DE102016203895A1 - Refrigerating appliance with a freezer compartment and a refrigerant circuit and method for operating a refrigeration appliance - Google Patents

Abstract

In a refrigerator with a freezer and a refrigerant circuit, which has a compressor (21) and a first evaporator (33, 63), wherein the first evaporator, a stop valve (36, 67) and a first capillary (31, 61) are connected upstream, the first evaporator (33, 63) is followed by a gas valve (68). A method for operating a refrigerant circuit in a refrigerator with a freezer compartment, comprises the steps in any order: a) switching (81) of the compressor; b) switching (82) a stop valve in front of a first evaporator; c) switching (83) of a gas valve after the first evaporator.

Description

The present invention relates to a refrigeration appliance, in particular a domestic refrigeration appliance, with a freezer compartment and a refrigerant circuit and a method for operating such a refrigeration appliance, and more particularly to the construction of a refrigerator which can be used in such a refrigeration appliance.

From the DE 10 2014 211 133 is a refrigerator with a first and a second evaporator, which are arranged together with one upstream throttle in mutually parallel branches of a refrigerant circuit, wherein at the outlet of the second evaporator, a check valve is arranged, and in one embodiment, the first evaporator upstream first throttle point between a high and a low flow rate is switchable, the supply line to both the throttle points can be shut off.

In such a refrigeration device with a freezer compartment evaporator and an evaporator of another warmer compartment parallel to it in the refrigerant circuit, the evaporators are operated successively in time at different evaporation pressures and thus evaporation temperatures. In this case, a check valve is used to avoid a displacement of refrigerant from the warmer evaporator in the freezer evaporator in a standstill of a compressor.

The DE 10 2014 211 132 discloses a chiller comprising a first and a second evaporator, which are arranged together with a respective upstream throttle in mutually parallel branches of a refrigerant circuit. A downstream valve assembly disposed between outlets of the two evaporators and a suction port of a compressor is switchable between a position in which it allows a flow of refrigerant from the first evaporator to the compressor and blocks a flow of the refrigerant from the first to the second evaporator in a position it blocks a flow from the first evaporator to the compressor. The supply line to both the throttling points can not be shut off.

10 2014 217 674 describes a refrigerating machine for a household refrigerating appliance comprising a compressor a condenser, a first and a second evaporator which are arranged together with a respective upstream throttle in mutually parallel branches of a refrigerant pipe, and an upstream valve arrangement for selectively interrupting the branches respectively upstream of its evaporator. A control unit is arranged to detect an underfill of at least a first one of the evaporators and to operate the compressor in the event of an underfill while the upstream valve arrangement interrupts the branch of the second evaporator. The conventional check valve described above is here replaced by a stop valve. The supply line to both the throttling points can not be shut off.

At high ambient temperature or otherwise increased refrigeration demand of the freezer compartment, the amount of refrigerant stored in the evaporator after a cooling operation phase of the freezer may be greater than under normal operating conditions, so that in a subsequent cooling operation phase of the normal refrigeration compartment, the amount of circulating refrigerant is reduced. The resulting inappropriately low evaporation temperature affects the efficiency of the chiller.

Object of the present invention is to provide a refrigerator with a freezer and an operating method for this, which allows a reliable energy-efficient operation with an optimal amount of refrigerant in the evaporator.

The object is achieved by a refrigerating machine and an operating method therefor according to the independent claims.

A stop valve upstream of a restriction controls a two-phase mixture of the refrigerant, with a pipe diameter in the valve corresponding to a capillary diameter. A gas valve downstream of an evaporator switches the evaporated gaseous refrigerant, therefore, the gas valve preferably has a pipe diameter of a suction pipe. Such gas valves are unusual in household refrigerators and therefore relatively expensive, which in turn precludes their use. In the present invention, however, such a gas valve is used to control the refrigerant level in the evaporator in combination with a stop valve before the evaporator can.

First, the application of the present invention to freezers without further warmer evaporator will be described.

In this refrigerator with a freezer and a refrigerant circuit having a compressor and a first evaporator, wherein the first evaporator, a stop valve and a first capillary are connected upstream of the first evaporator is followed by a gas valve. Thus, for example, the technical advantage is achieved that depending on the ambient conditions such as outside temperature or operating conditions such as warehousing warm goods located in the evaporator refrigerant amount can be controlled.

The refrigerator has, according to an advantageous embodiment, a control unit ( 19 ) configured to control the compressor, the stop valve and the gas valve. Thus, for example, the technical advantage is achieved that the control of the refrigerant circuit components involved can be carried out by a common control unit.

In the method according to the invention for operating a refrigerant circuit in a refrigeration appliance having a freezer compartment, the method steps a) switching of the compressor take place in any order; b) switching a stop valve in front of a first evaporator; c) switching a gas valve after the first evaporator. Thus, for example, the technical advantage is achieved that both during a compressor run time and during a compressor service life in the evaporator, a desired amount of refrigerant is adjustable.

In an advantageous embodiment of the method, a defrosting phase of the first evaporator is switched by the method steps a1) switching off the compressor; b1) opening the stop valve; c1) closing the gas valve. Thus, for example, the technical advantage is achieved that during the defrosting phase of the first evaporator, the refrigerant can be kept deliberately in the evaporator area to realize a slight compressor start after defrosting, without high liquefaction and evaporation temperatures. High pressures make the compressor start difficult.

In a further advantageous embodiment of the method, a warm start phase of the refrigeration device is switched by the method steps a2) switching on the compressor; b2) opening the stop valve; c2) Alternating opening and closing of the gas valve. Thus, for example, the technical advantage is achieved that during a warm start of the cooling device, a so-called pulldown, the mass flow can also be limited via the gas valve, e.g. Timing to avoid too high, for the compressor damaging condensing temperatures. This may have the advantage that the refrigerant distribution in the evaporator is more uniform than in other measures.

In an advantageous embodiment of the method, a low-noise phase or a rapid cooling phase of the first evaporator is switched by the method steps a3) switching on of the compressor; b3) closing the stop valve; c3) opening the gas valve. Thus, for example, the technical advantage is achieved that quite deliberately refrigerant can be brought to the condenser side by e.g. to achieve acoustic effects.

Now the application of the present invention to freezers with at least one further warmer evaporator will be described. The warmer evaporator has a higher operating temperature during operation than the first evaporator in operation. In certain circumstances, such as the defrosting of the first evaporator, the actual temperature of the first evaporator may be higher than that of the second evaporator, but this is usually not the operating temperature of the first evaporator, since it is not in operation during defrosting. In a refrigeration device with a plurality of throttle points, a directional control valve is preferably used to supply the desired throttle point with refrigerant. When using a directional control valve, the stop valve can be arranged as a separate stop valve in front of the directional control valve or the stop valve can be integrated with the directional control valve as a stop valve with directional function or directional control valve with stop function. The embodiments described above may be combined with the following embodiments, for example, the configuration of the method for switching a defrosting phase then applies to the switching of a defrosting phase of one of the evaporators in the refrigerant circuit.

In a further embodiment of the refrigeration device, the refrigeration device has a second evaporator, wherein the second evaporator is preceded by a second capillary. Thus, for example, the technical advantage is achieved that with combination devices, a control of the amount of refrigerant in the currently operated evaporator is possible.

In an advantageous embodiment of the method, wherein now the refrigeration device has a second evaporator in the refrigerant circuit parallel to the first evaporator, a refrigerant supply phase is switched by the process steps a4) switching on the compressor; b4) closing the stop valve; c4) opening the gas valve. Thus, for example, a technical advantage is achieved with particularly high power requirements in a compartment, determined from the typically available information of the associated compartment and evaporator temperature sensor. In this situation, an "extra portion" of refrigerant is withdrawn from one of the other evaporators and provided to the needy compartment for full use of the given evaporator area.

According to an advantageous embodiment of the method, the refrigerant supply phase is initiated after detecting a transfer of warm goods in the freezer. Thus, for example, the technical advantage is achieved that influencing the storage temperature of the already existing product is influenced as little as possible by the added commodity.

According to an advantageous embodiment of the method, the refrigerant supply phase after a request for an ice making is initiated. Thus, for example, the technical advantage is achieved that the knowledge to use much "cold" for an ice-making in a compartment with an automatic icemaker, can be used efficiently.

In an advantageous embodiment of the method, a further refrigerant supply phase is switched after a working phase of the compressor. Thus, for example, the technical advantage is achieved that in accordance with the aforementioned relocation of the refrigerant this can be shifted back again at the end of the state. In particular, with knowledge of the mass flow from the design of the refrigeration cycle, the necessary times can be derived.

In an advantageous embodiment of the method, an evaporator-emptying phase is switched by the method steps a4) switching on the compressor; b4) closing the stop valve; c4) opening the gas valve; d) removing the entire refrigerant from the second evaporator; e) then defrost the first evaporator. Thus, for example, the technical advantage is achieved that, prior to a defrost, the warmer evaporator can be intentionally emptied of liquid refrigerant fractions in order to avoid vaporization of refrigerant and associated cooling of a portion of the evaporator. This typically affects the areas where gravity collects the liquid refrigerant. In an advantageous embodiment of the method, the evaporator is a vertical tube-on-sheet evaporator. Thus, for example, the technical advantage is achieved that the defrosting safety is improved in a vertical tube-on-sheet evaporator.

A switchable gas valve, in combination with a stop valve in front of the orifices in refrigerators with two or more evaporators, may allow for parallel connection of the evaporators - either one operated or the other - thereby preventing the above-mentioned refrigerant displacements instead of the mechanical check valve shown in the prior art , Unlike a mechanical check valve, an electrically switchable gas valve can reliably prevent inflow of refrigerant via the compressor evaporator side of the colder evaporator regardless of operating times or evaporating pressures of the warmer compartment.

A gas valve can also be used to deliberately move or hold refrigerant in convenient areas of the refrigeration system in single or multi-zone refrigerated Nofrostgeräte, especially after a defrosting phase and thus avoid high or too high condensing pressures. This improves the life of the compressor.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

1 a schematic representation of a refrigeration device according to the invention;

2 a schematic representation of the refrigerant circuit of a refrigerator according to the invention with a first evaporator;

3 a schematic representation of the refrigerant circuit of a refrigeration device according to the invention with a first evaporator and another warmer evaporator,

4 a flowchart of an embodiment of the method according to the invention; and

5 a flowchart of another embodiment of the method according to the invention.

1 shows a refrigerator as a representative of a refrigerator 10 with a refrigerator compartment door 12 to a refrigerator compartment and a freezer compartment door 14 to a freezer. For example, the refrigerator is used to refrigerate food, and includes a refrigerated compartment storage chamber cooled by a refrigerator compartment evaporator and a freezer storage compartment cooled by a freezer evaporator.

The in 2 shown refrigerant circuit 20 includes a compressor in the usual way 21 with an exit 22 for compressed refrigerant and one input 23 for sucking in refrigerant. At one of the exit 22 outgoing refrigerant line 24 are in turn a liquefier 25 , a dryer 26 , and a switchable between an on-state and a blocking state stop valve 27 arranged.

The stop valve 27 follow a capillary 31 and an evaporator 33 in row. The evaporator 33 cools a compartment 34 a refrigeration device 35 , After the evaporator 33 is an electrically controllable gas valve 36 in a suction line 37 to the compressor 21 arranged.

An electronic control unit 40 is with a temperature sensor 42 on the tray 34 connected to the operation of the compressor based on the temperatures measured there 21 as well as the position of stop valve 27 and gas valve 36 to control.

The in 3 shown refrigerant circuit 50 largely comprises the same elements as the refrigeration cycle 20 out 2 with the same reference numerals. The refrigerant circuit 50 includes against a compressor 21 , a refrigerant pipe 24 and in turn a condenser 25 , a dryer 26 , and a stop valve 27 ,

After the stop valve 27 now follows a directional control valve 52 at which the refrigerant line 24 in two branches 59 . 60 branched. The directional valve 52 may deviate from the representation of 3 in the stop valve 27 be integrated, the latter having three instead of two ports and two passage states, wherein in one of the passage states, the directional control valve the condenser 25 with the branch 59 and in the other with the branch 60 connects, and in the locked state to none of the branches 59 . 60 a connection exists.

On the branches 59 . 60 are each a capillary 61 respectively. 62 and an evaporator 63 respectively. 64 connected in series. Each of the two evaporators 63 . 64 cools a compartment 65 respectively. 66 of the refrigeration device. The mean operating temperature of the compartment 66 is higher than that of the subject 65 , for example, it may be the subject 66 around a normal refrigeration compartment and the compartment 65 to act as a freezer of the refrigerator.

The two branches 59 . 60 meet at a confluence 67 again on each other. In the branch 59 is between an outlet of the evaporator 63 and the confluence 67 a gas valve 68 arranged. The gas valve 68 allows in the open position the operation of the evaporator 63 , In the closed position, it closes on the one hand refrigerant in the evaporator 63 On the other hand, prevents and prevents refrigerant, which during a standstill of the compressor in the evaporator 64 the warmer cooling compartment evaporated, diffused into the evaporator of the colder freezer compartment and condensed there.

An electronic control unit 69 is with temperature sensors 70 . 71 at the subjects 65 . 66 connected to the operation of the compressor based on the temperatures measured there 21 as well as the position of stop valve 27 and directional valve 52 to control.

The inventive method is based on references 2 and 3 explains in which the evaporator 33 and 63 be referred to as the first evaporator and evaporator 64 as a second evaporator.

• a) Schalten 81 des Verdichters;
• b) Schalten 82 eines Stoppventils vor einem ersten Verdampfer;
• c) Schalten 83 eines Gasventils nach dem ersten Verdampfer.

4 shows in flow chart 80 a method for operating a refrigerant circuit in a refrigerator with a freezer with the method steps

• a) switching 81 the compressor;
• b) switching 82 a stop valve in front of a first evaporator;
• c) switching 83 a gas valve after the first evaporator.

The process steps can be carried out in any order. For this purpose, various embodiments of the invention are presented.

• a1) Ausschalten des Verdichters;
• b1) Öffnen des Stoppventils;
• c1) Schließen des Gasventils.

According to one embodiment of the method, a defrosting phase of the first evaporator is switched by the method steps

• a1) switching off the compressor;
• b1) opening the stop valve;
• c1) closing the gas valve.

• a2) Einschalten des Verdichters;
• b2) Öffnen des Stoppventils;
• c2) Alternierendes Öffnen und Schließen des Gasventils.

According to one embodiment of the method, a warm start phase of the refrigeration device is switched by the method steps

• a2) switching on the compressor;
• b2) opening the stop valve;
• c2) Alternating opening and closing of the gas valve.

• a3) Einschalten des Verdichters;
• b3) Schließen des Stoppventils;
• c3) Öffnen des Gasventils.

According to one embodiment of the method, a low-noise phase or a rapid-cooling phase of the first evaporator is switched by the method steps

• a3) switching on the compressor;
• b3) closing the stop valve;
• c3) opening the gas valve.

• a4) Einschalten des Verdichters;
• b4) Schließen des Stoppventils;
• c4) Öffnen des Gasventils.

According to one embodiment of the method, wherein the refrigeration device has a second evaporator in the refrigerant circuit parallel to the first evaporator, a refrigerant supply phase is switched by the method steps

• a4) switching on the compressor;
• b4) closing the stop valve;
• c4) opening the gas valve.

According to an embodiment of the method, the refrigerant supply phase is further initiated after detecting a warm goods introduction into the freezer.

According to one embodiment of the method, the refrigerant supply phase is initiated after a request for ice making.

According to one embodiment of the method, a further refrigerant supply phase is switched after a working phase.

• a4) Einschalten 91 des Verdichters;
• b4) Schließen 92 des Stoppventils;
• c4) Öffnen 93 des Gasventils;
• d) Entfernen 94 des gesamten Kältemittels aus dem zweiten Verdampfer;
• e) anschließend Abtauen 95 des ersten Verdampfers.

4 shows in flow chart 90 an embodiment of the method for operating a refrigerant circuit in a refrigerator with a freezer, wherein the refrigeration device has a second Evaporator in the refrigerant circuit parallel to the first evaporator. Here an evaporator discharge phase is switched through the process steps

• a4) Switch on 91 the compressor;
• b4) Close 92 the stop valve;
• c4) Open 93 the gas valve;
• d) Remove 94 the entire refrigerant from the second evaporator;
• e) then defrost 95 of the first evaporator.

According to one embodiment of the method, the evaporator is a vertical tube-on-sheet evaporator.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014211133 [0002]
• DE 102014211132 [0004]

Claims (13)

Refrigerating appliance with a freezer compartment and a refrigerant circuit containing a compressor ( 21 ) and a first evaporator ( 33 . 63 ), wherein the first evaporator, a stop valve ( 36 . 67 ) and a first capillary ( 31 . 61 ), characterized in that the first evaporator ( 33 . 63 ) a gas valve ( 68 ) is connected downstream. Refrigerating appliance according to claim 1, characterized in that the refrigeration device has a control unit ( 40 . 69 ), which is adapted to the compressor ( 21 ), the stop valve ( 27 ) and the gas valve ( 68 ) to control. Refrigerating appliance according to claim 1 or 2, characterized in that the refrigerating appliance has a second evaporator ( 64 ), wherein the second evaporator, a second capillary ( 62 ) is connected upstream. Method for operating a refrigerant circuit in a refrigerator with a freezer, characterized by the method steps in any order a) switching ( 81 ) of the compressor; b) switching ( 82 ) a stop valve in front of a first evaporator; c) switching ( 83 ) of a gas valve after the first evaporator. A method according to claim 4, characterized in that a defrosting phase of the first evaporator is switched by the method steps a1) switching off the compressor; b1) opening the stop valve; c1) closing the gas valve. A method according to claim 4, characterized in that a warm start phase of the refrigeration device is switched by the process steps a2) switching on the compressor; b2) opening the stop valve; c2) Alternating opening and closing of the gas valve. A method according to claim 4, characterized in that a low-noise phase or a rapid cooling phase of the first evaporator is switched by the process steps a3) switching on the compressor; b3) closing the stop valve; c3) opening the gas valve. The method of claim 4, wherein the refrigeration device comprises a second evaporator in the refrigerant circuit parallel to the first evaporator, characterized in that a refrigerant supply phase is switched by the process steps a4) switching on the compressor; b4) closing the stop valve; c4) opening the gas valve. A method according to claim 8, characterized in that the refrigerant supply phase is initiated after detection of introduction of warm goods in the freezer. A method according to claim 8, characterized in that the refrigerant supply phase is initiated after a request for ice making. Method according to one of claims 8 to 10, characterized in that after a working phase, a further refrigerant supply phase is switched. The method of claim 4, wherein the refrigeration device has a second evaporator in the refrigerant circuit parallel to the first evaporator, characterized in that an evaporator-emptying phase is switched by the process steps a4) switching on ( 91 ) of the compressor; b4) Close ( 92 ) of the stop valve; c4) opening ( 93 ) of the gas valve; d) Remove ( 94 ) of the entire refrigerant from the second evaporator; e) then defrost ( 95 ) of the first evaporator. A method according to claim 12, characterized in that the evaporator is a vertical tube-on-sheet evaporator.

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