WO2022088813A1

WO2022088813A1 - Compressor, dual-compressor series heat pump unit and control method therefor

Info

Publication number: WO2022088813A1
Application number: PCT/CN2021/109663
Authority: WO
Inventors: 张治平; 华超; 周堂; 曹理恒
Original assignee: 珠海格力节能环保制冷技术研究中心有限公司
Priority date: 2020-10-26
Filing date: 2021-07-30
Publication date: 2022-05-05
Also published as: CN112197453A; CN112197453B

Abstract

Provided by the present disclosure are a compressor, a dual-compressor series heat pump unit, and a control method therefor, wherein the compressor comprises a first compression part and a first driving part. The first driving part is arranged in a first gearbox housing. The first compression part is arranged in a first air intake housing. The first air intake housing is connected to the first gearbox housing to form an integral body. The first air intake housing is configured with a first bypass port. A first lubricating oil inlet and a first balance port are configured on the first gearbox housing. According to the present disclosure, the first bypass port, the first balance port, and the first lubricating oil inlet provided on a compressor housing may facilitate the connection of the unit in different operation modes by means of setting corresponding communication pipelines when applied to a dual-compressor series heat pump unit. Thus, in both a single-compressor operation mode and the dual-compressor operation mode, lubricating oil in the compressors may smoothly return to an external oil tank.

Description

Compressor, dual compressor series heat pump unit and control method thereof

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on the CN application number of 202011155298.5 and the application date of October 26, 2020 as basis, and claim its priority, the disclosure of this CN application is hereby incorporated into this application in its entirety.

technical field

The present disclosure belongs to the technical field of air conditioning, and in particular relates to a compressor, a dual-compressor series heat pump unit and a control method thereof.

Background technique

The schematic diagram of the structure of the dual-compressor series heat pump unit (also called the dual-compressor series high-temperature heat pump unit) is shown in Figure 1. It mainly consists of an evaporator 300, a condenser 400, a low-pressure compressor 100, a high-pressure compressor 200, an electric butterfly valve 500, The return valve 600 is composed of the throttling electronic expansion valve 800 and the corresponding pipeline structure; the suction port 100a of the low pressure compressor is connected to the evaporator 300, the exhaust port 100b of the low pressure compressor is connected to the condenser 400 all the way, and the exhaust pipe is close to the condenser. An electric butterfly valve 500 and a check valve 600 are installed on the side of the compressor, and the low-pressure compressor discharge port 100b is connected to the high-pressure compressor suction port 200a; the high-pressure compressor suction port 200a is connected to the low-pressure compressor discharge pipe, and the high-pressure compressor discharge pipe The air port 200b is connected to the condenser 400, and a check valve 700 is installed on the side of the exhaust pipe close to the condenser;

When operating under normal and non-severe conditions, the low-pressure compressor 100 is turned on only, the electric butterfly valve 500 is opened, and the high-pressure refrigerant compressed by the low-pressure compressor 100 is directly discharged to the condenser 400 along the exhaust pipe, as shown in FIG. 2 . When operating under severe working conditions of high temperature and high pressure, the double-opening compressor (that is, the high-pressure compressor 200 and the low-pressure compressor 100 operate at the same time), the electric butterfly valve 500 is closed, and the high-pressure refrigerant compressed by the low-pressure compressor 100 is discharged along the exhaust pipe. The high pressure compressor 200 is sucked in and compressed again and then discharged to the condenser 400 , as shown in FIG. 3 .

As shown in FIG. 5 , the lubricating oil tank 130 stores lubricating oil, and the oil pump 160 pumps the lubricating oil in the lubricating oil tank 130 to the low-pressure compressor oil supply pipe 140 and enters the gear box of the low-pressure compressor 100 . It flows back into the lubricating oil tank 130 through the low pressure compressor oil return pipe 150 . Similarly, the oil pump 170 pumps the lubricating oil in the lubricating oil tank 130 to the high-pressure compressor oil supply pipe 180 and enters the high-pressure compressor oil supply pipe 180 and enters the gear box of the high-pressure compressor 200, and the lubricating oil passes through The high pressure compressor oil return line 190 flows back into the lubricating oil tank 190 . As shown in FIG. 4 , the two sides of the compressor bearing 900 are the compressor impeller side 900a and the compressor gear box side 900b respectively. Since the compressor impeller side 900a and the gear box side 900b are connected by a comb seal 900c (FIG. 4 shown), when the compressor impeller side 900a generates high-pressure gas, the high-pressure gas will inevitably run to the gearbox side 900b along the gap of the comb seal 900c, so that the internal pressure of the gearbox cavity is continuously increased. The gear transmission system on the gearbox side of the compressor needs to be lubricated. The lubricating oil in the bottom oil pool returns to the external lubricating oil tank through the oil return port, and the lubricating oil in the external lubricating oil tank 130 is pumped through the oil pump 160. The pump is pumped into the gear box to lubricate the gear train, bearings and other moving parts, and when this conventional lubrication structure is applied to the dual-compressor series heat pump unit, as shown in Figure 5, when the unit operates in the single-compressor mode At this time (that is, the operating mode shown in Figure 2), the high-pressure compressor does not operate, only the low-pressure compressor 100 operates, the electric butterfly valve 500 is opened, and the low-pressure compressor exhaust gas is directly discharged to the condenser. It is directly connected to the exhaust pipe of the low-pressure compressor, so the suction port of the high-pressure compressor is also in a high-pressure state at the moment, that is, the compressor impeller side is under high pressure. The gap leaks into the gearbox cavity, and because the high-pressure compressor does not work, the oil circuit on the high-pressure compressor side does not operate, causing the high-pressure gas leaked in the gearbox cavity to flow back to the external oil tank along the high-pressure compressor oil return pipe. The pressure in the external oil tank becomes higher. When the high-pressure compressor leaks more and more high-pressure gas, the pressure in the external oil tank becomes higher and higher, which finally leads to the oil gathered in the low-pressure compressor gearbox and the low-pressure compressor oil return pipe. It becomes more and more difficult for the oil in the pipeline to flow back to the fuel tank, which eventually leads to less and less oil in the fuel tank, and the unit reports an abnormal shutdown;

When the unit allows the dual-compressor mode (that is, the operating mode shown in Figure 3), the high-pressure compressor and the low-pressure compressor operate at the same time, the electric butterfly valve is closed, and the exhaust gas of the low-pressure compressor is directly absorbed by the suction port of the high-pressure compressor and performs work It is further pressurized and then discharged into the condenser. Because the high-pressure compressor impeller further pressurizes the gas, the high-pressure compressor impeller side is in a high-pressure state at the moment. The gap between the tooth seals leaks into the gearbox cavity, which is beneficial when leaking part of the high-pressure gas. More (only in but not out), resulting in higher and higher pressure of high-pressure gas. The space of the closed system composed of the gear box, the external oil tank and the pipeline is limited. When the pressure is higher, it is easy to make the gasket and other seals. The high pressure gas leaked in the gearbox cavity flows back to the external oil tank along the oil return pipe of the high pressure compressor or the balance pipe, causing the pressure in the external oil tank to change. High, when the high-pressure compressor leaks more and more high-pressure gas, the pressure in the external oil tank is also getting higher and higher, and finally the oil gathered in the low-pressure compressor gear box and the oil in the low-pressure compressor oil return pipe become more and more. The more difficult it is to flow back to the fuel tank, and eventually lead to less and less oil in the fuel tank, and the unit reports an abnormal shutdown. The present disclosure is made based on this phenomenon.

SUMMARY OF THE INVENTION

Therefore, the present disclosure provides a compressor, a dual-compressor series heat pump unit and a control method thereof. The first bypass port, the first balance port and the first lubricating oil inlet provided on the compressor shell can facilitate the When it is applied to a dual-compressor series heat pump unit, the corresponding communication pipelines are set to realize the connection under different operation modes of the unit, and then the lubrication in the compressor can be guaranteed in both the single-compressor operation mode and the dual-compressor operation mode. Oil flows smoothly back to the external tank.

In order to solve the above problems, the present disclosure provides a compressor, which includes a first compression part and a first driving part, the first driving part is disposed in the first gear box casing, and the first compression part is disposed in the first intake casing In the body, the first air intake housing is connected with the first gear box housing as a whole, the first air intake housing is configured with a first bypass port, and the first gear box housing is configured with a first lubricating oil inlet port and the first balance port.

In some embodiments, the first lubricating oil inlet is provided at the top of the first gearbox housing.

In some embodiments, a first lubricating oil tank is connected to the first lubricating oil inlet.

In some embodiments, the first lubricating oil inlet is located at an upper portion of one end of the rotating shaft in the first gearbox housing away from the first compression part.

The present disclosure also provides a dual-compressor series heat pump unit, including a low-pressure compressor, a high-pressure compressor, and an external oil tank, where the external oil tank is used to input lubricating oil to the low-pressure compressor and the high-pressure compressor and return excess lubricating oil for storage Among them, the low-pressure compressor and the high-pressure compressor are the above-mentioned compressors, the first bypass port of the low-pressure compressor and the second balance port of the high-pressure compressor are selectively connected through the first balance pipe, and the first balance The pipe is also communicated with the external fuel tank through the second balance pipe so as to keep the external fuel tank in communication with the first bypass port.

In some embodiments, an electromagnetic on-off valve is provided on the first balance pipe between the second balance pipe and the second balance port.

In some embodiments, the external oil tank is further provided with a first oil pump and a second oil pump, and the first oil pump pumps the lubricating oil in the external oil tank to the first lubricating oil oil inlet of the low-pressure compressor through the first oil inlet pipe , the second oil pump pumps the lubricating oil in the external oil tank to the second lubricating oil inlet of the high-pressure compressor through the second oil inlet pipe.

The present disclosure also provides a control method for a dual-compressor series heat pump unit, which is used to control the above-mentioned dual-compressor series heat pump unit, including:

Obtain the operation mode of the dual-compressor series heat pump unit, and the operation modes include single-compressor operation mode and dual-compressor operation mode;

The on-off of the first bypass port and the second balance port is controlled according to the obtained operation mode.

In some embodiments, when the obtained operation mode is the single compressor operation mode, controlling the first bypass port to communicate with the second balance port;

When the acquired operation mode is the dual compressor operation mode, the first bypass port is controlled to be disconnected from the second balance port.

In some embodiments, when an electromagnetic on-off valve is provided on the first balance pipe and the obtained operation mode is the single-compressor operating mode, the electromagnetic on-off valve is controlled to pass through;

When the first balance pipe is provided with an electromagnetic on-off valve and the obtained operating mode is the dual-compressor operating mode, the electromagnetic on-off valve is controlled to be disconnected.

The present disclosure provides a compressor, a dual-compressor series heat pump unit, and a control method thereof. The first bypass port, the first balance port and the first lubricating oil inlet provided on the compressor shell can facilitate the When applied to the dual-compressor series heat pump unit, the corresponding connecting pipelines are set to realize the connection under different operation modes of the unit, and then the lubricating oil in the compressor can be guaranteed in both the single-compressor operation mode and the dual-compressor operation mode. The smooth return to the external tank can also prevent the occurrence of seal failure due to excessive pressure in the first gearbox housing in dual compressor operation mode.

Description of drawings

Fig. 1 is the schematic diagram of the pipeline structure of refrigerant circulation of the dual-compressor series heat pump unit in the prior art;

Fig. 2 is a schematic diagram of refrigerant circulation of the dual-compressor series heat pump unit in Fig. 1 in a single-compressor operation mode;

Fig. 3 is a schematic diagram of refrigerant circulation of the dual-compressor series heat pump unit in Fig. 1 in a dual-compressor operation mode;

Figure 4 is a schematic structural diagram of one end of the compressor in the compressor that is close to the compression part;

FIG. 5 is a schematic structural diagram of the lubricating oil circulation pipeline corresponding to the dual-compressor series heat pump unit in FIG. 1 in the prior art;

6 is a schematic structural diagram of the lubricating oil circulation pipeline of the dual-compressor series heat pump unit of the present disclosure;

Fig. 7 is the schematic diagram of lubricating oil circulation when the dual-compressor series heat pump unit in Fig. 6 is in the single-compressor operation mode;

FIG. 8 is a schematic diagram of the flow of lubricating oil when the dual-compressor series heat pump unit in FIG. 6 is in a dual-compressor operation mode.

Reference numerals are indicated as:

1. Low-pressure compressor; 11. The first intake casing; 111, The first bypass port; 12, The first gearbox casing; 121, The first balance port; 122, The first lubricating oil tank; 123, The first Oil return port; 2. High pressure compressor; 21. Second intake housing; 211, Second bypass port; 22, Second gearbox housing; 221, Second balance port; 222, Second lubricating oil tank; 223, the second oil return port; 3, the external oil tank; 31, the first oil pump; 32, the second oil pump; 41, the first balance pipe; 42, the electromagnetic on-off valve; 43, the second balance pipe; 44, the first An oil inlet pipe; 45, a second oil inlet pipe; 46, a first oil return pipe; 47, a second oil return pipe.

Detailed ways

Referring to FIG. 1 to FIG. 8 , according to an embodiment of the present disclosure, a compressor is provided, which includes a first compression part and a first driving part, and the first driving part is disposed in the first gear box housing 12 , The first compression part is arranged in the first intake casing 11, the first intake casing 11 is connected with the first gear box casing 12 as a whole, and the first intake casing 11 is configured with a first bypass port 111. A first lubricating oil inlet and a first balance port 121 are configured on the first gearbox housing 12, and a first oil return port 123 is also configured at a lower position of the first gearbox housing 12. In this technical solution, the first bypass port, the first balance port and the first lubricating oil inlet which are arranged on the compressor shell can facilitate the setting of corresponding communication when they are applied to the dual-compressor series heat pump unit. The pipeline can be connected in different operating modes of the unit, so that the lubricating oil in the compressor can be smoothly returned to the external oil tank in the single compressor operation mode and the dual compressor operation mode, and it can also be operated in the dual compressor operation mode. In the mode, the phenomenon of sealing failure caused by excessive pressure in the first gearbox housing is prevented.

In some embodiments, the first lubricating oil inlet is provided at the top position of the first gearbox housing 12, so that the lubricating oil entering the first gearbox The gear train and the corresponding bearings are lubricated. In one embodiment, a first lubricating oil tank 122 is connected to the first lubricating oil oil inlet, so that when the oil pump in the external oil tank 3 stops running, a sufficient amount of lubricating oil can be stored in the first lubricating oil tank 122 and under the effect of its own weight It continues to enter the first gear box housing 12, so as to be able to lubricate the rotating shaft and the bearing which still keep rotating under the action of inertia although the compressor is controlled to stop. In some embodiments, corresponding to the first lubricating oil inlet, the first gearbox housing 12 is configured with lubricating flow channels for different lubrication target positions, and one end of the lubricating flow channel is connected to the first lubricating oil inlet. The other end of the lubricating flow channel is divided into multiple branches, which are respectively set for different lubricating target points. The first gear box housing 12 is specifically formed by casting, and the lubricating flow channel is cast in the first gear box housing 12 . In some embodiments, the first lubricating oil inlet is located at the upper part of the end of the inner shaft of the first gearbox housing 12 that is away from the first compression part.

According to an embodiment of the present disclosure, as shown in FIG. 6 , a dual-compressor series heat pump unit is also provided, including a low-pressure compressor 1 , a high-pressure compressor 2 and an external oil tank 3 , and the external oil tank 3 is used for the low-pressure compressor 1. The high-pressure compressor 2 inputs lubricating oil and stores the excess lubricating oil in it. The low-pressure compressor 1 and the high-pressure compressor 2 are the above-mentioned compressors, and it can be understood that the low-pressure compressor 1 and the high-pressure compressor 2 It has the same structure in terms of mechanical structure. Specifically, the high-pressure compressor 2 includes a second compression part and a second driving part. In the second air intake housing 21 , the second air intake housing 21 is integrally connected with the second gear box housing 22 , the second air intake housing 21 is formed with a second bypass port 211 , and the second gear box housing A second lubricating oil inlet (a second lubricating oil tank 222 can also be provided on it) and a second balance port 221 are constructed on the 22, and a second oil return port 223 is also constructed at the lower position of the second gear box housing 22. The difference between low pressure and high pressure can be realized by the rotation speed of the corresponding motor drive components. The first bypass port 111 of the low pressure compressor 1 and the second balance port 221 of the high pressure compressor 2 are realized by the first balance pipe 41 . Optionally, the first balance pipe 41 is also connected to the external fuel tank 3 through the second balance pipe 43 to keep the external fuel tank 3 and the first bypass port 111 connected. In this technical solution, through the arrangement of the first balance pipe 41 and the second balance pipe 43, the first bypass port 111, the second balance port 221 and the external fuel tank 3 are penetrated under preset conditions, and then the In both single-compressor operation mode and dual-compressor operation mode, the lubricating oil in the compressor can be smoothly returned to the external oil tank, and in the dual-compressor operation mode, it can also prevent the pressure in the first gearbox casing from being too high. The phenomenon of seal failure occurs. In some embodiments, an electromagnetic on-off valve 42 is provided on the first balance pipe 41 between the second balance pipe 43 and the second balance port 221 , and the valve can be realized by electrifying and de-energizing the electromagnetic on-off valve 42 . Body on-off control.

The first oil return port 123 and the second oil return port 223 communicate with the external oil tank 3 through the first oil return pipe 46 and the second oil return pipe 47 respectively.

In some embodiments, the external oil tank 3 is further provided with a first oil pump 31 and a second oil pump 32. The first oil pump 31 pumps the lubricating oil in the external oil tank 3 to the low-pressure compressor 1 through the first oil inlet pipe 44. The first lubricating oil inlet, the second oil pump 32 pumps the lubricating oil of the external oil tank 3 to the second lubricating oil inlet of the high-pressure compressor 2 through the second oil inlet pipe 45, corresponding to the low-pressure compressor 1 and the second lubricating oil inlet respectively. The high-pressure compressor 2 is provided with the first oil pump 31 and the second oil pump 32 one by one, so that the pump oil amount can be adjusted independently, which enables the amount of lubricating oil to match the operating speed of the corresponding compressor.

According to an embodiment of the present disclosure, a method for controlling a dual-compressor series-connected heat pump unit is also provided, for controlling the above-mentioned dual-compressor series-connected heat pump unit, including:

The on-off of the first bypass port 111 and the second balance port 221 is controlled according to the acquired operation mode.

Specifically, when the obtained operation mode is the single compressor operation mode, the first bypass port 111 and the second balance port 221 are controlled to communicate with each other, so that the high pressure leaked in the high-pressure compressor gearbox can be released along the pipeline. to the suction bypass port of the low-pressure compressor to ensure internal pressure balance; when the obtained operation mode is the dual-compressor operation mode, the first bypass port 111 and the second balance port 221 are controlled to be disconnected, so that the high-pressure compressor gear The high-pressure pressure leaked in the box can be used to assist the lubrication in the high-pressure compressor gear box to be pressed back to the external oil tank 3, thereby speeding up the oil return speed of the unit, thereby improving the reliability of the unit's operation.

In some embodiments, when the electromagnetic on-off valve 42 is provided on the first balance pipe 41 and the obtained operating mode is the single compressor operating mode, the electromagnetic on-off valve 42 is controlled to pass through; when the first balance pipe 41 is provided with an on-off valve 42 When the electromagnetic on-off valve 42 and the acquired operating mode is the dual-compressor operating mode, the electromagnetic on-off valve 42 is controlled to be off.

It can be easily understood by those skilled in the art that, on the premise of no conflict, the above advantageous manners can be freely combined and superimposed.

The above are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present disclosure should be included within the protection scope of the present disclosure. Inside. The above are only the preferred embodiments of the present disclosure. It should be pointed out that for those skilled in the art, without departing from the technical principles of the present disclosure, several improvements and modifications can also be made, and these improvements and modifications should also be It is regarded as the protection scope of the present disclosure.

Claims

A compressor, comprising a first compressing part and a first driving part, the first driving part is arranged in a first gear box casing (12), the first compressing part is arranged in a first intake casing Inside the body (11), the first air intake housing (11) is connected with the first gearbox housing (12) as a whole, and the first air intake housing (11) is configured with a first side A through port (111), a first lubricating oil inlet and a first balance port (121) are configured on the first gearbox casing (12).
The compressor according to claim 1, wherein the first lubricating oil inlet is provided at a top position of the first gearbox housing (12).
The compressor according to claim 1 or 2, wherein a first lubricating oil tank (122) is connected to the first lubricating oil inlet.
The compressor according to any one of claims 1 to 3, wherein the first lubricating oil inlet is located at one end of the rotating shaft in the first gearbox housing (12) away from the first compression part the upper part.
A dual-compressor series heat pump unit, comprising a low-pressure compressor (1), a high-pressure compressor (2), and an external oil tank (3), wherein the external oil tank (3) is used for the low-pressure compressor (1) . The high-pressure compressor (2) inputs lubricating oil and returns excess lubricating oil to store in it, wherein the low-pressure compressor (1) and the high-pressure compressor (2) are described in any one of claims 1 to 4 The compressor, the first bypass port (111) of the low-pressure compressor (1) and the second balance port (221) of the high-pressure compressor (2) can be realized through the first balance pipe (41) Optionally, the first balance pipe (41) is also connected to the external fuel tank (3) through a second balance pipe (43), so that the external fuel tank (3) is bypassed with the first bypass The port (111) remains open.
The dual-compressor series heat pump unit according to claim 5, wherein the first balance pipe (41) between the second balance pipe (43) and the second balance port (221) is provided with a Solenoid on-off valve (42).
The dual compressor series heat pump unit according to claim 5 or 6, wherein the dual compressor series heat pump unit further comprises a first oil pump (31) and a second oil pump (32), the first oil pump (31) The lubricating oil in the external oil tank (3) is pumped to the first lubricating oil inlet of the low-pressure compressor (1) through the first oil inlet pipe (44), and the second oil pump (32) pumps The lubricating oil in the external oil tank (3) is pumped to the second lubricating oil oil inlet of the high-pressure compressor (2) through a second oil inlet pipe (45).
A method for controlling a dual-compressor series-connected heat pump unit, for controlling the dual-compressor series-connected heat pump unit according to any one of claims 5 to 7, comprising:

obtaining the operation mode of the dual-compressor series heat pump unit, the operation mode includes a single-compressor operation mode and a dual-compressor operation mode;

The on-off of the first bypass port (111) and the second balance port (221) is controlled according to the acquired operation mode.
The control method according to claim 8,

When the acquired operation mode is the single-compressor operation mode, controlling the first bypass port (111) to communicate with the second balance port (221);

When the acquired operation mode is the dual compressor operation mode, the first bypass port (111) is controlled to be disconnected from the second balance port (221).
The control method according to claim 8 or 9, when the first balance pipe (41) is provided with an electromagnetic on-off valve (42) and the obtained operation mode is a single compressor operation mode, the electromagnetic on-off valve (42) is controlled The shut-off valve (42) is connected;

When the first balance pipe (41) is provided with an electromagnetic on-off valve (42) and the obtained operating mode is a dual-compressor operating mode, the electromagnetic on-off valve (42) is controlled to be disconnected.