve Ql ta - + b through the gate 2 to the refrigerating evaporator (to prevent refrigerant from flowing into the building).

When both cooling chambers (41, (7) are below the predetermined lower limit temperature, the temperature controller (2) is activated by the signal from the temperature detection sensor Q3.Q-.
), AND gate surface by the ae rainbow signal.

The operation of the compressor (11) is stopped via the OR gate.

FIG. 4 is a cooling system diagram showing another embodiment according to the present invention (11 is installed downstream of the refrigerant branch path to the check valve C121 instead of the three-way valve I in FIG. 2). This is a second on-off valve.This second on-off valve (to) is open when the flow path of the three-way valve αυ in FIG. 2 is from a to bK.
When the first on-off valve is open, it is closed, and when the first on-off valve 6I is closed, it is closed depending on the temperature inside the refrigerator compartment (4). Even if configured in this manner, it has the same function and the same effect.

In the above embodiment, a capillary tube is used as a pressure reducer, but it goes without saying that an expansion valve or the like may also be used, and even in the case of multiple systems with two or more load sides, the pressure reduction device is adapted to each temperature level. The present invention can be applied to multiple systems by setting a refrigerant control valve for each system and setting refrigerant control valves for multiple systems.

As described above, the present invention can improve the operating efficiency of the entire compressor and cooling system that distributes refrigerant to evaporators with different evaporation pressures in time series, and also It is possible to independently control the temperature of each cooling chamber, and cooling of the -1 large high temperature side cold storage chamber is performed at an appropriately high evaporation temperature.

Problems such as drying of the cold storage compartment on the high temperature side do not occur.

Furthermore, in conventional refrigeration systems in which evaporators are connected in parallel, refrigerant flows through both evaporators at the same time, so a pressure adjustment section is required to match the post-evaporation pressures of both evaporators to the same suction pressure. ), but this is not necessary in the present invention.

Furthermore, during the cooling operation on the low temperature side, the refrigerant sucked into the EE compressor is sufficiently superheated, and efficiency can be improved from this aspect as well.

[Brief explanation of drawings]

Figure 1 is a cooling system diagram of a conventional household refrigerator-freezer, Figure 2 is a diagram of a cooling system of a household refrigerator-refrigerator showing an embodiment of this invention, and Figure 3 is its operation control block diagram. FIG. 4 is a cooling system diagram showing another embodiment of the present invention. The same reference numerals in the figures indicate the same or corresponding parts. (1) is the compressor, (21 is the condenser, (3) is the first capillary, (4) is the refrigerator compartment, (5) is the Fi refrigeration evaporator, (6) is the second capillary. (7) is the refrigeration chamber, (81 is the refrigeration evaporator, 0 is the first on-off valve, αIll Fi crossing valve, α2 check valve, αm,
04Fi Temperature Detector Temperature Detector Temperature Controller (2) is an AND gate, or an OR gate. Agent Shin Kuzuno - 111! l8 j12 Figure 3rd Ward No. 41! i

Claims (2)

[Claims] (1) A refrigerant circuit including a plurality of cooling chambers with different cold storage temperatures, an on-off valve, a pressure reducer, and an evaporator connected in series in the direction of refrigerant flow to individually cool each cooling chamber. These refrigerant circuits are connected in parallel and connected in series to one compressor and condenser, and the temperature of each cooling chamber is detected,
A temperature controller that controls the opening/closing valves of each of the refrigerant circuits to selectively flow the refrigerant into any one of the refrigerant circuits, and a cooling chamber on the high temperature side where the refrigerant exiting the evaporator is kept within a predetermined temperature range. 1. A cooling device comprising: a refrigerant control valve that allows a refrigerant to flow through a check valve to an inlet of a high-temperature side evaporator. (2) The cooling device according to claim 1, characterized in that when the cooling chamber consists of two chambers, the pressure reducer is constructed of a capillary tube, thereby omitting an on-off valve for the low-temperature side refrigerant circuit. (31) The cooling device according to claim 1 or 2, wherein the refrigerant control valve is a three-way valve.