DE102004057432A1 - Cooling appliance for switchgear cubicle, or other housing containing electronic components, incorporating coolant circuit with evaporator, compressor and liquefier, with cubicle waste heat fed directly to evaporator, to liquid coolant - Google Patents

Abstract

Cooling appliance for housing, or its part, for electronic components, comprises cooling circuit with coolant, incorporating evaporator (16), compressor (10) and liquefier (12). Waste heat from housing etc. is directly fed into evaporator, as is liquid coolant. Preferably carbon dioxide, NH3, or R134a, or water are used as coolant. Evaporator may may be located on outer surface of housing etc., with surface fitted with thermally insulating layer.

Description

The The invention relates to a cooling device for a control cabinet or any other electronic components housing or Housing part, with a refrigerant receiving refrigeration cycle, which comprises an evaporator unit, a compressor unit and a condensing having.

modern Electronic modules housed in control cabinets or other device housings usually require no cooling at ambient temperatures of 20 ° C to 35 ° C. High on the other hand, loaded components are provided with a special heat sink. But there are also versions, as for example in personal computers, known which require a "ventilation" of the housing. at especially heat critical Components, such as processors, is here with a heat sink and a small fan in addition lowered the operating temperature. A development goal in component development is the reduction of power consumption, also to the operating temperature to lower. The cooling measures serve largely the life extension.

With the increase of the working speed and clocking of processors In spite of the reduction in power consumption, increasingly intensive cooling is necessary. It is known with mounted on the processors heat exchangers the heat by water cooling removed from the processors. A disadvantage of this method is that predominantly only the processor specially cooled is. Work memory and system bus control will be available in the future be the critical components in water-cooled processors.

From the DE 44 13 128 C2 is a cooling device is known in which as a refrigerant water or a water-containing solution is used. To absorb the heat occurring in the cabinet or in the other, electronic components housing or housing part heat, a heat exchanger is provided in the known solution. However, the use of heat exchangers brings a significant design effort with it. In addition, heat exchangers have only a limited efficiency.

It The object of the invention is to provide a cooling device, which the cooling of housings with high heat loads allows for high reliability. About that In addition, the cooling device according to the invention should have a have simple structural design and inexpensive to manufacture be.

The The object of the invention is characterized by the features of claim 1 solved. The dependent claims relate to advantageous developments of the subject invention.

Accordingly, it is envisaged that in the evaporator unit in the cabinet, housing or housing part accumulating heat is initiated immediately. This allows the use of heat exchangers be avoided. The refrigerant used is in liquid state fed to the evaporator unit.

According to a preferred embodiment, the refrigerant may be CO ₂ or carbon dioxide. CO ₂ is a low-cost refrigerant, does not damage the environment in the event of a leak, is non-flammable and has a good refrigeration rate. Above 31.7 ° C, however, CO ₂ is gaseous and therefore not suitable for high temperatures. Instead of CO ₂ , however, the use of other Kätemittel is possible.

According to an alternative embodiment, the caking agent may be, for example, NH ₃ or R134a. R134a has higher evaporation and condensing temperatures than CO ₂ . However, since R134a is known as a so-called greenhouse gas, high demands are placed on its use in the tightness of the refrigerant system.

According to a further preferred embodiment, the refrigerant may also be H ₂ O or water. In particular, the high specific heats for boiling and condensing make water a suitable refrigerant.

The refrigerant evaporates at the evaporator unit ( 16 ) directly. This direct evaporation provides efficient cooling without the losses associated with heat exchangers.

The Evaporator unit can be attached to the outer surface of the Control cabinet, housing or housing parts be arranged, wherein the surface is a thermal insulation layer having. Such a construction is easy to realize.

Around a particularly effective cooling especially To allow highly thermally loaded components, can be cooled to the housing part a housing wall an electronic component form and the evaporator unit directly on the housing part be arranged. With this measure is the direct cooling of the component possible.

According to a preferred embodiment, a flat cover is in immediate area Contact arranged to the housing part. The cover member has grooves extending thereon, which are formed as coolant lines. The Kätemittel can absorb the dissipated heat directly from the housing part. This simple design ensures effective cooling. To avoid cold losses, the housing part can carry a thermal insulating layer.

Especially when using water as a refrigerant must freeze be avoided on the evaporator. For this purpose, the in Cover formed grooves run inclined so that the liquid refrigerant under the influence of gravity in a below the cover arranged collecting trough drains off. It can the grooves at an angle or even vertically.

to Creation of a refrigerant density Connection between cover and housing part can both parts together glued, soldered or the like may be sealed together.

To compensate for losses due to evaporation, the refrigerant CO ₂ may be stored in the refrigeration cycle within a refrigerant receiver.

The Invention will be described below with reference to an illustrated in the drawings embodiment explained in more detail.

It demonstrate:

1 in schematic representation a cooling device, and

2 in side view and in section an evaporator unit according to 1 ,

The 1 shows a schematic representation of a cooling device, which has a cooling circuit that carries the refrigerant CO ₂ has. The cooling circuit has a recooling unit consisting of a compressor unit 10 and a condenser unit 12 , an expansion valve 14 and an evaporator unit 16 on.

The chiller is connected to one or more personal computer server cabinets (not shown) via a liquid and suction line of the refrigeration cycle. The liquid lines lead to the individual consumers 22 ,

According to an alternative embodiment (not shown), the recooling plant may be designed in two stages to increase the cooling capacity. In this case, NH ₃ or R134a can be used as the refrigerant in the first stage.

By means of the compressor unit 10 the refrigerant is under a high pressure of the condenser unit 12 added. In the condenser unit 12 Heat is removed from the refrigerant. This can be done, for example, by means of a fan (not shown). As a result of the heat extraction, the refrigerant liquefies in the condenser unit. The liquefied refrigerant is stored in a refrigerant storage tank 18 collected. In the expansion valve 14 the refrigerant is throttled to a lower pressure. Subsequently, the refrigerant of the evaporator unit 16 fed. In the evaporator unit 16 Heat is supplied to the refrigerant, so that it passes from the liquid phase to the gaseous phase and thus as the gas evaporator unit 16 leaves again. The gas is supplied to the compressor again, so that a closed circuit is formed. The evaporator unit 16 the heat is supplied directly.

The evaporator unit 16 is designed as a direct evaporator. The direct evaporation of refrigerant in refrigeration is an efficient way of cooling. It saves the use of heat exchangers to the cooling liquid.

In particular, the use of CO ₂ as a cheap refrigerant is particularly advantageous because no environmental damage is to be feared in case of leaks. CO ₂ is not flammable and is often used as a fire extinguishing agent. In addition, CO _{2 has} a good refrigeration rate.

Of the Evaporator can be designed differently.

In In a first embodiment (not shown), the surface of the to be cooled equipment designed as an evaporator. Here comes a cooling principle like the fridge for use. The to be cooled Space is outward thermally insulated, the interior largely dense is to minimize condensation.

According to another embodiment (not shown), the evaporator is placed directly on a component to be cooled, wherein the refrigerant CO ₂ is injected directly.

According to yet another embodiment (not shown), the housing serves as a pressure chamber and is simultaneously used as an evaporator. The liquid refrigerant CO ₂ is injected from capillaries onto electronic components to be cooled and evaporates inside the housing. The remaining components arranged inside the housing are simultaneously exposed by the refrigerant vapor also cooled.

Also Can the used circuit board and the electronic components directly designed as an evaporator be. For this purpose, the components to be cooled have appropriate connections for liquid line and suction gas line.

An embodiment of the evaporator unit 16 is based on the 2 explained in more detail.

A cover or floor panel 30 a housing to be cooled is on the inside of the housing with another sheet 32 stuck or soldered. There are grooves in this inner panel 32.1 . 32.2 . 32.3 . 32.4 and 32.5 pressed, which give refrigerant channels. The refrigerant CO ₂ flows through these channels and absorbs the heat directly from the inside of the housing during evaporation.

To the outside is on the housing to be cooled insulation 34 applied. Due to the high pressures that occur at CO ₂ , the channels are dimensioned narrow for reasons of strength and arranged at a closer distance from each other. The ratio of the channel width to the mounting surface between the webs is adapted to the higher pressure level. To ensure the cooling capacity, a very low evaporation temperature is provided (less than 0 ° C, eg -20 ° C).

to Avoid condensation or icing on the inside of the case the housing very tightly stirred. This tightness is also used for EMC shielding.

As 1 shows is the evaporator unit with a pressure relief valve 20 equipped, which discharges the refrigerant to the outside when a predetermined, permissible pressure is exceeded. In CO ₂ , this discharge is not critical and is necessary, for example, in case of power failure over a longer period.

The evaporator unit 16 is connected to the cooling circuit of the compressor unit (compressor) 10 and the condenser unit 12 connected recooling plant connected. For this purpose, quick-release fasteners are used, which can be easily assembled and disassembled. For the pressure reduction is a thermostatic E-valve 14 intended.

For regulation with several parallel connected consumers 22 In addition, a solenoid valve 24 used.

If a partial cooling, for example, is provided directly on a component, can on the liquid side of the E-valve 14 taken via a not shown capillary refrigerant and fed to a small evaporator on a device. The refrigerant vapor is recirculated via the steam side.

For the end of the operation there is the possibility through the solenoid valve 24 in front of the E-valve 14 shut off the fluid line. If the E-valve 14 Also designed switchable, can also be the E-valve 14 the shut-off function of the solenoid valve 24 perceive. The compressor unit 10 is still a short adjustable period of time after shutting off the liquid line continues to operate. The compressor unit sucks 10 the still evaporating refrigerant and presses it into the condenser unit 12 ,

If, for example, due to power failure or malfunction, the refrigerant from the evaporator unit 16 can not be sucked off, the evaporator unit 16 through an attached pressure relief valve 20 , which opens automatically when a critical pressure is reached, protected.

The liquid line must be closed in such a case, in order to avoid a backflow of the refrigerant. For this purpose, the solenoid valve 24 designed so that it locks in the de-energized state. The draining of refrigerant is monitored to ensure that the refrigerant is replenished when a critical amount is reached. For this purpose, the fluid level is in front of the solenoid valve 24 arranged refrigerant collector 18 supervised.

The refrigerant is from a storage bottle 26 passing through a valve 28 is shut off, refilled via a hose connection. A manual but also an automatic refilling is conceivable. For this purpose, from the storage bottle 26 via the designed as electronically controllable solenoid valve 28 the refrigerant is supplied to the suction side of the cooling circuit.

Condensate predominantly forms at the coldest point in the evaporator unit 26 , A valve 17 is at the evaporator unit 26 provided, which represents a drainage possibility of condensate to a small tub. The condensate is discharged in particular when the refrigeration system is switched off. The accumulated in the tub amount of condensate is monitored with semiconductor sensors.

When using water as the coolant, further measures for increasing the operational safety are possible in comparison with the use of CO ₂ . So to avoid freezing in the cover ( 32 ) formed grooves ( 32.1 . 32.2 . 32.3 . 32.4 and 32.5 ) so inclined downwards that the liquid refrigerant is influenced of gravity in the below the cover ( 32 ) arranged collecting tray can drain.

The grooves ( 32.1 . 32.2 . 32.3 . 32.4 and 32.5 ) inclined obliquely downwards or vertically downwards. The walls of the drip pan are inclined at all sides obliquely, so that when ice formation, the ice can only press against the sloping surfaces.

With the help of the E-valve 14 Can in case of failure of the refrigerator or at standstill of the compressor unit (compressor) 10 the water in the system in the tub of the evaporator 16 To be drained for this purpose is the E-valve 14 open when de-energized.

Claims (12)

Cooling device for a control cabinet or other electronic components housing or housing part ( 30 ), with a refrigerant receiving refrigerant circuit, which is an evaporator unit ( 16 ), a compressor unit ( 10 ) and a condenser unit ( 12 ), characterized in that in the evaporator unit ( 16 ) in the control cabinet, housing or housing part ( 30 ) heat is introduced directly and the refrigerant in the liquid state of the evaporator unit ( 16 ) is supplied. Refrigerator according to claim 1, characterized in that the refrigerant is CO ₂ or carbon dioxide. Refrigerator according to claim 1, characterized in that the refrigerant is NH ₃ or R134a. Refrigerator according to claim 1, characterized in that the refrigerant is H ₂ O or water. Refrigerator according to one of claims 1 to 4, characterized in that the refrigerant at the evaporator unit ( 16 ) evaporated directly. Refrigerator according to one of claims 1 to 5, characterized in that the evaporator unit ( 16 ) on the outer surface of the control cabinet, housing or housing part ( 30 ), the surface being a thermal insulation layer ( 34 ) having. Refrigerator according to one of claims 1 to 6, characterized in that the housing part to be cooled ( 30 ) forms a housing wall of an electronic component and the evaporator unit ( 16 ) directly on the housing part ( 30 ) is arranged. Refrigerator according to one of claims 1 to 7, characterized in that a flat cover ( 32 ) in direct surface contact with the housing part ( 30 ), wherein the cover part ( 32 ) grooves formed therein ( 32.1 . 32.2 . 32.3 . 32.4 and 32.5 ), which are designed as coolant lines. Refrigerator according to one of claims 1 to 7, characterized in that in the cover ( 32 ) formed grooves ( 32.1 . 32.2 . 32.3 . 32.4 and 32.5 ) so inclined that the liquid refrigerant under the influence of gravity in a below the cover ( 32 ) arranged collecting tray drains. Refrigerator according to one of claims 1 to 9, characterized in that the housing part ( 30 ) a thermal insulating layer ( 34 ) for external insulation. Refrigerator according to claim 8 or 9, characterized in that the cover ( 32 ) with the housing part ( 30 ) are glued, soldered or the like refrigerant tightly connected to each other. Refrigerator according to one of claims 1 to 7, characterized in that the refrigerant in the refrigeration cycle within a refrigerant collecting container ( 18 ) is stored.