JP2002285971A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration device using a sealed compressor, capable of continuously operating by preventing pressure of a sealed vessel of the sealed compressor from becoming high, exceeding the designated pressure. SOLUTION: The refrigeration device 1 includes a compression part, composed of a first stage compression part compressing refrigerant sucked in the sealed vessel from a suction pressure to an intermediate pressure and a second stage compression part compressing the refrigerant of the intermediate pressure from the first stage compression part to a discharge pressure, and is provided with the sealed compressor 2, having a pressure in the sealed vessel set same as the intermediate pressure, a pressure detecting device 8 detecting the intermediate pressure, a selector device 7 selecting operations of only the first stage compression part or operation of the first stage compression part and the second stage compression part of the compression part, and a control device 9 controlling the selector device 7 to select operation of only the first stage compression part on the compression part, when the intermediate pressure detected by the pressure detection device 8 reaches the designated pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system using a hermetic compressor.

[0002]

2. Description of the Related Art Freon refrigerant has conventionally been used as a refrigerant used in a refrigeration system. It has been found that the refrigerant contains a chlorine group and causes ozone layer destruction. As an alternative refrigerant, there is utilization of a carbon dioxide refrigerant which is a natural refrigerant.

[0003] Generally, a hermetic-type compressor having a single-stage refrigerant compression section has a structure in which refrigerant gas compressed to cool an electric motor section is discharged into a closed vessel and discharged to the outside. Is the discharge pressure.

When a carbon dioxide refrigerant is used in a refrigeration system, it requires a higher operating pressure than a chlorofluorocarbon refrigerant.
The pressure in the sealed container of the sealed compressor increases.

[0005] In order to reduce the pressure in the hermetic container of the hermetic compressor, the hermetic compressor having a plurality of stages of compression sections is used to reduce the pressure in the hermetic container of the hermetic compressor by the suction pressure and discharge pressure. Some pressures are intermediate pressures.

Some refrigeration systems of this type include a refrigerant-to-water heat exchanger that can supply hot water by utilizing the heat of the refrigerant.

[0007]

However, for example, when the supply water temperature or the outside air temperature of the refrigerant-to-water heat exchanger provided in the refrigeration system increases, the suction pressure of the refrigerant into the hermetic compressor increases,
The pressure in the sealed container of the sealed compressor increases. When this becomes high, there is a problem that the operation of the hermetic compressor is stopped by the operation of the protection mechanism.

An object of the present invention has been made in view of the above circumstances, and prevents the pressure in a closed vessel of a hermetic compressor from becoming higher than a predetermined pressure, thereby enabling continuous operation. It is an object of the present invention to provide a refrigeration apparatus using a hermetic compressor capable of performing the above-mentioned operations.

[0009]

According to the first aspect of the present invention,
In a closed vessel, a compression section comprising a pre-compression section that compresses the suction refrigerant from suction pressure to an intermediate pressure and a post-compression section that compresses the intermediate-pressure refrigerant from the pre-compression section to a discharge pressure, In a refrigeration system including a hermetic compressor in which the pressure in a closed vessel is set equal to the intermediate pressure, a pressure detection device that detects the intermediate pressure, and the compression section operates only the rear compression section, or A switching device for switching to one of the operation of the first-stage compression section and the second-stage compression section,
When the intermediate pressure detected by the pressure detection device reaches a predetermined pressure, the control device controls the switching device, and controls the compression unit to operate only the rear-stage compression unit. Is what you do.

The first aspect of the invention has the following operation.

When the intermediate pressure in the hermetic container of the hermetic compressor reaches a predetermined pressure, the operation of the compression section is switched to the operation of only the subsequent compression section to lower the pressure in the hermetic vessel and exceed the predetermined pressure. Can be prevented from rising.

According to a second aspect of the present invention, in the first aspect of the invention, the switching device includes a first suction circuit provided on a refrigerant suction side of the first-stage compression section, and a refrigerant suction side of the second-stage compression section. A control unit that stops the flow of the suction refrigerant into the first suction circuit when the intermediate pressure detected by the pressure detection device reaches a predetermined pressure. And controlling the suction refrigerant to flow into the second suction circuit, so that the operation of the compression unit is the operation of only the rear compression unit.

The invention according to claim 2 has the following operation.

When the intermediate pressure in the hermetic container of the hermetic compressor reaches a predetermined pressure, the operation of the compression section is stopped by interrupting the flow into the first suction circuit and allowing the suction refrigerant to flow only into the second suction circuit. By switching to the operation of only the latter-stage compression section, the pressure in the closed vessel can be reduced, and it is possible to prevent the pressure from exceeding the predetermined pressure and increasing.

According to a third aspect of the present invention, there is provided a pre-compressor for compressing a suction refrigerant from a suction pressure to an intermediate pressure in a closed vessel and a post-compression for compressing the intermediate-pressure refrigerant from the pre-compressor to a discharge pressure. And a pressure detecting device for detecting the intermediate pressure, wherein the pressure in the closed container is set to be equal to the intermediate pressure. A cooling device that enables on / off control of the cooling of the compressor; and a control device that turns on the cooling device when the intermediate pressure detected by the pressure detection device reaches a predetermined pressure. Things.

The third aspect of the invention has the following operation.

When the intermediate pressure in the hermetic container of the hermetic compressor reaches a predetermined pressure, the hermetic compressor is cooled by the cooling device, and the temperature of the refrigerant in the hermetic container is reduced to thereby reduce the temperature of the hermetic compressor. It is possible to reduce the pressure in the closed vessel and prevent the pressure from exceeding a predetermined pressure.

According to a fourth aspect of the present invention, in the third aspect of the invention, the cooling device cools the hermetic compressor with water.

The invention according to claim 4 has the following operation.

When the intermediate pressure in the hermetic container of the hermetic compressor reaches a predetermined pressure, the hermetic compressor is water-cooled and the temperature of the refrigerant in the hermetic container is lowered to thereby reduce the temperature in the hermetic container of the hermetic compressor. Can be prevented from increasing beyond a predetermined pressure.

According to a fifth aspect of the present invention, there is provided a pre-compressor for compressing a suction refrigerant from a suction pressure to an intermediate pressure in a closed container, and a post-compression for compressing the intermediate pressure refrigerant from the pre-compressor to a discharge pressure. And a heat exchange between the high-pressure refrigerant from the hermetic compressor and the external water supply. In a refrigeration system including a refrigerant-to-water heat exchanger and a water supply circuit for supplying water to the refrigerant-to-water heat exchanger, a pressure detection device that detects the intermediate pressure, and on / off control of cooling of the hermetic compressor can be performed. A cooling device, and a control device for turning on the cooling device when the intermediate pressure detected by the pressure detection device reaches a predetermined pressure, wherein the cooling device guides water supply from the water supply circuit. Circuit and It is characterized in that it has a water cooling circuit for water cooling the hermetic compressor with water led by the water guide circuit.

The fifth aspect of the invention has the following operation.

When the intermediate pressure in the sealed container of the sealed compressor reaches a predetermined pressure, water is introduced from the water supply circuit of the refrigerant-to-water heat exchanger to water-cool the sealed compressor, and the temperature of the refrigerant in the sealed container is reduced. By reducing the pressure, the pressure in the sealed container of the hermetic compressor can be reduced, and it can be prevented that the pressure exceeds a predetermined pressure.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the cooling device includes a pull-back circuit for returning the water used for cooling the hermetic compressor in the water cooling circuit to the water supply circuit. It is characterized by having.

The sixth aspect of the invention has the following operation.

When the intermediate pressure in the hermetic container of the hermetic compressor reaches a predetermined pressure, water is introduced from the water supply side of the refrigerant-to-water heat exchanger to water-cool the hermetic compressor, and the water is cooled by the refrigerant-to-water heat exchanger. Back to the water supply side and supply water to the refrigerant-to-water heat exchanger, lowering the temperature of the refrigerant in the closed container, thereby lowering the pressure in the closed container of the sealed compressor, and exceeding the predetermined pressure. Can be prevented.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the refrigerant is a carbon dioxide refrigerant.

The invention according to claim 7 has the following operation.

When a carbon dioxide refrigerant requiring a higher operating pressure than a Freon refrigerant is used as the refrigerant,
When the intermediate pressure in the hermetic container of the hermetic compressor reaches a predetermined pressure, the intermediate pressure in the hermetic container can be reduced to prevent it from exceeding the predetermined pressure.

[0030]

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

In the refrigerating apparatus according to the embodiment of the present invention, a case will be described in which a carbon dioxide refrigerant which is a natural refrigerant is used as the refrigerant.

[A] First Embodiment FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to a first embodiment of the present invention.

Reference numeral 1 denotes a refrigeration apparatus, and this refrigeration apparatus 1
A hermetic compressor 2 for compressing the suction refrigerant in one stage or two stages, and a refrigerant-to-water heat exchanger 3 for exchanging heat between high-pressure refrigerant discharged from the hermetic compressor 2 and external water supply.
An expansion valve 4 for expanding the refrigerant exchanged by the refrigerant-water heat exchanger 3; an evaporator 5 for exchanging heat between the refrigerant expanded by the expansion valve 4 and the outside air; Accumulator 6 for performing gas-liquid separation of the refrigerant that has undergone heat exchange with the compressor, and one-stage compression of suction refrigerant of the hermetic compressor 2 and 2
And a switching device 7 for switching between stepwise compression.

The refrigerating device 1 is a closed type compressor 2
And a control device 9 for controlling the switching device 7 in accordance with the detection result of the pressure detection device 8. This pressure detecting device 8 is a pressure sensor.

As shown in FIG. 2, the hermetic compressor 2 has a hermetic container 10, and an electric motor 11 and a compressor 12 are provided inside the hermetic container 10. Compression unit 1
2 includes a first-stage compression unit 13 and a second-stage compression unit 14. The first-stage compression section 13 is provided with a refrigerant suction port 13a and a discharge port 13b, and the second-stage compression section 14 is provided with a refrigerant suction port 14a and a discharge port 14b. A first suction pipe 15 for guiding a suction refrigerant is connected to a suction port 13a of the first-stage compression section 13. A discharge pipe 13b for discharging the refrigerant compressed by the pre-compression unit 13 into the closed vessel 10 is provided at a discharge port 13b of the pre-compression unit 13. The discharge pipe of the pre-compression unit 13 A check valve 17 for preventing the refrigerant from flowing back to 13a is provided.

The suction port 14a of the second compression unit 14 is disposed inside the closed container 10, and the refrigerant inside the closed container 10 is sucked through the suction port 14a of the second compression unit 14. A discharge pipe 18 is connected to a discharge port 14b of the rear compression unit 14,
The refrigerant compressed by the rear compression unit 14 is discharged. A second suction pipe 19 for guiding the suction refrigerant is connected to the closed container 10.

The switching device 7 includes a first suction circuit 31 and a second suction circuit 32. The first suction circuit 31 is connected to the first suction pipe 15, and the second suction circuit 32 is connected to the second suction pipe 19. The first suction circuit 31 includes a solenoid valve 41
The opening and closing of the solenoid valve 41 controls the suction of the suction refrigerant into the pre-stage compression section 13. The second suction circuit 32 has an electromagnetic valve 42, and the opening and closing of the electromagnetic valve 42 controls the suction of the suction refrigerant into the closed container 10.

The pressure inside the closed casing 10 is an intermediate pressure P3 between the suction pressure P1 of the suction refrigerant and the discharge pressure P2 of the refrigerant compressed by the rear compression unit 14.

In the above configuration, for example, in summer, the supply water temperature and the outside air temperature of the refrigerant / water heat exchanger 3 increase.
Alternatively, one of the temperatures increases. When the refrigeration apparatus 1 is operated in this state, the suction pressure P1 of the refrigerant into the hermetic compressor 2 increases, and the intermediate pressure P3 of the refrigerant compressed in the first-stage compression section 13 increases.

Normally, when the intermediate pressure P3 rises, a protection mechanism (not shown) of the hermetic compressor 2 operates to stop the operation of the hermetic compressor 2.

In the present embodiment, the intermediate pressure P3 inside the closed casing 10 is detected by the pressure sensor which is the pressure detecting device 8. The control device 9 controls the solenoid valve 4 of the first suction circuit 31 according to the detection result of the pressure sensor that is the pressure detection device 8.
1 and the opening and closing of the solenoid valve 42 of the second suction circuit 32 is controlled.

In normal operation, the control device 9 controls to open the solenoid valve 41 of the first suction circuit 31 and controls to close the solenoid valve 42 of the second suction circuit 32. By this control, the suction refrigerant having the suction pressure P1 is compressed by the pre-compressor 13, and the refrigerant having the intermediate pressure P3 passes through the passage pipe 16 and is discharged into the closed container 10. This refrigerant is further compressed by the latter-stage compression section 14 and discharged at the discharge pressure P2. That is, the hermetic compressor 2 is in a two-stage compression operation.

When the intermediate pressure P3 in the closed container 10 reaches a predetermined pressure, the control device 9 controls the first suction circuit 31.
Is controlled to open the electromagnetic valve 41 of the second suction circuit 32. With this control, the inflow of the suction refrigerant into the pre-stage compression section 13 is blocked, and the closed container 10
The suction refrigerant having the suction pressure P1 flows into the suction port. The check valve 17 prevents the refrigerant from flowing into the discharge port 13b of the first-stage compression section 13. The refrigerant inside the sealed container 10 is compressed by the second-stage compression section 14 and discharged from the discharge port 14b of the second-stage compression section 14. The compression operation by the first-stage compression section 13 is not performed, and the hermetic-type compressor 2 includes only the first-stage compression section 14.
Since the step compression operation is performed, the discharge pressure P2 decreases. Then, the pressure inside the closed container 10 decreases due to the inflow of the suction refrigerant having the suction pressure P1.

Therefore, it is possible to prevent the pressure in the sealed container 10 of the sealed compressor 2 from exceeding a predetermined pressure and increasing. Therefore, the refrigerating apparatus 1 using the hermetic compressor 2 can be continuously operated without stopping the operation by the protection mechanism (not shown) of the hermetic compressor 2 operating.

[B] Second Embodiment FIG. 3 is a refrigerant circuit diagram of a refrigeration apparatus according to a second embodiment of the present invention, and FIG. 4 is a closed circuit according to a second embodiment of the present invention. It is sectional drawing of a mold compressor. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 3, reference numeral 101 denotes a refrigeration apparatus according to the second embodiment. In the refrigeration apparatus 101, a hermetic compressor 102 that compresses the suction refrigerant in two stages, a water supply circuit 51 that supplies water to the refrigerant-to-water heat exchanger 3 from outside, and a cooling device 52 that cools the hermetic compressor 102 It is configured with.

The water supply circuit 51 is provided with an electromagnetic valve 61. The cooling device 52 includes a water guide circuit 62, a water cooling circuit 63, and a pullback circuit 64. The water supply is guided by the water guide circuit 62 from the upstream side of the solenoid valve 61 of the water supply circuit 51. The water guide circuit 62 includes an electromagnetic valve 65. The hermetic compressor 102 is water-cooled by the water supply circuit 62 by the water cooling circuit 63. The water cooling circuit 63 includes a water cooling pipe 66. The water-cooled pipe 66 (FIG. 4) is
2 is spirally and closely attached to the outer periphery of 2. The water used for cooling the hermetic compressor 102 is returned by the water cooling pipe 66 to the downstream side of the solenoid valve 61 of the water supply circuit 51 by the return circuit 64.

The intermediate pressure P3 inside the closed container 10 is detected by a pressure sensor which is a pressure detecting device 8 for detecting the pressure inside the closed container 10. According to this detection result,
The electromagnetic valve 61 of the water supply circuit 51 and the electromagnetic valve 65 of the water supply circuit 62
Control of the hermetic compressor 102
A control device 71 for controlling on / off of the cooling of the air conditioner is provided.

In the present embodiment, when the suction pressure P1 of the refrigerant into the hermetic compressor 102 increases, the intermediate pressure P3 of the refrigerant compressed in the first-stage compression section 13 also increases.

In a normal operation, the control device 71 opens the electromagnetic valve 61 of the water supply circuit 51 and the electromagnetic valve 6 of the water introduction circuit 62.
5 is turned off. By this off control, the water supply passes through the solenoid valve 61 of the water supply circuit 51 and is supplied directly to the refrigerant-to-water heat exchanger 3.

The suction refrigerant having the suction pressure P1 is compressed by the pre-stage compression section 13, and the refrigerant having the intermediate pressure P3 is compressed by the passage pipe 1
6 and is discharged into the closed container 10. This refrigerant is further compressed by the post-compression unit 14, and the discharge pressure P2
And discharged.

When the intermediate pressure P3 in the closed container 10 reaches a predetermined pressure, the control device 71 controls the solenoid valve 61 of the water supply circuit 51 to be closed and the solenoid valve 65 of the water guide circuit 62 to be opened. By this ON control, the cooling device 5
The water supply flows in the order of the second water introduction circuit 62, the water cooling circuit 63, and the retraction circuit 64, and the hermetic compressor 102 is cooled by the water cooling pipe 66 of the water cooling circuit 63.

When the hermetic compressor 102 is water-cooled, the refrigerant inside the hermetic container 10 is cooled, and
The intermediate pressure P3 inside 0 decreases.

Therefore, this also allows the hermetic compressor 1
02 can be prevented from increasing beyond the predetermined pressure. Therefore, the refrigeration system 1 using the hermetic compressor 102 can be continuously operated without stopping the operation by operating the protection mechanism (not shown) of the hermetic compressor 102.

As described above, the present invention has been described based on one embodiment, but the present invention is not limited to this.

The electromagnetic valve 61 of the water supply circuit 51 and the water guide circuit 62
The case where the inflow direction of feed water is controlled by the electromagnetic valve 65 to cool the hermetic compressor 102 has been described.
The second solenoid valve 65 can be omitted. The cooling device 52 has a large resistance to water, and when the solenoid valve 61 is in an open state, water supply mainly flows through the solenoid valve 61, and when the solenoid valve 61 is in a closed state, water supply is performed by the cooling device 52. Because it flows toward you.

Further, instead of providing the solenoid valve 61 of the water supply circuit 51 and the solenoid valve 65 of the water guide circuit 62, the water supply circuit 51
A three-way valve (not shown) may be provided at the junction between the water supply circuit 62 and the control device 71 to control the three-way valve to control the inflow direction of the feedwater.

[0058]

According to the present invention, the hermetic compressor can be used without stopping the hermetic compressor without stopping the operation of the hermetic compressor by preventing the pressure in the hermetic container of the hermetic compressor from exceeding a predetermined pressure. Refrigeration equipment can be operated continuously.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a refrigeration apparatus according to the present invention.

FIG. 2 is a sectional view of the hermetic compressor according to the first embodiment.

FIG. 3 is a circuit diagram showing a refrigeration apparatus according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a hermetic compressor according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus 2 Hermetic compressor 3 Refrigerant-water heat exchanger 4 Expansion valve 5 Evaporator 6 Accumulator 7 Switching device 8 Pressure detection device 9 Control device 10 Hermetic container 11 Electric motor part 12 Compression part 13 Front compression part 13a Suction port 13b Discharge port 14 Rear compression unit 14a Suction port 14b Discharge port 31 First suction circuit 32 Second suction circuit 51 Water supply circuit 52 Cooling device 62 Water conduction circuit 63 Water cooling circuit 64 Retraction circuit 71 Control device 101 Refrigeration device 102 Hermetic compressor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 1/00 395 F25B 1/00 395Z 1/10 1/10 B (72) Inventor Kiyoshi Koyama Ashikaga, Tochigi No. 1, Otsukicho, Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Yoshinori Toya No. 1, Otsukicho, Ashikaga City, Tochigi Pref. Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Masanobu Saito 1 Otsuki-machi, Ashikaga, Tochigi Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Shigeya Ishigaki 1 Otsuki-cho, Ashikaga, Tochigi Sanyo Electric F term (reference) 3H029 AA04 AA09 AA13 AA22 AB03 BB12 BB47 BB53 CC02 CC09 CC26 CC48 CC52 CC63 3H045 AA05 AA15 AA27 BA20 BA41 CA04 DA32 EA13 EA26 EA34 EA42

Claims (7)

[Claims] 1. A compression unit comprising a first stage compression unit for compressing a suction refrigerant from a suction pressure to an intermediate pressure and a second stage compression unit for compressing the intermediate pressure refrigerant from the first stage compression unit to a discharge pressure in a closed container. A refrigerating apparatus having a hermetic compressor in which the pressure in the closed vessel is set equal to the intermediate pressure, wherein a pressure detecting device for detecting the intermediate pressure; and Operation, or a switching device for switching to any of the operation of the pre-stage compression unit and the operation of the post-stage compression unit, When the intermediate pressure detected by the pressure detection device reaches a predetermined pressure, the switching device is controlled, A refrigeration system comprising: a control device that controls the operation of the compression unit to operate only the rear compression unit. 2. The pressure detection device according to claim 1, wherein the switching device includes a first suction circuit provided on a refrigerant suction side of the first-stage compression section and a second suction circuit provided on a refrigerant suction side of the second-stage compression section. When the intermediate pressure detected by has reached a predetermined pressure, the control device controls to stop the suction refrigerant flowing into the first suction circuit and control to flow the suction refrigerant into the second suction circuit, The refrigeration apparatus according to claim 1, wherein the operation of the compression unit is performed only by the operation of the rear compression unit. 3. A compression unit comprising a first stage compression unit for compressing a suction refrigerant from a suction pressure to an intermediate pressure and a second stage compression unit for compressing the intermediate pressure refrigerant from the first stage compression unit to a discharge pressure in a closed container. A refrigeration system including a hermetic compressor in which the pressure in the hermetic container is set equal to the intermediate pressure, wherein a pressure detector for detecting the intermediate pressure, and cooling on / off of the hermetic compressor A refrigeration apparatus comprising: a cooling device that can be controlled; and a control device that turns on the cooling device when the intermediate pressure detected by the pressure detection device reaches a predetermined pressure. 4. The refrigeration apparatus according to claim 3, wherein the cooling apparatus water-cools the hermetic compressor. 5. A compression section comprising a first compression section for compressing a suction refrigerant from a suction pressure to an intermediate pressure and a second compression section for compressing the intermediate pressure refrigerant from the first compression section to a discharge pressure in a closed container. A hermetic compressor in which the pressure in the hermetic container is set equal to the intermediate pressure, and a refrigerant-to-water heat exchanger for exchanging heat between the high-pressure refrigerant from the hermetic compressor and external water supply And a refrigeration system including a water supply circuit that supplies water to the refrigerant-to-water heat exchanger, a pressure detection device that detects the intermediate pressure, and a cooling device that enables on-off control of cooling of the hermetic compressor, When the intermediate pressure detected by the pressure detecting device reaches a predetermined pressure, the control device turns on the cooling device, the cooling device is a water conveyance circuit that guides water supply from the water supply circuit, and the water conveyance circuit Led by Refrigeration system characterized in that it comprises a water cooling circuit for water cooling the hermetic compressor with water was. 6. The refrigeration apparatus according to claim 5, wherein the cooling device includes a return circuit for returning water used for cooling the hermetic compressor in the water cooling circuit to the water supply circuit. . 7. The refrigeration apparatus according to claim 1, wherein the refrigerant is a carbon dioxide refrigerant.