Multi-system parallel high-temperature water source heat pump unit

Abstract

The utility model relates to the technical field of high-temperature water sources, in particular to a multi-system parallel high-temperature water source heat pump unit. The multi-system parallel high-temperature water source heat pump unit comprises a refrigerant circulating system and a lubricating oil circulating system. The refrigerant circulating system comprises at least two compressors, and an oil separator, a condenser, an electronic expansion valve, a flooded evaporator and a return air collecting pipe which are connected in sequence. The lubricating oil circulating system comprises an oil storage device, an oil inlet of the oil storage device is communicated with an oil outlet of the oil separator, and an oil outlet of the oil storage device is respectively communicated with oil supply ports of at least two compressors. The lubricating oil circulating system further comprises a flooded evaporator oil return device. The unit realizes parallel operation of multiple scroll compressors, and ensures that lubricating oil is continuously and normally supplied to the compressors. In addition, through the oil way design, lubricating oil of all the compressors can be kept at the reasonable liquid level, and compressor damage caused by poor lubrication is prevented. And compared with multi-system parallel connection, the unit is low in cost and better in economic benefit.

Description

Technical Field

[0001] The utility model relates to the technical field of high-temperature water sources, and particularly relates to a multi-system parallel high-temperature water source heat pump unit. Background Art

[0002] In the production process of using scroll compressors in the field of high-temperature water source heat pumps, due to the small heating capacity of scroll compressors, generally multiple independent circulation systems are assembled into a finished unit, and the electronic control system controls the independent circulation systems respectively. Generally, each compressor is equipped with a set of independent thermal systems, resulting in many components, a large volume of the equipment, and generally the electronic control system also matches the control circuits of multiple systems, resulting in high production costs and it is difficult to form multi-system assembly.

[0003] Therefore, a new technology is urgently needed to solve the above problems. Summary of the Utility Model

[0004] To make up for the deficiencies of the prior art, the present application provides a multi-system parallel high-temperature water source heat pump unit. This unit realizes the parallel operation of multiple scroll compressors and ensures the continuous and normal supply of lubricating oil to the compressors. In addition, through the oil circuit design, this unit can keep the lubricating oil of each compressor at a reasonable level, preventing compressor damage caused by poor lubrication. And compared with multi-system parallel connection, this unit has lower costs and better economic benefits.

[0005] To achieve the above object, the utility model provides a multi-system parallel high-temperature water source heat pump unit.

[0006] The multi-system parallel high-temperature water source heat pump unit includes a refrigerant circulation system and a lubricating oil circulation system.

[0007] The refrigerant circulation system includes at least 2 compressors, an oil separator, a condenser, an electronic expansion valve, a flooded evaporator, and a suction header connected in sequence. The outlet of at least 2 compressors is connected to the inlet of the oil separator, and the suction port of at least 2 compressors is connected to the suction header.

[0008] The lubricating oil circulation system includes an oil storage tank. The oil inlet of the oil storage tank is connected to the oil outlet of the oil separator, and the oil outlet of the oil storage tank is respectively connected to the supply ports of at least 2 compressors.

[0009] The lubricating oil circulation system further includes a flooded evaporator oil return device. One end of the flooded evaporator oil return device is connected to the oil outlet of the flooded evaporator, and the other end is connected to the suction header.

[0010] Preferably, the oil return device of the flooded evaporator is an ejector, which includes a high-pressure fluid inlet, a low-pressure fluid inlet, and a mixed fluid outlet. The high-pressure fluid inlet is connected to the oil storage tank, the low-pressure fluid inlet is connected to the oil outlet of the flooded evaporator, and the mixed fluid outlet is connected to the suction header.

[0011] Preferably, an ejector solenoid valve is provided on the pipeline where the high-pressure fluid inlet is connected to the oil storage tank.

[0012] Preferably, oil return bends corresponding to the number of compressors are provided on the suction header, and the suction ports of at least two compressors are all connected to the corresponding oil return bends provided on the suction header.

[0013] Preferably, the compressor is a scroll compressor.

[0014] Preferably, the refrigerant circulation system includes 3 to 7 compressors.

[0015] Preferably, an electronic oil level controller and an oil supply solenoid valve are respectively provided on the pipelines where the oil outlet of the oil storage tank is connected to the supply ports of at least two compressors.

[0016] Preferably, the upper end of the oil storage tank is connected to the suction header, and an oil pressure difference check valve is provided on the pipeline where the oil storage tank is connected to the suction header.

[0017] Preferably, the multi-system parallel high-temperature water source heat pump unit further includes a lubricating oil heating system, which includes an oil storage tank electric heating device and an oil storage tank temperature measuring device, and both the oil storage tank electric heating device and the oil storage tank temperature measuring device are arranged inside the oil storage tank.

[0018] Preferably, the lubricating oil heating system further includes a compressor electric heating device, which is arranged at the bottom of the compressor.

[0019] Compared with the prior art, the beneficial effects of the present application are as follows:

[0020] First of all, this unit uses multiple compressors in parallel to change the internal components of the system from multiple components into one component, reducing the number of components. At the same time, the heat exchanger also changes from multiple systems to a single system, greatly reducing the processing cost.

[0021] In addition, this unit can accurately control oil replenishment according to the oil level of the compressor. And according to the characteristics of the high-temperature heat pump itself, it adds the function of preheating the oil, preventing the adverse effects of too long shutdown time of the unit, increased viscosity of the oil itself, and affecting the system circulation. At the same time, it can reduce refrigerant migration and prevent liquid carry-over during compressor startup. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By describing the embodiments of the present application in combination with the accompanying drawings, the present application can be better understood. In the drawings:

[0023] Figure 1 This is a schematic structural diagram of a multi-system parallel high-temperature water source heat pump unit of the present application.

[0024] Explanation of the reference numerals in the attached drawings:

[0025] 1. Compressor; 2. Oil separator; 3. Condenser; 4. Electronic expansion valve; 5. Flooded evaporator; 6. Suction header; 7. Oil storage tank; 8. Electronic oil level controller; 9. Oil supply solenoid valve; 10. Ejector; 11. Ejector solenoid valve; 12. Return bend; 13. Oil differential pressure check valve; 14. Suction pipe; 15. Electric heating device for the oil storage tank; 16. Temperature measuring device for the oil storage tank; 17. Electric heating device for the compressor. Specific embodiments

[0026] Unless otherwise defined, the technical terms or scientific terms used in this specification and the claims shall have the ordinary meanings understood by those of ordinary skill in the technical field to which the present utility model belongs.

[0027] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0028] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "plurality" is two or more.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood through specific situations.

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0031] This embodiment relates to a multi-system parallel high-temperature water source heat pump unit as Figure 1 shown. In Figure 1 , LP represents the low-pressure, and HP represents the high-pressure.

[0032] The multi-system parallel high-temperature water source heat pump unit includes a refrigerant circulation system and a lubricating oil circulation system.

[0033] The refrigerant circulation system includes at least 2 compressors 1 and an oil separator 2, a condenser 3, an electronic expansion valve 4, a flooded evaporator 5, and a suction header 6 connected in sequence. The outlet ports of at least 2 compressors 1 are all connected to the inlet of the oil separator 2, and the suction ports of at least 2 compressors 1 are all connected to the suction header 6. In some embodiments, the compressor 1 can be a scroll compressor. The refrigerant circulation system can include 3 to 7 compressors. In the embodiment shown in the figure, the multi-system parallel high-temperature water source heat pump unit includes 4 scroll compressors.

[0034] When the refrigerant circulation system operates, the low-temperature and low-pressure superheated refrigerant vapor forms a high-temperature and high-pressure gaseous refrigerant through the scroll compressor 1 and enters the oil separator 2 and the condenser 3 in sequence. In the condenser 3, the high-temperature and high-pressure gaseous refrigerant condenses into a high-temperature and high-pressure liquid refrigerant, and after throttling and depressurizing through the electronic expansion valve 4, it becomes a low-temperature and low-pressure liquid refrigerant, and then enters the flooded evaporator 5 to evaporate and absorb heat to become a low-temperature and low-pressure superheated vapor, and enters the suction header 6. Through the suction header 6, the low-temperature and low-pressure superheated vapor uniformly enters the suction ports of each compressor 1 to complete a thermal cycle process.

[0035] The lubricating oil circulation system includes an oil storage tank 7. The inlet of the oil storage tank 7 is connected to the outlet of the oil separator 2, and the outlet of the oil storage tank 7 is respectively connected to the oil supply ports of at least 2 compressors 1. In some embodiments, an electronic oil level controller 8 and an oil supply solenoid valve 9 are respectively provided on the pipelines connecting the outlet of the oil storage tank 7 to the oil supply ports of at least 2 compressors 1.

[0036] The lubricating oil circulation system further includes a flooded evaporator oil return device. One end of the flooded evaporator oil return device is connected to the outlet of the flooded evaporator 5, and the other end is connected to the suction header 6.

[0037] In some embodiments, the oil return device of the flooded evaporator is an ejector 10. The ejector 10 includes a high-pressure fluid inlet, a low-pressure fluid inlet, and a mixed fluid outlet. The high-pressure fluid inlet is communicated with the oil storage tank 7, the low-pressure fluid inlet is communicated with the oil outlet of the flooded evaporator 5, and the mixed fluid outlet is communicated with the suction header 6. An ejector solenoid valve 11 may be provided on the pipeline where the high-pressure fluid inlet is communicated with the oil storage tank 7.

[0038] In some embodiments, oil return bends 12 corresponding to the number of compressors 1 are provided on the suction header 6, and the suction ports of at least two compressors 1 are communicated with the corresponding oil return bends 12 provided on the suction header 6.

[0039] In some embodiments, the upper end of the oil storage tank 7 is communicated with the suction header 6, and an oil pressure difference check valve 13 is provided on the pipeline where the oil storage tank 7 is communicated with the suction header 6.

[0040] Next, the working principle of the lubricating oil circulation system will be briefly described.

[0041] The low-temperature and low-pressure superheated refrigerant vapor forms a high-temperature and high-pressure gaseous refrigerant through the scroll compressor 1 and enters the oil separator 2, and the lubricating oil entrained in the refrigerant is separated through the oil separator 2. The separated lubricating oil then enters the oil storage tank 7. In order to ensure sufficient flow rate of the oil return, there must be a certain controllable pressure difference between the oil storage tank 7 and the suction header 6. Therefore, an oil pressure difference check valve 13 may be provided between the oil storage tank 7 and the suction header 6. When the electronic oil level controller 8 detects a decrease in the oil level of the compressor 1, the float type oil level switch is turned on, and the oil supply solenoid valve 9 is energized to send the lubricating oil into the compressor 1. When the oil level of the compressor 1 rises, the float type oil level switch is turned off, and the oil supply solenoid valve 9 is turned off to stop the oil supply.

[0042] Since the multi-system parallel high-temperature water source heat pump unit uses a flooded evaporator 5, the oil separator 2 cannot completely separate the lubricating oil in the refrigerant, and the lubricating oil carried by the refrigerant will be deposited in the flooded evaporator 5 when the refrigerant evaporates in the evaporator. If this situation is maintained for a long time, a large amount of lubricating oil will accumulate in the flooded evaporator 5, thereby reducing the effective heat transfer area of the flooded evaporator 5 and reducing the lubricating oil amount of the scroll compressor 1. As Figure 1In the illustrated embodiment, an ejector 10 is employed as the oil return device for the flooded evaporator. The ejector 10 converts the pressure energy of the high-pressure lubricating oil in the oil storage tank 7 into kinetic energy, increasing the velocity of the high-pressure lubricating oil after it passes through the nozzle and creating a negative pressure region around the lubricating oil, thereby introducing the low-pressure lubricating oil in the flooded evaporator 5. After the two streams of lubricating oil are mixed, they enter the diffuser of the ejector 10 to convert their kinetic energy into pressure energy, completing the entire ejection action. Subsequently, the lubricating oil follows the refrigerant in the suction pipe 14 into the suction header 6. The suction header 6 can ensure that the refrigerant circulation amounts returning to each compressor 1 are basically the same. Meanwhile, in order to prevent lubricating oil from accumulating at the bottom of the suction header 6, an oil return bend 12 can be provided at the bottom of the suction header 6 for each compressor 1 to ensure that there is oil returning to the bottom of the suction header 6 and normal operation without oil. In a specific embodiment, the oil return bend 12 is of a U-shaped structure. One top side of the U-shaped structure is connected to the bottom of the suction header 6, and the other side of the U-shaped structure is connected to the pipe for transporting the refrigerant between the suction header 6 and the compressor 1 through a horizontal pipe. The horizontal pipe of the oil return bend 12 is arranged below the suction header 6 to ensure that the lubricating oil accumulated at the bottom of the suction header 6 can smoothly flow into the compressor 1.

[0043] In some embodiments, the multi-system parallel high-temperature water source heat pump unit further includes a lubricating oil heating system. The lubricating oil heating system includes an oil storage tank electric heating device 15 and an oil storage tank temperature measuring device 16, both of which are arranged inside the oil storage tank 7. In some embodiments, the lubricating oil heating system further includes a compressor electric heating device 17, which is arranged at the bottom of the compressor 1.

[0044] The multi-system parallel high-temperature water source heat pump unit uses a special high-temperature refrigerant to match a special lubricating oil. Such lubricating oil has a high viscosity and poor fluidity at normal temperature. Therefore, it is necessary to preheat the lubricating oil and make it reach the corresponding lubricating oil temperature before the unit can be started up and operated normally. As Figure 1 shown in the illustrated embodiment, an oil storage tank electric heating device 15 and an oil storage tank temperature measuring device 16 are arranged inside the oil storage tank 7 to jointly control the lubricating oil temperature before the unit is started. When the oil storage tank temperature measuring device 16 detects that the lubricating oil temperature in the oil storage tank 7 has not reached the starting lubricating oil temperature, the unit cannot start. Meanwhile, when the unit is in the standby state, the oil storage tank electric heating device 15 and the compressor electric heating device 17 operate to ensure the lubricating oil temperature and prevent liquid carry-over of the compressor 1 during unit startup caused by refrigerant migration.

[0045] In the above specific embodiments, the purpose, technical solutions, and beneficial effects of the present utility model have been further described in detail. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A multi-system parallel high-temperature water source heat pump unit, characterized in that The multi-system parallel high-temperature water source heat pump unit includes a refrigerant circulation system and a lubricating oil circulation system; among them, the refrigerant circulation system includes at least two compressors, an oil separator, a condenser, an electronic expansion valve, a flooded evaporator, and a suction header connected in sequence. The outlet of each of the at least two compressors is connected to the inlet of the oil separator, and the suction port of each of the at least two compressors is connected to the suction header; the lubricating oil circulation system includes an oil storage tank. The oil inlet of the oil storage tank is connected to the oil outlet of the oil separator, and the oil outlet of the oil storage tank is respectively connected to the oil supply ports of the at least two compressors; the lubricating oil circulation system further includes a flooded evaporator oil return device. One end of the flooded evaporator oil return device is connected to the oil outlet of the flooded evaporator, and the other end of the flooded evaporator oil return device is connected to the suction header.

2. The multi-system parallel high-temperature water source heat pump unit according to claim 1, characterized in that The flooded evaporator oil return device is an ejector, which includes a high-pressure fluid inlet, a low-pressure fluid inlet, and a mixed fluid outlet. The high-pressure fluid inlet is connected to the oil storage tank, the low-pressure fluid inlet is connected to the oil outlet of the flooded evaporator, and the mixed fluid outlet is connected to the suction header.

3. The multi-system parallel high-temperature water source heat pump unit according to claim 2, wherein, An ejector solenoid valve is provided on the pipeline where the high-pressure fluid inlet is connected to the oil storage tank.

4. The multi-system parallel high-temperature water source heat pump unit according to claim 1, wherein Oil return bends corresponding to the number of compressors are provided on the suction header, and the suction ports of the at least two compressors are respectively connected to the corresponding oil return bends provided on the suction header.

5. The multi-system parallel high-temperature water source heat pump unit according to claim 1, characterized in that, The compressor is a scroll compressor.

6. The multi-system parallel high-temperature water source heat pump unit according to claim 1, characterized in that The refrigerant circulation system includes 3 to 7 compressors.

7. The multi-system parallel high-temperature water source heat pump unit according to claim 1, characterized in that, An electronic oil level controller and an oil supply solenoid valve are respectively provided on the pipelines where the oil outlet of the oil storage tank is connected to the oil supply ports of the at least two compressors.

8. The multi-system parallel high-temperature water source heat pump unit according to claim 1, characterized in that The upper end of the oil storage tank is connected to the suction header, and an oil pressure difference check valve is provided on the pipeline where the oil storage tank is connected to the suction header.

9. The multi-system parallel high-temperature water source heat pump unit according to claim 1, wherein, The multi-system parallel high-temperature water source heat pump unit further includes a lubricating oil heating system, which includes an oil storage tank electric heating device and an oil storage tank temperature measuring device, and both the oil storage tank electric heating device and the oil storage tank temperature measuring device are arranged inside the oil storage tank.

10. The multi-system parallel high-temperature water source heat pump unit according to claim 9, wherein The lubricating oil heating system further includes a compressor electric heating device, and the compressor electric heating device is arranged at the bottom oil sump position of the compressor.

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