JPH01252881A - Cold-regenerative refrigerator - Google Patents

Abstract

PURPOSE:To lower the temperature of the cold-regenerative material at the end of the time zone for a cold-storing operation by repeating a cold-storing run by shifting the passage for refrigerant to the one for cold-storing evaporator when a temperature sensor finds the temperature of the cold-regenerative material to be above a prescribed temperature even after completion of a cold storing. CONSTITUTION:On a day's time schedule of the operating mode of a cold-regenerative refrigerator, starting the operation at 10.00 p.m. in an unbroken time zone from B2 to B1, the refrigerator alternates an ordinary cooling run with a cold-storing run, that is, while maintaining the storage space temperature at a constant point by ordinary cooling runs, the refrigerator stores cold by cold-storing runs. To store cold, a solenoid valve for cold storing 15 is opened, whereas a main solenoid valve 9 is closed, and a liquid refrigerant is fed to a cold-storing evaporator 19 by driving a compressor 1. When, as a result of cold-storing runs, a cold-storing evaporator sensor 33 finds that the temperature T of the cold-regenerative material 18 has touched a point T1 signifying completion of the cold storing, for example, -29 deg.C, the operation shifts to the ordinary cooling; however, when the temperature T of the cold-regenerative material 18 has risen to T2, for example, -26 deg.C, even during the ordinary cooling operation, the cold-storing operation is resumed and continued until the temperature T of the cold- regenerative material declines to -29 deg.C again.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a cold storage refrigerator.

(Prior Art) A conventional cold storage type refrigerator is provided with a cold storage evaporator surrounded by a cold storage material, and a compressor is provided with a refrigerant flow path that can be switched between the main evaporator and the cold storage evaporator. In addition, a heat transfer path consisting of, for example, a thermosiphon was provided between the main evaporator and the cool storage evaporator. The heat transfer path between the main evaporator and the cool storage evaporator can be opened and closed by opening and closing a solenoid valve arranged in this path.

A fan for circulating cold air inside the refrigerator is provided near the main evaporator, and a cold storage evaporator sensor for detecting the temperature T of the cold storage material is arranged in the cold storage evaporator.

This cold storage refrigerator had the following three operating modes corresponding to certain time periods of the day. FIG. 5 is a diagram showing operating modes of a conventional regenerator refrigerator according to time of day.

That is, for example, the time periods A1 and 1 from 9:00 to 13:00
During the time period A2 from 6:00 to 21:00, the normal cooling operation mode is executed. During these times, the refrigerant flow path from the compressor is switched to the main evaporator side, and the compressor is operated to supply liquid refrigerant to the main evaporator. When the fan is driven while supplying liquid refrigerant to the main evaporator in this manner, the interior of the refrigerator is cooled.

In the time period B1 from 0:00 to 8:00 and the time period b2 from 22:00 to 24:00, normal cooling operation and cold storage operation are performed alternately. That is, while the temperature inside the refrigerator is kept constant through the normal cooling operation, cold is stored in the cold storage material through the cold storage operation. Cold storage is performed by switching the refrigerant flow path from the compressor to the cold storage evaporator side, operating the compressor, and supplying liquid refrigerant to the cold storage evaporator. At this time, the operation of the fan is stopped. and,
The temperature T of the cold storage material detected by the cold storage Eva sensor decreases to T1
For example, when the completion of cold storage is detected by reaching -29°C, the cold storage operation is terminated, and only the normal cooling operation is performed on the road side during this time period, that is, until 8 o'clock.

During time period CI from 8:00 to 9:00, time period C2 from 13:00 to 16:00, and time period C3 from 21:00 to 22:00, compressor operation is forcibly stopped and the main evaporator and cold storage are used. Execute cold storage cooling operation to open the heat transfer path between the evaporator and the evaporator. At this time, cooling is released from the cold storage material arranged around the cold storage evaporator to the main evaporator. When the fan is operated while performing cooling in this manner, the inside of the refrigerator is cooled even though the compressor is not operating.

(Problems to be Solved by the Invention) In the conventional cold storage type refrigerator described above, during the time periods B and B during which the cold storage operation is performed, the storage/removal material temperature T decreases and once the cold storage completion temperature T1, for example, -29 ℃
After reaching this time, only normal cooling operation was performed without performing cold storage operation again until the roadside during this time.
After the cold storage operation ends, the temperature T of the cold storage material may rise due to heat leakage or the like. Therefore, the temperature T of the cold storage material on the rented road side increases during this time, and the cold storage cooling operation time period C1°C
2 or C3, the refrigerating capacity of the cold storage material was insufficient, and the cold storage cooling operation could not be continued.

The present invention has been made in consideration of the above circumstances, and provides a cold storage type refrigerator that can keep the cold storage material temperature T low on the roadside during the cold storage operation period even if there is heat leakage of the cold storage material. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the cold storage type refrigerator of the present invention includes a main evaporator from the compressor and a cold storage evaporator having a cold storage material arranged around the compressor. In addition to being equipped with a flow path switching means for switching the refrigerant flow path, it also has a salinity sensor that detects the temperature of the cold storage material, and even after the cold storage is completed, the temperature of the cold storage material detected by this temperature sensor exceeds a predetermined temperature. In this case, the refrigerant flow path is switched to the cool storage evaporator side by the flow path switching means and the cool storage operation is re-executed.

(Function) By switching the refrigerant flow path to the cold storage evaporator side by the flow path switching means and executing the cold storage operation, cold storage is performed in the cold storage material arranged around the cold storage evaporator. Even after the cold storage is completed by this cold storage operation, the temperature T of the cold storage material is reduced to a predetermined temperature 1 due to heat leakage, etc.
If the number is 2 or more, the refrigerant flow path is switched from the main evaporator side to the cool storage evaporator side and the cool storage operation is re-executed. Therefore, the temperature T of the cold storage material on the roadside during the cold storage operation execution time period is kept lower than T2.

(Example) FIG. 1 is a configuration diagram of a regenerator refrigerator according to an example of the present invention.

A discharge side 1a of the compressor 1 is connected to one end of the condenser 3 via a discharge pipe. The other end of the capacitor 3 is connected to the inflow side L3a of the main evaporator 13 via the differential pressure valve 5, the main electromagnetic valve 9, and the main capillary tube 11 in this order. Further, the outflow side of the differential pressure valve 5 is connected to the inflow side 19 of a cold storage evaporator 19 around which a cold storage material 18 is arranged, through a cold storage solenoid valve 15 and a cold storage capillary tube 17 in sequence.
connected to a.

The outflow side 19b of the cold storage evaporator 19 is connected to the inflow side 13a of the main evaporator 13. The outflow side 13b of the main evaporator 13 is connected to the suction side 1b of the compressor I via an accumulator 21 and a check valve 23 in this order. This pressure on the suction side 1b is applied to the differential pressure valve 5.

Furthermore, the main evaporator 13 and the cold storage evaporator 19
For example, a gravity-type closed-loop thermosiphon 25 is provided as an independent heat transfer path between the two, and a cooling solenoid valve 27 is disposed in the middle of this thermosiphon 25. A fan 29 for circulating cold air inside the refrigerator is provided near the main evaporator 13. Further, a cold storage evaporator 33 is arranged in the cold storage evaporator 19 to detect the temperature T of the cold storage material 18 .

FIG. 2 is a block diagram of the control circuit of the above regenerator refrigerator.

The outputs of the F sensor 31 that detects the temperature inside the freezer compartment and the cold storage evaporator sensor 33 are both input to the control circuit 35. Further, this control circuit 35 controls the operation/stop of the compressor 1 and the fan 29, and also controls the main solenoid valve 9.
, controls the opening and closing of the cold storage solenoid valve 15 and the cold release solenoid valve 27.

The daily time schedule of the operation mode of the cold storage refrigerator according to the embodiment of the present invention described above is as follows:
It is basically the same as that described above with respect to FIG.

In time periods A 1 and A 2 , normal cooling operation is performed as in the conventional case. In normal cooling operation, the cold storage solenoid valve 15 is closed, the main solenoid valve 9 is opened, the compressor l is driven to supply liquid refrigerant to the main evaporator 13, and the fan 2
This is done by driving 9. This normal cooling operation is started when the temperature of the freezer compartment detected by the F sensor 31 becomes higher than a predetermined temperature, and continues until the temperature reaches a predetermined temperature slightly lower than this temperature. As a result, the temperature of the freezer compartment is maintained at approximately -22°C.

From 22:00 onwards in the continuous time period from B2 to 81, normal cooling operation and cold storage operation are performed alternately. That is,
The temperature inside the refrigerator is kept constant through normal cooling operation, and the cold is stored through cold storage operation. The cold storage operation is performed by closing the main solenoid valve 9, opening the cold storage solenoid valve 15, and driving the compressor 1 to supply liquid refrigerant to the cold storage evaporator 19.

The operation of the fan 29 is stopped during cold storage. As a result of several cold storage operations, the cold storage material 1 detected by the cold storage Eva sensor 33
8 is the cold storage completion temperature T1, for example -29°C
reach. Immediately after the cool storage material temperature T reaches -29°C, a normal cooling operation is performed, but even during this normal cooling operation, if the temperature T of the cool storage material 18 rises and T2 reaches, for example, -26°C. restarts the cold storage operation and continues the cold storage operation until the temperature T of the cold storage material decreases and this temperature reaches -29°C again.

In other words, even after the cool storage material temperature T once reaches -29°C, what happens if the cool storage material temperature T rises due to heat leakage during normal cooling operation and reaches -26°C? The cold storage operation is re-executed even once, so that the temperature of the cold storage material does not rise above -26°C.

FIG. 3 shows how the cool storage material temperature T changes over time in this case.

First, as in the past, normal cooling operation and cold storage operation are performed alternately, and the cold storage material temperature T is -29℃ at time 111.
reach. Immediately after the cool storage material temperature T reaches -29° C., the normal cooling operation b1 is performed. During this normal cooling operation b1,
Although the inside of the refrigerator is cooled, no refrigerant is supplied from the compressor to the cold storage evaporator 19, so the temperature T of the cold storage material increases due to heat leakage or the like. Cold storage material temperature T
rises and this temperature reaches -26°C at time t2,
Cool storage operation b2 is restarted. Therefore, the cold storage material temperature T
decreases again. Below, normal cooling operation b1 and cold storage operation b
While repeating these steps, at time t6, the end of time zone B1, that is, 8 o'clock has arrived. Therefore, the temperature T of the cold storage material at time ta is suppressed to 126° C. or less.

During time periods C, C, and C3, by opening the solenoid valve 27 for cooling while forcibly stopping the operation of the combiner thermos, cooling is released from the cold storage material 18 that has stored refrigeration capacity to the main evaporator 13 through the thermosiphon 25. will be done. At this time, the refrigerant circulates within the thermosiphon 25 due to the temperature difference between the main evaporator 13 and the cold storage material 18 surrounding the cold storage evaporator 19 and the action of gravity, so power is supplied from the outside for cooling. There's no need to. In the cold storage cooling operation mode in which the fan 29 is operated while discharging cold from the cold storage material 18 in this manner, the inside of the refrigerator is cooled even though the compressor is not operating. However, if the refrigerating capacity of the cold storage material 18 is used up during the cold storage cooling operation, if the cold storage cooling operation is continued as it is, the temperature inside the refrigerator will rise. When the temperature reaches −18° C., loss of refrigerating capacity of the cold storage material 18 is detected, and the cold storage cooling operation is stopped and switched to normal cooling operation. However, since the cold storage material temperature T on the roadside during time period B1 is suppressed to a low temperature T2 of, for example, -26°C or lower, as described above,
During the cold storage cooling operation, it is rare that the refrigerating capacity of the cold storage material 18 becomes insufficient and the cold storage cooling operation cannot be continued.

In addition, in the time periods B and B2, the normal cooling operation b1 and the cold storage operation b2 may be performed alternately, with the normal cooling operation time β1 and the cool storage operation time β2 each being set as a fixed time. At this time, even if the temperature T of the cold storage material 18 detected by the cold storage evaporator 33 once drops below T1, for example, -29°C, the temperature T of the cold storage material 18 at the starting material for the set cold storage operation time β2 is T2, for example, -26°C. Cool storage operation b2 is executed only when the above conditions are met.

FIG. 4 shows how the cool storage material temperature T changes over time in this case.

The normal cooling operation time β1 and the cold storage operation time β2 are, for example, 23 minutes and 9 minutes, respectively. In this case, the cold storage material temperature T reaches the cold storage completion temperature -29° C. at time t1□ within a certain cold storage operation time β2 during the alternating execution of the normal cooling operation b and the cold storage operation b2. Therefore, this time β
On the roadside of No. 2, T is lower than -29°C. When this cool storage operation time β2 has elapsed, even if the next normal cooling time β1 has elapsed and the next cool storage operation time β2 has arrived, the normal cooling operation b1 is continued without executing the cool storage operation b2.

During this normal cooling operation b1, the cool storage material temperature T gradually rises due to heat leakage, etc., as described above. When the cold storage material temperature T rises and reaches, for example, -26°C at time t1□, although the cold storage material temperature T slightly exceeds -26°C on the roadside during the normal cooling operation time β1, the cold storage material temperature T will not be activated during the next cold storage operation time β2. b2 is restarted, and the cool storage material temperature T decreases again. At time t13 during this cold storage operation b, the storage/removal material temperature T reaches -29°C again, and becomes lower than -29°C at the end of this cold storage operation b2. Same normal cooling operation b
and cold storage operation b2 are repeated.

(2) Therefore, the temperature T of the cold storage material on the roadside during the time period B1 is suppressed to approximately -26°C or less.

In addition, a temperature T higher than the cold storage operation restart temperature T2 and a temperature T4 higher than this temperature T are set, and the time period C,
The cold storage cooling operation of C and C3 may be started only when the cold storage material temperature T detected by the cold storage Eva sensor 33 is below T3, and may be ended when the cold storage material temperature T becomes 14 or higher. Note that when T2 is -26°C, T3. T4 for example -24℃ and -20℃ respectively
And it is sufficient. In this case, by setting a temperature difference between T2 and T3 that is larger than the temperature increase due to heat leakage of the cold storage material 18, the start of the cold storage cooling operation will not be prohibited.

In addition, in the embodiment described above, since the heat transfer path between the main evaporator 13 and the cool storage evaporator 19 is a gravity-type closed-loop thermosiphon 25, it is necessary to supply power from the outside for cooling. However, this heat transfer path may be configured by other means such as a heat vibrator. Inlet side 13 of main evaporator 13 from compressor 1
A main solenoid valve 9 and a cold storage solenoid valve 15 serve as flow path switching means for switching between the refrigerant flow path leading to a refrigerant flow path and another refrigerant flow path leading from the compressor l to the inflow side 19a of the cold storage evaporator 19.
Although two solenoid valves are used, one three-way solenoid valve may be used instead.

[Effect of the invention] As explained above, the cold storage refrigerator according to the present invention has the following effects:
Even after the cold storage operation is once terminated when the cold storage is completed, if the temperature of the cold storage material rises above the predetermined temperature due to heat leakage, the cold storage operation will be re-executed as many times as necessary. It is possible to keep the temperature of the cold storage material low.

Therefore, during the cold storage cooling operation that utilizes the cooling capacity of the cold storage material, it is possible to prevent as much as possible from being unable to continue the cold storage cooling operation due to insufficient freezing capacity of the cold storage material.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a cold storage refrigerator according to an embodiment of the present invention,
Figure 2 is a block diagram of the control circuit of the previous cold storage refrigerator.
FIG. 3 is a time chart showing temporal changes in the temperature of the cold storage material in the cold storage refrigerator of FIG. 1, and FIG. 4 is a time chart showing temporal changes in the temperature of the cold storage material in the cold storage refrigerator according to another embodiment of the present invention. , FIG. 5 is a diagram showing operating modes of a conventional regenerator refrigerator according to time of day. Explanation of symbols■...Compressor, 9...Main solenoid valve, 13...
Main evaporator, 15... Solenoid valve for cold storage, 18...
Cold storage material, 19... Evaporator for cold storage, 25... Thermosiphon, 27... Solenoid valve for cooling, 29... Fan, 31... F sensor, 33... Cool storage evaporator, T. ...Cold storage material temperature. One Idiot Figure 1 Figure 2

Claims (1)

[Claims] 1. A flow path switching means is provided for switching between a refrigerant flow path from the compressor to the main evaporator and another refrigerant flow path from the compressor to a cold storage evaporator around which a cold storage material is arranged, and the temperature of the cold storage material is detected. In a refrigerant refrigerator having a temperature sensor, when the temperature of the regenerator material detected by the temperature sensor exceeds a predetermined temperature even after completion of regenerator, the refrigerant flow path is switched to the refrigerant evaporator side by the refrigerant flow path switching means. A cold storage type refrigerator characterized in that the cold storage operation is re-executed by switching to the cold storage mode.