JP2001165511A - Method for operating compressor in refrigeration circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the operation method of a compressor in a refrigeration circuit for reducing the load and consumption power of the compressor when the compressor starts operating. SOLUTION: As the operation stop control of a compressor 3 when temperature in a chamber 1A reaches a set temperature (operation stop temperature of the compressor), the operation of the compressor 3 is stopped in specific time td after the supply of a refrigerant to an evaporator 2A is broken by totally closing an electronic expansion valve 15A as a flow rate adjustment means. More specifically, by operating the compressor 3 only for the specific time td, the refrigerant in the evaporator 2A is sucked and eliminated, the load of the compressor is reduced when operation is resumed, and at the same time the response of the degree of superheating of the refrigerant is improved, thus reducing entire consumption power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a compressor in a refrigeration circuit suitable for, for example, a cooling device of a vending machine, and more particularly, to efficiently cooling a system to be cooled and contributing to energy saving. The present invention relates to a method for operating a compressor in a refrigeration circuit.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional cooling device of a general vending machine. A well-known refrigeration circuit is constituted by the evaporators 2A, 2B and 2C arranged in each of the refrigerators 1A, 1B and 1C, the compressor (compressor) 3 and the condenser 4 arranged outside the refrigerator, and each of the evaporators 2A to 2C Upstream of the solenoid valve 5A,
5B and 5C and capillary tubes 6A, 6B and 6C
Thus, the flow rate adjusting means of the refrigerant is constituted.

The refrigerant discharged from the compressor 3 is supplied to the condenser 4 in a high-temperature and high-pressure gas state, where it radiates heat to the outside air to become a high-temperature and high-pressure liquid. Capillary tubes 6A-6C
The refrigerant which has been decompressed by the heat and becomes a low-temperature and low-pressure liquid is supplied to the evaporators 2A to 2C, where it absorbs the air in the chambers 1A to 1C to become a gas, and is sucked into the compressor 3 and again a high-temperature and high-pressure gas. It is discharged in a state. By repeating the above-mentioned known operation, the insides 1A to 1C are cooled.

The solenoid valves 5A to 5C are constituted by ON / OFF valves which take only two positions of fully open and fully closed. When the chambers 1A to 1C are cooled to a set temperature (for example, 5 ° C.), Upon receiving the output, it fully closes and shuts off the supply of refrigerant. As a result, the cooling operation of the refrigerator in which the supply of the refrigerant is shut off is stopped.

In the drawings, reference numerals 8A, 8B and 8C
Is an in-compartment fan for circulating cooling air or heated air in the in-compartment, 9A, 9B and 9C are in-compartment temperature sensors for detecting the in-compartment temperature, and 11 is to regulate the refrigerant temperature at the outlet of the condenser 4. The outside fan, and reference numeral 13
The check valve which prevents the backflow of the refrigerant | coolant from the compressor 3 to the evaporators 2A-2C side is each shown. In addition, warehouses 1B and 1
C is provided with heaters 12B and 12C as heaters, and the refrigerators 1B and 1C are configured as refrigerators for selling cold drinks or hot drinks according to the season. On the other hand, the storage 1A is configured as a storage for selling cold drinks throughout the year.

Here, for ease of explanation, it is assumed that the left storage 1A is a cooling room, and the middle storage 1B and the right storage 1C are all heating rooms. That is, the solenoid valves 5B and 5C are closed, and the refrigerant discharged from the compressor 3 is supplied to the evaporator 2 of the left storage 1A.
A case where only A is supplied will be described.

When the refrigerator 1A is cooled to the set temperature, the operation of the compressor 3 is stopped because there is no need to circulate the refrigerant through the refrigeration cycle. So conventionally,
As shown in FIG. 5, the operation of the compressor 3 was stopped when the temperature of the refrigerator 1A reached the set temperature (operation stop temperature), and then, for example, after 60 seconds, the operation of closing the solenoid valve 5A was performed. When the internal temperature rises and exceeds the set temperature, the solenoid valve 5A is opened again and the operation of the compressor 3 is restarted.

[0008]

However, in the conventional method of stopping the operation of the compressor 3 described above, it is necessary to suck the refrigerant remaining inside the evaporator 2A when the operation of the compressor 3 is restarted, Since the residual refrigerant inside has a large amount of liquid phase components, there is a problem that the load on the compressor 3 is large, and thus the power consumption is large.

The present invention has been made in view of the above-described problems, and provides a method of operating a compressor in a refrigeration circuit, which can reduce the load on the compressor and reduce power consumption when the operation of the compressor is started. Make it an issue.

[0010]

SUMMARY OF THE INVENTION The above objects are achieved by a compressor and a condenser arranged outside the system to be cooled, at least one evaporator arranged inside the system to be cooled, the condenser and the evaporator. In a method of operating a compressor in a refrigeration circuit that circulates a refrigerant through a refrigeration circuit configured by a flow rate adjustment unit of a refrigerant disposed between a cooling unit and a cooling system,
A method for operating a compressor in a refrigeration circuit, characterized in that the operation of the compressor is stopped after a predetermined time has elapsed since the supply of the refrigerant to the evaporator was interrupted by the flow rate adjusting means. Is done.

According to the present invention, the operation of the compressor is stopped after a lapse of a predetermined time after the supply of the refrigerant to the evaporator is interrupted by the flow rate adjusting means, so that the amount of the residual refrigerant inside the evaporator is suppressed as much as possible. The load on the compressor is reduced by reducing the amount of suctioned refrigerant when the operation of the compressor is restarted. This allows
In addition to suppressing the increase in power consumption, the amount of residual refrigerant in the evaporator is small, so that an excellent cooling effect can be obtained immediately after restarting the operation, and the power consumption can be greatly reduced as a whole.

As the flow rate adjusting means, a combination of a solenoid valve and a capillary tube or an electronic expansion valve can be applied. In the former case, the solenoid valve is closed, and in the latter case, the electronic expansion valve is closed. By the fully closing operation, the supply of the refrigerant to the evaporator can be shut off.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, a case will be described in which the present invention is applied to a cooling device of a vending machine, but, of course, the present invention is not limited to this.

FIG. 1 shows a refrigeration cycle of a vending machine cooling apparatus according to a first embodiment of the present invention. In the figure, parts corresponding to those in FIG. 4 are denoted by the same reference numerals.

The interior of the compartment is divided into three compartments, a left compartment 1A, a middle compartment 1B, and a right compartment 1C, with a heat insulating material 7 interposed therebetween. In the present embodiment, the left warehouse 1A is configured as a warehouse that sells cold drinks throughout the year, and the middle warehouse 1B and the right warehouse 1C are configured as warehouses that sell cold drinks or hot drinks according to the season. That is, only the evaporator 2A as a cooler is disposed in the left warehouse 1A, whereas the evaporators 2B, 2
C and heaters 12B and 12C as heaters are arranged.

Evaporators 2A to 2A arranged in each of the storages 1A to 1C
2C is connected in parallel to a compressor (compressor) 3 and a condenser 4 arranged outside the storage, respectively, and each storage 1A
A refrigeration circuit that cools the inside of 1C is configured. Therefore, in the present embodiment, between the condenser 4 and each of the evaporators 2A to 2C, the electronic expansion valve 15A,
15B and 15C are provided. Each electronic expansion valve 15A ~
15C are provided with pulse motors (or stepping motors) 16A, 16B and 16C, respectively, and the opening of each of the electronic expansion valves 15A to 15C is adjusted based on a pulse signal supplied from the control means 20.

Inlet and outlet temperature sensors 17A, 17B and 17C for detecting the temperature of the refrigerant and outlet temperature sensors 18 are provided at the inlet and outlet of each of the evaporators 2A to 2C.
A, 18B and 18C are installed respectively. The outputs of these temperature sensors 17A to 17C and 18A to 18C are supplied to the control means 20, and the temperature difference of the refrigerant at the entrance and exit of the evaporator, that is, the degree of superheat, is calculated for each of the evaporators 2A to 2C.

In this embodiment, each electronic expansion valve 15
A to 15C function as shut-off valves for shutting off the flow of the refrigerant when fully closed, and the temperature sensors 9A, 9B, and 9C in the refrigerator indicate that the refrigerators 1A to 1C have been cooled to a set temperature (for example, 5 ° C) or less. , The corresponding electronic expansion valves 15A to 15C are fully closed, and the evaporators 2A to 2C
The supply of refrigerant to the refrigerator is stopped, and the cooling operation in the refrigerator is stopped. When the refrigerator to be cooled has been cooled to the set temperature or lower, the operation of the compressor 3 is stopped by a method described later.

Next, the operation of the present embodiment will be described. In the present embodiment, a case will be described in which the left storage 1A is configured as a cooling room, and the middle storage 1B and the right storage 1C are configured as a heating room.

The middle storage 1B and the right storage 1C include a heater 12B,
The air heated by 12C is circulated by the internal fans 8B and 8C and is heated to a predetermined temperature (for example, 55 ° C.). On the other hand, in the left warehouse 1A, the air cooled by the evaporator 2A is circulated by the internal fan 8A and cooled. At this time, the electronic expansion valves 15B and 15C are fully closed and the supply of the refrigerant to the evaporators 2B and 2C is shut off.

Referring to FIG. 3, when compressor 3 starts operating, refrigerant circulates in a refrigeration circuit constituted by compressor 3, condenser 4, electronic expansion valve 15A and evaporator 2A. The opening degree of the electronic expansion valve 15A is sequentially controlled by the control means 20 so that the degree of superheat of the refrigerant in the evaporator 2A becomes a predetermined value (for example, 5 ° C.) (step S1). Thereby, the storage 1A is efficiently cooled. The above operation is performed by the warehouse 1A.
Is continued until the set temperature is reached (step S
2).

When the refrigerator 1A is cooled down to the set temperature, the driving of the compressor 3 is stopped. Therefore, in the present embodiment, as shown in FIG. 2, when the refrigerator 1A reaches the set temperature, the electronic expansion valve 15A is fully closed (step S3), and then the operating time tc of the compressor 3 is reduced to a predetermined time td (second). The control means 2 stops the operation of the compressor 3 after the elapse of
0 (steps S4 and S5). That is,
After the electronic expansion valve 15A is fully closed, the compressor 3 is operated for a predetermined time td to suck and remove the refrigerant in the evaporator 2A.

Accordingly, when the operation of the compressor 3 is restarted, the load on the compressor 3 can be reduced by reducing the amount of the suctioned refrigerant, and the superheat degree can be reduced by the small amount of the residual refrigerant inside the evaporator 2A. Responsiveness is improved, so that an excellent cooling effect can be obtained immediately after restart of operation, and overall power consumption can be significantly reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. Also in the present embodiment, only the left storage 1A will be described as a cooling room, and the other storages 1B and 1C will be described as heating rooms.

That is, in the present embodiment, the flow rate adjusting means for adjusting the flow rate of the refrigerant from the condenser 4 to the evaporator 2A is constituted by the solenoid valve 5A and the capillary tube 6A. And form. Therefore, warehouse 1A
When the compressor is cooled to the set temperature and the operation of the compressor 3 is stopped, the control means is configured to stop the operation of the compressor 3 after operating the compressor 3 for a predetermined time td after closing the solenoid valve 5A. 10 is constituted. Thereby, an effect similar to that of the above-described first embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these embodiments.
Various modifications are possible based on the technical idea of the present invention.

For example, in each of the embodiments described above, the case where only the refrigerator 1A is configured as a cooling chamber has been described. However, the present invention is not limited to this, and the present invention is also applicable to a case where the other refrigerators 1B and 1C are also configured as cooling chambers. Applicable. In this case, the count of the operating time tc of the compressor 3 may be started after the electronic expansion valves 15A to 15C or the solenoid valves 5A to 5C corresponding to the storage to which the refrigerant has been supplied to the end are fully closed.

Further, in each of the embodiments described above, the case where the present invention is applied to a refrigeration circuit in a cooling device of a vending machine has been described. Of course, the present invention is not limited to this, and stores food that requires refrigeration or freezing. The present invention can be applied to other storages.

[0029]

As described above, according to the method of operating a compressor in a refrigeration circuit of the present invention, an excellent cooling effect can be obtained immediately after the start of operation of the compressor, and the load on the compressor can be reduced. As a result, the power consumption can be significantly reduced as a whole.

According to the fourth aspect of the present invention, an excellent energy-saving effect can be obtained by applying the present invention to a vending machine which operates all year round and is installed outdoors.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a refrigeration circuit of a cooling device of a vending machine for explaining a first embodiment of the present invention.

FIG. 2 is a time chart illustrating a method of operating a compressor in the refrigeration circuit.

FIG. 3 is a flowchart illustrating an operation of the refrigeration circuit.

FIG. 4 is a schematic diagram showing a refrigeration circuit of a cooling device of a general vending machine, or a refrigeration circuit of a cooling device of a vending machine for explaining a second embodiment of the present invention.

FIG. 5 is a time chart illustrating a method of operating a compressor in a conventional refrigeration circuit.

[Explanation of symbols]

 Reference Signs List 1A Left warehouse 1B Middle warehouse 1C Right warehouse 2A Evaporator 2B Evaporator 2C Evaporator 3 Compressor 4 Condenser 5A Electromagnetic valve 5B Electromagnetic valve 5C Electromagnetic valve 6A Capillary tube 6B Capillary tube 6C Capillary tube 10 Control means 15A Electronic expansion valve 15B Electronic expansion valve 15C Electronic expansion valve 20 Control means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuaki Nagayama 5-6-6 Koyodai, Ryugasaki-shi, Ibaraki Pref. VM-PT within Kubota Ryugasaki Plant (72) Inventor Nobuhiko Tanaka 5-6-koyodai, Ryugasaki-shi, Ibaraki Inside the Kubota Ryugasaki Plant VM-PT (72) Inventor Hiromitsu Kowada 5--6 Koyodai, Ryugasaki City, Ibaraki Prefecture Inside the VM-PT Kubota Ryugasaki Plant VM-PT (72) Inventor Tanewa Chiba, Koyodai, Ryugasaki City, Ibaraki Prefecture 5th-6th F-term in the Kubota Ryugasaki Plant VM-PT (reference) 3E044 AA01 DB16 FB11 3H045 AA09 AA12 AA27 BA32 CA24 CA29 DA01 DA15 EA35 EA38 3L045 AA02 BA01 DA02 EA01 GA07 HA03 HA07 JA03 PA05

Claims (4)

[Claims] 1. A compressor and a condenser arranged outside a system to be cooled, at least one evaporator arranged inside the system to be cooled, and a refrigerant arranged between the condenser and the evaporator In a method for operating a compressor in a refrigeration circuit that circulates a refrigerant through a refrigeration circuit configured by a flow rate adjusting means and cools the inside of the system to be cooled, the supply of the refrigerant to the evaporator is cut off by the flow rate adjusting means. A method of operating a compressor in a refrigeration circuit, wherein the operation of the compressor is stopped after a predetermined time has elapsed since the start of the operation. 2. The method for operating a compressor in a refrigeration circuit according to claim 1, wherein an electronic expansion valve capable of shutting off the flow of refrigerant when fully closed is used as said flow rate adjusting means. 3. The method for operating a compressor in a refrigeration circuit according to claim 1, wherein a combination of an electromagnetic valve capable of flowing / blocking a refrigerant and a capillary tube is used as said flow rate adjusting means. 4. The inside of the system to be cooled is an interior of a vending machine in which commodities are stored, and when the interior of the interior of the vending machine is cooled to a set temperature or lower, the flow rate adjusting means transfers refrigerant to the evaporator. The method for operating a compressor in a refrigeration circuit according to any one of claims 1 to 3, wherein the supply is shut off.