JP3212632B2 - Refrigeration cycle with refrigerant recovery mode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle with a refrigerant recovery mode to which a refrigerant recovery device for recovering internal refrigerant can be connected.

[0003]

2. Description of the Related Art Refrigerant in a refrigerating cycle in an air conditioner, a refrigerator, a freezer, or the like may cause a shortage of the refrigerant due to repetition of movement of the device or leakage. In this case, since the amount of the refrigerant remaining in the refrigeration cycle cannot be determined, it is difficult to optimize the amount of the refrigerant by adding the refrigerant, and the remaining refrigerant is discharged into the atmosphere and newly set in advance. A small amount of refrigerant.

Freon, which is generally used as a refrigerant, has extremely high chemical stability, and when released into the atmosphere, reaches the stratosphere, destroys the ozone layer, causes an increase in ultraviolet rays reaching the ground surface, and increases greenhouse temperature. It has been pointed out that the temperature at the surface increases as a cause of the effect. Therefore, discharging the refrigerant into the atmosphere is not preferable from the viewpoint of preventing air pollution and protecting the global environment, and is not preferable from the viewpoint of effective use of resources.

For this reason, attempts have conventionally been made to recover the refrigerant in the refrigeration cycle using a refrigerant recovery device. A refrigeration cycle configuration of a cooling / heating device with a refrigerant recovery mode to which a refrigerant recovery device can be connected will be described with reference to FIG.
This cooling and heating device is provided with a refrigerant heating heat exchanger 3 for directly heating the refrigerant by the refrigerant heater 1 in order to improve the performance at the time of heating, and an indoor unit 5 installed indoors and an indoor unit 5 installed outdoors. The outdoor unit 7 is a pipe 9
And 11 are connected by connecting portions 17 and 19 which are parts of packed valves 13 and 15 respectively interposed therebetween. The one packed valve 13 is provided with a service port 13a serving as a refrigerant gas inlet / outlet to which a refrigerant recovery device (not shown) can be connected.

[0006] The indoor unit 5 has an indoor heat exchanger 21 and a fan 23 incorporated therein. The outdoor unit 7 includes a compressor 25, a four-way valve 27 that switches the flow direction of the refrigerant between heating and cooling, the refrigerant heater 1 and the refrigerant heat exchanger 3, the outdoor heat exchanger 29, Fan 3
1, gas-liquid separator 33, electronic expansion valve 35, two-way valve 3
7, the check valves 39 and 41, and the capillary tube 43 are incorporated.

In such a cooling and heating apparatus, during heating, the four-way valve 27 switches to the state shown by the solid line, and the two-way valve 37 is opened, so that the refrigerant discharged from the compressor 25 flows as shown by the solid line arrow. On the other hand, at the time of cooling, the four-way valve 27 switches to the state shown by the broken line, and the two-way valve 37 is closed.
The refrigerant discharged from 5 flows as indicated by a broken arrow.

When the refrigerant in the refrigeration cycle is recovered in the cooling and heating device, the refrigerant recovery device is connected to the service port 13a of the packed valve 13 with the operation of the cooling and heating device stopped. When the operation is stopped, all the valves are turned off, the electronic expansion valve 35 is throttled, and the four-way valve 27 is generally in a cooling mode state indicated by a broken line. Therefore, when the refrigerant is recovered from the service port 13a in such a state, the indoor unit 5
The side can collect the refrigerant in the pipe from the indoor heat exchanger 21 and the gas-liquid separator 33 to the expansion valve 35, while the outdoor unit 7 can collect the refrigerant in the pipe from the four-way valve 27 to the check valve 39. . Refrigerant piping sections in these refrigerating cycles that can be recovered are limited as shown by thick solid lines.

[0009]

As described above, the expansion valve 3 is provided.
When various valves such as 5 and check valves 39 and 41 are used, a closed circuit may be partially configured as in the above-described refrigeration cycle, and the collection operation is performed with the valves kept throttled. It becomes difficult to recover the entire amount of the refrigerant. If the refrigerant remains in the closed circuit, it becomes difficult to secure an appropriate amount of refrigerant when newly filling the refrigerant, and it becomes difficult to operate the device with high efficiency. Further, when the equipment is to be discarded, the refrigerant is discarded while the refrigerant is sealed therein, and there is a possibility that the remaining refrigerant will be released into the atmosphere.

Accordingly, an object of the present invention is to make it possible to recover almost all of the refrigerant in a refrigeration cycle efficiently in a short time.

[Structure of the Invention]

[0012]

According to the present invention, a compressor, a heat exchanger, an expansion valve and the like are connected to each other by pipes, and an inlet and outlet of an internal refrigerant are provided in the middle of the pipes. In a refrigeration cycle with a refrigerant recovery mode in which a refrigerant recovery device can be connected to the inlet / outlet, a valve opening means for opening all valves for changing a pipe passage area such as the expansion valve provided in the middle of the pipe is provided. It is.

[0013]

In the refrigeration cycle with the refrigerant recovery mode configured as described above, when the refrigerant recovery device is connected to the inlet / outlet in the middle of the pipe to collect the refrigerant, all the valves provided in the middle of the pipe are set to valves. It is opened by the opening means.

[0014]

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

FIG. 1 is an overall configuration diagram of a refrigeration cycle with a refrigerant recovery mode in a cooling and heating apparatus according to an embodiment of the present invention. The configuration of the refrigeration cycle is the same as that shown in FIG. 3, and the same components as those in FIG. 3 are denoted by the same reference numerals. And the four-way valve 2 in this refrigeration cycle
7. The expansion valve 35 and the two-way valve 37 can be switched or opened and closed by the switching operation unit 45 as a valve opening means in the refrigerant recovery mode. When the switching operation unit 45 is operated during refrigerant recovery, the four-way valve 2
7 is in the heating mode indicated by the solid line, and both the expansion valve 35 and the two-way valve 37 are open. Such a switching operation unit 45 is provided on the outdoor unit 7 side.

Service port 13 of packed valve 13
FIG. 2 shows an example of the refrigerant recovery device connected to a. The tank 47 for collecting and storing the refrigerant in the refrigeration cycle shown in FIG. 1 is provided with a recovery port 49 at the upper end side and a return port 51 at the lower center. A collection passage 53 is connected to the collection port 49, and a return passage 55 is connected to the return port 51. The respective passages 53 and 55 join on the outdoor unit 7 side to form a merge passage 57. The recovery passage 53
, A return valve 61 is provided in the return passage 55, and a recovery valve 63 is provided in the merge passage 57.

The tank 47 includes a compressor 65, a condenser 67,
The evaporator 71 is integrally formed with a refrigerant recovery refrigeration cycle including an expansion valve 69 and an evaporator 71. The evaporator 71 is disposed in a coil shape in the tank 47, and the evaporator 71 cools the inside of the tank 47 during refrigerant recovery. The pressure is reduced. On the other hand, the outer periphery of the tank 47 is covered with an electric heater 73. When the refrigerant in the tank 47 is returned to the refrigeration cycle of the cooling and heating device shown in FIG. The pressure is increased. Reference numerals 75 and 77 are a sensor and an electric circuit for checking the amount of the collected refrigerant in the tank 47. Reference numeral 79 denotes a volume for increasing the minute difference in the amount of refrigerant in the tank 47 for accurate measurement, and reference numeral 81 denotes a temperature sensor.

When the refrigerant in the refrigerating cycle of the air conditioner is recovered in the tank 47 by the refrigerant recovery device, the switching operation unit 45 of the outdoor unit 7 is operated to set the refrigerant recovery mode. The expansion valve 35 and the two-way valve 37 are opened respectively in the heating mode indicated by the solid line 27. Then, as shown in FIG. 2, the merging passage 57 of the refrigerant recovery device is connected to the service port 1 of the packed valve 13.
3a. In this state, the inside of the tank 47 is cooled and decompressed by the evaporator 71, the recovery valves 59 and 63 are opened and the return valve 61 is closed, and the pressure inside the tank 47 and the pressure inside the refrigeration cycle on the side of the cooling and heating device are generated. The refrigerant is recovered in the tank 47 by the pressure difference of (1). At this time, the collection passage 53 from the collection valve 59 to the service port 13a.
And the return passage 55 from the return valve 61 to the service port 13a are previously kept in a vacuum by a vacuum pump (not shown).

At the time of recovering the refrigerant, the indoor heat exchanger 21, the gas-liquid separator 33, the electronic expansion valve 35, the two-way valve 3 are arranged from the indoor unit 5 side in accordance with the flow of the refrigerant during the heating operation.
7. The refrigerant up to the refrigerant heating heat exchanger 3 and the compressor 25 is recovered, and further from the branch point 83 between the compressor 25 and the refrigerant heating heat exchanger 3, the check valve 39, the four-way valve 27, the outdoor heat exchanger 29, capillary tube 43 and check valve 4
Up to one refrigerant is recovered. Since the capillary tube 43 serving as a resistor is located at the end of the refrigerant recovery route, there is almost no effect on shortening the recovery time. On the other hand, refrigerant from the outdoor unit 7 to the compressor 25 via the four-way valve 27 is recovered. Thereby, almost all of the refrigerant in the refrigeration cycle can be efficiently recovered without remaining in a short time.

Therefore, when refilling the refrigerant in the refrigerating cycle of the cooling / heating device, it is possible to fill the refrigerant with an optimal amount, and high efficiency operation is achieved. Also, when the air conditioner is discarded, the refrigerant hardly remains in the refrigeration cycle, so that there is no risk of air pollution. Further, since the refrigerant is not released into the atmosphere, it can contribute to effective use of resources.

In order to refill the refrigerant in the refrigeration cycle of the cooling and heating device after the refrigerant is recovered, the switching operation unit 45 of the outdoor unit 7 is operated to set the refrigerant recovery mode, and the four-way valve 27 is set in the solid line as in the case of the refrigerant recovery. In the heating mode indicated by,
The expansion valve 35 and the two-way valve 37 are opened.
The refrigerant recovery device supplies power to the electric heater
The inside is heated to increase the pressure, the return valve 61 and the recovery valve 63 are opened and the recovery valve 59 is closed, and the refrigerant in the tank 47 is charged into the refrigeration cycle of the cooling and heating device by the pressure difference generated thereby. For the filling amount, the collected amount is determined by the sensor 75 and the electric circuit 7.
7, the shortage is replenished into the tank 47 to a predetermined amount, and this is supplied to the refrigeration cycle of the cooling and heating device. Since it is provided on the side, it contributes to improving workability.

The operation method of the switching operation unit 45 may be a short-circuit method such as inserting a switch or a pin, a switching method, or a method using a change in resistance value. Further, the present invention is not limited to the cooling and heating device, and may be applied to a refrigeration cycle in a refrigerator, a freezer, or the like.

[0023]

As described above, according to the present invention, at the time of recovering the refrigerant, all valves for changing the area of the pipe passage provided in the middle of the refrigeration cycle are opened. Work efficiently and in a short time,
Almost all can be recovered without leaving the refrigerant. As a result, when the refrigerant is re-sealed in the refrigeration cycle, it is possible to fill the refrigerant with an optimal amount, and high efficiency operation can be achieved.
Also, when the equipment is discarded, the refrigerant hardly remains in the refrigeration cycle, so that there is no risk of air pollution by the refrigerant. Further, since the refrigerant is not released into the atmosphere, it can contribute to effective use of resources.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle showing one embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a refrigerant recovery device connectable to the refrigeration cycle of FIG.

FIG. 3 is a configuration diagram of a refrigeration cycle showing a conventional example.

[Explanation of symbols]

 13a Service port (entrance / exit) 21 Indoor heat exchanger 25 Compressor 29 Outdoor heat exchanger 35 Expansion valve 45 Switching operation part (valve opening means)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sumi Kagawa 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Toshiba Living Space Systems Research Laboratory (72) Inventor Yasuhiro Arai 8-8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Corporation Living Space System Technology Research Institute (72) Inventor Toshihiko Saito 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Living Space System Technology Research Institute (56) References JP-A-3-168570 (JP, A JP-A-61-175459 (JP, A) JP-A-4-60356 (JP, A) JP-A-2-187580 (JP, A) JP-A-1-193567 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F25B 45/00

Claims (1)

(57) [Claims] 1. A refrigeration system with a refrigerant recovery mode in which a compressor, a heat exchanger, an expansion valve and the like are connected to each other by pipes, and an inlet / outlet for the internal refrigerant is provided in the middle of the pipes. A refrigeration cycle with a refrigerant recovery mode, wherein a valve opening means for opening all valves for changing a pipe passage area such as the expansion valve provided in the middle of the pipe in the cycle is provided.