JP2929732B2 - Refrigerant recovery and regeneration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant recovery / regeneration apparatus provided with an oil separator for separating oil contained in a refrigerant recovered from a refrigeration cycle to be recovered.

[0002]

2. Description of the Related Art When a refrigerant is recovered and regenerated from a refrigeration cycle (recovered refrigeration cycle) used in a vehicle air conditioner or the like, as shown in FIG.
An oil separator 50 is provided in the refrigerant recovery and regeneration device 100 to separate oil contained in the refrigerant recovered from the refrigerant (Japanese Patent Laid-Open No. 48-23232).

[0003]

However, in the oil separator used in the conventional refrigerant recovery and regeneration, the oil in the refrigerant separated in the oil separator is subjected to the gravity of oil from a discharge pipe provided below the oil separator. Since the oil is manually discharged, it has been difficult to surely discharge the oil in the oil separator in a short time. Therefore, there is a problem that the regenerative performance of the refrigerant is reduced by the oil remaining in the oil separator.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and by automatically and reliably discharging oil in an oil separator in a short period of time, it is possible to prevent deterioration in refrigerant regeneration performance, The purpose is to automate the discharge work of wastewater.

[0005]

In order to achieve the above object, the present invention provides an oil separator for separating oil contained in a refrigerant recovered from a refrigeration cycle to be recovered, and a method for recovering the oil separated by the oil separator. An oil tank, a first on-off valve provided in the refrigerant recovery path of the refrigeration cycle to be recovered and the oil separator, and a second on-off valve provided in the oil recovery path of the oil separator and the oil tank. A first valve for recovering the refrigerant from the refrigeration cycle to be recovered to the oil separator;
Using a technical means comprising: a state in which the on-off valve is opened and the second on-off valve is closed; and a control means for controlling the state in which the first on-off valve is closed and the second on-off valve is opened. Further, it is effective to use technical means for controlling the valve opening time of the second on-off valve to be shorter as the outside air temperature is higher.

[0006]

According to the above means, the first on-off valve opens and the second on-off valve opens.
While the open / close valve is closed, refrigerant is introduced from the recovered refrigeration cycle to the oil separator, but the pressure inside the oil separator is significantly higher than the atmospheric pressure due to the saturation pressure according to the outside air temperature of the introduced refrigerant. Becomes Next, while the first on-off valve is closed and the second on-off valve is open, the oil separated at the lower portion of the oil separator by the previous recovery and regeneration operation is caused by the high refrigerant saturation pressure in the oil separator.
The oil is automatically discharged to the oil tank via the second on-off valve in a short time.

The opening time of the second on-off valve is controlled in accordance with the outside air temperature because the saturation pressure of the refrigerant changes depending on the outside air temperature. Is reliably discharged to the oil tank, while the refrigerant in the oil separator does not need to be discharged.

[0008]

FIG. 1 shows the configuration of a refrigerant recovery / regeneration apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a refrigerant recovery / regeneration device, 2 denotes a refrigerant recovery / regeneration device 1 and a refrigeration cycle 200 to be recovered such as a vehicle
And the inside of the refrigerant recovery and regeneration device 1
It is configured as follows in the order in which the refrigerant flows.

Reference numeral 3 denotes a first opening / closing valve comprising an electromagnetic valve or the like for controlling the flow of refrigerant from the recovered refrigeration cycle 200 by opening and closing a passage.
A check valve 5 for preventing backflow to 00, an oil separator 5 for separating oil in the refrigerant, a dryer 6, and a desiccant 6 a for absorbing moisture in the refrigerant are set therein. 7
Is a condenser for liquefying the refrigerant flowing from the refrigeration cycle 200 to be recovered, and the evaporator 8a of the hermetic refrigeration unit 8 is set inside. Reference numeral 7a denotes an on-off valve for recovering liquid refrigerant, such as an electromagnetic valve for controlling the flow rate of the refrigerant liquefied by the condenser 7 by opening and closing a passage. Reference numeral 9 denotes a recovery tank for storing the liquefied refrigerant. Each of the above devices is a refrigerant pipe 10a, 1
0b, 10c, and 10d. The refrigerant pipes 10a, 10a are provided on the lower surface of the oil separator 5.
Apart from b, a capillary 11 for preventing the collected oil from scattering, a second on-off valve 12 composed of a solenoid valve and the like, and an oil tank 13 are connected by an oil pipe 14.

FIG. 2 is an electric circuit diagram of the refrigerant recovery / regeneration apparatus 1 of the present invention. In FIG. 2, reference numeral 20 denotes an AC power supply that is a power supply of the refrigerant recovery and regeneration device 1, and reference numeral 21 denotes a refrigerant recovery and regeneration device 1.
This is a power switch for starting and stopping the power supply. Reference numeral 22 denotes a compressor motor of the refrigerating device 8 and 23 denotes a blower motor for the condenser of the refrigerating device 8. Reference numeral 24 denotes an AC / DC converter for converting the AC power supply 20 into a DC power supply, and reference numerals 25, 26, 27, and 28 denote compressor motors 22, blower motors 23, and respective on-off valves 3, 7.
Relays that open and close circuits to a and 12, 29 is relay 2
Microcomputer for controlling 5, 26, 27, 28;
An outside temperature thermistor that sends a signal to

Next, the operation of the refrigerant recovery and regeneration apparatus of the present invention will be described with reference to FIGS. When the power switch 21 is closed in step S1, the AC / DC converter 24 is energized, and the microcomputer 29 is driven by the DC power generated thereby, and the internal program is operated to regenerate the refrigerant of the refrigeration cycle 200 to be recovered. And the collection starts automatically.

First, in step S2, the first on-off valve 3 is opened.
In step S3, the first on-off valve 3₁Open for a second.
At this time, the refrigerant in the recovered refrigeration cycle 200 is
Due to the condition, the pressure is the saturation pressure for the outside air temperature at that time.
It is almost equal. For example, if the recovered refrigerant is R-12 and the outside air temperature
5.6kgf / cm if the temperature is 25 ° C ^TwoG. Obedience
Therefore, at the moment when the first on-off valve 3 is opened,
From the vehicle 200 through the connection port 2, the refrigerant recovery and regeneration device 1
Since the refrigerant flows into the inside, the oil recovery
The pressure P in the parator 5 rises and is several atmospheres higher than the atmospheric pressure.
Pressure. At the bottom of the oil separator 5, the previous
The oil separated from the refrigerant by the refrigerant recovery and regeneration operation is accumulated.
Have been. Next, in step S4, the first on-off valve 3 is closed.
Then, by opening the second on-off valve 12, the oil
The oil under the separator 5 is pushed by the internal pressure P,
The oil is discharged into the oil tank 13 through the pipe 14. Ki
The capillary 11 is used to discharge oil rapidly and
As a throttle to prevent oil from splashing
Play a role.

Assuming that the time for opening the second on-off valve 12 and discharging the oil in step 5 is t ₂ seconds, t ₂ is a function of the outside air temperature T ° C. detected by the outside air temperature thermistor 30.

[0014]

The control is performed as follows: t ₂ = t ₀ −K · T (t ₀ and K are constants). This is for the following reason. In general, when the refrigerant is recovered and regenerated from the air conditioner cycle of the vehicle, about 10 g of oil is accumulated in the lower portion of the oil separator 5 each time. Accordingly, the second on-off valve 12, so that the 10g of oil may be set the valve opening time t ₂ as can be discharged. However, the time t ₂ changes depending on the pressure P in the oil separator 5. This is shown in FIG.

FIG. 4 (I) shows the oil separator 5 on the vertical axis.
The horizontal axis indicates the time required to discharge 10 g of oil, that is, the valve opening time t ₂ of the second on-off valve 12. The higher the pressure P of the oil separator 5, the valve opening time t ₂ becomes possible be short. Since the pressure P in the oil separator 5 becomes substantially equal to the saturated vapor pressure of the refrigerant in the refrigeration cycle 200 to be recovered, (I) in FIG.
It shows characteristics like I). As shown in FIG. 4, when the outside air temperature is 0 ° C., the valve opening time t ₂ is required to be 38 seconds, and when the outside air temperature is 40 ° C., t ₂ is only 3 seconds.

Therefore, if the opening time t ₂ of the second on-off valve 12 is fixed to the required time of 38 seconds when the outside air temperature is 0 ° C., if the outside air temperature is 40 ° C., 38−3 = 35
For a second, the refrigerant to be recovered and regenerated is released. Conversely, the valve opening time t ₂ of the second on-off valve 12 when thus fixed at the required time when the outside air temperature 40 ° C. 3 seconds, the outside air temperature is low condition, the oil is accumulated in the oil separator 5 As a result, the oil separation performance is remarkably reduced, and a sufficient regenerating ability cannot be obtained.

In order to solve such a problem, the opening time t ₂ of the second on-off valve 12 is calculated as a function of the outside air temperature T ° C.
It is necessary to control as follows. After performing the above oil discharge control, in step S6, the second on-off valve 12 is closed, the first on-off valve 3 and the on-off valve 7a for recovering the liquid refrigerant are opened, and at the same time, the relay 25 is closed and the compressor is opened. By operating the motor 22 and the blower motor 23, the refrigeration system 8 is operated to recover and regenerate the refrigerant. The refrigerant of the refrigeration cycle to be collected 200 flowing from the connection port 2 flows into the oil separator 5 through the first on-off valve 3 and the pipe 10a.

Here, the oil in the refrigerant is separated by the evaporation of the refrigerant, and accumulated in the lower portion of the oil separator 5. The evaporated refrigerant flows into the dryer 6 from above the oil separator 5 through the pipe 10b. Here, when the refrigerant comes into contact with the desiccant 6a, moisture in the refrigerant is removed, and flows into the condenser 7 through the pipe 10c as a regenerated refrigerant. Since the evaporator 8a of the refrigerating device 8 is installed in the condenser 7, the refrigerant is cooled and liquefied. Collected.

Since the above is controlled by the timer function set in the microcomputer 29, after a certain period of time has passed in step S7 after the power switch 21 has been closed, the first on-off valve 3 is closed in step 8 The device 8 also stops, and the process automatically ends. By configuring and controlling as described above, the conventional manual oil discharge can be performed automatically and in a short time. Further, since the discharge of oil, the time t ₂ is opened a second on-off valve 12 as a function of ambient temperature, by controlling the Equation 1, is possible to discharge the oil without releasing refrigerant into the atmosphere It becomes possible. As a result, the recovery and regeneration of the refrigerant can be performed completely automatically.

FIG. 5 shows another embodiment. In FIG.
Reference numeral 31 denotes a connection port with the refrigeration cycle to be recovered, 32 denotes a first opening / closing valve for controlling the inflow of refrigerant by opening / closing a passage, 33
Is a check valve for preventing backflow of the refrigerant to the refrigeration cycle to be recovered, and 34a is a connection port 31, a first opening / closing valve 32 and a check valve 3
3 shows a pipe connecting each of them. Reference numeral 35 denotes an oil separator container, in which an oil separator portion 36 for separating oil by evaporation of the refrigerant and a dryer portion 37 for absorbing the moisture of the refrigerant are provided. A wire mesh filter 38 for adsorbing oil mist and a liquid level sensor 39 for detecting a refrigerant liquid level are provided in the oil separator section 36. Dryer part 37
Is provided with a cylindrical container 40, a felt 41 for adsorbing oil, and a desiccant 4 for absorbing moisture in the refrigerant in the container 40.
2 are provided.

A pipe 3 is provided above the oil separator container 35.
4b is installed, and the regenerated refrigerant is sent from the pipe 34b to the condenser 7 (see FIG. 1). Oil separator container 3
On the upper surface of 5, a cap 43 is detachably installed. 44 is a bolt for tightening the cap 43, and 45 is an O-ring for sealing between the cap 43 and the oil separator container 35.

An oil discharger 34c is connected to a lower surface of the oil separator container 35, and a capillary 46, a second on-off valve 47, and an oil tank 48 are connected to each other. With this configuration, the same effect as the configuration shown in FIG. 1 can be obtained, and the dryer 6 shown in FIG.
In addition, the number of parts can be reduced by integrating the oil separator 5 and the size of the refrigerant recovery / regeneration device itself can be reduced.

In the above-described example, the switching operation of the first switching valve 3 and the switching operation of the second switching valve 12 are synchronized with each other. It may include a state of being temporarily opened or a state of being closed. For example, when the first on-off valve 3 is switched from open to closed, the second on-off valve 12 may be switched with a slight time delay instead of immediately switching from closed to open.

[0024]

According to the present invention, as described above, the oil in the oil separator is automatically and reliably discharged into the oil tank in a short period of time, so that the performance of the refrigerant is deteriorated. Is prevented, and the operation of discharging the oil from the oil separator is automated, so that the handling of the refrigerant recovery and regeneration device becomes easy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigerant recovery and regeneration device of the present invention.

FIG. 2 is an electric circuit diagram of a main part of the device.

FIG. 3 is an operation flowchart of refrigerant recovery and regeneration of the same device.

FIG. 4 is an explanatory diagram showing a relationship between a refrigerant pressure in an oil separator with respect to an outside air temperature and a time required for discharging oil.

FIG. 5 is a configuration diagram showing another embodiment of the refrigerant recovery and regeneration device.

FIG. 6 is a configuration diagram of a conventional refrigerant recovery and regeneration device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerant collection | recovery reproduction | regeneration apparatus 3 1st on-off valve 5 Oil separator 12 2nd on-off valve 13 Oil tank 29 Microcomputer (control means) 200 Refrigeration cycle to be collected

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norihiko Hagiwara 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Inside Denso Co., Ltd. (72) Inventor Hiroshi Tamura 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Denso Co., Ltd. (72) Inventor Reiji Zaimae 1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 45/00

Claims (2)

(57) [Claims] 1. An oil separator for separating oil contained in a refrigerant recovered from a recovered refrigeration cycle, an oil tank for recovering oil separated by the oil separator, a refrigerant for the recovered refrigeration cycle and a refrigerant for the oil separator. A first on-off valve provided in a recovery path, a second on-off valve provided in an oil recovery path of the oil separator and the oil tank, and a refrigerant from the refrigeration cycle to be recovered to the oil separator. In the case of collection, the first
And a control means for controlling the second on-off valve to be closed and the first on-off valve to be closed and the second on-off valve to be open. Refrigerant recovery and regeneration device. 2. The refrigerant recovery and regeneration device according to claim 1, wherein the valve opening time of the second on-off valve is controlled to be shorter as the outside air temperature is higher.