JP2849489B2 - Gas filling device for temperature-sensitive cylinder of expansion valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas filling device for an expansion valve, which is for filling a mixed gas of a refrigerant gas and an inert gas into the expansion valve provided in a refrigeration cycle.

[0002] The temperature-sensitive cylinder is generally filled with the same refrigerant gas as the refrigerant used in the refrigeration cycle. However, when it is desired to change the degree of heating when the expansion valve opens due to the evaporation pressure of the evaporator, a mixed gas obtained by mixing a refrigerant gas different from the refrigerant used in the refrigeration cycle and an inert gas at an appropriate pressure ratio is used. , Filling the temperature-sensitive cylinder.

[0003]

2. Description of the Related Art FIG. 2 shows a first example of a conventional gas filling device, in which a main valve 5 connected to a temperature-sensitive cylinder 51 of an expansion valve.
2, a refrigerant gas supply pipe 53 and an inert gas supply pipe 54 are connected in parallel, and a vacuum pump 55 for previously evacuating the temperature-sensitive cylinder 51 is connected in parallel to the pipes. Are connected to valves 56, 57, 58 in the middle of the process.
Reference numeral 59 denotes a pressure regulator for adjusting the filling pressure of the inert gas.

When a gas mixture of a refrigerant gas and an inert gas is charged into the temperature sensing cylinder 51 by such a gas filling apparatus, first, the main valve 52 and the vacuum pump valve 58 are opened to open the inside of the temperature sensing cylinder 51. Is evacuated, the valve 58 for the vacuum pump is closed,
The refrigerant gas valve 56 is opened to charge the refrigerant gas into the temperature-sensitive cylinder 51.

When the charging of the refrigerant gas into the temperature-sensitive cylinder 51 is completed, the main valve 52 and the refrigerant gas valve 56 are closed, the vacuum pump valve 58 is opened, and the refrigerant gas in the middle of the pipeline is removed.

Next, the vacuum pump valve 58 is closed, and the inert gas valve 57 is opened to supply the inert gas to the temperature-sensitive cylinder 5.
Fill into 1. However, this filling time must be instantaneous of about 0.5 seconds. If I do not,
This is because the refrigerant gas already filled in the temperature sensing tube 51 flows backward and leaks out of the temperature sensing tube 51. When the operation is completed, all the valves 52, 56, 57, 58 are completely closed, and the charging operation of the mixed gas is completed.

FIG. 3 shows a second example of a conventional gas filling apparatus, in which a refrigerant gas supply pipe 53 and an inert gas supply pipe 5 are provided.
4 are respectively interposed with pressure regulators 60 and 59, and a refrigerant gas tank 61 and an inert gas tank 62 store a refrigerant gas and an inert gas of a predetermined pressure, respectively.

The temperature-sensitive cylinder 51 is filled according to the ratio of the opening ratio of the mixed gas discharge valve 63 for discharging the mixed gas to the atmosphere, the refrigerant gas valve 56, and the inert gas valve 57. The mixing ratio between the refrigerant gas and the inert gas in the mixed gas is constant.

[0009]

However, in the above-mentioned first conventional gas filling apparatus, the filling operation is complicated, and the time for opening the inert gas valve 57 must be very strictly controlled. There was a drawback that handling was severe and the mixing ratio tended to be inaccurate.

In the above-mentioned second conventional gas filling apparatus, the mixed gas is discharged into the atmosphere in order to stabilize the mixing ratio, which is extremely uneconomical and has become a serious problem in recent years. There was a drawback that led to environmental destruction.

Therefore, the present invention provides a temperature-sensitive cylinder for an expansion valve which is easy to handle, controls a mixture ratio of a refrigerant gas and an inert gas accurately and does not discharge a refrigerant gas or the like to the atmosphere. It is an object of the present invention to provide a gas filling device capable of filling a gas.

[0012]

In order to achieve the above object, a gas filling device for a temperature-sensitive cylinder of an expansion valve according to the present invention is provided.
A refrigerant tank containing a liquid refrigerant at a lower portion and connected to a temperature sensing cylinder of an expansion valve at an upper portion thereof, and a temperature at which a saturated vapor pressure of the refrigerant matches a refrigerant gas pressure filling the temperature sensing cylinder. Refrigerant tank temperature control means for controlling the temperature of the refrigerant tank, an inert gas tank containing an inert gas to be filled in the temperature-sensitive cylinder and connected to the refrigerant tank, and the internal pressure of the inert gas tank, Pressure control means for controlling the sum of the inert gas pressure and the refrigerant gas pressure to be charged into the thermosensitive cylinder; and the inert gas so that gas can flow only from the inert gas tank to the refrigerant tank. A check valve connected between a connection pipe connecting the gas tank and the refrigerant tank is provided.

[0013]

In the refrigerant tank, the pressure of the refrigerant gas keeps the saturated vapor pressure at the temperature controlled by the refrigerant tank temperature control means as long as the refrigerant liquid exists in the tank, and the pressure of the inert gas becomes The pressure difference between the pressure of the refrigerant gas and the internal pressure of the inert gas tank is maintained.

[0014]

An embodiment will be described with reference to the drawings.

In FIG. 1, a mixed gas filling pipe 2 connected to a temperature sensing cylinder 1 of an expansion valve of a refrigeration cycle is provided with first and second main valves 3 and 4, both of which are disposed. Between them, a vacuum pump 5 is connected.

Therefore, by opening the vacuum pump valve 6 and opening and closing the first and second main valves 3 and 4, the interior of the temperature-sensitive cylinder 1 and the interior of the mixed gas filling pipe 2 and the like are previously emptied. can do. When filling the temperature-sensitive cylinder 1 with the mixed gas, the vacuum pump valve 6 is closed.

Reference numeral 11 denotes a refrigerant tank containing a liquid refrigerant (for example, butane) 100 in the lower part, and the base end of the mixed gas filling pipe 2 is connected to the upper part of the liquid level of the refrigerant.

The temperature of the refrigerant tank 11 is controlled by a temperature controller 12 so as to be a desired constant temperature.
The pressure P of the refrigerant gas existing above the refrigerant liquid level in the refrigerant tank 11 becomes the saturated vapor pressure at that temperature. Therefore, the temperature control device 12 controls the temperature of the refrigerant tank 11 to, for example, 25 degrees Celsius so that the saturated vapor pressure of the refrigerant matches the refrigerant gas pressure to be charged into the temperature-sensitive cylinder 1.

Reference numeral 14 denotes an inert gas tank containing an inert gas (for example, nitrogen). The inert gas tank 14 is supplied with an inert gas from an inert gas cylinder (not shown), and is controlled by a pressure regulating valve 15 interposed therebetween. , Inert gas tank 1
4 is maintained at a constant pressure. The pressure Q is the sum of the pressure P of the refrigerant gas in the refrigerant tank 11 and the pressure R of the inert gas to be charged into the thermosensitive cylinder 1, that is, Q = P + R.

The capacity of the inert gas tank 14 is very large, for example, about 100 times as large as the capacity of the refrigerant tank 11.
A check valve 18 is provided in the middle of the connection pipe 17 so that gas can flow only from the inert gas tank 14 side to the refrigerant tank 11.
The second connection pipe 20 is always closed and opened only when the pressure (P + R) in the refrigerant tank 11 becomes higher than the pressure Q in the inert gas tank 14. An electromagnetic valve 21 that connects the tanks 11 and 14 is connected.

According to the gas filling apparatus thus constructed, the pressure P of the refrigerant gas in the refrigerant tank 11 is
As long as the refrigerant liquid 100 is present in the refrigerant tank 11, the saturated vapor pressure at the temperature controlled by the temperature control device 12 is maintained, and the inert gas pressure R is equal to the refrigerant gas pressure P and the inert gas tank 14 Differential pressure R (R
= QP).

Therefore, after the interior of the temperature-sensitive cylinder 1 and the mixed gas filling pipe 2 are evacuated, the valve 6 for the vacuum pump is closed, and the two main valves 3 and 4 are opened. The refrigerant gas and the inert gas at the pressure (QP) are always filled into the temperature-sensitive cylinder 1 at a stable and accurate mixing ratio.

However, when the temperature control of the refrigerant tank 11 is not stable, for example, at the beginning of the operation of charging the mixed gas, the pressure in the refrigerant tank 11 becomes higher than the pressure in the inert gas tank 14. Sometimes.

In such a case, the solenoid valve 21 is opened, and the mixed gas in the refrigerant tank 11 is supplied to the inert gas tank 1.
Send within 4. By reducing the pressure in the refrigerant tank 11 in this manner, the pressure of the inert gas in the mixed gas in the refrigerant tank 11 can be reduced to a predetermined pressure (QP).

Since the volume of the inert gas tank 14 is sufficiently larger than the volume of the refrigerant tank 11, it can be considered that the pressure does not increase due to the inflow of the mixed gas as described above. Further, since the pressure of the refrigerant gas in the refrigerant tank 11 always becomes the saturated vapor pressure, the refrigerant gas sent out to the inert gas tank 14 is again discharged into the refrigerant tank 11.
Does not affect the refrigerant gas pressure in the refrigerant tank 11 at all.

[0026]

According to the gas filling device for the temperature sensing cylinder of the expansion valve of the present invention, the temperature of the refrigerant tank can be simply controlled.
Since the refrigerant gas pressure and the inert gas pressure in the refrigerant tank can be respectively maintained at predetermined pressures, the refrigerant gas or the inert gas can be easily handled by simply moving the mixed gas into the temperature-sensitive cylinder. It has an excellent effect that a mixed gas of a refrigerant gas and an inert gas can always be filled into a thermosensitive cylinder at a stable and accurate mixing ratio without releasing any gas into the atmosphere.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment.

FIG. 2 is a configuration diagram of a first conventional example.

FIG. 3 is a configuration diagram of a second conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermosensitive cylinder 11 Refrigerant tank 12 Temperature control device 14 Inert gas tank 15 Pressure control valve 18 Check valve

Claims (1)

(57) [Claims] 1. A refrigerant tank containing a liquid refrigerant in a lower part and connected to a temperature-sensitive cylinder of an expansion valve above the liquid refrigerant, and a refrigerant gas pressure filling the temperature-sensitive cylinder with a saturated vapor pressure of the refrigerant. A refrigerant tank temperature control means for controlling the temperature of the refrigerant tank to match the temperature, an inert gas tank containing an inert gas filled in the thermosensitive cylinder and connected to the refrigerant tank, Pressure control means for controlling the internal pressure of the gas tank to be the sum of the inert gas pressure and the refrigerant gas pressure to be filled in the temperature-sensitive cylinder, so that gas can flow only from the inert gas tank to the refrigerant tank And a check valve connected between a connection pipe connecting the inert gas tank and the refrigerant tank to the expansion valve.