CN117553441A

CN117553441A - Refrigerating system and control method thereof

Info

Publication number: CN117553441A
Application number: CN202311478237.6A
Authority: CN
Inventors: 钟海玲; 程琦; 李龙
Original assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Current assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Priority date: 2023-11-07
Filing date: 2023-11-07
Publication date: 2024-02-13

Abstract

The invention provides a refrigerating system and a control method thereof, wherein the refrigerating system comprises a compressor, an oil separator, an exhaust pipe and a cooling assembly; one end of the exhaust pipe is connected with the compressor, and the other end of the exhaust pipe is connected with the oil separator; the cooling component can acquire the cold energy generated by the refrigerant, and when the superheat degree of the exhaust gas of the compressor is larger than a set value, the cooling component releases the cold energy to the exhaust pipe so as to cool the refrigerant in the exhaust pipe; when the superheat degree of the exhaust gas of the compressor is recovered to the set value, the cooling assembly stops releasing the cold energy to the exhaust pipe. When the cooled refrigerant is exhausted, oil drop particles become larger, and the oil drop particles are easier to intercept after entering the oil separator, so that the separation efficiency of the oil separator is improved, and the oil return effect of the oil separator on the frozen oil is improved.

Description

Refrigerating system and control method thereof

Technical Field

The invention belongs to the technical field of refrigeration oil recovery, and particularly relates to a refrigeration system and a control method thereof.

Background

In the screw air-cooled chiller, the normal operation of the compressor is required to rely on sealing, lubrication, load adjustment and the like of the refrigeration oil, and the refrigeration oil can be discharged along with exhaust gas in the operation process of the compressor, so that the interception and recovery of the refrigeration oil are particularly mild. The internal oil separator of the compressor and the external oil separator of the exhaust gas of the compressor are generally realized, but when the internal oil separator of the compressor is used, the cost of the compressor is increased, and the exhaust pressure drop of the compressor is increased to influence the performance of the whole machine. If the built-in oil separator is not arranged, the oil return of the compressor is totally close to the external oil separator, the oil recovery effect of the external oil separator is influenced by oil drop particles, the larger the oil drop particles are, the easier the recovery is, the smaller the oil drop particles are, the worse the recovery effect is, and the influence of the size of the oil drop particles is influenced by the exhaust superheat degree.

Patent CN105299956a discloses a compressor oil return control device and method and an air conditioner with the device, which achieve the purpose of regulating the supply amount of the refrigerating oil by adding an oil return pipeline at an oil separator, but the refrigerating oil recovery effect of the oil separator and the refrigerating oil recovery in a system are not mentioned; patent CN111623558A discloses an air conditioning system, which achieves the purpose of meeting the oil supply requirement of a compressor by additionally providing an oil storage device for storing redundant refrigerating oil, but the refrigerating oil recovery effect of an oil separator and the refrigerating oil recovery in the system are not mentioned.

Disclosure of Invention

The invention provides a refrigerating system and a control method thereof, which can solve the technical problems that the oil recovery effect of an external oil separator is influenced by oil drop particles, and the oil recovery effect of the external oil separator is poor when the exhaust superheat degree of an exhaust pipe is large.

The invention provides a refrigerating system, which comprises a compressor, an oil separator and an exhaust pipe, and is characterized by further comprising a cooling assembly;

one end of the exhaust pipe is connected with the compressor, and the other end of the exhaust pipe is connected with the oil separator;

the cooling component can acquire the cold energy generated by the refrigerant, and when the superheat degree of the exhaust gas of the compressor is larger than a set value, the cooling component releases the cold energy to the exhaust pipe so as to cool the refrigerant in the exhaust pipe; when the superheat degree of the exhaust gas of the compressor is recovered to the set value, the cooling assembly stops releasing the cold energy to the exhaust pipe.

In some embodiments, the cooling assembly is provided with a coolant supply that delivers a coolant into the cooling assembly.

In some embodiments, the cooling assembly includes a first heat exchanger connected to a coolant supply that delivers a coolant to the first heat exchanger, the first heat exchanger generating cooling energy and releasing the cooling energy to an exhaust pipe.

In some embodiments, the cooling assembly further comprises a delivery tube connecting the first heat exchanger and the coolant supply, the delivery tube having a water pump disposed thereon.

In some embodiments, a fan is arranged on the first heat exchanger, an air outlet of the fan faces the exhaust pipe, and cold energy generated by the first heat exchanger is blown to the exhaust pipe.

In some embodiments, the refrigeration system includes a third heat exchanger, the third heat exchanger being a coolant supply.

In some embodiments, the compressor further includes a first controller for causing the cooling assembly to release cold to the discharge pipe based on a degree of superheat of the discharge of the compressor.

In some embodiments, when the cooling assembly includes a water pump, the first controller is configured to turn on the water pump based on a discharge superheat of the compressor, causing the first heat exchanger to release cold to the discharge pipe.

In some embodiments, a second heat exchanger is also included;

the oil separator is provided with a first oil return pipeline, and one end of the first oil return pipeline, which is far away from the oil separator, is connected with the air suction pipe so as to return the frozen oil in the oil separator to the compressor;

the first oil return pipeline comprises a first oil return pipe, a first stop valve second electromagnetic valve, a filter second electromagnetic valve, a first electromagnetic valve second electromagnetic valve and a second stop valve second electromagnetic valve which are sequentially arranged on the first oil return pipe, the first stop valve second electromagnetic valve is close to the oil separator, and the second stop valve second electromagnetic valve is close to the compressor.

An electronic expansion valve second electromagnetic valve is arranged between the second electromagnetic valve of the second heat exchanger and the second electromagnetic valve of the third heat exchanger, a second oil return pipeline is arranged on the second electromagnetic valve of the second heat exchanger, and one end, far away from the second electromagnetic valve of the second heat exchanger, of the second oil return pipeline is connected with the first oil return pipeline so as to return frozen oil in the second electromagnetic valve of the second heat exchanger to the first oil return pipeline.

In some embodiments, the second oil return line includes a second oil return pipe, and a second solenoid valve and a first check valve provided on the second oil return pipe, the second solenoid valve being openable or closable according to a discharge superheat degree of the compressor.

In some embodiments, the refrigeration system further comprises a second controller for refluxing the refrigeration oil in the second heat exchanger to the first oil return line according to the discharge superheat of the compressor and the opening of the electronic expansion valve.

In some embodiments, when the second oil return line includes a second solenoid valve, the second controller is configured to control opening of the second solenoid valve to return the refrigerant oil in the second heat exchanger to the first oil return line.

In some embodiments, the third heat exchanger second solenoid valve is provided with a third oil return line, and an end of the third oil return line, which is far away from the third heat exchanger second solenoid valve, is connected with the air suction pipe so as to return the frozen oil in the third heat exchanger second solenoid valve to the compressor.

In some embodiments, the third oil return line includes a third oil return pipe and a third solenoid valve second solenoid valve and a second check valve second solenoid valve disposed on the third oil return pipe.

In some embodiments, a third controller is further included for returning the chilled oil in the third heat exchanger second solenoid valve to the compressor based on the on-run time of the compressor.

In some embodiments, when the third oil return line includes a third solenoid valve, the third controller is configured to control opening of the third solenoid valve to return the refrigerant oil in the third heat exchanger to the suction pipe.

A control method of a refrigeration system is provided, wherein the refrigeration system is the refrigeration system,

when the cooling assembly is provided with a cooling liquid supply device, the cooling liquid supply device conveys a refrigerant into the cooling assembly, and the cooling assembly releases cold energy to the exhaust pipe according to the exhaust superheat degree of the compressor;

when an electronic expansion valve second electromagnetic valve is arranged between the second electromagnetic valve of the second heat exchanger and the second electromagnetic valve of the third heat exchanger, the second electromagnetic valve of the second heat exchanger is provided with a second oil return pipeline, one end of the second oil return pipeline, which is far away from the second electromagnetic valve of the second heat exchanger, is connected with the first oil return pipeline so as to return the frozen oil in the second electromagnetic valve of the second heat exchanger to the first oil return pipeline, and the frozen oil in the second heat exchanger is returned to the first oil return pipeline according to the exhaust superheat degree of the compressor and the opening degree of the electronic expansion valve;

when the second electromagnetic valve of the third heat exchanger is provided with a third oil return pipeline, one end of the third oil return pipeline, which is far away from the second electromagnetic valve of the third heat exchanger, is connected with the air suction pipe so as to return the frozen oil in the second electromagnetic valve of the third heat exchanger to the compressor

In some embodiments, when the cooling assembly includes a first heat exchanger, the first heat exchanger is configured to release cold to the discharge pipe based on a degree of superheat of the discharge gas of the compressor.

In some embodiments, when the second oil return line includes a second solenoid valve, opening of the second solenoid valve is controlled to return the frozen oil in the second heat exchanger to the first oil return line.

In some embodiments, when the third oil return line includes a third solenoid valve, controlling the opening of the third solenoid valve returns the refrigerant oil in the third heat exchanger to the suction pipe

The refrigerating system and the control method thereof provided by the invention have the following beneficial effects:

the mixture of the high-temperature and high-pressure refrigerant discharged by the compressor and the refrigerating oil enters the oil separator through the exhaust pipe to carry out oil-gas separation, and most of the separated refrigerating oil flows back to the compressor through an oil return pipeline of the separator. When the superheat degree of the exhaust gas of the compressor is large, the temperature of the refrigerant in the exhaust pipe is high, the cold energy generated in the cooling assembly is released to the exhaust pipe, the exhaust pipe is cooled, and then the refrigerant in the exhaust pipe is cooled. When the cooled refrigerant is exhausted, oil drop particles become large, and the oil drop particles are easier to intercept after entering the oil separator, so that the separation efficiency of the oil separator is improved, and the oil return effect of the oil separator on the frozen oil is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those skilled in the art from this disclosure that the drawings described below are merely exemplary and that other embodiments may be derived from the drawings provided without undue effort.

The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the ambit of the technical disclosure.

Fig. 1 is a schematic diagram of a refrigerant system according to an embodiment of the invention.

The accompanying drawings: 1-a compressor; 2-oil separator; 3-a second heat exchanger; 4-an electronic expansion valve; 5-a third heat exchanger; 6-a first shut-off valve; 7-a filter; 8-a first solenoid valve; 9-a second shut-off valve; 10-a first heat exchanger; 11-a water pump; 12-a second solenoid valve; 13-a third solenoid valve; 14-a first one-way valve; 15-an exhaust pipe; 16-a conveying pipe.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the authorization specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present invention, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present invention; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present invention.

Referring now to fig. 1 in combination, in accordance with an embodiment of the present invention, there is provided a refrigeration system comprising a compressor 1, an oil separator 2, and a discharge pipe 15, and further comprising a cooling assembly; one end of the exhaust pipe 15 is connected with the compressor 1, and the other end of the exhaust pipe 15 is connected with the oil separator 2; the cooling component can acquire the cold energy generated by the refrigerant, and when the superheat degree of the exhaust gas of the compressor 1 is larger than a set value, the cooling component releases the cold energy to the exhaust pipe 15 so as to cool the refrigerant in the exhaust pipe 15; when the discharge superheat degree of the compressor 1 is restored to the set value, the cooling unit stops releasing the cold amount to the discharge pipe 15.

The mixture of the high-temperature and high-pressure refrigerant discharged by the compressor 1 and the refrigerating oil enters the oil separator 2 through the exhaust pipe 15 for oil-gas separation, and most of the separated refrigerating oil flows back into the compressor 1 through an oil return pipeline of the separator. When the degree of superheat of the discharge gas of the compressor 1 is large, the refrigerant temperature in the discharge pipe 15 is high, and the amount of cold generated in the cooling unit is released to the discharge pipe 15, thereby cooling the discharge pipe 15 and further cooling the refrigerant in the discharge pipe 15. When the cooled refrigerant is exhausted, oil drop particles become large, and the oil drop particles are easier to intercept after entering the oil separator 2, so that the separation efficiency of the oil separator 2 is improved, and the oil return effect of the oil separator 2 on the frozen oil is improved.

The cooling assembly is provided with a cooling liquid supply device which conveys a cooling medium into the cooling assembly.

The cooling assembly includes a first heat exchanger 10, the first heat exchanger 10 being connected to a coolant supply device that delivers a coolant to the first heat exchanger 10, the first heat exchanger 10 generating cold and releasing the cold to an exhaust pipe 15.

The cooling assembly further comprises a delivery pipe 16 connecting the first heat exchanger 10 and the cooling liquid supply device, and a water pump 11 is arranged on the delivery pipe 16.

As a specific embodiment, a bulb and a pressure sensor are provided at the discharge port of the compressor 1 for detecting and acquiring the discharge temperature and the discharge pressure at the discharge port of the compressor 1, at the saturation temperature corresponding to the discharge superheat=discharge temperature-discharge pressure. When the exhaust superheat degree at the exhaust port of the compressor 1 is higher, it means that the exhaust temperature of the refrigerant discharged into the exhaust pipe 15 is high, the exhaust superheat degree is high, oil drops in the refrigerant are small, at this time, the water pump 11 works, the conveying pipe 16 conveys the external refrigerant into the first heat exchanger 10, the first heat exchanger 10 works to generate cold energy to be released onto the exhaust pipe 15, and then the temperature of the refrigerant in the exhaust pipe 15 is reduced. The oil drop particles in the cooled refrigerant are larger, and then the cooled refrigerant is discharged into the oil separator 2 from the exhaust pipe 15, the oil separator 2 is easier to intercept and recycle as the oil drop particles are larger, and the oil recovery effect of the oil separator 2 is further improved.

A fan is arranged on the first heat exchanger 10, an air outlet of the fan faces the exhaust pipe 15, and cold generated by the first heat exchanger 10 is blown to the exhaust pipe 15.

Specifically, when the first heat exchanger 10 needs to release the cold energy to the exhaust pipe 15, the fan is started to blow the cold energy to the exhaust pipe 15, so that the cold energy can be uniformly released to the exhaust pipe 15, and the fan is arranged to increase the speed of releasing the cold energy to the exhaust pipe 15, so as to increase the cooling speed of the exhaust pipe 15.

As a specific embodiment, the refrigeration system further includes a third heat exchanger 5, and the third heat exchanger 5 is a cooling liquid supply device. The third heat exchanger 5 is provided with a chilled water supply pipe to which the cooling module is connected, the chilled water supply pipe being for supplying chilled water to the cooling module.

As a specific embodiment, one end of the delivery pipe 16 far away from the first heat exchanger 10 is communicated with a chilled water supply pipe, the refrigerant absorbs heat of water in the third heat exchanger 5 and evaporates into a refrigerant with low temperature and superheat, in the process, the water is absorbed with heat and cooled, the chilled water is prepared, the chilled water flows into the chilled water pipe, a part of the chilled water is delivered into the delivery pipe 16, the refrigerant is provided for the first heat exchanger 10, in other embodiments, the cooling liquid supply device can be an external device, and the delivery pipe 16 can be provided with the refrigerant from the outside. The conveying pipe 16 can fully utilize the chilled water generated by the third heat exchanger 5, so that the chilled water can be reused, and sufficient refrigerant is provided for the cooling assembly.

And a first controller for causing the cooling assembly to release cold to the discharge pipe 15 according to the degree of superheat of the discharge gas of the compressor 1. Specifically, the first controller is configured to turn on the water pump 11 according to the superheat degree of the exhaust gas of the compressor 1, so that the first heat exchanger 10 releases the cooling capacity to the exhaust pipe 15.

The refrigerating system comprises a second heat exchanger 3, wherein a mixture of high-temperature and high-pressure refrigerant discharged by the compressor 1 and refrigerating oil enters the oil separator 2 for oil-gas separation, and most of the separated refrigerating oil flows back to the compressor 1 through an oil return pipeline; the rest high-temperature refrigerant carries little refrigerating oil and enters the second heat exchanger 3 to exchange heat with air to realize condensation, in the process, one part of the refrigerating oil stagnates in a pipeline, the other part of the refrigerating oil and the condensed refrigerant enter the third heat exchanger 5 after throttling, the refrigerant absorbs the heat of water in the third heat exchanger 5 to evaporate into low-temperature overheated refrigerant, the refrigerant enters the compressor 1 to reciprocate, and the refrigerating oil is accumulated in the second heat exchanger 3 and the third heat exchanger 5 along with the continuous circulation of the refrigerant.

The oil separator 2 is provided with a first oil return line, one end of which, which is remote from the oil separator 2, is connected to an air suction pipe to return the frozen oil in the oil separator 2 to the compressor 1. The refrigerant and the refrigerant oil mixture discharged from the compressor 1 enter the oil separator 2 to intercept oil, and the separated refrigerant oil flows back to the air suction pipe through the first oil return pipeline and flows back to the compressor 1 in the air suction process of the compressor 1. The first oil return pipeline is arranged to enable the frozen oil in the oil separator 2 to flow back to the compressor 1, so that the recovery of the frozen oil in the oil separator 2 is realized.

The first oil return pipeline comprises a first oil return pipe, a first stop valve 6, a filter 7, a first electromagnetic valve 8 refrigerating system and a second stop valve 9 which are sequentially arranged on the first oil return pipe, wherein the first stop valve 6 is close to the oil separator 2, and the second stop valve 9 is close to the compressor 1.

Specifically, when the refrigerant oil in the oil separator 2 needs to flow back, the first stop valve 6, the first electromagnetic valve 8 refrigerating system and the second stop valve 9 are opened, the refrigerant oil flows into the first oil return pipe, and the discharged refrigerant oil flows into the air suction pipe after being filtered by the filter 7. The first stop valve 6 and the second stop valve 9 play a role in cutting off or filling up the refrigerant, are favorable for adjusting the amount of the refrigerant flowing back into the compressor 1, meet the requirements of different refrigerant reflux amounts, and are provided with the filter 7 for filtering the refrigerating oil, so that impurities in the refrigerating oil are filtered, and the impurities are prevented from flowing into the compressor 1.

The second heat exchanger 3 is provided with the second oil return pipeline, is provided with electronic expansion valve 4 between second heat exchanger 3 and the third heat exchanger 5, and the one end that the second oil return pipeline kept away from second heat exchanger 3 is connected with first oil return pipeline to with the freezing oil backward flow in the second heat exchanger 3 in the first oil return pipeline. The refrigerant carries a small amount of frozen oil to enter the second heat exchanger 3 to exchange heat with air to realize condensation, and in the process, the frozen oil accumulated at the bottom of the second heat exchanger 3 is collected into the first oil return pipeline through the second oil return pipeline, so that the frozen oil in the second heat exchanger 3 flows back to the compressor 1. The invention is provided with the second oil return pipeline, so that the frozen oil in the second heat exchanger 3 can be discharged in time, and the reliable oil supply for the compressor 1 is ensured.

The second oil return line includes a second oil return pipe, a second solenoid valve 12 and a first check valve 14 provided on the second oil return pipe, the second solenoid valve 12 being openable and closable according to the discharge superheat of the compressor 1.

The system also comprises a second controller, wherein the second controller is used for returning the frozen oil in the second heat exchanger 3 to the first oil return pipeline according to the exhaust superheat degree of the compressor 1 and the opening degree of the electronic expansion valve 4. Specifically, the second controller is configured to control opening of the second electromagnetic valve 12 to return the frozen oil in the second heat exchanger 3 to the first oil return line.

In the present embodiment, when the second heat exchanger 3 needs to discharge the frozen oil, the second controller opens the second solenoid valve 12 and the first check valve 14, and the frozen oil merges into the first oil return pipe from the second oil return pipe and flows back into the compressor 1 from the first oil return pipe. The first check valve 14 is arranged to prevent the refrigerating oil in the second oil return pipe from flowing back to the second heat exchanger 3, when the superheat degree of the exhaust gas in the compressor 1 is high, oil drop particles in the exhaust pipe 15 are smaller, the separation effect of the oil separator 2 is reduced, the amount of the refrigerating oil flowing into the second heat exchanger 3 is increased, the second electromagnetic valve 12 is arranged to flexibly adjust the on-off state of the second oil return pipe according to the superheat degree of the exhaust gas of the compressor 1, the refrigerating oil is discharged from the second heat exchanger 3 in time, and excessive accumulation of the refrigerating oil in the second heat exchanger 3 is avoided.

The third heat exchanger 5 is provided with a third oil return line, and one end of the third oil return line, which is far away from the third heat exchanger 5, is connected with an air suction pipe so as to return the frozen oil in the third heat exchanger 5 to the compressor 1. The refrigerant absorbs the heat of water in the third heat exchanger 5 and evaporates into a refrigerant with low temperature and overheating, in the process, the third heat exchanger 5 also accumulates the frozen oil, and the third oil return pipeline is arranged to timely collect the frozen oil in the third heat exchanger 5 into the air suction pipe and then flow back into the compressor 1. The invention is provided with the second oil return pipeline and the third oil return pipeline, so that the refrigerating oil in the second heat exchanger 3 and the third heat exchanger 5 can be respectively discharged, the residual refrigerating oil in the heat exchangers in the refrigerant system can be timely recovered, the reliable oil supply of the compressor 1 is ensured, and the reliable operation of the compressor 1 is ensured.

The third oil return pipeline comprises a third oil return pipe, a third electromagnetic valve 13 arranged on the third oil return pipe and a second one-way valve.

A third controller is also included for returning the refrigerant oil in the second solenoid valve 12 of the third heat exchanger 5 to the compressor 1 according to the open operation time of the compressor 1. Specifically, the third controller is configured to control opening of the third electromagnetic valve 13 to return the refrigerant oil in the third heat exchanger 5 to the suction pipe.

In the present embodiment, when a certain amount of frozen oil is accumulated in the third heat exchanger 5, the third solenoid valve 13 and the second check valve are opened, and the frozen oil is converged into the suction pipe from the third oil return pipe and then flows back into the compressor 1. In the present embodiment, the third solenoid valve 13 can be opened or closed according to the opening operation time of the compressor 1, thereby discharging the refrigerant oil from the third heat exchanger 5 in time.

It should be noted that, the control of the water pump 11, the second electromagnetic valve 12, and the third electromagnetic valve 13 may be controlled by a first controller, a second controller, and a third controller, respectively, or may be controlled by the same controller.

The control method of the refrigerating system is characterized in that the refrigerating system can control the oil return process of the second heat exchanger 3 and the third heat exchanger 5 and can also control the working process of the cooling assembly.

The refrigeration oil recovery control of the second heat exchanger 3 is as follows:

when the exhaust superheat degree of the compressor 1 is more than or equal to the upper limit value delta T1 of the exhaust superheat degree in the continuous time T1, and the opening degree of the electronic expansion valve 4 in the continuous time T2 is less than or equal to X, the second electromagnetic valve 12 is opened, the second oil return pipeline is communicated with the first oil return pipeline, and the second oil return pipeline conveys the frozen oil to the first oil return pipeline;

when the exhaust superheat degree of the compressor 1 is less than or equal to the exhaust superheat degree upper limit value delta T1-5 in the continuous time T3, the second oil return pipeline is disconnected from the first oil return pipeline, and the second oil return pipeline stops conveying the frozen oil into the first oil return pipeline. That is, in a certain range of the degree of superheat of the exhaust gas, the oil droplet particles are large, the separation effect of the oil separator 2 is good, and at this time, the amount of the frozen oil accumulated in the second heat exchanger 3 is relatively small, and recovery is not required.

When the superheat degree of the exhaust gas of the compressor 1 exceeds the upper limit value, it is described that the temperature of the refrigerant in the exhaust pipe 15 is high, the oil drop particles in the oil separator 2 are small, the separation effect of the oil separator 2 is poor, the amount of the refrigerant entering the second heat exchanger 3 is large, the opening degree of the electronic expansion valve 4 is small, the amount of the refrigerant flowing into the third heat exchanger 5 is small, the circulation amount of the refrigerant in the refrigeration system is small, and finally, the amount of the refrigerant in the second heat exchanger 3 is large. The degree of accumulation of the refrigerant in the second heat exchanger 3 can be determined according to the degree of superheat of the exhaust gas of the compressor 1 and the opening degree of the electronic expansion valve 4 during a period of time when the compressor 1 is operated, so that the refrigerant is discharged in time, the opening time of the second electromagnetic valve 12 is set according to the continuous time t1, and a small amount of refrigerant is discharged during the process of discharging the refrigerant from the second heat exchanger 3, but the refrigerant supply of the refrigeration system is not affected.

The refrigeration oil recovery control of the third heat exchanger 5 is as follows:

when the starting operation time of the compressor 1 is more than or equal to Deltat 1, the third electromagnetic valve 13 is opened, a third oil return pipeline is communicated with the air suction pipe, and the third oil return pipeline conveys the frozen oil to the air suction pipe;

when the opening time of the third electromagnetic valve 13 is more than or equal to the recovery time Deltat 2 of the refrigerating oil of the third heat exchanger 5, the third electromagnetic valve 13 is closed.

In the present refrigeration system, the recovery of the refrigerant oil is mainly achieved by the oil separator 2, and the amount of refrigerant oil accumulated in the second heat exchanger 3 and the third heat exchanger 5 is sequentially reduced, so that the refrigerant oil recovery time for the third heat exchanger 5 is determined based on the operation time of the compressor 1.

The control of the cooling assembly is as follows:

when the exhaust superheat degree of the compressor 1 is not less than the exhaust superheat degree upper limit value DeltaT 1 in the continuous time T1 and the exhaust temperature of the compressor 1 is not less than the exhaust temperature set value DeltaT 2 in the continuous time T4, the cooling component releases cold energy to the exhaust pipe 15;

when the discharge superheat degree of the compressor 1 is less than or equal to the discharge superheat degree upper limit value deltat 1-10 in the continuous time T5 and the discharge temperature of the compressor 1 is less than or equal to the discharge temperature set value deltat 2-5 in the continuous time T6, the cooling unit stops releasing the cooling capacity to the discharge pipe 15.

The parameters are described as follows:

name of the name	Unit (B)	(Code)	Range	Remarks
					Exhaust temperature	℃	/	0～110℃	Controller detection value
Exhaust pressure	kPa	/	0～3550	Controller detection value
					Upper limit value of exhaust superheat degree	℃	ΔT1	0～50	Setting value, default setting 20
Exhaust temperature set point	℃	ΔT2	0～110℃	Set point, default setting 60
					Electronic expansion valve set point	％	X	10～100％	Setting value, default setting 40
Detection time	s	t1	0～180s	Generally take 60
					Detection time	s	t2	0～180s	Generally take 120
Detection time	s	t3	0～180s	Generally take 60
					Detection time	s	t4	0～180s	Generally take 60
Detection time	s	t5	0～180s	Generally take 60
					Detection time	s	t6	0～180s	Generally take 60

It will be readily appreciated by those skilled in the art that the above advantageous ways can be freely combined and superimposed without conflict.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention. The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. A refrigeration system comprising a compressor (1), an oil separator (2) and an exhaust pipe (15), characterized in that it further comprises a cooling assembly;

one end of the exhaust pipe (15) is connected with the compressor (1), and the other end of the exhaust pipe (15) is connected with the oil separator (2);

the cooling component can acquire cold energy generated by a refrigerant, and when the superheat degree of the exhaust gas of the compressor (1) is larger than a set value, the cooling component releases the cold energy to the exhaust pipe (15) so as to cool the refrigerant in the exhaust pipe (15); when the superheat degree of the exhaust gas of the compressor (1) is recovered to a set value, the cooling unit stops releasing the cooling capacity to the exhaust pipe (15).

2. The refrigeration system of claim 1, wherein the cooling assembly is provided with a coolant supply that delivers a coolant to the cooling assembly.

3. A refrigeration system according to claim 2, characterized in that the cooling assembly comprises a first heat exchanger (10), the first heat exchanger (10) being connected to the cooling liquid supply, which delivers cooling medium to the first heat exchanger (10), the first heat exchanger (10) generating cooling energy and releasing cooling energy to the exhaust pipe (15).

4. A refrigeration system according to claim 3, wherein the cooling assembly further comprises a delivery pipe (16) connecting the first heat exchanger (10) and the cooling liquid supply, the delivery pipe (16) being provided with a water pump (11).

5. A refrigeration system according to claim 4, wherein a fan is arranged on the first heat exchanger (10), and an air outlet of the fan faces the exhaust pipe (15) to blow cold generated by the first heat exchanger (10) to the exhaust pipe (15).

6. A refrigeration system according to any of claims 2 to 5, characterized in that the refrigeration system comprises a third heat exchanger (5), the third heat exchanger (5) being the coolant supply.

7. The refrigeration system of claim 4, further comprising a first controller for causing the cooling assembly to release cold to the discharge pipe (15) in accordance with a discharge superheat of the compressor (1).

8. A refrigeration system according to claim 7, wherein when the cooling assembly comprises the water pump (11), the first controller is configured to turn on the water pump (11) in accordance with the discharge superheat of the compressor (1), causing the first heat exchanger (10) to discharge cold to the discharge pipe (15).

9. A refrigeration system according to claim 6, further comprising a second heat exchanger (3);

the third heat exchanger (3) is connected with the compressor (1) through an air suction pipe, the oil separator (2) is provided with a first oil return pipeline, and one end of the first oil return pipeline, which is far away from the oil separator (2), is connected with the air suction pipe so as to return the frozen oil in the oil separator (2) to the compressor (1);

the first oil return pipeline comprises a first oil return pipe, and a first stop valve (6), a filter (7), a first electromagnetic valve (8) and a second stop valve (9) which are sequentially arranged on the first oil return pipe, wherein the first stop valve (6) is close to the oil separator (2), and the second stop valve (9) is close to the compressor (1);

an electronic expansion valve (4) is arranged between the second heat exchanger (3) and the third heat exchanger (5), the second heat exchanger (3) is provided with a second oil return pipeline, and one end, far away from the second heat exchanger (3), of the second oil return pipeline is connected with the first oil return pipeline so as to return the frozen oil in the second heat exchanger (3) to the first oil return pipeline.

10. The refrigeration system according to claim 9, characterized in that the second return line comprises a second return line, as well as a second solenoid valve (12) and a first one-way valve (14) arranged on the second return line, the second solenoid valve (12) being openable or closable depending on the discharge superheat of the compressor (1).

11. The refrigeration system of claim 10, further comprising a second controller for returning the refrigerant oil in the second heat exchanger (3) to the first oil return line in accordance with a discharge superheat of the compressor (1) and an opening degree of the electronic expansion valve (4).

12. A refrigeration system according to claim 11, wherein when the second return line comprises the second solenoid valve (12), the second controller is adapted to control the opening of the second solenoid valve (12) to return the frozen oil in the second heat exchanger (3) back into the first return line.

13. A refrigeration system according to claim 9, characterized in that the third heat exchanger (5) is provided with a third return line, the end of which remote from the third heat exchanger (5) is connected to the suction line for returning the refrigerant oil in the third heat exchanger (5) to the compressor (1).

14. A refrigeration system according to claim 13, characterized in that the third return line comprises a third return line and a third solenoid valve (13) and a second non-return valve provided on the third return line.

15. The refrigeration system according to claim 14, further comprising a third controller for returning chilled oil in the third heat exchanger (5) to the compressor (1) in accordance with an on-run time of the compressor (1).

16. A refrigeration system according to claim 15, wherein when the third return line comprises the third solenoid valve (13), the third controller is adapted to control the opening of the third solenoid valve (13) to return the frozen oil in the third heat exchanger (5) to the suction pipe.

17. A control method of a refrigeration system according to any one of claims 7 to 9, 11, 12, 15, 16,

when a cooling assembly is provided with a cooling liquid supply device which conveys a refrigerant into the cooling assembly, the cooling assembly releases cold energy to the exhaust pipe (15) according to the exhaust superheat degree of the compressor (1);

when an electronic expansion valve (4) is arranged between the second heat exchanger (3) and the third heat exchanger (5), the third heat exchanger (3) is connected with the compressor (1) through an air suction pipe, the second heat exchanger (3) is provided with a second oil return pipeline, and one end of the second oil return pipeline, which is far away from the second heat exchanger (3), is connected with a first oil return pipeline, the frozen oil in the second heat exchanger (3) is returned to the first oil return pipeline according to the exhaust superheat degree of the compressor (1) and the opening degree of the electronic expansion valve (4);

when the third heat exchanger (5) is provided with a third oil return pipeline, and one end, far away from the third heat exchanger (5), of the third oil return pipeline is connected with the air suction pipe, refrigerating oil in the third heat exchanger (5) is returned to the compressor (1) according to the starting operation time of the compressor (1).

18. A control method of a refrigeration system according to claim 17, characterized in that when the cooling assembly comprises a first heat exchanger (10), the first heat exchanger (10) is caused to release cold to the discharge pipe (15) in accordance with the degree of superheat of the discharge of the compressor (1).

19. A control method of a refrigeration system according to claim 17, characterized by controlling the opening of the second solenoid valve (12) to return the refrigerant oil in the second heat exchanger (3) to the first return line when the second return line comprises the second solenoid valve (12).

20. A control method of a refrigeration system according to claim 17, characterized in that when the third return line comprises a third solenoid valve (13), the opening of the third solenoid valve (13) is controlled to return the refrigerant oil in the third heat exchanger (5) to the suction pipe.