JPH04143563A - Refrigerant recovering device - Google Patents

Abstract

PURPOSE:To reduce in size and weight and to shorten recovering time by providing low and high pressure side solenoid valves provided to connecting tubes, a differential pressure switch provided to open or close the valve to detect a pressure difference of a recovering gas cylinder from the high pressure sic of a refrigerant circuit, and a low pressure switch for detecting a pressure in the circuit. CONSTITUTION:When a high pressure side solenoid valve 14 and a recovery gas cylinder side solenoid vale 16 are opened and a low pressure side solenoid valve 15 is closed, the high pressure side of a refrigerant circuit 21 is connected to a recovery gas cylinder 10, and high pressure liquid refrigerant cooled and condensed by a compressor 6 and a condenser 7 of the circuit 21 is fed into the low pressure cylinder 10. In this case, the liquid refrigerant is passed through an oil separator 20, and impurities in the refrigerant such as oil, etc., of the compressor 6 flowing out together with the refrigerant are removed. When the recovery of the refrigerant is started, a recovery timer 17 is simultaneously operated, and the solenoid valve 16 is closed after about two minutes. Then, a differential pressure sensing timer 18 is operated, and the valve 16 is released after 15 seconds. Thus, if a small space is provided around a facility, the refrigerant can be recovered, and the recovering time can be greatly shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for refrigerant used in air conditioning, refrigeration equipment, etc.
The present invention relates to a refrigerant recovery device that can automatically recover refrigerant without releasing it into the atmosphere during removal or repair.

[Prior Art] In recent years, the deterioration of the environment surrounding the earth, such as environmental pollution and destruction, has become a problem. One example of this is the harmful nature of fluorocarbon gas, which is used as a refrigerant in air conditioning and refrigeration equipment. This gas has been widely used because it is harmless to the human body, but in recent years it has been discovered that it has the effect of destroying ozone. Since the specific gravity of fluorocarbon gas is lighter than air, the gas released into the atmosphere rises and reaches the ozone layer surrounding the earth, where it gradually begins to deplete. The Earth's ozone layer blocks most of the harmful ultraviolet rays emitted by the sun. These ultraviolet rays can cause cancer in the human body, but until now, only a small amount of ultraviolet rays reached the ground due to the ozone layer, so this ultraviolet ray had almost no effect on the human body. However, if the ozone layer continues to be destroyed, it will become a major problem.

Therefore, recently, refrigerant recovery devices have been provided that can recover the fluorocarbon gas used as a refrigerant when removing or repairing air conditioning or refrigeration equipment, etc., without releasing it into the atmosphere.

That is, as shown in FIG. 3, this conventional refrigerant recovery device includes a compressor 32 connected to an oil separator 34 to a suction connecting pipe 31 that is connected to a refrigerant outlet of an air conditioner or refrigeration equipment during recovery. A refrigeration cycle with a condenser 33 is connected. A receiver 35 and a dryer 36 are connected in this order to this refrigeration cycle, and after the refrigerant passes through this dryer 36, it is collected in a separately provided collection receiver 37.

To recover fluorocarbon gas, which is a refrigerant from air conditioning and refrigeration equipment, etc., with this device, connect the refrigerant υU outlet of the equipment to the suction connecting pipe 3.
1, and the refrigerant is sucked into the recovery device in a gas state. The sucked fluorocarbon gas passes through a compressor 32 which is a refrigeration cycle, is compressed, and is discharged to an oil separator 34 in the form of compressed gas refrigerant. The oil separator 34 removes impurities such as oil from the compressor 32 that flows out together with the compressed gas refrigerant. The dregs refrigerant from which impurities have been removed passes through the condenser 33 and is cooled, and the refrigerant is condensed and liquefied. This condensed and liquefied refrigerant is
It is sent to the receiver 35, where impure gases such as air and gas refrigerant are separated. Thereafter, the liquefied refrigerant is sent to a recovery receiver 37 provided separately from the recovery device via the dryer 36 and recovered.

[Problems to be Solved by the Invention] However, in the conventional refrigerant recovery apparatus, since the refrigerant is recovered in a gas state, it is necessary to condense and liquefy the refrigerant, and a refrigeration cycle for this purpose is required.

By including the compressor 32 and the condenser 33 as the refrigeration cycle, the device becomes large and its weight becomes considerable.

Moreover, in this recovery route, it is essential to cool and condense the gas refrigerant in a refrigeration cycle, which takes time. Furthermore, since this device requires various recovery members such as a refrigeration cycle, it becomes expensive. -L As mentioned above, there are many problems with conventional recovery equipment, such as installation location, recovery time, and equipment cost, so although the importance of fluorocarbon gas recovery is generally acknowledged, there are still few companies using it.

The present invention was provided in order to solve the problems of the prior art as described above, and its purpose is to provide a refrigerant recovery device that is small and lightweight, can shorten the recovery time, and is inexpensive. That's true.

[Means for Solving the Problems] The refrigerant recovery device of the present invention includes connections connected to the high-pressure side and low-pressure side of a refrigerant circuit provided in air conditioning or refrigeration equipment, and to a separately provided recovery cylinder. pipes, high-pressure side and low-pressure side solenoid valves provided in each of the connecting pipes, and a differential pressure provided to open and close the solenoid valves to detect the pressure difference between the high-pressure side of the refrigerant circuit and the recovery cylinder. switch and
A low pressure switch that detects the pressure within the refrigerant circuit;

[Function] In the present invention having the above configuration, first, when the recovery cylinder is connected to the high pressure side of the equipment via the high pressure side solenoid valve, the high pressure is compressed and condensed by the compressor and condenser on the equipment side. The condensed refrigerant flows into the low-pressure cylinder, and liquid refrigerant accumulates inside the cylinder. The inflow of condensed refrigerant continues until the differential pressure between the inside of the cylinder and the equipment side becomes small. When the differential pressure switch detects a decrease in this differential pressure, the high pressure side solenoid valve is closed and the low pressure side solenoid valve is closed. Opening connects the collection cylinder to the low pressure side of the equipment. Then,
The high-pressure gas refrigerant inside the cylinder is released to the low-pressure side of the equipment, and self-cooling at this time lowers the internal pressure of the cylinder. When the differential pressure switch confirms the differential pressure between the internal pressure of the cylinder and the high pressure side of the equipment, the solenoid valve on the low pressure side is closed and the solenoid valve on the high pressure side is opened. flow inside.

By repeating the following steps: (1) inflow of condensed refrigerant from the high-pressure side using the compressor and condenser on the equipment side, (2) lowering the internal pressure of the cylinder by releasing gas refrigerant to the low-pressure side, the refrigerant in the equipment is transferred to the cylinder. The refrigerant pressure inside the equipment is set to OK using the low pressure switch.
g/(1!Iil), it is determined that the collection is complete, and each of the electromagnetic valves is closed to disconnect the cylinder from the equipment.

[Embodiment 1] An embodiment of the refrigerant recovery apparatus of the present invention will be described below with reference to FIGS. 1 and 2.

That is, FIG. 1 is a circuit diagram in which the refrigerant recovery device of this embodiment is connected to the refrigerant circuit on the equipment side. The provided refrigerant circuit 21 includes a compressor 6 for compressing refrigerant and a condenser 7 for condensing the refrigerant into liquid refrigerant.
An evaporator 22 is connected to the condensed saliva refrigerant to gasify it and absorb heat, and the evaporator 22 is connected again to the compressor 6 to compress the gasified refrigerant. Further, the refrigerant circuit 21 is provided with a high pressure side check joint 8 behind the condenser 7 or a low pressure side check joint 9 in front of the compressor 6 in order to connect the refrigerant recovery device of this embodiment. .

In order to recover the refrigerant from the above-mentioned equipment, the refrigerant recovery device 1 of this embodiment and the recovery cylinder 10 connected thereto and separately provided are required.

As shown in FIGS. 1 and 2, this refrigerant recovery device 1 includes a high-pressure side check joint 8, a low-pressure side check joint 9, and a recovery bong 10 of a refrigerant circuit 21 provided in the equipment. Three connecting pipes 3, 4.5 connected to the main body case 2 are provided within the main body case 2. These connecting pipes 3,
4.5 are connected to each other via a branch pipe 13. Further, each of these container pipes is provided with a high pressure side solenoid valve 14, a low pressure side solenoid valve 15, and a side solenoid valve 16 for the recovery cylinder in order to open and close the pipes. In addition, in order to control the opening and closing of each of these solenoid valves, a set value of 1 kg/c is used to detect the differential pressure between the high pressure side pressure of the refrigerant circuit 21 and the internal pressure of the recovery cylinder t\10.
A male differential pressure switch 11 and a low pressure switch 12 with a set value Okg/C- for detecting the low pressure side pressure of the refrigerant circuit 21 are provided. In addition, in order to set the operating time of these electromagnetic valves 14 to 16 and to operate the differential pressure switch 11 at a constant time, a recovery timer 17, a differential pressure detection timer 18, and a timer 19 for self-cooling pressure reduction in the cylinder are provided. It is being

Note that an oil separator 20 is attached to a part of the high-pressure side connecting pipe 3 to remove impurities.

In order to recover refrigerant from the equipment with the refrigerant recovery apparatus of this embodiment configured as described above, first, connect the high pressure side connecting pipe 3 to the high pressure side check joint 8 of the refrigerant circuit 21, and connect the high pressure side connecting pipe 3 to the low pressure side check joint 9. The low pressure side connecting pipe 4 is connected to the cylinder 10, and the cylinder connecting pipe 5 is connected to the recovery cylinder 10. In this state, the power to the refrigerant recovery device 1 is turned on, and the low pressure switch 12 indicates that there is even a small amount of refrigerant in the refrigerant circuit 21 of the equipment that requires refrigerant recovery, that is, the low pressure side pressure is lower than Okg/cd. When a large state is detected, the high pressure side solenoid valve 14 and the recovery phone side solenoid valve 16 are opened, and the low pressure side solenoid valve 15 is closed. As a result, the high pressure side of the refrigerant circuit 21 and the recovery cylinder 10 are connected, and the compressor 6 of the refrigerant circuit 21 is connected to the recovery cylinder 10.
The high-pressure liquid refrigerant cooled and condensed by the condenser 7 is
Flows into the low pressure recovery phone 10. At this time, the liquid refrigerant passes through the oil separator 20, and impurities in the refrigerant, such as oil from the compressor 6, which flow out together with the refrigerant, are removed.

At the same time as refrigerant recovery is started, the recovery timer 17 is activated, and about 2 minutes later, the recovery cylinder side solenoid valve 16 is closed. Thereafter, the differential pressure detection timer 18 is activated, and the side solenoid valve 16 is again released to the collection phone after 15 seconds. This 15
The differential pressure between the high-pressure side pressure of the refrigerant circuit 2 and the internal pressure of the recovery cylinder 10 is detected by the differential pressure switch 11 every second, and if this value is larger than 1 kg/crl,
Since the differential pressure is sufficient, connect 10 to the high pressure side and the recovery phone again to continue recovery. Differential pressure decreases to 1kg/cd
In the case of less than 1, the high-pressure side solenoid valve 14 is closed and the low-pressure side solenoid valve 15 is opened to connect the recovery cylinder 10 to the low-pressure side of the refrigerant circuit 21. At this time, the low-pressure side solenoid valve 15 is closed one minute later by the timer 19 for self-cooling pressure reduction in the cylinder. During this one minute, gasified refrigerant is discharged from the high-pressure recovery cylinder 10 to the low-pressure side of the refrigerant circuit 21, and the internal pressure of the cylinder decreases due to self-cooling at this time.

After the low pressure side solenoid valve 15 is closed, the differential pressure switch 11 switches between the high pressure side pressure of the refrigerant circuit 21 and the refrigerant recovery cylinder 10.
After confirming that the differential pressure with the internal pressure is greater than 1 kg/cd, the high pressure side of the refrigerant circuit 21 and the recovery cylinder 10 are connected again, and the high pressure condensed liquefied refrigerant is transferred to the low pressure recovery cylinder 10. It flows in and is collected. This refrigerant circuit 2
1. The process of recovering condensed liquefied refrigerant from the high-pressure side into the recovery cylinder 10 and the process of releasing the gas refrigerant in the recovery cylinder 10 to the low-pressure side of the refrigerant circuit 21 to lower the internal pressure of the recovery pump 10 are repeated. The refrigerant is recovered into the recovery cylinder 10. In this way, the refrigerant in the refrigerant circuit 21 is recovered, and the low pressure switch 12 detects that the refrigerant pressure on the low pressure side has reached Okg/ctA, and the high pressure side solenoid valve 14,
The low pressure side solenoid valve 15 and the recovery cylinder side solenoid valve 16 are closed, and the recovery device 1 and the recovery cylinder 10 are connected to the refrigerant circuit 2 on the equipment side.
Separate it from 1 and complete the collection.

Incidentally, the oil separator 20 provided in the high-pressure side connecting pipe 3 stores oil from the compressor 6 that would otherwise flow out together with the refrigerant during refrigerant recovery, and also returns this oil to the compressor 6, so that the purity of the recovered refrigerant can be reduced. In addition, cooling of the refrigerant can be continued without impairing the function of the compressor 6.

As described above, according to the refrigerant recovery device of this embodiment, by using the refrigerant circuit of air conditioning, refrigeration equipment, etc., the refrigerant recovery device does not require a refrigerant circuit for cooling, which makes the device smaller and lighter. It can be easily stored and carried. Moreover, the manufacturing process becomes simple, and an inexpensive device can be provided. Furthermore, the cooling of the gas refrigerant, which takes time in the conventional recovery route, is performed in the refrigerant circuit of the equipment that requires refrigerant recovery, and the refrigerant is recovered in the liquid refrigerant state by the refrigerant recovery equipment, so the recovery time is shorter than that of the conventional recovery route. It can be significantly shortened compared to

Note that the present invention is not limited to the embodiments described above, and the specific shape of each member, the position and method of mounting each member, etc. can be changed as appropriate.

For example, the settings of switches and timers are not limited to the examples, but can be set to appropriate values based on the temperature, the capacity of the compressor of the equipment that requires refrigerant recovery, etc., and by correcting them, more efficient recovery can be achieved. can.

It is also conceivable to provide pressure gauges before and after the differential pressure switch, near the low pressure switch, or near the refrigerant circuit or cylinder connection of each connecting pipe. With this pressure gauge, it is possible to obtain accurate measurements of the differential pressure between the high-pressure side pressure of the refrigerant circuit and the internal pressure of the refrigerant recovery cylinder, as well as the low-pressure side pressure of the refrigerant circuit. can be known. Furthermore, it can be used as a reference for timer settings, etc., and maintenance of refrigerant recovery equipment. Further, although this embodiment is automated by providing a timer, collection can also be performed manually by providing a pressure gauge. Furthermore, by using a high-precision differential pressure switch and low pressure switch that can measure the differential pressure and low pressure side pressure during the process where refrigerant is collected into the cylinder, collection can be performed efficiently without using a timer. I can do it.

Additionally, water tanks and cooling pipes are installed around the refrigerant recovery cylinder.
It is also possible to always keep it cool with cooling water.

As a result, it is possible to suppress an increase in the temperature inside the refrigerant recovery cylinder, the internal pressure of the cylinder can be reduced in a short time, and the recovery time can be shortened.

[Effects of the Invention] The refrigerant recovery device of the present invention is smaller and lighter than conventional devices and can be easily carried, so if there is a small space around the equipment that requires refrigerant recovery, can be collected. In addition, the recovery time can be significantly shortened, and since it is inexpensive, it can be easily incorporated into the process of removing and repairing air conditioning and refrigeration equipment, making refrigerant recovery more widespread. becomes. That is, it is possible to provide a refrigerant recovery device that can promote refrigerant recovery for the protection of the global environment.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the refrigerant recovery device of the present invention,
FIG. 2 is a similar layout diagram, and FIG. 3 is a schematic configuration diagram showing a conventional refrigerant recovery device. 1... Refrigerant recovery device, 2... Main body case, 3...
High pressure side connecting pipe, 4... Low pressure side connecting pipe, 5... Cylinder connecting pipe, 6... Compressor, 7... Condenser,
8... High pressure check joint, 9... Low pressure check joint, 10... Recovery cylinder, 11... Differential pressure switch, 12... Low pressure switch, 13... Branch pipe, 14... ...High pressure side solenoid valve, 15...Low pressure side solenoid valve, 16...Recovery cylinder side solenoid valve, 17...Recovery timer, 18...Differential pressure detection timer, 19...Inside cylinder Self-cooling pressure reduction timer, 20... Oil separator, 21... Refrigerant circuit, 22... Evaporator, 31
...Suction connecting pipe, 32...Compressor, 33...
・Capacitor, 34...Oil separator, 35...
-Receiver, 36...Dryer, 37...Receiver for collection.

Claims (1)

[Scope of Claims] Connecting pipes connected to the high-pressure side and low-pressure side of a refrigerant circuit provided in air conditioning or refrigeration equipment, and a separately provided recovery cylinder, and connecting pipes provided in each of the connecting pipes. a solenoid valve on a high-pressure side and a low-pressure side; a differential pressure switch that is provided to open and close the solenoid valve and detects a pressure difference between the high-pressure side of the refrigerant circuit and the recovery cylinder;
A refrigerant recovery device comprising: a low pressure switch that detects pressure within a refrigerant circuit;