CN214065231U

CN214065231U - System capable of improving unit partial load performance

Info

Publication number: CN214065231U
Application number: CN202023276582.6U
Authority: CN
Inventors: 韩旭; 刘江; 高志刚; 贾云俊; 胡家强; 李曼
Original assignee: Beijing Yongyuan Heat Pump Co ltd
Current assignee: Beijing Yongyuan Heat Pump Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-08-27
Anticipated expiration: 2030-12-29

Abstract

The utility model relates to a system that can improve unit partial load performance relates to air conditioning unit's field, including refrigeration unit and first oil return unit, refrigeration unit includes many compressors, and is many the compressor sets up in parallel, and is many compressor gas outlet department installs the condenser, is provided with oil separator between compressor and condenser, first oil return unit sets up at oil-out and many of oil separator between the compressor, including setting up many oil return lines between oil-out and every compressor of oil separator, every all be provided with control on the oil return line the controlling means of oil return line degree of opening and shutting. This application has can make the even effect of oil return under different loads of many compressors.

Description

System capable of improving unit partial load performance

Technical Field

The application relates to the field of air conditioning units, in particular to a system capable of improving the partial load performance of a unit.

Background

With the development of society, the problem of energy consumption has become an important problem facing the world, so that the trend of improving the energy efficiency of units and reducing the energy consumption is the current development. At present, in practical application, when a unit is selected, the unit is generally selected and matched according to the worst working condition, but in practice, most of the units run under the partial load working condition, so that the improvement of the partial load performance of the unit is an important method for improving the energy efficiency of the unit at present.

In order to fully utilize the area of the heat exchanger, improve the evaporation temperature of the unit and reduce the condensation temperature of the unit when the unit operates at partial load, the form of parallel units can be adopted, and the aim of improving the overall operation efficiency of the unit is finally achieved. The parallel unit is characterized in that a plurality of compressors are connected in parallel, the number of the working units of the compressors is automatically adjusted under the control of a special controller to match the constantly changing cold requirement, and the unit is always kept in the highest efficiency state, so that the aims of saving energy and reducing the operating cost are fulfilled. However, in the design of the parallel unit at present, how to lead a plurality of compressors to return oil uniformly under different loads is a key problem.

SUMMERY OF THE UTILITY MODEL

In order to make the oil return of many compressors under different loads even, this application provides a system that can improve unit part load performance.

The system capable of improving the unit partial load performance provided by the application adopts the following technical scheme:

the utility model provides a can improve system of unit part load performance, includes refrigeration unit and first oil return unit, refrigeration unit includes many compressors, and is many the compressor is parallelly connected to be set up, and is many compressor gas outlet department installs the condenser, is provided with oil separator between compressor and condenser, first oil return unit sets up at oil-out and many of oil separator between the compressor, including setting up many oil return lines between oil separator's oil-out and every compressor, every all be provided with control on the oil return line the controlling means of oil return line degree of opening and shutting.

By adopting the technical scheme, the lubricating oil and the gas can be separated through the oil separator, the separated lubricating oil returns to the compressor through each oil return pipeline, the oil quantity on each oil return pipeline can be controlled by the control device, the consistency of the oil quantity on each oil return pipeline is ensured, the effect that multiple compressors return oil uniformly under different loads is realized, the unit is always kept in the highest efficiency state, and the purposes of saving energy and reducing the operating cost are achieved.

Optionally, an oil filter is installed at an oil discharge port of the oil separator, and the oil filter is located between the oil separator and the first oil return unit.

Through adopting above-mentioned technical scheme, oil filter can filter the lubricating oil that oil separator separates to filter the impurity in the lubricating oil.

Optionally, the control device comprises an oil balance solenoid valve.

Through adopting above-mentioned technical scheme, can control every oil return pipeline's break-make and degree of opening and shutting through the solenoid valve to the lubricating oil of control flow to in every compressor.

Optionally, the control device further includes a first liquid sight glass disposed on each oil return pipeline.

By adopting the technical scheme, the flowing state of the lubricating oil in each oil return pipeline can be observed in real time through the first liquid sight glass.

Optionally, an oil balance pipeline is arranged between two adjacent compressors.

By adopting the technical scheme, when the oil quantities in the two adjacent compressors are inconsistent, the oil in the compressor with more oil quantity can flow into the other compressor along the oil balance pipeline, so that the oil quantity balance in each compressor is ensured.

Optionally, an electromagnetic valve is arranged on the oil balance pipeline.

By adopting the technical scheme, the on-off of the oil balance pipeline can be controlled through the electromagnetic valve, and the oil balance pipeline is more flexible to use.

Optionally, the refrigeration unit further includes an electronic expansion valve and an evaporator connected in series in sequence at the outlet of the condenser, and the outlet end of the evaporator is connected to the air inlets of the plurality of compressors.

By adopting the technical scheme, high-temperature and high-pressure gas discharged by the compressor is converted into high-temperature and high-pressure liquid through the condenser, is converted into low-temperature and low-pressure liquid through throttling and pressure reduction of the electronic expansion valve, then enters the evaporator, absorbs heat in the evaporator and is evaporated to be converted into low-temperature and low-pressure gas, and then enters the compressor to finish a refrigeration cycle.

Optionally, the evaporator and the air inlet ends of the plurality of compressors are further provided with a second oil return unit, and the second oil return unit is used for conveying oil in the evaporator to the plurality of compressors.

By adopting the technical scheme, after the lubricating oil and the high-temperature and high-pressure gas discharged from the compressor enter the oil separator, most of the lubricating oil flows back into the compressor from the oil return pipeline through the separation of the oil separator, a small amount of oil reaches the condenser and flows into the evaporator along with the high-temperature and high-pressure liquid flowing out of the condenser, and because the boiling point of the lubricating oil is far greater than that of the refrigerant, the refrigerant is evaporated by absorbing heat in the evaporator into the low-temperature and low-pressure gas and flows into the compressor, and the lubricating oil accumulated in the evaporator can flow back into the compressor again through the second oil return unit.

Optionally, the second oil return unit includes an air pump and a check valve installed between the evaporator and the inlet end of the air pump to limit that the lubricating oil can only flow from the evaporator to the air pump, the outlet end of the air pump is connected to the inlet ends of the plurality of compressors, and a control port of the air pump is provided with a control loop for controlling the air pump to suck the lubricating oil from the evaporator into the air pump or discharge the lubricating oil in the air pump to the compressors.

Through adopting above-mentioned technical scheme, can control the air pump through control circuit and inhale lubricating oil from the evaporimeter to the air pump in or discharge lubricating oil from the air pump to the compressor in, realize finally discharging the lubricating oil in the evaporimeter to the compressor.

Optionally, the control circuit includes a first air pump solenoid valve disposed between the condenser and the air pump control port, and a second air pump solenoid valve connected between the air pump control port and the inlet ends of the plurality of compressors.

By adopting the technical scheme, the second air pump electromagnetic valve is opened, the gas in the upper chamber inside the air pump is discharged, negative pressure is generated in the lower chamber inside the air pump, the lubricating oil in the evaporator is sucked into the lower chamber inside the air pump, then the second air pump electromagnetic valve is closed, the first air pump electromagnetic valve is opened, the gas in the condenser flows into the upper chamber inside the air pump through the first air pump electromagnetic valve, the gas pressure in the lower chamber inside the air pump is increased at the moment, and the check valve is installed between the air pump inlet end and the evaporator, so the lubricating oil in the lower chamber inside the air pump is directly discharged from the air pump outlet end and flows back into the compressor, and the control of the air pump is realized.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the oil return pipelines and the control device are arranged, so that the lubricating oil separated by the oil separator can flow back to each compressor through each oil return pipeline, the flow of the lubricating oil flowing to each oil return pipeline can be controlled through the control device, the flow of the lubricating oil flowing to each oil return pipeline is consistent, and a plurality of compressors can return oil uniformly under different loads;

2. the arrangement of the oil balance pipelines ensures that when the oil quantities of the lubricating oil in two adjacent compressors are different, the oil in the compressor with more oil quantity can flow into the compressor with less oil quantity along the balance pipelines, and the oil quantity in each compressor is ensured to be balanced;

3. the second oil return path is arranged to pump the lubricating oil in the evaporator into the compressor, so that the lubricating oil is prevented from accumulating in the evaporator and affecting the normal heat exchange work of the evaporator.

Drawings

Fig. 1 is a schematic view of the overall structure of the present application.

Description of reference numerals: 1. a refrigeration unit; 11. a compressor; 111. a suction manifold; 112. an exhaust manifold; 12. an oil separator; 13. a condenser; 14. an electronic expansion valve; 15. an evaporator; 16. a main path filter; 2. a first oil return unit; 21. an oil return line; 22. a control device; 221. an oil balance solenoid valve; 222. a first liquid sight glass; 23. an oil filter; 3. an oil balance pipeline; 31. an electromagnetic valve; 4. a second oil return unit; 41. a diaphragm pump; 411. a control port; 412. an inlet; 413. an outlet; 42. a one-way valve; 43. a control loop; 431. a first air pump solenoid valve; 432. a second air pump solenoid valve; 44. a filter; 5. and a second liquid sight lens.

Detailed Description

The present application is described in further detail below with reference to fig. 1.

The embodiment of the application discloses a system capable of improving the partial load performance of a unit. Referring to fig. 1, a system that can improve unit part load performance includes a refrigeration unit 1 and a first oil recovery unit 2.

Referring to fig. 1, a refrigeration unit 1 includes a plurality of compressors 11, the plurality of compressors 11 are arranged in parallel, an intake manifold 111 is formed at an intake port where the plurality of compressors 11 are connected in parallel, and an exhaust manifold 112 is formed at an exhaust port where the plurality of compressors 11 are connected in parallel, and the two compressors 11 are described as an example in this application. An oil separator 12 is installed at one end of a discharge header 112 formed by connecting two compressors 11 in parallel, which is far away from the compressor 11, the discharge header 112 is connected to the inlet of the oil separator 12, the high-temperature and high-pressure refrigerant gas and oil discharged from the compressor 11 directly reach the oil separator 12, the lubricating oil is discharged from the oil outlet of the oil separator 12 through the separation of the oil separator 12, and the refrigerant gas is discharged from the air outlet of the oil separator 12.

A condenser 13, an electronic expansion valve 14 and an evaporator 15 are connected in series in sequence at the air outlet of the oil separator 12, and the outlet of the evaporator 15 is connected with an air suction header pipe 111 formed by the two compressors 11. The refrigerant gas discharged from the gas outlet of the oil separator 12 directly reaches the condenser 13, is condensed into high-temperature and high-pressure refrigerant liquid in the condenser 13, then flows into the electronic expansion valve 14 along the outlet of the condenser 13, is reduced in pressure by throttling of the electronic expansion valve 14 to become low-temperature and low-pressure refrigerant liquid, then enters the evaporator 15, absorbs heat in the evaporator 15 and is evaporated to become low-temperature and low-pressure gas, and finally flows to the suction manifold 111 from the outlet of the evaporator 15 and flows back to the plurality of compressors 11 along the suction manifold 111, thereby completing a refrigeration cycle.

A main path filter 16 is disposed between the outlet of the condenser 13 and the electronic expansion valve 14, and can filter the refrigerant liquid flowing out of the condenser 13, so as to filter out impurities in the refrigerant liquid and prevent the impurities in the refrigerant liquid from damaging the refrigeration equipment.

Referring to fig. 1, the first oil return unit 2 is disposed between an oil outlet of the oil separator 12 and the compressors 11, and includes a plurality of oil return pipelines 21 disposed between the oil outlet of the oil separator 12 and each compressor 11, and a control device 22 for controlling on/off of the oil return pipeline 21 is disposed on each oil return pipeline 21. Specifically, the control device 22 includes an oil balance solenoid valve 221 disposed between the oil outlet of the oil separator 12 and each compressor 11, and the amount of oil flowing into each oil return line 21 can be controlled by the oil balance solenoid valve 221, so as to control the amount of oil flowing from the oil separator 12 to each compressor 11, so that the oil returns of the plurality of compressors 11 under different loads are uniform.

In actual use, the oil balance solenoid valve 221 may be set to be normally open according to the operating state of the compressor 11, or may be set to be intermittently turned on or off. When the oil balance solenoid valve 221 is set to be turned on and off intermittently, an electro-optical oil level switch (not shown in the figure) is further provided in each compressor 11, the electro-optical oil level switch is used for detecting the amount of oil in each compressor 11 in real time, the electro-optical oil level switch is electrically connected to the oil balance solenoid valve 221 connected thereto through a PLC controller, and the oil balance solenoid valve 221 is configured to be turned on when the electro-optical oil level switch detects that the amount of oil in the compressor 11 is lower than a set value. In a normal state, the oil balance solenoid valve 221 is set to be intermittently started and stopped, and when the photoelectric oil level switch detects that the oil amount in the compressor 11 is lower than a set value, the oil balance solenoid valve 221 is opened, so that lubricating oil is timely supplemented to the compressor 11, and normal operation of the compressor 11 is guaranteed.

Meanwhile, in order to facilitate the observation of the flowing state of the lubricating oil in each oil return pipeline 21 by the worker, a first liquid observation mirror 222 is installed on each oil return pipeline 21, and the worker can monitor the lubricating oil in each oil return pipeline 21 in real time through the first liquid observation mirror 222.

In order to avoid the blockage of each oil return pipeline 21 by impurities contained in the lubricating oil, an oil filter 23 is further arranged at an oil outlet of the oil separator 12, the oil filter 23 is installed between the oil outlet of the oil separator 12 and the first oil return unit 2, and the lubricating oil flowing from the oil outlet of the oil separator 12 to the first oil return unit 2 can be filtered, so that the impurities in the lubricating oil can be filtered.

Referring to fig. 1, an oil balance pipeline 3 is further disposed between the two compressors 11, the oil balance pipeline 3 may balance oil amounts in the two compressors 11, and when the oil amounts in the two compressors 11 are inconsistent, oil in the compressor 11 with a larger oil amount may flow into the other compressor 11 along the oil balance pipeline 3, so as to ensure that the oil amounts in the two compressors 11 are balanced. Meanwhile, the electromagnetic valve 31 is further arranged on the oil balance pipeline 3, the electromagnetic valve 31 can control the on-off of the oil balance pipeline 3, when only one compressor 11 works, the electromagnetic valve 31 can be closed, so that the oil balance pipeline 3 is disconnected, and sufficient lubricating oil is ensured in the working compressor 11.

When the oil separator 12 separates the refrigerant gas and the lubricating oil with high temperature and high pressure discharged from the compressor 11, 99.9% of the lubricating oil can be separated by the oil separator 12, but a small amount of oil still reaches the condenser 13 along with the refrigerant gas and reaches the evaporator 15 through the electronic expansion valve 14 along with the condensed refrigerant liquid with high temperature and high pressure, and since the boiling point of the refrigerant is much higher than that of the lubricating oil, after the lubricating oil reaches the evaporator 15 along with the refrigerant, the refrigerant can absorb heat to be evaporated and converted into gas with low temperature and low pressure to flow back to the compressor 11, and the lubricating oil will remain in the evaporator 15, so that a layer of oil film can be formed on the inner wall of the evaporator 15 to affect the normal heat exchange efficiency of the evaporator 15.

Therefore, a second oil return unit 4 that draws the lubricating oil in the evaporator 15 into the compressor 11 is provided between the evaporator 15 and the compressor 11.

Referring to fig. 1, the second oil return unit 4 includes an air pump disposed between the evaporator 15 and the suction manifold 111, and a specific air pump may be a diaphragm pump 41, the inside of the diaphragm pump 41 is divided into two chambers, which are referred to as an upper chamber and a lower chamber, respectively, a control port 411 connected to the upper chamber is disposed on one side of the diaphragm pump 41, an inlet 412 connected to the lower chamber is disposed on one end of the diaphragm pump 41, an outlet 413 connected to the lower chamber is disposed on the other side of the diaphragm pump 41, and a check valve 42 disposed between the inlet 412 of the diaphragm pump 41 and the evaporator 15 for limiting the flow of the lubricant oil from the evaporator 15 to the lower chamber of the diaphragm pump 41 only, so that the lubricant oil in the evaporator 15 can flow to the lower chamber of the diaphragm pump 41 through the check valve 42 and cannot flow to the evaporator 15 from the lower chamber of the diaphragm pump 41. The outlet 413 end of the diaphragm pump 41 is communicated to the suction manifold 111, and the lubricating oil flowing from the evaporator 15 to the lower cavity of the diaphragm pump 41 can directly flow from the outlet 413 end of the diaphragm pump 41 to the suction manifold 111 and finally reach the compressor 11. Meanwhile, a control circuit 43 for controlling the pressure change inside the upper cavity of the diaphragm pump 41 is arranged at the control port 411 of the diaphragm pump 41, and the pressure in the upper cavity of the diaphragm pump 41 can be changed through the control circuit 43, so as to change the pressure in the lower cavity of the diaphragm pump 41, and thus the lubricating oil in the evaporator 15 can be sucked into the lower cavity of the diaphragm pump 41 or the lubricating oil in the lower cavity of the diaphragm pump 41 can be discharged from the outlet 413 end of the diaphragm pump 41.

Referring to fig. 1, the control circuit 43 includes a first air pump solenoid valve 431 connected between the condenser 13 and the control port 411 of the diaphragm pump 41, and a second air pump solenoid valve 432 connected between the outlet 413 side of the diaphragm pump 41 and the suction manifold 111. In a normal state, the first air pump solenoid valve 431 and the second air pump solenoid valve 432 are both in a closed state, and when the second air pump solenoid valve 432 is opened, the air in the upper cavity of the diaphragm pump 41 will be discharged from the control port 411 of the diaphragm pump 41, so that the pressure in the lower cavity of the diaphragm pump 41 is reduced, and the lubricating oil in the evaporator 15 will flow to the lower cavity of the diaphragm pump 41 along the check valve 42. Then, the second air pump solenoid valve 432 is closed, the first air pump solenoid valve 431 is opened, the air in the condenser 13 will flow into the upper cavity of the diaphragm pump 41 through the control port 411, the pressure in the lower cavity of the diaphragm pump 41 is increased, and the lubricating oil in the lower cavity of the diaphragm pump 41 will flow into the suction manifold 111 from the outlet 413 end of the diaphragm pump 41 and reach the compressor 11 along the suction manifold 111 because the one-way valve 42 for preventing the lubricating oil from flowing from the diaphragm pump 41 to the evaporator 15 is installed at the inlet 412 end of the diaphragm pump 41. It is understood that since the amount of lubricant in the evaporator 15 is small and does not affect the uniformity of the oil return of each compressor 11, the oil in the diaphragm pump 41 can be directly discharged to the suction manifold 111. If the oil in the evaporator 15 is large, in order to ensure uniform oil return in each compressor 11, the oil in the diaphragm pump 41 may be led to the suction port of each compressor 11, and the oil amount flowing to each compressor 11 may be controlled by the solenoid valve.

Wherein, a filter 44 is further disposed between the evaporator 15 and the check valve 42, and the filter 44 can filter the lubricating oil flowing from the evaporator 15 to the check valve 42, so as to filter out impurities in the lubricating oil.

Meanwhile, in order to facilitate the staff to monitor the state of the lubricating oil flowing from the second oil return unit 4 to the air suction main pipe 111 in real time, a second liquid sight glass 5 is further arranged between the second oil return unit 4 and the air suction main pipe 111.

The implementation principle of the system capable of improving the unit partial load performance in the embodiment of the application is as follows: this application is through the combination of first oil return unit 2 and oil balance pipeline 3, and the oil return volume of convection to every compressor 11 that can be better is controlled for it is even that many compressors 11 also can the oil return under different loads, makes the unit remain at the highest efficiency state all the time, thereby reaches energy-conservation, reduces the purpose of working costs. Through the second oil return unit 4, the oil in the evaporator 15 can be discharged to the compressor 11, that is, the lubricating oil can be prevented from accumulating in the evaporator 15 to influence the heat exchange efficiency of the evaporator 15, and the oil quantity of the compressor 11 can be increased to reduce the probability of oil shortage of the compressor 11.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A system capable of improving unit part load performance is characterized in that: including refrigeration unit (1) and first oil return unit (2), refrigeration unit (1) is including many compressors (11), many compressor (11) parallel arrangement is many compressor (11) gas outlet department installs condenser (13), is provided with oil separator (12) between compressor (11) and condenser (13), first oil return unit (2) set up at the oil-out and many of oil separator (12) between compressor (11), including setting up many oil return line (21) between the oil-out of oil separator (12) and every compressor (11), every all be provided with control on oil return line (21) the controlling means (22) of the degree that opens and shuts.

2. The system for improving the unit part load performance according to claim 1, wherein: an oil filter (23) is installed at an oil discharge port of the oil separator (12), and the oil filter (23) is located between the oil separator (12) and the first oil return unit (2).

3. The system for improving the unit part load performance according to claim 1, wherein: the control device (22) comprises an oil balance solenoid valve (221).

4. A system for increasing unit part load performance according to claim 3, wherein: the control device (22) further comprises a first liquid sight glass (222) arranged on each oil return pipeline (21).

5. The system for improving the unit part load performance according to claim 1, wherein: an oil balance pipeline (3) is arranged between every two adjacent compressors (11).

6. The system for improving the unit part load performance according to claim 5, wherein: and the oil balance pipeline (3) is provided with an electromagnetic valve (31).

7. The system for improving the unit part load performance according to claim 1, wherein: the refrigeration unit (1) further comprises an electronic expansion valve (14) and an evaporator (15) which are sequentially connected in series at the outlet of the condenser (13), and the outlet end of the evaporator (15) is connected to the air inlets of the compressors (11).

8. The system for improving the unit part load performance according to claim 7, wherein: and a second oil return unit (4) is arranged between the evaporator (15) and the air inlets of the plurality of compressors (11), and the second oil return unit (4) is used for conveying the oil in the evaporator (15) to the plurality of compressors (11).

9. The system for improving the unit part load performance according to claim 8, wherein: the second oil return unit (4) comprises an air pump and a one-way valve (42) which is arranged between the evaporator (15) and an air pump inlet (412) end and limits lubricating oil to flow from the evaporator (15) to the air pump only, the air pump outlet (413) end is connected to inlet ends of a plurality of compressors (11), and a control port (411) of the air pump is provided with a control loop (43) for controlling the air pump to suck the lubricating oil from the evaporator (15) into the air pump or discharge the lubricating oil in the air pump to the compressors (11).

10. The system for improving the unit part load performance according to claim 9, wherein: the control circuit (43) comprises a first air pump electromagnetic valve (431) arranged between the condenser (13) and the air pump control port (411) and a second air pump electromagnetic valve (432) connected between the air pump control port (411) and the inlet (412) ends of the plurality of compressors (11).