JPH0436561A - Deaerating process for refrigerant - Google Patents

Abstract

PURPOSE:To enable a positive judgment for the completion of deaeration process for refrigerant in an on-line basis by a method wherein a temperature of refrigerant near its surface liquefied by heating or boiling and another temperature at an upper end of a radiation part are measured and a difference between these temperature is calculated. CONSTITUTION:As liquid refrigerant 2A is heated and boiled by a heating part 9 arranged at a lower part of a hermetic container 1, the refrigerant ascends in its gaseous refrigerant 2B. It is cooled by a radiation part 10. This is condensed and liquefied, and descends. Noncondensed gas in the refrigerant 2 is accumulated at the upper end of the radiation part 10. In this case, a thermometer 7 indicates a temper ature of the gaseous refrigerant 2B. A thermometer 8 indicates a temperature of non-condensed gas 3, so that there occurs a substantial difference between these temperatures. Then, a valve 5A is opened, and non-condensed gas 3 is sucked by a vacuum pump through a discharging pipe 5. The non-condensed gas 3 is dehydrated and the gaseous refrigerant 2B ascends up to the upper end of the radiation part 10 and finally a difference in temperature of the thermometers 7 and 8 becomes zero. With such as arrangement, the completion of the dehydration process can be judged. As the thermometer 8 is placed at a part 8A of the discharging pipe 5, it becomes the upper-most end of the radiation part 10 and this is more effective.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a deaeration process of a refrigerant used in a boiling cooling device used for cooling heat pipes or electronic equipment, etc., and particularly a method for determining the completion of the process. Regarding.

[Conventional technology]

In boiling cooling devices used to cool heat pipes or electronic equipment, a liquid refrigerant such as fluorocarbon sealed in a sealed container is heated and boiled by the object to be cooled, and becomes a gaseous refrigerant that flows inside the container. The gaseous refrigerant rises to the top, where it is cooled by the container itself or a heat radiator attached to the container, and this gaseous refrigerant condenses and liquefies to become a liquid refrigerant that descends and is heated again by the object to be cooled. .

In this way, the heat of the object to be cooled is transferred to the heat radiation section, and the object to be cooled is cooled. For example, if a non-condensable gas such as air (strictly speaking, within the temperature range normally used for cooling electronic equipment, etc.) is mixed into the refrigerant, the heat transfer area in the heat dissipation section will decrease and the cooling performance will decrease. If the non-condensable gas is air, for example, the container may be corroded by the oxygen contained therein.

For this reason, it is important to remove as much non-condensable gas as possible from the refrigerant.Generally, first, the liquid refrigerant is placed in a deaeration container and vacuum degassed, and the degassed liquid refrigerant is vacuumed in advance. Place it in the container of the cooling device, and then evacuate the container of the cooling device under vacuum.

[Problem to be solved by the invention]

As mentioned above, the refrigerant is first vacuum degassed, and then the refrigerant is placed in a container of a cooling device and then vacuum degassed again to remove non-condensable gases contained in the refrigerant. However, the method of determining the completion of the degassing process is usually to sample the degassing gas emitted during the degassing process, perform a component analysis, and judge based on the amount of non-condensable gas in the degassing gas. That's what I do. Since this method is off-line and requires time for analysis, the current situation is to perform vacuum degassing for a longer time than necessary. Therefore, in the degassing process,
The loss of refrigerant that is exhausted in gaseous form increases, and
Due to product quality control, there is a problem in which the completion of the degassing process cannot be confirmed.

An object of the present invention is to solve the above-mentioned problems and provide a degassing process that can accurately determine the completion of the refrigerant degassing process online.

[Means to solve the problem]

In order to solve the above-mentioned problems, in the refrigerant degassing process of the present invention, a liquid refrigerant is sealed in a closed container equipped with a heat dissipation section at the top, and this refrigerant is heated and boiled to gasify it. When the gasified refrigerant is cooled and condensed and liquefied in the heat dissipation section, the remaining non-condensable gas is exhausted from the closed container in a refrigerant deaeration process in which non-condensable gas is removed from the refrigerant. The temperature near the top of the liquid surface of the refrigerant liquefied by heating and boiling and the temperature at the upper end of the heat dissipation section were measured, and when the difference between these temperatures became almost zero, it was determined that the non-condensable gas in the refrigerant had been removed. The process is determined to be complete.

[For production]

In the refrigerant degassing process of the present invention, a liquid refrigerant sealed in an airtight container having a heat dissipation section at the top is heated and boiled. The refrigerant, which becomes gaseous due to this heating and boiling, rises and reaches the heat radiation section, where it is cooled, condenses and liquefies, and descends again as a liquid refrigerant, but the refrigerant contains non-condensable gases. If this happens, this non-condensable gas will accumulate at the top of the heat sink. Since this non-condensable gas has poor thermal conductivity, heat cannot be sufficiently transferred from the high temperature gaseous refrigerant that has been heated and boiled, so the temperature of this non-condensable gas decreases. When the non-condensable gas is removed from the refrigerant, the upper end of the heat radiating section is filled with highly pure gaseous refrigerant, and the temperature of the upper end of the heat radiating section rises to the temperature of the heated and boiled gaseous refrigerant.

Therefore, as the temperature of the heated and boiled gaseous refrigerant, the refrigerant temperature near the liquid level and the temperature at the upper end of the heat radiation part are measured, and when the difference between these temperatures becomes almost zero, non-condensable gas is removed. The process of degassing the refrigerant is complete.
Can be accurately determined online.

〔Example〕

FIG. 1 is a cross-sectional view of a refrigerant deaerator that performs the refrigerant deaeration process of the present invention.

The airtight container 1 is provided with a heat radiating part 10 at the upper part, and a refrigerant 2 for degassing treatment is sealed in the heat radiating part 10. This refrigerant 2 is in a liquid state and has a current of 2A at room temperature. An exhaust pipe 5 for degassing is provided at the upper end of the closed container. This exhaust pipe 5 is connected to a vacuum pump (not shown) via a valve 5A, or is opened to the atmosphere as the case may be. A heating section 9 provided at the bottom of the closed container 1 heats and boils the liquid refrigerant 2A.

The liquid refrigerant 2A becomes a gaseous refrigerant 2B by heating and boiling and rises to the upper part of the closed container 1. In the heat radiation section 10, this gaseous refrigerant 2B is cooled, condensed and liquefied, and descends as a liquid refrigerant. 2C shows the refrigerant that has liquefied and descended along the inner wall of the closed container.

If the refrigerant 2 contains non-condensable gas, this non-condensable gas accumulates at the upper end of the heat dissipation section 10. 3 indicates the state. Since the heat conduction of this gas is poor, the amount of heat cannot be sufficiently transferred from the high temperature gaseous refrigerant 2B that has been heated and boiled, so the temperature of this non-condensable gas decreases. 7 is a temperature needle provided near the liquid level 4 of the liquid refrigerant; 8
is a temperature needle provided at the upper end of the heat dissipation section. In this case, the thermometer 7 indicates the temperature of the heated and boiled gaseous refrigerant 2B, and the thermometer 8 indicates the temperature of the non-condensable gas 3.

Therefore, at the zeroth order, where there is a large difference between these temperatures, the pulp 5A is opened and the non-condensable gas 3 is discharged from the exhaust pipe 5 by a vacuum pump (not shown).

If the internal pressure of the closed container 1 is higher than atmospheric pressure due to heating, for example, it can be discharged by opening it to the atmosphere.

When the non-condensable gas 3 is degassed, the gaseous refrigerant 2B rises to the upper end of the heat radiation part 1O, and the difference in temperature between the thermometers 7 and 8 becomes zero. This allows determination of completion of the degassing process. It should be noted that if the thermometer 8 is attached to the exhaust pipe 5 as shown in 8A, it will be at the uppermost end of the heat dissipation part 10, which is more effective.

Note that in the deaeration process of the present invention, the refrigerant is heated and boiled, but in the conventional deaeration process, if the vacuum is simply drawn, the lower layer of the liquid refrigerant 2A sealed in the airtight container 1 The refrigerant had the problem of being difficult to degas due to the liquid pressure of the refrigerant in the upper layer, but since non-condensable gases are directly released from the refrigerant by heating and boiling, the deaeration process is highly efficient. This further reduces the processing time of the degassing process.

FIG. 2 is a sectional view of an evaporative cooling device for electronic equipment to which the refrigerant degassing process of the present invention is applied. The electronic device 12 as a cooled object is attached to the lower part of the closed container 1 constituting the cooling device. The airtight container l is provided with a heat dissipation part 10 at its upper part, and a refrigerant 2 is sealed therein so that the electronic equipment is immersed therein. This refrigerant 2 is in a liquid state and has a current of 2A at room temperature. Airtight container 1
An exhaust pipe 5 for degassing is provided at the upper end. This exhaust pipe 5
is connected to a vacuum pump (not shown) via a valve 5A, or is opened to the atmosphere as the case may be. 7 is a temperature needle provided near the liquid surface 4 of the liquid refrigerant, and 8 is a temperature needle provided at the upper end of the heat radiation section. 8A shows the case where it is attached to the exhaust pipe 5 as a temperature needle at the upper end of the heat radiation section.

In this embodiment, the operation and function are the same as in the embodiment shown in FIG. 1, except that the liquid refrigerant 2A is heated and boiled by the electronic device as the object to be cooled.

〔Effect of the invention〕

In the refrigerant degassing process of the present invention, a liquid refrigerant to be degassed sealed in an airtight container with a heat dissipation section at the top is heated and boiled, and the gaseous refrigerant near the liquid level is heated and boiled. We measured the temperature and the temperature at the top of the heat dissipation section, and when the difference between these temperatures became zero, we determined that the refrigerant degassing process was complete. Completion of the degassing process can be accurately determined. Conventionally, vacuum degassing was performed for a longer time than necessary, which was a factor in increasing costs, but costs have been reduced by reducing the processing time of the degassing process to the minimum necessary. In addition, during the long vacuum degassing process, there is no increase in the loss of the refrigerant that is exhausted in the gaseous state, further reducing costs.In addition, the completion of the degassing process can be confirmed, which has an effect on Shinaga management. Furthermore, in the degassing process of the present invention, the lower refrigerant sealed in the sealed container is heated and boiled.
Non-condensable gases are released directly from the refrigerant by heating and boiling, which is difficult to degas due to the liquid pressure of the upper refrigerant, making the deaeration process more efficient and further shortening the deaeration process time. There is.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a refrigerant deaerator to which the refrigerant deaeration process of the present invention is applied, and FIG. 2 is a sectional view of an evaporative cooling device for electronic equipment to which the refrigerant deaeration process of the invention is applied.

Claims (1)

[Claims] 1) When a liquid refrigerant is sealed in an airtight container equipped with a heat dissipation section at the top, this refrigerant is heated and boiled to gasify it, and this gasified refrigerant is cooled in the heat dissipation section and condensed and liquefied. In the refrigerant degassing process, in which non-condensable gas is degassed from the refrigerant by exhausting the remaining non-condensable gas from the sealed container, the temperature and heat dissipation near the liquid surface of the refrigerant liquefied by heating and boiling. refrigerant degassing, characterized in that the temperature at the upper end of the refrigerant is measured, and it is determined that the degassing process of the non-condensable gas of the refrigerant is completed when the difference between these temperatures becomes almost zero. process.