JPH08271065A - Refrigerator - Google Patents

Abstract

PURPOSE: To reduce the starting torque of a drive motor by alleviating the starting load of a compressor. CONSTITUTION: This refrigerator pressurizes refrigerant gas generated by an evaporator 1 to be supplied to an evaporator 2, and comprises a shut-off valve 12 which is fully closed when the motor 4 is started and fully opened in a steady operation state between the evaporator 1 and a compressor 3, wherein the starting load of the compressor 3 is alleviated to reduce the starting torque of the motor 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump and a refrigerating device used in a low temperature field of 0.degree.

[0002]

2. Description of the Related Art In recent years, in building air-conditioning, a heat pump, which secures a heating heat quantity by an electric refrigerating device as clean energy, has attracted attention.

In such a refrigerating apparatus, the heat source water for the heating specification has a general cooling condition (the inlet temperature is 10 ° C. to 1 ° C.).
Unlike 2 ℃, the temperature condition is high (the inlet temperature is 25 ℃ to 3 ℃).
5 ° C.), the difference between the hot water outlet temperature and the heat source water inlet temperature is smaller than in the cooling condition. Therefore, the required heat insulation head of the compressor is lower than that of the cooling specification, and less power is required.

On the other hand, when the compressor is started, relatively high temperature water is passed through the heat exchanger in the refrigeration system, so that the density of the refrigerant gas in the machine becomes high. In a refrigeration system including an evaporator, a condenser, and a compressor, a capacity control device including a plurality of blades is generally provided on the suction side of the compressor. In order to make the operation of this capacity control device smooth, a certain amount of gap is generated between the blades even in the fully closed state. At start-up, the refrigerant gas is sucked into the compressor through this gap, so that the load torque on the drive source becomes high, and the drive source needs to generate a start-up torque that exceeds this.

On the other hand, in a refrigeration system used in the low temperature field, brine of 0 ° C. or lower flows through the heat transfer tube of the evaporator,
Since the temperature inside the evaporator during operation is lower than that in general cooling specifications, the density of the suction gas of the compressor is low, and less power is required even under the conditions of the same required heat insulation head and compressor required air volume as in the cooling specifications. However, at the time of startup, when the brine temperature rises from a relatively high condition, the density of the refrigerant gas inside the machine becomes high, so the load torque becomes high, and a startup torque superior to this is required.

As described above, the required power during operation is small,
In refrigeration equipment for applications that require a high drive torque at startup, conventionally, the drive source and the startup method (for example, in the case of an electric motor, the reactor tap is increased as the startup method so that the load torque at startup is satisfied. Etc.) are selected.

[0007]

In the refrigerating apparatus of such a system, when the electric motor is used as the drive source, the starting system is restricted and the capacity of the power supply equipment must be increased. If the start-up method cannot be used, the price will rise because it is necessary to increase the capacity of the electric motor itself (use an electric motor with a large output).

An object of the present invention is to provide a relatively simple and inexpensive refrigerating apparatus which uses a drive source suitable for a specified capacity during operation and which can start the drive source without being restricted by a starting method. It is in.

Specifically, it is intended to reduce the load torque of the compressor when starting the refrigeration system so that the drive motor can be started easily.

[0010]

One of the features of the present invention is as follows.
A compressor that sucks and pressurizes the refrigerant gas generated in the evaporator, a condenser that radiates the pressurized refrigerant gas to liquefy and recirculate to the evaporator, and a drive source that drives the compressor In the refrigerating apparatus, there is provided a refrigerant gas regulation unit that regulates the refrigerant gas flowing into the compressor when it is in the fully closed state when the drive source is started.

[0012] Specifically, the refrigerant gas regulating means is characterized by including a shutoff valve for shutting off the refrigerant gas flowing into the compressor, or a capacity installed at the suction port of the compressor. It is characterized in that the control device interrupts the flow of the refrigerant gas.

Another feature of the present invention is a compressor for sucking and pressurizing a refrigerant gas generated in an evaporator, and a condenser for radiating the pressurized refrigerant gas by heat to liquefy it and returning it to the evaporator. In a refrigeration apparatus having a drive source for driving the compressor, a shutoff valve between the evaporator and the compressor is in a fully closed state when the drive source is started, and is in a fully open state in a steady operation state. Has been established.

Further, specifically, a capacity control device having a plurality of blades is provided at the suction port of the compressor, and the shutoff valve is installed between the capacity control device and the evaporator. Alternatively, the shutoff valve is controlled to a fully closed state when the drive source is started, and is controlled to a fully open state during steady operation and during stop, and the shutoff valve is a butterfly valve. And

Still another feature of the present invention is that a condenser which radiates heat of a pressurized refrigerant gas to liquefy the refrigerant gas and circulates it to the evaporator, and an economizer provided in a reflux passage between the condenser and the evaporator. In a refrigeration apparatus including a multi-stage compressor that pressurizes a refrigerant gas generated in the evaporator and the economizer to supply the evaporator, and a drive source that drives the compressor, the evaporator, the economizer, and the multi-stage compression are provided. A shut-off valve that is in a fully closed state when the drive source is started and that is in a fully opened state in a steady operation state is provided between the machines.

Specifically, a capacity control device having a plurality of blades is provided at the suction port of the multi-stage compressor, and a shut-off valve provided between the evaporator and the multi-stage compressor is the capacity control device and the evaporation valve. Characterized by being installed between vessels, or
The shutoff valve is controlled to a fully closed state when the drive source is started, and is controlled to a fully open state during steady operation and stop, and the shutoff valve is a butterfly valve.

Still another feature of the present invention is that a condenser that radiates the pressurized refrigerant gas to liquefy and circulates it to the evaporator, and an economizer provided in a reflux path between the condenser and the evaporator. A multi-stage compressor having a capacity control device in the middle stage for pressurizing the refrigerant gas generated in the evaporator and the economizer and supplying the same to the evaporator, and a refrigeration system provided with a drive source for driving the compressor, A shut-off valve is provided between the evaporator and the multi-stage compressor, which is in a fully closed state when the drive source is started and is in a fully opened state in a steady operation state.

More specifically, the middle stage capacity control device is characterized in that it is brought into a fully closed state when the drive source is started.

[0018]

When the power source is started, the refrigerant gas flowing into the compressor is regulated, so that the compressor is in a no-load state or a slight load state, and the power source can be started with a small starting torque.

Specifically, the shut-off valve or the capacity control device shuts off the refrigerant gas flowing into the compressor from the evaporator or the economizer when the power source is started, and puts the compressor in the no-load state. Then, the shutoff valve is in a fully opened state during operation and stop to eliminate the influence on the refrigeration cycle,
This prevents the refrigerant liquid generated by condensing the refrigerant gas from accumulating in the shutoff valve.

Further, the shutoff valve using the butterfly valve and the capacity control device having the function as the shutoff valve can regulate the refrigerant gas flowing into the compressor at the time of starting with a simple structure.

[0021]

Embodiments of the present invention will be described with reference to FIGS.

FIG. 1 is a system diagram of a refrigerating apparatus showing a first embodiment of the present invention. This refrigeration system comprises an evaporator 1, a condenser 2, a compressor 3, a drive motor for driving the compressor 3, and a starter 5 such as a star-delta switch for controlling the start of the drive motor 4. The compressor 3 includes a capacity control device 8 having a plurality of blades 6 and an electric drive 7.

The compressor 3 sucks the refrigerant gas generated in the evaporator 1 through the intake pipe 9 and pressurizes it, and supplies the pressurized refrigerant gas to the condenser 2 through the compressed gas pipe 10. The refrigerant liquid radiated by radiating heat in the condenser 2 is supplied to the evaporator 1 through the refrigerant liquid pipe 11. Then, the refrigerant liquid supplied to the evaporator 1 absorbs heat to be vaporized into a refrigerant gas.

In the middle of the intake pipe 9, a shutoff valve 12 having a high degree of airtightness for interrupting the refrigerant gas flowing through the intake pipe 9 and an electric drive 13 for opening and closing the shutoff valve 12 are installed.
The shutoff valve 12 is a butterfly valve that is of a general-purpose type and has a high degree of sealing, and the electric drive unit 13 has a built-in fully closed sensor that detects that the shutoff valve 12 is fully closed.

The control board 14 controls the electric drive 13 to open / close the shutoff valve 12, controls the starter 5 which starts the drive motor 4, and causes the capacity controller 8 to operate. It has a control function for controlling 7.

With the above-mentioned structure, when the starting condition of the refrigerating apparatus is established, the control panel 14 first controls the electric drive unit 13 so that the shutoff valve 12 is fully closed. Then, when a detection signal for detecting that the shutoff valve 12 is in the fully closed state is received from the fully closed sensor of the electric drive motor 13, the starter 5 is controlled to start the drive motor 4. Until the drive motor 4 reaches full speed and the tap of the starter 5 is switched (in this embodiment, before switching from the star connection to the delta connection), the shut-off valve 12 is held in the fully closed state, and the tap is maintained. The electric drive unit 13 is controlled so that the shutoff valve 12 is fully opened when the switch is switched to the fully open state during the subsequent operation. Therefore, when the drive motor 4 is started, the refrigerant gas from the evaporator 1 does not flow into the compressor 3, so that the compressor 3 is in a light load state and the drive motor 4 can be started with a small starting torque.

On the other hand, the capacity control device 7 controls the electric drive machine 7 so as to exert the capacity control function after the tap of the starter 5 is switched.

When stopping this refrigeration system, the control panel 1
4 controls the starter 5 so as to stop the drive motor 4. Shut-off valve 1 even during the stop period after the drive motor 4 is stopped
2 controls the electric drive machine 13 so as to maintain the fully opened state. This is to prevent the inconvenience that the refrigerant liquid generated by the condensation of the refrigerant gas during the stoppage is accumulated on the cutoff valve 12 and is sucked into the compressor 3 at the next start depending on the mounting position of the cutoff valve 12. According to such a refrigerating apparatus, a relatively simple and inexpensive refrigerating apparatus can be used which uses a drive motor and a power supply device suitable for a specification capacity during operation and can start the drive motor without restriction of a starting method. Can be provided.

FIG. 2 is a system diagram of a refrigerating apparatus showing a second embodiment of the present invention. This refrigeration system is different from the above-described first embodiment in that the compressor 3 includes two-stage impellers 3a and 3b, and an economizer 15 and a second cutoff valve 16 are provided. The same reference numerals are given to the constituent means corresponding to the constituent means of the first embodiment described above, and the duplicated description will be omitted.

In this embodiment, the refrigerant gas discharged from the impeller 3b at the latter stage of the compressor 3 is supplied to the evaporator 2 through the compressed gas pipe 10. The gas-liquid mixed refrigerant, which is supplied to the evaporator 2 and partially liquefied, is supplied to the economizer 15 through the gas-liquid refrigerant return pipe 17, the refrigerant liquid returns to the evaporator 1 through the refrigerant liquid pipe 11, and the refrigerant gas is the refrigerant. Gas pipe 1
It is supplied to the suction port of the intermediate stage of the multi-stage compressor 3 through 8. The second shutoff valve 16 that is opened and closed by the electric drive unit 19 is connected so as to intervene in the middle of the refrigerant gas pipe 18. The electric drive unit 19 has a built-in fully closed sensor that detects that the second cutoff valve 16 is in the fully closed state.

The control panel 14 also controls an electric drive 19 for opening and closing the second shutoff valve 16.

In the above structure, when the starting condition of this refrigerating apparatus is satisfied, the control panel 14 sets the first shutoff valve 12 and the second shutoff valve 16 to the fully closed state.
3 and 19 are controlled. Then, when a detection signal which detects that the shutoff valves 12 and 16 are in the fully closed state is received from the fully closed sensors of the electric motors 13 and 19, the starter 5 is controlled to start the drive motor 4. . Both shutoff valves 12, 1
The fully closed state of 6 continues until the drive motor 4 becomes the full speed state. When the drive motor 4 enters the steady operation state, the electric drive devices 13, 19 are operated so that both the shutoff valves 12, 16 are fully opened.
Control. Therefore, the multi-stage compressor 3 can be started in a light load state.

When stopping this refrigeration system, the control panel 1
4 controls the starter 5 so as to stop the drive motor 4. The electric drive motor 1 is configured so that the shutoff valves 12 and 16 are kept in the fully opened state even during the stop period after the drive motor 4 is stopped.
3 and 19 are controlled.

FIG. 3 is a system diagram of a refrigerating apparatus showing a third embodiment of the present invention. This refrigeration system is different from the second embodiment described above in that the multi-stage compressor 3 has a second capacity control device 2 having a plurality of blades 20 installed in the suction part of the intermediate stage.
1 and an electric drive 2 for operating the second capacity control device 21
2 in that the second shutoff valve 16 is omitted. The same reference numerals are given to the constituent means corresponding to the constituent means of the above-described first and second embodiments, and the duplicated description will be omitted.

The electric drive motor 22 for operating the second capacity control device 21 is provided with a fully closed sensor for detecting that the blade 20 is in a fully closed state, and the control panel 14 is provided with the second capacity control device 21. It also controls the electric drive unit 22 that operates the.

In the above structure, when the starting condition of the refrigerating apparatus is satisfied, the control panel 14 sets the shutoff valve 12 and the second capacity control device 21 to the fully closed state.
3 and 22 are controlled. Then, the shut-off valve 12 and the second capacity control device 21 from the fully closed sensor of the electric drive machines 13 and 22.
When it receives a detection signal that detects that the drive motor is in the fully closed state, the starter 5 is controlled to start the drive motor 4. The shutoff valve 12 and the second displacement control device 21 are kept in the fully closed state until the drive motor 4 reaches the full speed state. When the drive motor 4 enters a steady operation state, the electric drive motor 13 is controlled so as to fully open the shutoff valve 12, and the multi-stage compressor 3 can be started in a light load state.

When stopping this refrigeration system, the control panel 1
4 controls the starter 5 so as to stop the drive motor 4. Shut-off valve 1 even during the stop period after the drive motor 4 is stopped
2 controls the electric drive machine 13 so as to maintain the fully opened state.

If it is desired to further reduce the starting load torque, the second shutoff valve 16 may be added in the middle of the ninth stage of the refrigerant gas 18. At this time, the second capacity control device 21
Can be omitted.

The blade 6 in the capacity control device 8 is set to 1
If the number of round blades is reduced and the outer diameter gap of the blades is reduced as much as possible or a material having a sealing property (for example, rubber or Teflon) is coded on the outer diameter portion to increase the degree of sealing, the capacity control device 8 Can also be used as the shutoff valve 12.

In the case of a refrigerating apparatus having a low activation frequency, the shutoff valves 12 and 16 can be manually operated.

[0041]

According to the present invention, since the starting load of the compressor can be reduced and the starting torque of the drive source can be reduced, a drive source suitable for the specified capacity during operation is used, and It is possible to provide a relatively simple and inexpensive refrigeration system that can start the drive source without being restricted.

[Brief description of drawings]

FIG. 1 is a system diagram of a refrigeration system showing a first embodiment of the present invention.

FIG. 2 is a system diagram of a refrigeration system showing a second embodiment of the present invention.

FIG. 3 is a system diagram of a refrigeration system showing a third embodiment of the present invention.

[Explanation of symbols]

1 ... evaporator, 2 condenser, 3 ... compressor, 4 ... drive motor,
5 ... Starter, 6 ... Blade, 7 ... Electric drive machine, 8 ... Capacity control device, 12 ... Shutoff valve, 13 ... Electric drive machine, 14 ... Control panel.

Claims (13)

[Claims] 1. A compressor for sucking and pressurizing a refrigerant gas generated in an evaporator, a condenser for radiating the pressurized refrigerant gas to liquefy it and returning it to the evaporator, and a compressor for driving the compressor. A refrigerating apparatus provided with a drive source, wherein a refrigerating apparatus for regulating a refrigerating gas that is in a fully closed state when the drive source is activated and regulates refrigerant gas flowing into the compressor is provided. 2. The refrigerating apparatus according to claim 1, wherein the refrigerant gas regulating means includes a shutoff valve that shuts off the refrigerant gas flowing into the compressor. 3. The refrigerating apparatus according to claim 1, wherein the refrigerant gas regulating means is configured to cut off the refrigerant gas flow by a capacity control device installed at the suction port of the compressor. 4. A compressor for sucking and pressurizing a refrigerant gas generated in an evaporator, a condenser for radiating the pressurized refrigerant gas to liquefy it and returning it to the evaporator, and a compressor for driving the compressor. In a refrigerating apparatus having a drive source, a shutoff valve is provided between the evaporator and the compressor, which is in a fully closed state when the drive source is started and is in a fully opened state in a steady operation state. Refrigeration equipment. 5. The compressor according to claim 4, wherein a capacity control device having a plurality of blades is provided at a suction port of the compressor, and the cutoff valve is installed between the capacity control device and the evaporator. Refrigerating device. 6. The refrigerating apparatus according to claim 4, wherein the shutoff valve is controlled to a fully closed state when the drive source is started, and is controlled to a fully opened state during steady operation and stop. 7. The refrigerating apparatus according to claim 4, wherein the shutoff valve is a butterfly valve. 8. A condenser for radiating a pressurized refrigerant gas to liquefy it and return it to the evaporator, an economizer provided in a return passage between the condenser and the evaporator, and the evaporator and the economizer. In a multi-stage compressor that pressurizes the refrigerant gas generated in step 1 and supplies it to the evaporator, and a refrigeration apparatus that includes a drive source that drives this compressor, between the evaporator and the economizer and the multi-stage compressor, the drive A refrigeration apparatus provided with a shutoff valve that is in a fully closed state when the power source is started and is in a fully opened state in a steady operation state. 9. The capacity control device according to claim 8, wherein a capacity control device having a plurality of blades is provided at the suction port of the multi-stage compressor, and a shut-off valve provided between the evaporator and the multi-stage compressor is the capacity control device and the evaporation device. Refrigerating device characterized by being installed between the containers. 10. The refrigerating apparatus according to claim 8, wherein the shutoff valve is controlled to a fully closed state when the drive source is started, and is controlled to a fully open state during steady operation and stop. 11. The refrigerating apparatus according to claim 8, wherein the shutoff valve is a butterfly valve. 12. A condenser that radiates heat of a pressurized refrigerant gas to liquefy it and return it to the evaporator, an economizer provided in a return passage between the condenser and the evaporator, and the evaporator and the economizer. In a multi-stage compressor having a capacity control device in the middle stage of pressurizing the refrigerant gas generated in step 1 and supplying the same to the evaporator, and a refrigeration system provided with a drive source for driving the compressor, the evaporator and the multi-stage compressor are A refrigeration apparatus provided with a shut-off valve that is in a fully closed state when the drive source is started and that is in a fully opened state in a steady operation state. 13. The refrigerating apparatus according to claim 12, wherein the middle capacity control device is brought into a fully closed state when the drive source is started.