JPH0378550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a hot gas defrosting device that defrosts a cooler using a hot gas method.

[Conventional technology]

In a cooling device that defrosts using a hot gas method, hot gas is passed through the cooler during defrosting, and the heat is used to melt the frost in the cooler. During defrosting, the gas condenses and becomes liquefied, so it is necessary to evaporate the condensed liquid refrigerant and draw it into the compressor.

Conventionally, a tank system shown in FIG. 2 has been known for evaporating condensed refrigerant that is liquefied during defrosting.
In the figure, a refrigeration circuit is configured in which a compressor 31, a condenser 32, an expansion valve 33, and a cooler 34 are connected in series, and a discharge pipe 35 coming out of the compressor 31 is configured.
is connected to a coil 37 in tank 36 to heat the water or brine in tank 36. In addition, the inlet piping part of the on-off valve 38 which is provided before the condenser 32 and is closed during defrosting, and the inlet piping part of the cooler 34 are connected to a branch where an on-off valve 39, which is opened during defrosting, is provided in the middle. Piping 40
connected by. The pipe exiting the cooler 34 is connected to the suction pipe 42 of the compressor 31 through an on-off valve 41 that is opened during cooling operation, and is connected to the intake pipe 42 of the compressor 31 through an on-off valve 43 that is opened during defrosting. The suction pipe 42 is connected to the suction pipe 42 through the coil 44 .

With this configuration, the liquid refrigerant condensed in the cooler 34 during defrosting is transferred to the tank 36.
The water or brine is heated and gasified as it passes through the coil 44 inside. In addition, during cooling operation, the refrigerant flows through the arrow shown by the solid line.
During defrosting, the refrigerant flows through the path indicated by the dashed arrow.

In addition to the tank method, which uses the heat capacity of water or brine to evaporate condensed refrigerant, the condensed refrigerant discharged from the cooler during defrosting is passed through a coil of a heat exchanger, and the other coil of this heat exchanger is There is a heat exchange method in which the condensed refrigerant is evaporated by passing cooling water through the refrigerant and releasing the exchanged heat to the atmosphere.

[Problem that the invention seeks to solve]

However, when the condensed liquid refrigerant is evaporated using the tank method described above, there is a problem in that the water tank is corroded by the accumulated water.

Furthermore, the above-described heat exchange method has a problem in that the condensed liquid refrigerant cannot be efficiently evaporated when the cooling water temperature is low.

Therefore, the present invention was proposed to solve these conventional problems, and unlike the conventional tank system, the water tank does not corrode due to accumulated water, and the condensate refrigerant An object of the present invention is to provide a hot gas defrosting device that can obtain sufficient heat to gasify.

[Means for solving the problem]

In order to achieve this object, the hot gas defrosting device of the present invention is provided with containers in which hydrogen storage alloys with different thermal equilibrium pressures are individually sealed, and these containers are connected by piping, and hydrogen storage alloys with low thermal equilibrium pressures are installed. A first and second heat exchange coil is provided in a container enclosing a hot gas refrigerant, and during cooling operation, the hot gas refrigerant discharged from the compressor is passed through the first heat exchange coil, and when the cooler is defrosted, the first heat exchanger is passed through the first heat exchange coil. The configuration is characterized in that the supply of hot gas refrigerant to the exchange coil is stopped, the hot gas refrigerant is passed through the cooler, and the condensed liquid refrigerant after defrosting of the cooler is passed through the second heat exchange coil. ing.

[Effect]

In the above-described present invention, when the hot gas refrigerant is passed through the first heat exchange coil during cooling operation, the hydrogen storage alloy on the low pressure side is heated and the pressure increases, and hydrogen gas is released from this alloy. It is absorbed by the hydrogen storage alloy in the other container.

Also, during defrosting, the supply of hot gas refrigerant to the first heat exchange coil is stopped and the condensed liquid refrigerant after defrost is passed through the second heat exchange coil in the same container, so that The hydrogen storage alloy is cooled and the pressure decreases. As a result, hydrogen gas is released from the hydrogen storage alloy on the high pressure side sealed in the other container, and the hydrogen gas is absorbed by the hydrogen storage alloy on the low pressure side. At this time, the condensed liquid refrigerant is gasified by heat generation in the low-pressure side alloy due to absorption of hydrogen gas.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows the configuration of a hot gas defrosting device according to the present invention.

In the same figure, a discharge pipe 2 coming out of a compressor 1 that compresses gas refrigerant is provided with an on-off valve 4 following a three-way switching valve 3, and further connected with a condenser 5, followed by an expansion valve 6. Cooler 7 is connected. Note that cooling water is passed through the cooling coil 5a of the condenser 5.
If the port on the compressor 1 side of the three-way switching valve 3 is the first port 3a, and the on-off valve 4 side is the second port 3b, the third port 3c absorbs the granular hydrogen storage alloy 8 on the low pressure side. It is connected to one end of a first heat exchange coil 10 that is buried in the hydrogen storage alloy 8 in the container 9 containing the hydrogen, and the piping connected to the other end of the coil 10 is connected to the inlet side of the on-off valve 4. It merges with the piping connected to. Further, one end of a branch pipe 12 having an on-off valve 11 in the middle is connected to the inlet side pipe of the on-off valve 4.
The other end is connected to a pipe connecting the expansion valve 6 and the cooler 7.

The other end of the cooling coil 7a in the cooler 7 and the compressor 1 are connected by a suction pipe 14 having a suction main valve 13 in the middle. Hydrogen storage alloy 8
A second heat exchange coil 15, which is embedded in the heat exchanger coil 15, is connected in parallel. Note that an on-off valve 20 is provided on the inlet side of the coil 15.

In addition to the container 9, a container 17 containing a granular hydrogen storage alloy 16 on the high pressure side having a different thermal equilibrium pressure from the hydrogen storage alloy 8 in the container 9 is provided. connected by. Here, the hydrogen storage alloys 8 and 16 include:
For example, a lanthanum nickel alloy is used, and by changing the proportion of the alloy, the reaction temperature with hydrogen gas is changed. Further, within this container 17, a cooling coil 19 through which cooling water flows is disposed so as to be buried in the granular hydrogen storage alloy 16.

In the hot gas defrosting device configured as described above, during cooling operation of the cooling device, the three-way switching valve 3 is switched so that the first port 3a and the third port 3c are connected, and the on-off valves 11 and 20 are closed and closed. Then, the on-off valve 4 and suction main valve 13 are opened. As a result, during cooling operation, the hot gas refrigerant discharged from the compressor 1 passes through the three-way switching valve 3 and flows into the coil 10 in the container 9, and the hydrogen storage alloy 8 on the low pressure side
is heated. When the hydrogen storage alloy 8 is heated, the pressure increases and the hydrogen gas stored in the alloy 8 is released. The released hydrogen gas moves to the container 17 through the pipe 18, reacts with the hydrogen storage alloy 16, and is absorbed by the alloy 16. At this time, the hydrogen storage alloy 16 generates heat due to the heat of reaction, so the cooling coil 1
9 to cool the alloy 16. In the figure, the direction indicated by the solid arrow is the flow direction of the refrigerant during cooling operation.

On the other hand, when defrosting the cooler 7, the three-way switching valve 3 is switched so that the first port 3a and the second port 3b are connected, and the on-off valve 4 and the suction main valve 1 are switched.
3 is closed, and the on-off valves 11 and 20 are opened.
As a result, the hot gas refrigerant discharged from the compressor 1 is supplied to the cooler 7 through the branch pipe 12 without passing through the coil 10 in the container 9, as shown by the broken line arrow in the figure. Defrosting is performed.
At this time, the hot gas refrigerant passes through the cooling coil 7a of the cooler 7 and is condensed and liquefied. The condensed refrigerant discharged from the cooler 7 is transferred to the coil 1 in the container 9.
5, the hydrogen storage alloy 8 on the low pressure side is cooled. Cooled hydrogen storage alloy 8
As the pressure decreases, hydrogen gas is released from the hydrogen storage alloy 16 on the high pressure side, moves to the hydrogen storage alloy 8 side on the low pressure side, and is absorbed by the alloy 8. At this time, the hydrogen storage alloy 8 on the low pressure side generates heat due to the hydrogen gas absorption reaction, and this heat generation promotes evaporation of the condensed liquid refrigerant passed through the coil 15.
The gasified refrigerant is sent to the compressor 1. On this occasion,
Since the hydrogen storage alloy 16 on the high pressure side absorbs heat due to the hydrogen gas release reaction, the heat of the atmosphere is supplemented by the cooling water passed through the cooling coil 19.

Here, if the amount of condensed refrigerant passed through the coil 15 increases, the temperature of the hydrogen storage alloy 8 on the low pressure side decreases and the pressure also decreases, so the amount of hydrogen gas transferred from the hydrogen storage alloy 16 on the high pressure side increases, and heat generation due to absorption of hydrogen gas in alloy 8 increases. Thereby, the amount of condensed refrigerant passed through the coil 15 and the heat generated by hydrogen gas absorption in the hydrogen storage alloy 8 are balanced, and the liquid refrigerant is evaporated under constant conditions.

〔Effect of the invention〕

As explained above, in the present invention, two types of hydrogen storage alloys with different thermal equilibrium pressures are each sealed in a container, and the heat generated when the hydrogen storage alloy sucks hydrogen gas is used to evaporate the condensed liquid refrigerant after defrosting. Therefore, unlike conventional tank systems, there is no problem of corrosion of the water tank due to accumulated water.

Further, according to the present invention, sufficient heat for evaporating the condensed liquid refrigerant can be obtained, so that the liquid refrigerant can be efficiently gasified. For example, when compared to a conventional tank system, a tank system that uses water has
If the temperature difference is 50℃, the amount of heat storage per volume is 50kca
1/1, but with a hydrogen storage alloy (when two containers are used), a heat storage amount of 70 to 100 kcal/ is obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a hot gas defrosting device according to the present invention, and FIG. 2 is a configuration diagram of a conventional defrosting device. In the figure, 1...compressor, 2...discharge piping, 3...
3-way switching valve, 4, 11, 20... Open/close valve, 5...
Condenser, 6... Expansion valve, 7... Cooler, 7a...
Cooling coil, 8, 16...Hydrogen storage alloy, 9, 1
7... Container, 10, 15... Heat exchange coil, 12
...Branch piping, 13...Suction main valve, 14...
...Suction piping, 18...Piping, 19...Cooling coil.

Claims (1)

[Claims] 1. Providing containers in which hydrogen storage alloys with different thermal equilibrium pressures are individually sealed, and connecting these containers with piping, and providing first and second heat exchange coils in the containers in which hydrogen storage alloys with low thermal equilibrium pressures are sealed. During the cooling operation, the hot gas refrigerant discharged from the compressor is passed through the first heat exchange coil, and when the cooler is defrosted, the supply of the hot gas refrigerant to the first heat exchange coil is stopped and the hot gas refrigerant is passed through the cooler. A hot gas defrosting device characterized in that a hot gas refrigerant is passed through the hot gas refrigerant, and condensed liquid refrigerant after defrosting of the cooler is passed through the second heat exchange coil.