DE102011017722A1 - Refrigerant migration device for use as part of vapor compression cooling system of small filling capacity, has buffer container with inlet and outlet, and device for dissipation or interruption of refrigerant circulation - Google Patents

Abstract

The refrigerant migration device (9) has a buffer container (10) with an inlet (11) and an outlet (12), a device for dissipation or interruption of refrigerant circulation (13), which is regulated over four channels. A channel is connected with the outlet at a recuperator (5). Another channel is provided for connection at the outlet to the buffer container. A third channel is provided for connection with the outlet at a condenser (4). A fourth channel is closed at a low pressure area of a cooling system circuit. An independent claim is also included for a method for refrigerant migration in a vapor compression refrigeration system of small filling capacity.

Description

TECHNICAL AREA

The present invention relates to a method for refrigerant migration in a reduced-capacity vapor-compression refrigeration system and to a device for implementing said method.

The method and the associated device are particularly adapted to systems for cooling milk, ie milk tanks; however, both the method and associated apparatus will find numerous applications in other areas where product cooling is required.

STATE OF THE ART

From a compressor, a condenser and a connected to the evaporator of the cooling tank pressure regulator cooling circuits are well known. Under the cooling tank is usually understood an open or closed, arbitrarily shaped container, which is suitable for receiving one or more liquid and / or solid products, which must be cooled or processed at low temperatures.

The basic principle of the cooling circuit is the evaporation of a refrigerant via pressure regulator and evaporator. The refrigerant changes from a liquid to a gaseous state of matter with the absorption of heat units, so that the contents of the tank are cooled. The low pressure refrigerant is then compressed in the compressor until the gas overheats under the high pressure. Thereafter, the refrigerant in the condenser changes from gaseous to liquid state by undergoing three phases: a first phase of steam forming, during which the superheated gas is cooled down to its condensation temperature as it exits the compressor, initiating a second phase of condensation the gas is converted from the gaseous into a liquid state and a third phase of the subcooling, during which the liquid is cooled down to a lower temperature than necessary for condensation.

In order to avoid considerable sizing of the various components of the refrigeration system, refrigerators with integrated containers are used.

This is especially true in the French patent application FR 2 919 713 as well as the international patent application WO 03/014637 the case.

The document FR 2 919 713 describes a method for cooling by means of a liquid, for example helium, which is intended to supply the system, wherein the liquid circulates in several stages by a compression phase, a pre-cooling phase and / or a cooling phase, while by means of a connection point the supply of the system with liquid and the Ensuring the collection of the liquid discharged from the system is ensured. A first part of the separated liquid from the pre-cooling and / or cooling phase is discharged via the connection point, a second part of the liquid can be returned via the pre-cooling and / or cooling phase, depending on whether the thermal continuous power required by the system is low or is increased, while a third part of the liquid is cooled and stored in changing liquid reservoirs, either depending on whether the thermal power required by the plant is low or increased, or already derived via the junction for cooling the first part of the liquid and stored amount is discharged to liquid.

The document WO 03/014637 in turn, describes a refrigeration system in which several compressors supply a main air condenser, followed by an indirect heat exchanger, a liquid collector and a second indirect heat exchanger, which cause a supercooling of the refrigerant. A subcooled refrigerant, connected to remote refrigerators, and a drain allow the recirculation of some of the refrigerant through its subcooling, thereby maintaining the flow of refrigerant in the supply network, even in the absence of cooling demand. The supply and return line networks are kept by a heat-insulating sheath in the same ambient temperature. Secondary cooling circuits run outside of operation time and form an ice mass which is pumped into an ice storage to cool the indirect heat exchanger. The heat exchanger operates at high ambient temperatures like an additional capacitor.

For cost reasons, it is common to use a single refrigeration unit group for multiple cooling tanks. Since the cooling requirement of each individual cooling tank differs depending on the time as well as accordingly in its need for refrigerant for each of the evaporators, it is necessary inside the refrigerant circuit, more specifically at the outlet of the condenser, where the refrigerant is in a liquid state, a To install a liquid receiver with sufficient capacity to capture excess refrigerant in case of limited cooling demand on one or more cooling tanks. The level in Liquid receiver varies between a minimum volume, which corresponds to a simultaneous use of all evaporators, and a maximum volume with only a single cooling evaporator used in the circuit. Such a system must therefore have a considerable total amount of refrigerant to supply without exception all components of the circuit, wherein the liquid collector falls a corresponding role for the storage.

From the field of milk tanks, more specifically milk refrigeration plants, the use of liquid collectors is also known for storing the excess liquid refrigerant which, regardless of the operating conditions of the refrigeration plant group, provides a good supply of pressure regulators and evaporators Ensure coolant circulation.

However, in order to reduce the cost of installation and environmental impact, cooling units without liquid samplers have been developed for the equipment of milk tanks. For such cooling groups without liquid collector requires a precise determination of the necessary for proper operation of the coolant circuit amount of liquid refrigerant.

The amount of the refrigerant fed into a cooling group of a small amount allows complete condensation of the refrigerant inside the condenser, thereby ensuring the discharge of the refrigerant at the outlet of said condenser in a fully condensed, d. H. liquid state, regardless of the operating conditions. It can be observed that the condenser is no longer completely filled with the refrigerant, but instead there is a two-phase mixture in most of the condenser circuit. By a two-phase mixture is meant a vapor-liquid mixture of the refrigerant.

In appliances with a heat recovery device, such as the U.S. Patent US 4,041,726 , the German patent DE 3512748 or the international patent application PCT / EP2009 / 059685 described by the applicant, the operation of the cooling circuit is disturbed at reduced capacity by the heat recovery.

In fact, the reduced-capacity refrigeration cycle does not have sufficient refrigerant to completely drop the condenser with the liquid refrigerant, and thus to ensure a good supply of liquid to the pressure regulator as soon as it condenses in the recuperator for heat recovery.

However, an increase in the capacity of the refrigerant in the cooling circuit is not possible because the condensation would take place in the condenser, it should not be possible in the recuperator. The excess charge of the refrigerant thus induces a large increase in the condensation pressure, which can lead to the release of the safety devices in the cooling circuit.

To compensate for this disadvantage, the use of a liquid receiver and an additional charge of the refrigerant is necessary, wherein the filling amount of the refrigerant is determined by a sufficient demand of the refrigeration cycle of refrigerant and regardless of the respective operating conditions.

However, adding a liquid receiver for refrigerant inside the refrigeration cycle of reduced capacity implies an increase in the amount of refrigerant necessary, and hence an increase in both the installation cost and the environmental impact of the equipment in the event of inadvertent leakage of refrigerant.

DISCLOSURE OF THE INVENTION

One of the objects of the invention is therefore to remedy these drawbacks and to propose a method for refrigerant migration in a low-capacity vapor-compression refrigeration system and apparatus for implementing said method, the concept of which is simple and inexpensive according to its conception, only a limited amount of the refrigerant used in the cooling circuit is required.

For this purpose and in accordance with the invention, a refrigerant migration device is presented in a vapor compression refrigeration system with small capacity, wherein the cooling system has at least one closed circuit with refrigerant circulation and compressor, evaporator, pressure regulator, condenser and recuperator for heat recovery. The remarkable feature of the device is its construction with at least one collector, that is buffer tank, with an inlet and a drain, a device for discharging and / or interrupting the refrigerant circulation, which has at least 4 channels. The first channel is connected to the drain on the recuperator, a second is used to connect to the inlet to the buffer tank, a third is connected to the inlet to the condenser, while the fourth channel is connected to the low pressure area of the cooling system circuit. The above device for discharging and / or interrupting the refrigerant circuit includes devices for Connection of the first channel with the second or third and at the same time those for linking the fourth channel with the third or the second and finally closure devices for the operations of buffer tank and condenser.

Preferably, the device for discharging and / or interrupting the refrigerant circulation consists of a 4-way valve, such as a 4-way gate valve.

As an alternative, there is a device for discharging and / or interrupting the refrigerant circulation consisting of two parallel-connected 3-way valves.

In addition, the closure device consists of two non-return valves. According to one embodiment, the closure device consists of a 3-way valve, which closes either the flow of the buffer tank or the condenser outlet.

In addition, the amount of the buffer tank corresponds to half the amount of condensers ( 4 ).

Another object of the invention is the vapor compression refrigerator low capacity, said cooling system has at least one closed circuit with refrigerant circulation, consisting of a compressor, an evaporator, a pressure regulator, a condenser, a recuperator for heat recovery and a device for the refrigerant migration , Above all, the design of the plant must be considered with at least one buffer tank with an inlet and a drain as well as a device for the discharge and / or interruption of the refrigerant circulation, which has at least 4 channels. The first channel is connected to the drain on the recuperator, a second is used to connect to the inlet to the buffer tank, a third is connected to the inlet to the condenser, while the fourth channel is connected to the low pressure area of the cooling system circuit. The above-mentioned apparatus for discharging and / or interrupting the refrigerant circuit includes means for connecting the first channel with the second or third and at the same time those for linking the fourth channel with the third or the second and finally closure devices for the operations of the buffer tank and the condenser.

• – Kältemittelmigration in Form des im Kondensator enthaltenen Dampfs durch seine Umgehung, sobald der Rekuperator zur Wärmerückgewinnung für eine Kondensation sorgt, während das Kältemittel auf der Ebene des Niederdruckbereichs im Kreislauf zwischen Druckregler und Kompressor wieder rückgeführt wird, indem überschüssige Flüssigkeit in mindestens einem Pufferbehälter gespeichert wird,
• – Kältemittelmigration in Form des im Pufferbehälter enthaltenen Dampfs durch seine Umgehung, sobald der Kondensator für die Kondensation sorgt, während das Kältemittel auf der Ebene des Niederdruckbereichs im Kreislauf zwischen Druckregler und Kompressor wieder rückgeführt wird, um eine gute Versorgung des Druckreglers mit dem Kältemittel in flüssiger Form sicherzustellen.

A final object of the invention relates to a method for refrigerant migration in the vapor-compression refrigeration system of small capacity with at least one closed circuit with refrigerant circulation, consisting of a compressor, an evaporator, a pressure regulator, a condenser and a recuperator for heat recovery; said method comprises at least the following steps:

• - Refrigerant migration in the form of the vapor contained in the condenser by its bypass, as soon as the recuperator for heat recovery provides for condensation, while the refrigerant is recycled at the level of the low pressure area in the circuit between the pressure regulator and the compressor by excess liquid is stored in at least one buffer tank .
• - Refrigerant migration in the form of the vapor contained in the buffer tank by its bypass, as soon as the condenser provides for the condensation, while the refrigerant at the level of the low pressure area in the circuit between the pressure regulator and the compressor is returned to a good supply of the pressure regulator with the refrigerant in liquid Ensure shape.

Preferably, the refrigerant migration takes place in the form of vapor in the condenser, as soon as the recuperator for heat recovery ensures the condensation caused by the pressure difference between the liquid pressure in the condenser and the liquid pressure in the low pressure region of the circuit.

Incidentally, a refrigerant migration occurs in the buffer tank as soon as the condenser ensures a condensation caused by the pressure difference between the liquid pressure in the buffer tank and the liquid pressure in the low-pressure area of the circuit.

Brief description of the drawings

Further advantages and character features will be more readily apparent from the following descriptions of various exemplary embodiments of the refrigerant migration device provided in accordance with the invention, the following referring to the attached drawings:

1 is the schematic representation of a cooling circuit of low capacity with a recuperator for heat recovery and equipped with a device according to the invention provided for the refrigerant migration,

2 exemplifies a possible future manifestation of the device according to the invention for the refrigerant migration,

3 is the schematic partial view of a cooling circuit of low capacity with a Recuperator for heat recovery and equipped with a device according to the invention provided for the refrigerant migration,

4 is the schematic partial view of a cooling circuit of low capacity with a recuperator for heat recovery and equipped with a device according to the invention provided for the refrigerant migration in a second embodiment,

5 is the schematic partial view of a cooling circuit of low capacity with a recuperator for heat recovery and equipped with a device according to the invention provided for the refrigerant migration in a final embodiment,

the 6A and 6B show schematic partial views of a cooling circuit of low capacity with a recuperator for heat recovery and equipped with a device according to the invention provided for the refrigerant migration, on the one hand during the condensation phase in the recuperator ( 6A ) and on the other hand during the condensation phase in the condenser ( 6B ).

EMBODIMENTS OF THE INVENTION

Hereinafter follows the model description of a cooling circuit of low capacity with at least one recuperator for heat recovery and a specially adapted to a milk tank device for refrigerant migration, it is quite natural, however, that provided for in accordance with the invention device for the refrigerant migration of each vapor compression refrigeration system low capacity can be adapted in numerous fields of application, without deviating too much from the specifications of the invention.

As in 1 As shown, the refrigeration system usually consists of a closed circuit with refrigerant circulation, to which a compressor 1 , an evaporator 2 , a pressure regulator 3 , a capacitor 4 and a recuperator for heat recovery 5 belong. It can be seen that it is the capacitor 4 of the 1 is a ventilated condenser with fans, however, of course, any other known in the art of capacitors type, which has no major deviations from the requirements of the invention, usable.

The refrigerant is, for example, the R404a refrigerant consisting of a zeotropic mixture of the fluoroethanols R143a (1,1,1-trifluoroethanol) (52%), R125 (pentafluoroethanol) (44%) and R134a (1,1 , 1,2-tetrafluoroethanol) (4%), which behave like an almost azeotopic fluid.

The compressor 1 is over a first line 6 to the inlet to the recuperator for heat recovery 5 and over a second line 7 to the drain on the evaporator 2 connected, in turn, is at its inlet via a third line 8th with the pressure regulator 3 connected. The circuit also includes a device for refrigerant migration 9 coming out of a buffer tank 10 with the feed 11 and the process 12 and a device for discharging and / or interrupting the refrigerant circulation 13 , which has at least 4 channels, composed. The first channel is via a first line 14 with the drain on the recuperator 5 connected, the line 15 serves the connection of inlet 11 on the buffer tank 10 and the second channel, a third one with the inlet on the condenser 4 over a line 16 connected while the fourth channel is connected to the low pressure area of the refrigeration system circuit, ie connected via a line 17 to the line 7 that the evaporator 2 with the compressor 1 combines. The sequence 12 on the buffer tank 10 and the drain on the condenser 4 are over the wires 18 and 19 with the respective closure devices 20 and 21 at the processes on the buffer tank 10 and at the condenser 4 and over the line 8th connected to the inlet to the evaporator.

Like from the 1 and 2 As can be seen, the device for the refrigerant migration filed with the invention consists of an almost cylindrical buffer container 10 and a 4-way gate valve 13 , The above-mentioned 4-way gate valve 13 thus allows the linking of the first to the second or third channel and simultaneously the connection of the fourth to the third or second channel. In addition, the 4-way gate valve 13 about one in the 1 and 2 not shown temperature sensor controlled, the water temperature at the inlet of the recuperator for heat recovery 5 measures.

Of course, the 4-way gate valve is of course to be replaced by any of the 4-way valve known to those skilled in the art and to be controlled by any suitable device, also known and not too far removed from the scope of the invention.

In this particular example of a variant embodiment, the closure devices exist 20 and 21 at the drain from the buffer tank 10 or from the condenser 4 each from a non-return valve 20 respectively 21 , these check valves 20 and 21 were installed opposite each other.

In addition, the amount of the buffer tank corresponds 10 half the amount of condenser 4 , Consequently, the dimensions of the buffer tank 10 in particular dependent on the amount produced by the condenser and / or the number of condensers used in the cooling circuit.

The first embodiment of the notified in the invention device for the refrigerant migration is how 3 shows, in the same structure as is usually the case, namely a system consisting of a closed circuit with refrigerant circulation, to which a compressor 1 , an evaporator 2 , a pressure regulator 3 , a capacitor 4 and a recuperator for heat recovery 5 belong, with the compressor 1 via a first line 6 to the inlet to the recuperator for heat recovery 5 and over a second line 7 to the drain on the evaporator 2 connected, in turn, at its inlet via a third line 8th with the pressure regulator 3 is connected. The circuit also includes a device for refrigerant migration 9 arising from a buffer tank 10 with the feed 11 and the process 12 and a device for discharging and / or interrupting the refrigerant circulation 13 , which has at least 4 channels, composed. The first channel is via a first line 14 with the expiry of the recuperator 5 connected, the line 15 serves the connection of inlet 11 on the buffer tank 10 and the second channel, a third one with the inlet on the condenser 4 over a line 16 connected while the fourth channel is connected to the low pressure area of the refrigeration system circuit, ie connected via a line 17 to the line 7 that the evaporator 2 with the compressor 1 combines. The sequence 12 on the buffer tank 10 and the drain on the condenser 4 are over the wires 18 and 19 with the respective closure devices 20 and 21 at the processes on the buffer tank 10 and at the condenser 4 and over the line 8th connected to the inlet to the evaporator.

This embodiment variant of the device for the refrigerant migration differs from the preceding one by the fact that the 4-way valve 13 by two parallel installed 3-way valves 22 and 23 was replaced. These 3-way valves 22 and 23 are controlled in the same way as in the previous variant via a temperature sensor, not shown in the figures, or a similarly suitable, known among experts, device, via the measurement of the water temperature at the inlet of the recuperator for heat recovery 5 can be done.

A second embodiment of the device for the refrigerant migration registered for the invention is, as 4 shows an announcement constructed in the same way as the previous, namely consisting of a closed circuit with refrigerant circulation, to which a compressor 1 , an evaporator 2 , a pressure regulator 3 , a capacitor 4 and a recuperator for heat recovery 5 belong, with the compressor 1 via a first line 6 to the inlet to the recuperator for heat recovery 5 and over a second line 7 to the drain of the evaporator 2 connected, in turn, at its inlet via a third line 8th with the pressure regulator 3 is connected. The circuit also includes a device for refrigerant migration 9 arising from an almost cylindrical buffer tank 10 with the feed 11 and the process 12 and a device for discharging and / or interrupting the refrigerant circulation 13 , which has at least 4 channels, composed. The first channel is via a first line 14 with the drain on the recuperator 5 connected, the line 15 serves the connection of inlet 11 on the buffer tank 10 and the second channel, a third one with the inlet on the condenser 4 over a line 16 connected while the fourth channel is connected to the low pressure area of the refrigeration system circuit, ie connected via a line 17 to the line 7 that the evaporator 2 with the compressor 1 combines. The drain 12 on the buffer tank 10 and the drain on the condenser 4 are over the wires 18 and 19 with the respective closure devices 20 and 21 at the processes on the buffer tank 10 and at the condenser 4 and over the line 8th connected to the inlet to the evaporator.

The notified for the invention device for the refrigerant migration here consists of an almost cylindrical buffer tank 10 and a 4-way gate valve 13 , The above-mentioned 4-way gate valve 13 thus allows the linking of the first to the second or third channel and simultaneously the connection of the fourth to the third or second channel.

This embodiment of the device differs from that in 1 described device by the fact that the closure devices of the processes on the buffer tank 10 and at the condenser 4 each consist of a 3-way valve for closing either the drain on the buffer tank or the drain on the condenser, wherein the 3-way valve 24 over two check valves 20 and 21 features. Consequently, a first channel of said 3-way valve 24 with the process 12 on the buffer tank 10 , a second with the drain on the condenser 4 and a third channel with the line 8th at the inlet of the evaporator 2 to connect, in 4 not shown. This 3-way valve 24 is via a temperature sensor, also not shown in the figures, the water temperature at the inlet of the recuperator 5 measures, regulated, as well as the 4-way valve 13 ,

It should be noted that the 3-way valve may be controlled by any similarly suitable device known to those skilled in the art and not falling within the scope of the invention.

A last variant of the invention for the device for the refrigerant migration is this, as 5 shows, constructed in the same way plant as the preceding, namely consisting of a closed circuit with refrigerant circulation, to which a compressor 1 , an evaporator 2 , a pressure regulator 3 , a capacitor 4 and a recuperator for heat recovery 5 belong, with the compressor 1 via a first line 6 to the inlet to the recuperator for heat recovery 5 and over a second line 7 to the drain of the evaporator 2 connected, in turn, at its inlet via a third line 8th with the pressure regulator 3 is connected. The circuit also includes a device for refrigerant migration 9 arising from a buffer tank 10 with the feed 11 and the process 12 and a device for discharging and / or interrupting the circulation of the refrigerant 13 , which has at least 4 channels, composed.

The notified for the invention device for the refrigerant migration here consists of an almost cylindrical buffer tank 10 and a 4-way gate valve 13 ,

This embodiment differs from the preceding ones by the fact that the first channel of the 4-way valve is connected to the drain 12 on the buffer tank via a line 14 , the second channel over one with the non-return valve 20 provided wire 18 with the line 8th at the inlet of the evaporator 2 , the third channel via a line 16 with the inlet on the condenser 4 and the fourth channel over the line 17 are connected to the low pressure area of the cooling system. The feed 11 on the buffer tank 10 is over a line 14 with the drain on the recuperator 5 and the drain on the condenser 4 one with the non-return valve 21 provided wire 19 with the in 5 not shown line 8th at the inlet of the evaporator 2 connected.

Now follows the explanation of the operation of the device applied for the invention with reference to the 6A and 6B ,

Once, as in 6A to see about the recuperator 5 the condensation is ensured, the slide of the 4-way valve responds respectively to the first channel in connection with the second and for the third with the fourth channel; the non-return valve 21 the line 19 is closed. In this way, this moves in the condenser 4 included refrigerant so in the low pressure area of the refrigeration system circuit that the refrigerant gradually in the buffer tank 10 to dry out the capacitor 4 collects. Consequently, it should be noted that the refrigerant in the condenser no longer behaves as in a trap. In this way, the refrigerant migrates into the circulation and into the buffer tank 10 , The capacitor 4 is then thanks to the non-return valve 21 bypassed and completely emptied of the liquid contained in it. It should be noted that the buffer tank 10 the continuous supply of the pressure regulator 3 permitted with the liquid refrigerant, whereby a proper function of the cooling circuit is ensured.

Once, as in 6B to see over the capacitor 4 the condensation is ensured, the position of the slide on the 4-way valve changes in each case for the first channel in conjunction with the second and for the third with the fourth channel, the non-return valve 20 the line 18 is closed while the check valve 21 is open. In this way, this moves in the buffer tank 10 contained refrigerant in the low pressure area of the refrigeration system circuit to the buffer tank 10 to empty. This dehydration of the buffer tank 10 takes place by the suction and evaporation of the in the buffer tank 10 present gaseous refrigerant via the line 17 in the low pressure area of the refrigeration system circuit, in conjunction with the line 15 via the slide of the 4-way valve 13 is regulated. The refrigerant then migrates into the areas of the cooling circuit where it is needed, ultimately into the condenser 4 ,

It should be noted that the capacitor 4 with the recuperator 5 connected in series while the buffer tank 10 is bypassed to avoid a pressure drop in the gaseous refrigerant filled high pressure area of the cooling circuit. So the refrigerant enters the outlet of the condenser 4 in liquid form to ensure proper supply to the pressure regulator 3 sure.

Once the recuperator 5 Ensuring the condensation again moves as in 6A seen, the slide of the 4-way valve back to its original position, where the first channel then reacts in conjunction with the second and the third in conjunction with the fourth channel, and so on.

It can be observed that, in comparison with the recuperator refrigeration unit and the formerly used liquid container, the use of this apparatus for the refrigerant migration does not affect the functioning of the refrigeration system: neither the pressure values nor the supply of the pressure regulator or the cooling capacity. Incidentally, the transitional periods between the individual Condensation phases in the recuperator 5 and in the condenser 4 shortens and the cooling system remains stable.

In conclusion, it should be noted that the examples given are merely illustrative and in no way intended to limit the scope of this invention.

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

• FR 2919713 [0006, 0007]
• WO 03/014637 [0006, 0008]
• US 4041726 [0013]
• DE 3512748 [0013]
• EP 2009/059685 [0013]

Claims (10)

Refrigerant migration device ( 9 ) as part of a vapor compression refrigeration system of small capacity, consisting of at least one closed circuit with refrigerant circulation and compressor ( 1 ), Evaporator ( 2 ), Pressure regulator ( 3 ), Capacitor ( 4 ) and recuperator for heat recovery ( 5 ), characterized in that it consists of at least one buffer container ( 10 ) each with a feed ( 11 ) and a procedure ( 12 ), a device for the discharge and / or interruption of the refrigerant circulation ( 13 ; 22 . 23 ), which has at least 4 channels, the first channel with the drain on the recuperator ( 5 ), a second connected to the inlet ( 11 ) on the buffer container ( 10 ), a third for connection to the inlet on the condenser ( 4 ) is determined and the fourth channel is connected to the low-pressure region of the refrigeration system circuit and the above-mentioned device for discharging and / or interruption of the refrigerant circuit ( 13 ; 22 . 23 ) of devices on the one hand for connecting the first channel to the second or third and on the other hand for linking the fourth channel with the third or the second and finally from closure devices ( 20 . 21 ; 24 ) for the operations of buffer tanks ( 10 ) and capacitor ( 4 ) is constructed. The refrigerant migration device according to the preceding claim is characterized in that the device for discharging and / or interrupting the refrigerant circulation from a 4-way valve ( 13 ) consists. The refrigerant migration device according to claim 1 is characterized in that the device for discharging and / or interrupting the refrigerant circulation from parallel-connected 3-way valves ( 22 . 23 ) consists. The refrigerant migration device according to one of the preceding claims 1 to 3 is characterized in that the closure device consists of two non-return valves ( 20 . 21 ) consists. The refrigerant migration device according to one of the preceding claims 1 to 3 is characterized in that the closure device consists of a 3-way valve which either the drain ( 12 ) on the buffer tank or the drain on the condenser ( 4 ) closes. The refrigerant migration device according to claim 1 is characterized in that the amount in the buffer tank ( 10 ) of half the amount of the capacitor ( 4 ) corresponds. The low-pressure vapor compression refrigerator, said refrigeration system comprising at least one closed circuit with refrigerant circulation and compressor ( 1 ), Evaporator ( 2 ), Pressure regulator ( 3 ), Capacitor ( 4 ), Recuperator for heat recovery ( 5 ) as well as a refrigerant migration device ( 9 ) is characterized in that it consists of at least one buffer container ( 10 ) each with a feed ( 11 ) and a procedure ( 12 ), a device for the discharge and / or interruption of the refrigerant circulation ( 13 ; 22 . 23 ), which has at least 4 channels, the first channel with the drain on the recuperator ( 5 ), a second connected to the inlet ( 11 ) on the buffer container ( 10 ), a third for connection to the inlet on the condenser ( 4 ) is determined and the fourth channel is connected to the low-pressure region of the refrigeration system circuit and with an above-mentioned device for discharging and / or interrupting the refrigerant circuit ( 13 ; 22 . 23 ) on the one hand for connecting the first channel to the second or third and on the other hand for linking the fourth channel to the third or the second and finally from a closure device ( 20 . 21 ; 24 ) for the operations of buffer tanks ( 10 ) and capacitor ( 4 ) is constructed. The method for refrigerant migration in the vapor compression refrigeration system of small capacity with at least one closed circuit with refrigerant circulation, consisting of a compressor ( 1 ), an evaporator ( 2 ), a pressure regulator ( 3 ), a capacitor ( 4 ) and a recuperator for heat recovery ( 5 ) is characterized in that said method comprises at least the following steps: - refrigerant migration in the form of in the condenser ( 4 ) by its bypass once the recuperator for heat recovery ( 5 ), while the refrigerant at the level of the low pressure area circulates between the pressure regulator ( 3 ) and compressor ( 4 ) is returned by excess liquid in at least one buffer tank ( 10 ), - refrigerant migration in the form of the in the buffer tank ( 10 ) bypassing it as soon as the condenser ( 4 ), while the refrigerant at the level of the low pressure area circulates between the pressure regulator ( 3 ) and compressor ( 1 ) is returned to ensure a good supply of the pressure regulator ( 3 ) with the refrigerant in liquid form. The method according to claim 8 is characterized in that the refrigerant migration in the form of the in the condenser ( 4 ) contained steam, as soon as the recuperator for heat recovery, due to the pressure difference between the Fluid pressure in the condenser ( 4 ) and the liquid pressure in the low pressure region of the circuit caused condensation ensured. The method according to claim 8 or 9 is characterized in that the refrigerant migration in the buffer tank ( 10 ) one from the capacitor ( 4 ) by the pressure difference between the liquid pressure in the buffer tank ( 10 ) and the liquid pressure in the low pressure region of the circuit caused condensation.

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