EP3426989A1

EP3426989A1 - Refrigerator having a freezer box and a refrigerant circuit and method for operating a refrigerator

Info

Publication number: EP3426989A1
Application number: EP17705407.9A
Authority: EP
Inventors: Hans Ihle; Berthold Pflomm
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2016-03-09
Filing date: 2017-02-16
Publication date: 2019-01-16
Also published as: WO2017153141A1; DE102016203895A1; CN108700348A

Abstract

In a refrigerator having a freezer box and a refrigerant circuit, which has a compressor (21) and a first evaporator (33, 63), wherein the first evaporator is arranged downstream of a stop valve (36, 67) and a first capillary tube (31, 61), the first evaporator (33, 63) is arranged upstream of a gas valve (68). A method for operating a refrigerant circuit, in a refrigerator having a freezer box, has the following method steps in any sequence: a) operating (81) the compressor; b) operating (82) a stop valve before a first evaporator; c) operating (83) a gas valve after the first evaporator.

Description

Refrigerating appliance with a freezer and a refrigerant circuit and

Method for operating a refrigeration device

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 DE 10 2014 21 1 133 is a refrigerator with a first and a second evaporator, which are arranged together with each 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 of the first evaporator is switchable between a high and a low flow rate, the supply line to both the

Throttle is 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.

DE 10 2014 21 1 132 discloses a chiller comprising a first and a second evaporator, which are arranged together with each upstream throttle point in parallel branches of a refrigerant circuit. A downstream valve arrangement 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 other reasons increased refrigeration demand of the freezer compartment can after a cooling phase of the freezer in its

Evaporator stored refrigerant amount to be greater than under normal

Operating conditions, so that in a subsequent cooling 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 in combination to be able to control the refrigerant level in the evaporator with a stop valve in front of the evaporator.

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, the one

Compressor and a first evaporator, wherein the first evaporator, a stop valve and a first capillary are connected upstream of the first evaporator, a gas valve downstream. Thus, for example, the technical advantage is achieved that depends on the ambient conditions such as outside temperature or

Operating conditions such as storage of warm goods located in the evaporator

Refrigerant quantity can be controlled.

The refrigeration device according to an advantageous embodiment, a control unit (19) which is adapted 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 of the first evaporator, the refrigerant can be kept deliberately in the evaporator section to a slight compressor start after defrosting, without high liquefaction and

To realize 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, via the gas valve, the mass flow can be limited, for example, clocks too high, harmful to the compressor

To avoid liquefaction 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 with the following

Embodiments are combined, for example, applies the embodiment of

A method for switching a defrosting then for switching a defrosting phase of the evaporator 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 at particularly high

Performance 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 detection of an introduction 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 is initiated after a request for ice making. 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 according to the aforementioned relocation of the refrigerant this at the end of the state again

can be moved back. 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 in which the liquid refrigerant collects by gravity.

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 case of a vertical tube-on-sheet evaporator

Defrost security is improved. A switchable gas valve can be used in combination with a stop valve in front of the

Throttles in refrigerators with two or more evaporators, a parallel circuit of the evaporator - either the one operated or the other - allow and thereby prevent 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 high or high

Avoid 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: Fig. 1 is a schematic representation of a refrigeration device according to the invention;

Fig. 2 is a schematic representation of the refrigerant circuit of a

Refrigerating appliance according to the invention with a first evaporator;

Fig. 3 is a schematic representation of the refrigerant circuit of a

inventive refrigeration device with a first evaporator and another warmer evaporator,

4 shows a flow chart of an embodiment of the invention

process; and

Fig. 5 is a flowchart of another embodiment of the invention

Process.

Fig. 1 shows a refrigerator 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 compartment evaporator.

The refrigerant circuit 20 shown in FIG. 2 includes a conventional manner

Compressor 21 having a compressed refrigerant outlet 22 and an inlet 23 for sucking refrigerant. At one of the output 22 outgoing

Refrigerant line 24, a condenser 25, a dryer 26, and a switchable between an on-state and a blocking state stop valve 27 are arranged in order.

The stop valve 27 is followed by a capillary 31 and an evaporator 33 in series. Of the

Evaporator 33 cools a compartment 34 of a refrigerator 35. After the evaporator 33 is an electrically controllable gas valve 36 in a suction line 37 to the compressor 21st

arranged.

An electronic control unit 40 is connected to a temperature sensor 42 on the compartment 34 in order to determine the operation of the temperature based on the temperatures measured there

Compressor 21 and the position of stop valve 27 and gas valve 36 to control. The refrigerant circuit 50 shown in FIG. 3 largely comprises the same elements as the refrigeration cycle 20 of FIG. 2 with the same reference numerals. The refrigerant circuit 50 comprises a compressor 21, a refrigerant line 24 and a condenser 25, a dryer 26, and a stop valve 27 in sequence. After the stop valve 27, a directional control valve 52 follows, at which the refrigerant line 24 into two branches 59, 60 branched. Deviating from the illustration of FIG. 3, the directional control valve 52 may be integrated in the stop valve 27, in that the latter has three instead of two connections 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 any of the branches 59, 60 is a connection.

At the branches 59, 60 are each a capillary 61 and 62 and an evaporator 63 and 64 connected in series. Each of the two evaporators 63, 64 cools a compartment 65 or 66 of the refrigerator. The mean operating temperature of the compartment 66 is higher than that of compartment 65, for example compartment 66 may be a standard refrigeration compartment and compartment 65 may be a freezer compartment of the refrigeration apparatus.

The two branches 59, 60 meet again at a confluence 67. In branch 59, a gas valve 68 is arranged between an exit of the evaporator 63 and the confluence 67. The gas valve 68 allows in the open position the

Operation of the evaporator 63. In the closed position, it includes on the one hand refrigerant in the evaporator 63 and on the other hand prevents refrigerant, which evaporates during a standstill of the compressor in the evaporator 64 of the warmer cooling compartment diffuses into the evaporator of the colder freezer compartment and condenses there.

An electronic control unit 69 is connected to temperature sensors 70, 71 to the

Compartments 65, 66 connected to control the operation of the compressor 21 and the position of the stop valve 27 and directional control valve 52 based on the temperatures measured there. The method according to the invention will be explained with reference to FIGS. 2 and 3, in which the evaporators 33 and 63 are referred to as the first evaporator and the evaporator 64 as the second evaporator. 4 shows, in flowchart 80, a method for operating a refrigerant circuit in a refrigerator with a freezer with the method steps

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.

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

According to one embodiment of the method, a defrosting phase of the first

Evaporator switched through the process steps

a1) switching off the compressor;

b1) opening the stop valve;

c1) closing the gas valve. 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.

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 of the compressor;

b3) closing the stop valve;

c3) opening the gas valve.

According to an 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 one embodiment of the method, the refrigerant preparation phase is further initiated after detecting the introduction of warm goods in the freezer compartment.

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.

4 shows in flow diagram 90 an embodiment of the method for operating a refrigerant circuit in a refrigeration device having a freezer compartment, wherein the refrigeration device has a second evaporator in the refrigerant circuit parallel to the first evaporator. Here, an evaporator-emptying phase is switched by the process steps a4) switching 91 of the compressor;

b4) closing 92 of the stop valve;

c4) opening 93 of the gas valve;

d) removing 94 of the total 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.

Claims

Refrigerating appliance having a freezer compartment 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, characterized in that a gas valve (68) is connected downstream of the first evaporator (33, 63).

Refrigeration appliance according to claim 1, characterized in that the refrigeration device comprises a control unit (40, 69) which is adapted to control the compressor (21), the stop valve (27) and the gas valve (68).

Refrigerating appliance according to claim 1 or 2, characterized in that the refrigeration device 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 compartment, 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 method 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

Having refrigerant circuit parallel to the first evaporator, characterized

characterized in that 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.

A method according to claim 8, characterized in that the refrigerant supply phase is initiated after detection of an 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.

Having refrigerant circuit parallel to the first evaporator, characterized

characterized in that an evaporator-emptying phase is switched by the method steps

a4) switching on (91) of the compressor;

b4) closing (92) the stop valve; c4) opening (93) of the gas valve;

d) removing (94) the entire refrigerant from the second evaporator; e) then defrosting (95) the first evaporator.

A method according to claim 12, characterized in that the evaporator is a vertical tube-on-sheet evaporator.