DE3431452A1 - Cooling or freezing apparatus used as a heat pump - Google Patents

Abstract

A cooling or freezing apparatus used as a heat pump, having a compression cooling machine whose condenser exchanges heat with a water reservoir and whose main evaporator system, which is allocated to the cooling or freezing space, has at least one additional evaporator which is located in parallel with the main evaporator system via a branch which can be switched alternatively, and which absorbs heat from the environmental air into the circuit when it is switched on. In this case, the additional evaporator (24) can be switched as a condenser, via a bypass (28) (which bridges over the condenser (12) and the switching device (15) for the alternative connection of the two parallel branches (16, 17)) and corresponding additional switching devices, with the aid of which condenser the heat energy which is extracted using a compressor cooling machine is emitted to the environmental air in the event of too little water being extracted from the water reservoir (13). <IMAGE>

Description

BOSCH-SIEMENS HAUSGERÄTE GMBH, 8000 Munich 80, July 26th, 1984

7000 Stuttgart Hochstrasse 17

TZP 84/409 Wi / hü

Refrigerator or freezer used as a heat pump

The invention relates in particular to a refrigerator or freezer used as a heat pump For household purposes, with a compression refrigeration machine whose condenser is in heat exchange with a water reservoir or the like. And whose the main evaporator system assigned to the refrigerator or freezer compartment has at least one additional evaporator which is connected to the main evaporator system via a alternatively switchable branch lies in parallel and when switched on in the circuit Absorbs heat from the ambient air.

In one known from DE-PS 10 32 774 device of the type mentioned is in Cooling circuit of the compression refrigeration machine used as a heat pump, both an additional evaporator and an additional condenser are provided. These additional heat exchangers are arranged outside the device and the room air exposed. They can optionally be switched on in the refrigeration cycle if, for example In the case of increased hot water consumption, the amount of heat dissipated from the device is not sufficient to heat the water in the desired manner or in the case of low or temporarily completely set hot water consumption There is a risk of the capacitor overheating.

In the first case, the ambient air is used with the additional evaporator Heat and moisture are withdrawn, while in the second case heat is released into the room air.

TZP 84/409

In a known from US-PS 27 00 279 other device is instead of the additional Condenser is a water-air heat exchanger controlled by a thermostatic valve provided, which removes heat from the water storage tank in the event of low hot water consumption. This additional heat exchanger and its connection with the water storage also require a lot of effort.

The additional heat exchanger used to dissipate excess heat in the water storage tank is replaced according to US-PS 29 68 934 by a seated in the water inlet of the water reservoir, temperature-controlled valve, which in the case of a impending overheating of the water tank and thus the condenser cold water can flow.

While in the first two cases expensive, additional heat exchangers both on the cold and on the warm side of the compression refrigeration machine are required, in the latter case a heat-controlled valve is required instead of the additional condenser, which is essential for reasons of operational safety must be reliable and therefore complex and expensive. In addition, with the last-mentioned solution, the increased water consumption has a cost-increasing effect the end.

The invention is based on the object of providing the refrigerator and freezer at the outset to simplify the type described and to increase their operational reliability.

According to the invention, this object is achieved in that the additional evaporator via the capacitor and the switching element for an alternative connection of the two parallel branches bridging bypass and corresponding additional switching devices can be switched as a condenser, with the help of which, if too little water is drawn from the water tank, the one discharged with the compressor refrigeration machine Heat energy is given off to the ambient air.

Due to the compression refrigeration machine used as a heat pump according to the invention in the circuit arranged bypass and corresponding switching elements, it is possible in a simple manner to use the additional evaporator if necessary as To use condenser and thereby reduce the costs, the space requirement and the weight of the device equipped with it and at the same time its functionality to increase.

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TZP 84/409

According to a preferred development of the subject matter of the invention, it is provided that as a switching element for the alternative circuit of the parallel containing the evaporator Branches a three-way shuttle valve is used and that the main evaporator system is followed by a straight-way shut-off valve, which when open Branch for the additional evaporator is closed.

As a result, in the case of commissioning the additional evaporator for Heat recovery from the air and the resulting changed operating conditions the compression refrigeration machine causes an undesirable largely avoided from the main evaporator system.

According to an additional advantageous development of the subject matter of Invention it is provided that in the branch of the additional evaporator a three-way shuttle valve located behind this in the flow direction is arranged, from in the case of switching the additional evaporator as a liquid condenser Refrigerant via a branch in the parallel branch of the main evaporator system is initiated before the throttle body.

Finally, according to another embodiment of the subject matter of the invention provided that the bypass for the condenser through a with a gate valve provided line is formed, which is in the refrigeration circuit of the compressor refrigeration machine in front of their condenser and behind the additional evaporator is connected to the parallel branch and that one of the two parallel branches connecting connecting line on the one hand behind the throttle body of the additional Evaporator and, on the other hand, is connected upstream of the throttle element of the main evaporator system.

Further advantageous embodiments of the invention characterized in the claims are explained in the following description with reference to two exemplary embodiments shown in the accompanying drawings as simplified circuit diagrams. Show it:

Fig. 1 The refrigeration circuit of a compression refrigeration machine used as a heat pump with an additional evaporator lying parallel to their main evaporator system, which via a condenser

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and the switching element for the alternative connection of the two parallel ones Branches bridging bypass can be switched as Kondenstor, as a first embodiment and

Fig. 2 shows a refrigeration circuit corresponding to FIG. 1, in which the bypass for the condenser is formed by a line provided with a through shut-off valve, which is in the refrigeration circuit of the compressor refrigerating machine is connected to the parallel branch in front of the condenser and behind the additional evaporator, as a second embodiment.

1 and 2 are two different but essential components Corresponding circuit diagrams, provided with the same reference numbers, of compression refrigeration machines that can be used as heat pumps for household refrigeration or freezers. Here, 10 denotes a compressor with which refrigerant vapor is sucked in and in a closed circuit is compressed. The outlet from the compressor 10 is via a pressure line 11 , compressed refrigerant vapor is fed to a condenser 12. This capacitor 12 can be used as a so-called direct capacitor or as a coaxial capacitor be formed, the latter with a secondary circuit for a heat transfer medium can be equipped. In the condenser 12, the heat absorbed during the evaporation of the refrigerant and, in addition, that converted into heat Dissipated power of the compressor 10 to a water storage 13, wherein the compressed refrigerant vapor liquefies and the water in the Water storage 13 heated. The refrigerant liquefied in this way is stored in a collector 14 connected downstream of the condenser 12. This Collector 14 fulfills the task of filling or volume differences of the downstream, alternatively, to balance elements of the refrigeration circuit that can be acted upon with liquid refrigerant.

The further three-way shuttle valve 15 is connected downstream of the collector 14 Path of the liquid refrigerant in the circuit between two parallel branches 16 and 17, each of which has a throttle element and a Evaporator is equipped. In the branch designated 16 there is a throttle member 18 m the main evaporator system 19 one only with dashed lines symbolically indicated refrigerator or freezer 20. This main evaporator system

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The stem 19 can be statically ventilated in the usual way as well as forcibly ventilated with an axial fan 21, the equipment with the fan 21 ^{allowing the refrigerator or freezer s 2} O to operate in Nofrost technology.

From the main evaporator system 19, the heat generated therein is removed Refrigerant vapor via a suction line provided with a through stop valve 22 23 sucked in by the compressor 10 and thus the alternative circuit via the branch 16 is closed.

In the designated 17, starting from the three-way shuttle valve 15 parallel Branch of the refrigeration cycle is an additional evaporator 24, which acts as a throttle element a thermostatically controlled expansion valve 25 is connected upstream. With the additional Evaporator 24, which in the illustrated embodiments can also be dynamically ventilated with an axial fan 26, can be used in the absence of heat absorption heat from the ambient air can be absorbed from the refrigerator / freezer 20 by switching the refrigeration cycle. In this case it will be simultaneous with the switching of the three-way shuttle valve 15, the straight-way shut-off valve 22 closed. The straight-way shut-off valve 22 is used for the now changed operating conditions and the significantly higher evaporator temperature to avoid a refrigerant shift. Via one connected to the suction line 23 downstream of the gate valve 22 in the direction of flow Connecting line 27, the alternative circuit is closed via the additional evaporator 24.

In the first exemplary embodiment of the refrigeration circuit shown in FIG. 1 Compressor cooling machine used as a heat pump for a refrigerator or freezer is the additional evaporator 24 via a condenser 12 and serving as a switching element for the alternative switching of the two parallel branches 16 and 17 Three-way valve 15 bridging bypass 28 and another three-way shuttle valve 29 as well as a third three-way changeover valve 30 and 30 located in the direction of flow behind the additional evaporator 24 in the connecting line 27 Finally, one connected at one output to the line branch 16 upstream of the throttle element 18 of the main evaporator system 19 in the direction of flow Bridging line 31 switchable as a capacitor.

TZP 84/409

This circuit as a capacitor takes effect when at only low or temporarily When the water is completely withdrawn from the water storage tank 13, there is a risk of overheating of that which is in heat exchange with the water storage tank 13 Capacitor 12 should occur. In this case, after the three-way changeover valves 15, 29 and 30 have been set accordingly, the additional evaporator works 24 as a capacitor and thus guarantees the Uninterrupted continuation of the cooling operation in the refrigerator or freezer. The three-way changeover valves can be switched over automatically in a known manner.

To convert the refrigeration circuit in the manner described, it is only necessary to interrupt the direct flow of refrigerant to the main evaporator system 19 via the three-way changeover valve 15 and the two three-way changeover valves 29 and 30 to be adjusted so that now the compressed air expelled by the compressor 10 Refrigerant vapor reaches the additional evaporator 24, which in this case acts as a condenser, via the bypass 28, where it releases heat the ambient air condenses and in liquid form over the appropriately set The three-way shuttle valve 30 and the bridge 31 enter the throttle element 18 and from there into the main evaporator system 19.

In the embodiment shown in Fig. 2 is one with a gate valve 32 provided bridging line 33 on the one hand between the compressor 10 and the condenser 12 to the pressure line 11 and on the other hand in Direction of flow behind the additional evaporator 24 to the connecting line 27 connected. The connection of the connecting line 27 to the suction line 23 is in this case provided with a three-way shuttle valve 34. Additionally located In this circuit there is also a connecting line 35 which, on the one hand, runs in the direction of flow in front of the throttle element 18 in the branch 16 of the main evaporator system 19 and on the other hand behind the throttle element 25 to the auxiliary evaporator 24 leading branch line 17 is connected and so, if necessary, allows the circuit of this additional evaporator 24 as a condenser. This is what it is then all that is required is the straight-way shut-off valve, which is closed during normal operation 32 in the bypass line 33Γ open and adjust accordingly

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of the three-way changeover valve 34 to ensure that now the compressor 10 ejected compressed refrigerant vapor through the connecting line 27 in FIG reverse flow direction in the one that also acts as a condenser in this case Additional evaporator 24 arrives. The refrigerant condensed in the additional evaporator 24 arrives in liquid form via the connecting line 35 and the Throttle element 18 containing line branch 16 in the main evaporator system 19, where it is stored under absorption of heat from the refrigerator or freezer Vaporized well. The refrigerant vapor produced there is then via the suction line 23, the opened gate stop valve 22 and the three-way shuttle valve 34 sucked in by the compressor 10.

Except for those shown in the illustrated and described embodiments Circuits, of course, other circuits are conceivable with which the essential Feature of the system described to use the additional evaporator 24 if necessary by switching as a condenser and thereby the otherwise for To save such purposes required additional capacitor, is achieved.

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Claims (5)

TZP 84/409 Expectations \\ J A refrigerator or freezer used as a heat pump, especially for household purposes, with a compression refrigerator, the condenser of which is in heat exchange with a water tank or the like and whose main evaporator system assigned to the refrigerator or freezer compartment has at least one additional evaporator, which is the main -Verdampfersystem is parallel via an alternatively switchable branch and absorbs heat from the ambient air when the circuit is switched on, characterized in that the additional evaporator (24) via one of the condenser (12) and the switching element (15) for alternative switching of the two parallel Branches (16, 17) bridging bypass (28) and corresponding additional switching elements can be switched as a capacitor, with the aid of which the heat energy discharged with the compressor-refrigerating machine is released into the ambient air if too little water is drawn from the water reservoir (13). 2. refrigerator and freezer according to claim 1, characterized in that as Switching element for the alternative switching of the parallel branches (16, 17) containing the evaporator (19, 24), a three-way shuttle valve (15) is used, and that the The main evaporator system (19) is followed by a straight-way shut-off valve (22) which, when the branch (17) is open, for the additional evaporator (24) closed is. 3. refrigerator and freezer, according to önspruch 1 or 2, characterized in that in the branch (17) of the additional evaporator (24) behind in the direction of flow This lying three-way shuttle valve (30) is arranged, from which in the case of the connection of the additional evaporator (24) as a condenser liquid Refrigerant via a line branch (3l) into the parallel branch (16) of the main evaporator system (19) is initiated in front of the throttle device (18). TZP 84/409 4. refrigerator and freezer according to claim 1 or 2, characterized in that the By-pass for the condenser (12) through one with a straight-way shut-off valve (32) vesehene line (33) is formed, which is in the refrigeration circuit of the compressor refrigerating machine before the condenser 12 and behind the additional evaporator (24) is connected to the parallel branch 17 and that one of the two parallel Branches 16 and 17 connecting connecting line (35) on the one hand behind the throttle element (25) of the additional evaporator (24) and on the other hand in front the throttle element (18) of the main evaporator system (19) is connected. 5. refrigerator and freezer according to claim 4, characterized in that the behind The merging of the parallel branches (16 and 17) lying on the evaporators (19 and 24) is provided with a three-way shuttle valve (34).