JPH09229499A - Cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make refrigerating fluid difficult to be sucked without increasing consumption of power even when the fluid forms a pool by connecting a bottom face of an oil storage section of a compressor with a low pressure section of a refrigerating circuit by means of a series circuit consisting of an open/close valve and a special throttling device. SOLUTION: A refrigerating circuit is constituted by annularly connecting a condenser 22, a throttling device 23 and an evaporator 24 to a compressor 21 in this order. A bottom face of an oil storage section of the compressor 21 and part of a low pressure portion of a refrigerating circuit (low pressure part of the compressor 21) are connected to each other through a series circuit consisting of an open/close valve 25 and a special throttling device 26 other than the throttling device 23. The open/close valve 25 is opened under conditions wherein refrigerating fluid forms a pool on the bottom face of the oil storage section of the compressor 21 so that the refrigerant pooled on the bottom face of the oil storage section within a shell of the compressor 21 is drained to a low pressure side. An undesired phenomenon of sucking the refrigerant fluid through an oil supply pipe is prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device, and more particularly to a cooling device for a vending machine.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional refrigerating circuit of a cooling device of this type has a structure in which a compressor 1, a condenser 2, a throttle device 3 and an evaporator 4 are sequentially connected in an annular shape, and a compression The machine 1 is, as shown in FIG. 6, in a horizontal cylindrical shell 5,
The motor section 6 and the refrigerant compression mechanism section 7 are connected by a horizontally arranged shaft 8, and an oil supply spring that is connected to a shaft 8 provided inside an oil supply pipe 9 connected to the tip of the shaft 8 to rotate. Lubricating oil was supplied to the sliding portion of the compression mechanism portion 7 by 10. In addition, as shown in FIG. 7, the control circuit of the compressor 1 compares the internal temperature sensor 11 for measuring the cooling temperature of the internal articles, the internal temperature detection unit 12, and this temperature with a set value, and the compressor 1 It comprises a comparison circuit 13 for deciding on / off of. As shown in FIG. 8, the operation flow chart of the control circuit of the compressor compares the inside temperature detected by the inside temperature sensor with a set value, and when the inside temperature is higher than the set value, the compressor is operated. However, when the internal temperature is lower than the set value, the compressor is stopped.

Further, as disclosed in JP-A-7-151090, a means for preventing the refrigerant from stagnation in the oil reservoir by attaching an electric heater to the lower surface of the shell of the compressor has been disclosed.

[0004]

However, in the above-described conventional configuration, when the shell 5 of the compressor is a high-pressure compressor and a non-dissolving oil that is difficult to dissolve with the refrigerant is used as the lubricating oil, the low During operation at outside temperature, the refrigerant liquid 15 is stored in the bottom portion of the lower lubricating oil 14 in the shell 5 and is sucked through the oil supply pipe 9 of the compressor. Refueling was hindered, resulting in accelerated wear of the sliding parts and eventually damage to the compressor.

Further, under many low temperature conditions, the refrigerant liquid 15 is often separated into two phases and accumulated on the bottom surface of the shell 5 of the compressor. Therefore, in JP-A-7-151090, all of these conditions are covered and the refrigerant is covered. In order to prevent the liquid 15 from accumulating, a large-capacity heater is required, and the operation time of the heater is lengthened, so that there is a problem that the power consumption increases.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and it is an object of the present invention to provide a cooling device for a refrigeration circuit in which refrigerant liquid is difficult to be sucked from an oil supply pipe without increasing power consumption. And

[0007]

In order to solve the above-mentioned problems, the present invention relates to an throttle valve which constitutes an opening / closing valve and a part of a refrigeration circuit with a bottom surface of an oil storage section in a shell of a compressor and a low-pressure section of the refrigeration circuit. It is connected via a series circuit of a special diaphragm device separate from the device. Further, the series circuit may be connected to the inlet side of the evaporator, and the opening / closing operation of the opening / closing valve may be performed according to the change of the outside air temperature or according to the elapsed time after the start of the compressor. Alternatively, the opening / closing operation time of the on-off valve is made variable according to the change of the outside air temperature. By such means, under operating conditions in which the refrigerant liquid accumulates on the bottom surface of the oil storage portion of the compressor shell, by opening the on-off valve, the refrigerant liquid can be drained to the low pressure side with low pressure. , The liquid level of the refrigerant liquid in the shell of the compressor becomes lower than the lower end suction surface of the oil supply pipe, the refrigerant liquid is not sucked into the compressor, and the disadvantage of obstructing oil supply to the sliding surface of the compression mechanism is eliminated. be able to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 for solving the above-mentioned problems is a throttle forming a bottom of an oil reservoir of a compressor and a low-pressure part of a refrigeration circuit as an opening / closing valve and a part of the refrigeration circuit. It is connected via a series circuit of a special expansion device different from the device, and under operating conditions where the refrigerant liquid accumulates due to this, by opening this on-off valve, the refrigerant liquid is drained to the low pressure side. be able to. Therefore, the liquid level of the refrigerant liquid accumulated on the bottom surface of the oil storage portion of the compressor is lowered, and suction of the refrigerant liquid from the oil supply pipe can be suppressed.

Further, according to the second aspect of the present invention, the evaporator inlet may be connected to the bottom surface of the oil storage portion of the compressor through an on-off valve.

Further, according to the third aspect of the present invention, the opening / closing operation of the opening / closing valve is performed according to the change in the outside air temperature.

According to the fourth aspect of the invention, the opening / closing operation of the on-off valve is performed according to the elapsed time after the start of the compressor.

Further, according to the invention of claim 5, the opening / closing operation time of the opening / closing valve is changed according to the change of the outside air temperature.

The invention according to claim 1 can be effectively realized by the inventions according to claims 2 to 5.

[0014]

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

(Embodiment 1) In FIG. 1, a condenser 21, a throttling device 23, and an evaporator 24 are sequentially connected in an annular shape to a compressor 21 having a high pressure inside the shell of the compressor to form a refrigeration circuit. The bottom surface of the oil storage section of the compressor and a part of the low-pressure section of the refrigeration circuit (here, the suction section of the compressor 21) are connected via an on-off valve 25 and a series circuit of a special expansion device 26 different from the expansion device 23 described above. doing. By opening the on-off valve 25 under the condition that the refrigerant liquid accumulates on the bottom surface of the oil storage portion of the compressor 21, the on-off valve 25 accumulates on the bottom surface of the oil storage portion in the shell of the compressor without significantly increasing the power consumption. Since the refrigerant liquid is drawn out to the low pressure side, the problem that the refrigerant liquid is sucked from the oil supply pipe can be eliminated.

(Embodiment 2) In FIG. 2, a compressor 21 is used.
On-off valve 25 and special throttle device 26 that are connected to the bottom surface of the oil reservoir of
Is connected to the inlet of the evaporator 24.
In the second embodiment, the refrigerant liquid withdrawn from the compressor 21 is not directly sucked into the compressor 21 and the evaporator 24
Since it is vaporized by the above and becomes a gaseous refrigerant and is sucked into the compressor 21, problems such as liquid compression do not occur.

(Embodiment 3) FIG. 3 is a block diagram showing the configuration of the control circuit. In the compressor, the signal from the in-compartment temperature sensor 27 is supplied to the in-compartment temperature detecting section 29 in the compressor control circuit 28. The operation is controlled by detecting it and comparing it with the set value in the comparison circuit 30. The compressor control circuit 28 includes an inside temperature detection unit 29 and a comparison circuit 30 that compares the inside temperature detection unit 29 with a set value. On the other hand, for the on-off valve, the outside air temperature 31 is detected by the outside air temperature detecting unit 32, and the signal is detected by the valve control circuit 33.
The valve control circuit 34 in FIG. 4 processes the signal together with the signal from the off-time detection timer 35 from the compressor control circuit 28 to open / close the opening / closing valve 25. The valve control circuit 33 includes an outside air temperature detection unit 32, a compressor off-time detection timer 35,
It is composed of a valve control circuit 34 and a timer 36.

FIG. 4 is a flow chart showing the operation of the valve control circuit 33. If the vending machine is powered on and the compressor is operating, the timer is cleared and the valve is closed when the timer set value is not reached. However, if the timer setting value is reached, the timer is cleared and stopped, and the outside air temperature is detected. If the outside air temperature becomes lower, the amount of the refrigerant liquid that separates into two phases increases, so if the outside air temperature is, for example, 5 ° C or less, the valve opening time is set to 5 minutes, and if the outside air temperature exceeds 5 ° C and 15 ° C or less, Open the valve for 3 minutes, less than 5 minutes,
Further, if the outside air temperature is higher than 15 ° C., it is assumed that the refrigerant liquid is not separated, and the valve is closed to return to the initial start. On the other hand, the valve opened for 5 minutes or 3 minutes is closed when the compressor is turned on and the timer reaches the set value, and the timer is cleared to return to the initial start. However, if the timer does not reach the set value, the valve will open until it reaches the set value. If the compressor is not on, the valve will turn off regardless of the timer set value.

In this way, the opening / closing operation of the on-off valve is operated according to the change in the outside air temperature, and the operation of the on-off valve is operated according to the time after the start of the compressor.
By changing the operating time of the on-off valve according to the change of the outside air temperature, it is possible to set the refrigerant liquid withdrawal condition corresponding to the condition that the refrigerant liquid accumulates on the bottom surface of the compressor oil reservoir, so that any outside air temperature condition can be set. Even in the lower part, the refrigerant liquid is not sucked from the oil supply pipe, and the lubricating oil of the compressor is drained to the low pressure side so that there is no problem such as insufficient lubricating oil.

[0020]

As is apparent from the above embodiment, since the present invention does not use an electric heater or the like at all, power consumption does not increase, and according to the invention of claim 1, two-phase separation is performed. Since the refrigerant liquid is accumulated under its own weight in the bottom of the oil storage portion of the compressor, the refrigerant liquid can be removed by opening the on-off valve and connecting it to the low pressure side.

According to the second aspect of the invention, since the refrigerant liquid to be removed is introduced into the inlet of the evaporator, the refrigerant liquid is sucked into the compressor in a vaporized state in the evaporator, so that the compressor is a liquid. Problems such as compression are eliminated.

According to the third aspect of the present invention, the opening / closing operation of the on-off valve that causes the refrigerant liquid to flow to the low pressure side is performed in accordance with the change in the outside air temperature, so that the refrigerant is separated only when the low outside air temperature causes two-phase separation. The liquid can be removed.

According to the fourth aspect of the present invention, since the opening / closing operation of the on-off valve is performed according to the elapsed time after the start of the compressor, only the refrigerant liquid is constantly withdrawn to the low pressure side. There is no shortage of lubricating oil due to drainage.

Further, according to the fifth aspect of the present invention, the opening / closing operation of the on-off valve is made variable according to the change of the outside air temperature, so that it is accumulated in the shell of the compressor according to the change of the outside air temperature. By changing the amount of the refrigerant liquid and changing the operating time of the on-off valve, only the refrigerant liquid is always withdrawn, so that even the lubricating oil is not withdrawn and problems such as insufficient lubricating oil are not caused.

[Brief description of drawings]

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

FIG. 2 is a refrigeration circuit diagram in Embodiment 2 of the present invention.

FIG. 3 is a block diagram of a control circuit according to a third embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the valve control circuit.

FIG. 5 is a refrigeration circuit diagram of a conventional example.

FIG. 6 is a sectional view of a conventional compressor.

FIG. 7 is a block diagram of a control circuit of a conventional example.

FIG. 8 is a flowchart showing the operation of a control circuit of a conventional example.

[Explanation of symbols]

 1, 21 Compressor 2, 22 Condenser 3, 23 Throttle device 4, 24 Evaporator 10 Refueling spring 11, 27 Internal temperature sensor 12, 29 Internal temperature detection unit 13, 30 Comparison circuit 15 Refrigerant liquid 25 Open / close valve 26 Special throttle device 28 Compressor control circuit 31 Outside air temperature 32 Outside air temperature detection unit 33 Valve control circuit 34 Valve control circuit 35 Off time detection timer 36 Timer

Claims (5)

[Claims] 1. A refrigeration circuit is formed by sequentially connecting a compressor, the condenser of which has a high pressure in a shell, a throttle device, and an evaporator, to form a refrigeration circuit. A cooling device in which a low pressure part is connected via a series circuit of an on-off valve and a special expansion device other than the expansion device described above. 2. A series circuit comprising an on-off valve and a special throttle device,
The cooling device according to claim 1, wherein the cooling device is connected to the bottom of the oil storage section of the compressor and the inlet of the evaporator. 3. The cooling device according to claim 1, wherein the opening / closing operation of the opening / closing valve is performed in accordance with a change in outside air temperature. 4. The cooling device according to claim 1, wherein the opening / closing operation of the opening / closing valve is performed according to the elapsed time after the start of the compressor. 5. The cooling device according to claim 1, wherein the opening / closing operation time of the opening / closing valve is changed according to the change of the outside air temperature.