JPH1062018A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase in vibration and generation abnormal noise when a compressor is started by interposing a parallel circuit comprising an on/off valve and a capillary tube in a suction line from a cooler to the suction side of the compressor. SOLUTION: A parallel circuit 33 comprising a solenoid valve 31 as an on/off valve and a capillary tube 32 is connected to a suction line 11 from a cooler 6 to a suction side 1S of a compressor 16. A control device 34 closes the solenoid valve 31 when the compressor 1 is started. The refrigerant from the cooler 6 is bypassed, and sucked through the capillary tube 32, and the suction of the gas refrigerant immediately after starting the compressor 1 is limited. Even when the specific capacity of the refrigerant is reduced in starting the compressor 1, the suction of the refrigerant immediately after starting compressor 1, and the work load of compression of the compressor 1 is reduced. Vibration and abnormal noise generated in starting the compressor 1 can be prevented or controlled to lower level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a compressor, a condenser,
The present invention relates to a cooling device in which a pressure reducing device, a cooler, and the like are sequentially connected in a circular pipe, and the cooler cools a storage room such as a low-temperature showcase or a refrigerator.

[0002]

2. Description of the Related Art Conventionally, a so-called built-in low-temperature showcase is provided with a cooling device as disclosed in Japanese Utility Model Laid-Open No. 6-69662 (F25B1 / 00). That is, a refrigerant circuit of the conventional cooling device 100 is shown in FIG. That is, in this figure, 1 is a rotary (rotary) type compressor, 2 is a condenser, 3 is a dryer, 4 is a capillary tube as a decompression device, 6 is a cooler, and 7 is an accumulator as a refrigerant liquid reservoir. , 8 are check valves, which are sequentially connected in a ring by a refrigerant pipe. The check valve 8 has the suction side 1S of the compressor 1 in the forward direction.

[0003] With the above arrangement, when the compressor 1 is started, the high-temperature and high-pressure gas refrigerant discharged from the discharge side 1D of the compressor 1 flows into the condenser 2, where it radiates heat and is liquefied. The liquid refrigerant that has exited the condenser 2 is depressurized by the capillary tube 4 via the dryer 3 and then flows into the cooler 6 to evaporate. The storage chamber (not shown) of the low-temperature showcase is cooled by the heat absorption effect generated at this time.

[0004] The refrigerant that has exited the cooler 6 flows into a suction pipe 11 between the cooler 6 and the compressor 1, and flows into an accumulator 7 interposed there to be separated into gas and liquid. Then, only the gas refrigerant passes through the check valve 8 and passes through the suction side 1 of the compressor 1.
S sucked.

[0005]

Here, the cooling device 10
0, the specific volume (volume / weight) v of the refrigerant gas sucked from the suction pipe 11 into the compressor 1 during the cooling operation is large, that is, the density of the refrigerant is small. For example, when R22 is used as the refrigerant, v = 0.074 cubic meters / kg (when the evaporation temperature is -10 ° C and the suction gas temperature is + 15 ° C).

However, since the refrigerant flows from the condenser 2 to the cooler 6 while the compressor 1 is stopped, the specific volume v of the refrigerant gas sucked from the suction pipe 11 when the compressor 1 is started.
Becomes smaller, and becomes about v = 0.026 cubic meters / kg (atmospheric temperature + 20 ° C., in the case of a saturated gas). That is,
The density of the refrigerant sucked when the compressor 1 is started (immediately after the start) is about three times as high as that during the operation, so that the compression work of the compressor 1 increases, which increases vibration and generates abnormal noise. Was causing it.

The present invention has been made to solve the above-mentioned conventional technical problem, and can prevent or suppress an increase in vibration and abnormal noise at the time of starting the compressor. A cooling device is provided.

[0008]

According to a first aspect of the present invention, there is provided a cooling device comprising a compressor, a condenser, a decompression device, a cooler, and the like, which are sequentially connected in a ring form. A parallel circuit of an on-off valve and a capillary tube is interposed in a suction pipe reaching the suction side. A cooling device according to a second aspect of the present invention includes a compressor, a condenser, a decompression device, a cooler, and the like, which are sequentially connected in a ring shape, and a suction pipe extending from the cooler to a suction side of the compressor. An on-off valve provided therein, the on-off valve includes a valve seat formed between an inlet and an outlet, a valve body that opens and closes a flow path by abutting on the valve seat in a detachable manner, and a valve seat. It has a narrow passage communicating between the inlet and the outlet in a detour form.

A cooling device according to a third aspect of the present invention is the above-mentioned invention, wherein the on-off valve is closed when the compressor is started.
According to a fourth aspect of the present invention, in the cooling device described above, the on-off valve is opened after a lapse of a predetermined period from the start of the compressor. According to a fifth aspect of the present invention, in the third aspect, the opening and closing valve is opened when the pressure in the suction pipe between the opening and closing valve and the compressor decreases to a predetermined value or less after the start of the compressor.

That is, according to the first or second aspect of the present invention, by closing the on-off valve at the time of starting the compressor as in the third aspect, the compressor can be cooled through a capillary tube or a narrow passage. The refrigerant comes to be sucked from. That is, since the suction amount of the gas refrigerant immediately after the start of the compressor can be limited by the capillary tube or the narrow passage, the vibration and abnormal noise generated at the time of start can be prevented or reduced. It is something that will be.

In particular, according to the second aspect of the present invention, since the narrow passage is provided in the on-off valve, there is no need to connect a capillary tube to the on-off valve in parallel, so that the number of parts is reduced and the cost is reduced and the assembling workability is improved. Can be achieved. Further, according to the invention of claim 4, in addition to the constitution of claim 3, the opening / closing valve is opened after the lapse of a predetermined period from the start of the compressor and there is no need to limit the refrigerant amount. After the valve is opened, the refrigerant hardly or hardly flows through the capillary tube or the narrow passage due to the flow resistance difference. Therefore, after that, it is possible to shift to the normal cooling operation without any trouble.

Furthermore, according to the invention of claim 5, according to claim 3,
In addition to the above, after the compressor is started, the pressure in the suction pipe between the on-off valve and the compressor is reduced to a predetermined value or less due to a decrease in the amount of refrigerant sucked into the compressor, and it is no longer necessary to limit the amount of refrigerant. In this case, the on-off valve is opened. Similarly, after the on-off valve is opened, the refrigerant does not flow at all or hardly through the capillary tube or the narrow passage due to the flow path resistance difference. Therefore, after that, it is possible to shift to the normal cooling operation without any trouble.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a low-temperature showcase 22 to which the cooling device 21 of the present invention is applied, FIG. 2 is a refrigerant circuit diagram of the cooling device 21 of the present invention, and FIG. In the following figures, the same reference numerals as those in FIG. 6 are the same.

The low-temperature showcase 22 of the embodiment is installed in a supermarket or a convenience store to display and sell products such as foods and beverages, and is transparent above a main body 23 in which a cooling device 21 is housed. A storage room 27 surrounded by the glass 24... And the front glass door 26 is formed. A plurality of shelves 28 are provided in the storage room 27, and the products are displayed on the shelves 28.

On the other hand, in the cooling device 21 of FIG. 2, 1 is a rotary (rotary) compressor, 2 is a condenser, 3 is a dryer, 4 is a capillary tube as a decompression device,
6 is a cooler, 7 is an accumulator as a coolant reservoir, 8
Is a check valve. The check valve 8 is connected to the suction side 1S of the compressor 1.
Is the forward direction. These are sequentially connected in a ring shape, and in a suction pipe 11 extending from the cooler 6 to the suction side 1S of the compressor 1, a parallel circuit 33 of an electromagnetic valve 31 as an on-off valve and a capillary tube 32 is connected. Thus, a refrigerant circuit of the cooling device 21 is configured.

The compressor 1, the condenser 2, etc.
While being installed in a machine room (not shown) formed in 3,
The cooler 6 is installed in a duct (not shown) formed in the main body 23. The duct communicates with the storage room 27, and a blower (not shown) for circulating cool air, which has exchanged heat with the cooler 6, into the storage room 27 is provided in the duct. The solenoid valve 31 is connected to a control device 34 having a timer T.

The operation of the cooling device 21 of the low-temperature showcase 22 will be described with reference to FIG. A thermostat or a temperature sensor (not shown) is attached to the storage room 27, and these are connected to the control device 34. Then, the control device 34 starts the compressor 1 when the thermostat or the like detects a predetermined upper limit temperature (for example, + 5 ° C.) and stops when the thermostat or the like detects a predetermined lower limit temperature (for example, + 3 ° C.).

When the compressor 1 is operated, the high-temperature and high-pressure gas refrigerant discharged from the discharge side 1D of the compressor 1 flows into the condenser 2, where it radiates heat and is liquefied. The liquid refrigerant that has exited the condenser 2 is depressurized by the capillary tube 4 via the dryer 3 and then flows into the cooler 6 to evaporate. At this time, the cooler 6 exhibits an endothermic effect. The cool air that has exchanged heat with the cooler 6 is circulated into the storage room 27 by the blower, whereby the inside of the storage room 27 is maintained at a refrigeration temperature such as + 4 ° C. on average.

The refrigerant flowing out of the cooler 6 flows into the suction pipe 11, and when the solenoid valve 31 is open, flows through the solenoid valve 31 due to the difference in flow path resistance with the capillary tube 32 and flows into the accumulator 7. . In the accumulator 7, gas-liquid separation is performed, and only the gas refrigerant passes through the check valve 8 to the compressor 1
To the suction side 1S. When the solenoid valve 31 is open, the capillary tube 32 is completely or
Almost no refrigerant flows.

When the compressor 1 is started, the control device 34 closes the solenoid valve 31. When the solenoid valve 31 is closed, the refrigerant from the cooler 6 is bypassed and sucked through the capillary tube 32, so that the suction amount of the gas refrigerant immediately after the start of the compressor 1 is limited (FIG. 3) Capillary tube bypass operation period. That is, even if the specific volume of the refrigerant is small when the compressor 1 is started, the amount of refrigerant suctioned immediately after the start of the compressor 1 is limited, so that the compression work of the compressor 1 is reduced, and thus the compressor 1 Thus, it is possible to prevent or suppress the vibration and abnormal noise generated at the time of start-up.

After starting the compressor 1, the control device 34 opens the solenoid valve 31 in, for example, 5 to 30 seconds based on the integration of the timer T. That is, after the specific volume of the refrigerant returns to normal after a predetermined period from the start, the solenoid valve 31 is opened, and after the opening, the refrigerant is completely or completely removed to the capillary tube 32 due to a difference in flow path resistance with the capillary tube 32. Since the flow hardly flows and flows through the electromagnetic valve 31, the cooling operation can be shifted to the normal cooling operation without any trouble.

FIG. 4 shows another embodiment of the present invention. In this figure, the same reference numerals as those in FIGS. 1 to 3 denote the same parts, and a description thereof will be omitted. In this case, the control device 3
4 is not provided with a timer T.
A pressure sensor 36 is provided for detecting the pressure in the suction pipe 11 between the valve 1 and the accumulator 7. Also in this case, the control device 34 controls the solenoid valve 31 when the compressor 1 is started, as described above.
Close. At this time, when the solenoid valve 31 is closed, the amount of refrigerant passing through the capillary tube 32 is smaller than the amount of rejection of the compressor 1, so that the pressure in the suction pipe 11 decreases after the compressor 1 is started. go.

The pressure in the suction pipe 11 is, for example, 0
When the pressure drops to kg / square centimeter (the pressure in the suction pipe 11 during a normal cooling operation is about 3 kg / square centimeter), the control device 34 detects this by the pressure sensor 36 and opens the solenoid valve 31. That is, after the compressor 1 is started, the amount of refrigerant sucked into the compressor 1 by the capillary tube 32 is restricted, and the electromagnetic valve 31
When the pressure in the suction pipe 11 between the compressor and the accumulator 7 decreases and the refrigerant amount need not be restricted, the solenoid valve 31 is opened. Similarly, after the solenoid valve 31 is opened, the flow with the capillary tube 32 is started. Due to the path resistance difference, the refrigerant does not or does not flow at all through the capillary tube 32. Therefore, after that, it is possible to shift to the normal cooling operation without any trouble.

FIG. 5 is a sectional view of another solenoid valve 31 according to the present invention. In this case, the solenoid valve 3
1 is also connected to the same position as the solenoid valve 31 of the refrigerant circuit shown in FIGS. 2 and 4, but the capillary tube 32 is omitted.
The opening and closing control of the solenoid valve 31 described later is the same as in FIGS. In this case, the electromagnetic valve 31 includes a main body 43 having an inlet 41 connected to the cooler 6 side of the suction pipe 11 and an outlet 42 connected to the accumulator 7 side,
A flow path 44 formed in the main body 43 and communicating between the inlet 41 and the outlet 42, and a valve seat 4 formed in the flow path 44.
6 and the valve seat 46 are provided so as to be freely separated from each other.
The plunger 48 includes a valve body 47 for opening and closing the plunger 4, a plunger 48 to which the valve body 47 is fixed, and a solenoid coil 49 for vertically driving the plunger 48.

Further, a narrow passage 51 having a small passage cross-sectional area is formed in the main body 43 so as to bypass the valve seat 46 and communicate the inlet 41 and the flow passage 44 on the outlet 42 side. With the above configuration, when the compressor 1 is started, the controller 34 turns off the solenoid coil 49. Thereby, plunger 4
8 falls under its own weight and closes the valve body 47 by pressing it against the valve seat 46, so that the flow path 44 of the solenoid valve 31 communicates between the inlet 41 and the outlet 42 by only the narrow passage 51, and as a result Therefore, the refrigerant suction amount of the compressor 1 is limited as described above.

After a lapse of a predetermined period or after a decrease in pressure, the control device 34 energizes the solenoid coil 49 to suck and pull up the plunger 48. As a result, the valve element 47 is separated from the valve seat 46 and opened, so that no or almost no refrigerant flows due to the difference in flow path resistance.
, And flows through the valve seat 46. That is, according to the solenoid valve 31 having such a configuration, in addition to the above-described effects, the capillary tube 32 as described above is added to the solenoid valve 31.
Need not be connected in parallel, so that cost can be reduced by reducing the number of parts and assembly workability can be improved.

It should be noted that the numerical values in each of the above embodiments are not limited to those values, and are set appropriately according to the capacity and capacity of the device. In the embodiment, the present invention is applied to a low-temperature showcase. However, the present invention is not limited thereto, and the present invention is also effective for refrigerators, air conditioners, and the like.

[0028]

As described in detail above, according to the first or second aspect of the present invention, by closing the on-off valve when the compressor is started as in the third aspect, the compressor can be a capillary tube or a fine tube. The refrigerant is sucked from the cooler through the passage. That is, since the suction amount of the gas refrigerant immediately after the start of the compressor can be limited by the capillary tube or the narrow passage, the vibration and abnormal noise generated at the time of start can be prevented or reduced. It is something that will be.

In particular, according to the second aspect of the present invention, since the narrow passage is provided in the on-off valve, it is not necessary to connect a capillary tube to the on-off valve in parallel, so that the number of parts is reduced and the cost is reduced and the assembling workability is improved. Can be achieved. Further, according to the invention of claim 4, in addition to the constitution of claim 3, the opening / closing valve is opened after the lapse of a predetermined period from the start of the compressor and there is no need to limit the refrigerant amount. After the valve is opened, the refrigerant hardly or hardly flows through the capillary tube or the narrow passage due to the flow resistance difference. Therefore, after that, it is possible to shift to the normal cooling operation without any trouble.

Further, according to the invention of claim 5, according to claim 3,
In addition to the above, after the compressor is started, the pressure in the suction pipe between the on-off valve and the compressor is reduced to a predetermined value or less due to a decrease in the amount of refrigerant sucked into the compressor, and it is no longer necessary to limit the amount of refrigerant. In this case, the on-off valve is opened. Similarly, after the on-off valve is opened, the refrigerant does not flow at all or hardly through the capillary tube or the narrow passage due to the flow path resistance difference. Therefore, after that, it is possible to shift to the normal cooling operation without any trouble.

[Brief description of the drawings]

FIG. 1 is a perspective view of a low-temperature showcase to which a cooling device of the present invention is applied.

FIG. 2 is a refrigerant circuit diagram of the cooling device of the present invention.

FIG. 3 is a diagram showing an operation mode of the cooling device of the present invention.

FIG. 4 is a refrigerant circuit diagram of a cooling device according to another embodiment of the present invention.

FIG. 5 is a longitudinal side view of another solenoid valve of the cooling device of the present invention.

FIG. 6 is a refrigerant circuit diagram of a conventional cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 4 Capillary tube (decompression device) 6 Cooler 11 Suction piping 31 Solenoid valve (opening / closing valve) 32 Capillary tube 33 Parallel circuit 34 Controller 36 Pressure sensor 41 Inlet 42 Outlet 44 Flow path 46 Valve seat 47 Valve Body 51 Narrow passage T timer

Claims (5)

[Claims] 1. A cooling device comprising a compressor, a condenser, a decompression device, a cooler, and the like connected in series in a ring shape, wherein an on-off valve and a capillary are provided in a suction pipe from the cooler to a suction side of the compressor. A cooling device, wherein a parallel circuit of tubes is provided. 2. A cooling device in which a compressor, a condenser, a decompression device, a cooler, and the like are sequentially connected in a ring-like manner, wherein an on-off valve provided in a suction pipe from the cooler to a suction side of the compressor. The on-off valve includes a valve seat formed between an inlet and an outlet, a valve body that comes into contact with the valve seat so as to be able to freely contact and open and closes the flow path, and the inlet that bypasses the valve seat. And a narrow passage communicating between the outlet and the outlet. 3. The cooling device according to claim 1, wherein the on-off valve is closed when the compressor is started. 4. The cooling device according to claim 3, wherein the on-off valve is opened after a lapse of a predetermined period from the start of the compressor. 5. The cooling device according to claim 3, wherein, after starting the compressor, the on-off valve is opened when a pressure in a suction pipe between the on-off valve and the compressor falls below a predetermined value.