WO2020143169A1

WO2020143169A1 - Air conditioning system and control method therefor

Info

Publication number: WO2020143169A1
Application number: PCT/CN2019/092227
Authority: WO
Inventors: 张仕强; 焦华超; 周冰; 武连发
Original assignee: 珠海格力电器股份有限公司
Priority date: 2019-01-07
Filing date: 2019-06-21
Publication date: 2020-07-16
Also published as: CN109631387A

Abstract

The present application relates an air conditioning system, comprising a compressor unit, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger. The compressor unit, the outdoor heat exchanger, the throttling device, and the indoor heat exchanger form a circulation loop. The compressor unit comprises at least two compressor branches which are connected in parallel. At least one compressor is provided on each compressor branch, and the total displacement of the compressors on any two compressor branches is different. The compressor branches with different compressor displacements are selected to be turned on according to different refrigeration or heating loads required, the compressor branches of corresponding compressor displacements are started under the requirements of a small load, a moderate load and a heavy load in the indoor environment, so that the actual requirements of cooling or heating of different loads of the indoor environment can be met, and the target temperature and the cooling or heating requirements of a user are met. The present application also provides a control method for the air conditioning system.

Description

Air conditioning system and its control method

Related application

This application requires the priority of the Chinese patent application with the application number of 2019100113746 and the name of "air conditioning system and its control method", which was applied on January 7, 2019. The entire content of which is hereby incorporated by reference.

Technical field

This application relates to the technical field of air conditioning, and more specifically, to an air conditioning system and a control method thereof.

Background technique

With the improvement of people's living standards, air conditioners are becoming more and more popular, and have almost become a necessity in people's living and working places. Commercial air-conditioning systems usually use multiple compressors in parallel because of their large capacity. In the prior art, multiple compressors of the same form are used. For example, the common Daikin multi-line uses multiple scroll compressors in parallel, and the Toshiba multi-line uses multiple rotor compressors in parallel. However, air-conditioning systems that use multiple compressors of the same form in parallel and in series are less energy efficient.

Summary of the invention

In view of this, this application provides a high-energy-efficiency air-conditioning system and its control method for the problem of low energy efficiency of the existing air-conditioning system.

An air-conditioning system includes a compressor unit, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger:

The compressor unit, the outdoor heat exchanger, the throttling device and the indoor heat exchanger form a circulation circuit;

The compressor unit includes at least two compressor branches parallel to each other, at least one compressor is provided on each compressor branch, and the total displacement of the compressors on any two of the compressor branches different.

In one of the embodiments, the compressor branch includes a first compressor branch and a second compressor branch connected in parallel with each other, the first compressor branch is provided with a first compressor, the second A second compressor is provided on the compressor branch, and the displacement of the first compressor is greater than the displacement of the second compressor.

In one of the embodiments, the first compressor is a scroll compressor, and the second compressor is a rotor compressor.

In one of the embodiments, a first control valve capable of controlling its on-off is provided on the first compressor branch, and a second control valve capable of controlling its on-off is provided on the second compressor branch .

In one of the embodiments, the first control valve and the second control valve are both solenoid valves.

In one of the embodiments, it further includes a four-way valve, the first port of the four-way valve communicates with the exhaust port of the compressor group, and the second port of the four-way valve communicates with the outdoor heat exchanger , The third port of the four-way valve communicates with the air inlet of the compressor group, and the fourth port of the four-way valve communicates with the indoor heat exchanger, wherein,

The first port of the four-way valve communicates with the second port of the four-way valve, and the third port of the four-way valve communicates with the fourth port of the four-way valve;

or,

The first port of the four-way valve communicates with the fourth port of the four-way valve, and the second port of the four-way valve communicates with the third port of the four-way valve.

In one of the embodiments, a gas-liquid separator is further included, and the gas-liquid separator is disposed between the four-way valve and the air inlet of the compressor unit.

In one of the embodiments, the throttle device is a thermal expansion valve or an electronic expansion valve.

A control method of an air-conditioning system, the control method adopts the air-conditioning system as shown in any one of the above technical solutions, the method includes: according to the actual load size of the air-conditioning system, select to turn on the compressor corresponding to the load road.

In one embodiment, when the compressor branch includes a first compressor branch and a second compressor branch connected in parallel, when the actual load of the air conditioning system is small, the second compressor branch is turned on Circuit, when the actual load of the air conditioning system is large, both the first compressor branch and the second compressor branch are opened.

In one of the embodiments, when the air-conditioning system has the four-way valve, when heating of the air-conditioning system is required, the first port of the four-way valve is controlled to communicate with the fourth port, and all The second port is connected to the third port;

When cooling of the air conditioning system is required, the first port of the four-way valve is controlled to communicate with the second port, and the third port and the fourth port are communicated.

The technical solutions in the above embodiments produce at least the following technical effects.

The above air-conditioning system includes a compressor unit, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger. The compressor unit, the outdoor heat exchanger, the throttle device, and the indoor heat exchanger form a circulation circuit. The compressor unit includes at least two compressor branches parallel to each other, at least one compressor is provided on each compressor branch, and the total displacement of the compressors on any two of the compressor branches different. According to the size of the required cooling or heating load, different compressor displacement compressor branches are selected to be connected to open the compressor with the corresponding compressor displacement when the indoor environment is under small load, medium load and large load demand. The branch circuit can meet the actual demand for cooling or heating of different loads in the indoor environment and reach the user's target temperature and cooling or heating demand. Effectively reduce power consumption, save energy and improve the energy efficiency of air conditioning systems. For example, when the air conditioning system is running at low load, open the small-displacement compressor branch and close the large-displacement compressor branch, so that the air-conditioning system can meet the heating or cooling needs of the indoor environment with lower power consumption. Realize lower unit output under low load, less room temperature fluctuation, higher comfort, effectively reduce power consumption, save energy and improve energy efficiency of air conditioning system; and when the air conditioning system is running at high load, At the same time, the large-displacement compressor branch and the small-displacement compressor branch are opened to meet the actual demands of high-load cooling or heating in the indoor environment.

BRIEF DESCRIPTION

The drawings forming a part of the application are used to provide a further understanding of the application. The schematic embodiments and descriptions of the application are used to explain the application, and do not constitute an undue limitation on the application.

In order to more clearly explain the technical solutions in the embodiments of the present application, the drawings required in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without paying any creative work, other drawings can be obtained based on these drawings.

1 is a schematic structural diagram of an air-conditioning system according to an embodiment of the application;

2 is a schematic diagram of the system principle when the air-conditioning system according to an embodiment of the present application is in a cooling mode and operates at a low load;

3 is a schematic diagram of the system principle when the air-conditioning system according to an embodiment of the present application is in a cooling mode and is under high-load operation;

4 is a schematic diagram of the system principle when the air-conditioning system according to an embodiment of the present application is in a heating mode and operates at a low load;

FIG. 5 is a schematic diagram of the system principle when the air-conditioning system according to an embodiment of the present application is in a heating mode and is under high-load operation.

Description of reference signs:

100-compressor unit

110-The first compressor branch

111-The first compressor

120-second compressor branch

121-Second compressor

200-outdoor heat exchanger

300-throttling device

400-indoor heat exchanger

500-four-way valve

510-first port

520-second port

530-third port

540-Fourth port

600-gas-liquid separator

detailed description

In order to make the purpose, technical solutions and advantages of the present application more clear, the following describes the present application in further detail with reference to the accompanying drawings and embodiments. The following descriptions of specific implementations are merely exemplary, and it should be understood that the specific implementations described here are only used to explain the present application, and are not intended to limit the present application and its application or usage.

It should be noted that when an element is said to be “fixed” to another element, it can be directly on the other element or there can also be a centered element. When an element is considered to be "connected" to another element, it may be directly connected to another element or there may be a centered element at the same time. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. In contrast, when an element is referred to as being "directly connected to" another element, there are no intervening elements present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

In the description of this application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", " The azimuth or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the azimuth or positional relationship shown in the drawings. The device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application.

The technical solution of the present application will be described in more detail below with reference to FIGS. 1 to 5.

Referring to FIG. 1, an embodiment of the present application provides an air conditioning system, including a compressor unit 100, an outdoor heat exchanger 200, a throttle device 300, and an indoor heat exchanger 400. The compressor unit 100, the outdoor heat exchanger 200, the throttle device 300, and the indoor heat exchanger 400 form a circulation circuit. The compressor unit 100 includes at least two compressor branches connected to each other in parallel, at least one compressor is provided on each compressor branch, and the total row of compressors on any two of the compressor branches The displacement is different, that is, the total displacement of the compressor on any one of the parallel branches of the compressor is different from the total displacement of the compressor on the other branches. According to the size of the required cooling or heating load, different compressor displacement compressor branches are selected to communicate to open the corresponding compressor displacement compressor branch when the air conditioning system is under small load, medium load and large load demand. To meet the actual demand for cooling or heating of different loads in the indoor environment, to achieve the user's target temperature and cooling capacity or heating demand. Effectively reduce power consumption, save energy and improve the energy efficiency of air conditioning systems.

Optionally, the throttle device 300 is a thermal expansion valve or an electronic expansion valve. Both the electronic expansion valve and the thermal expansion valve can be throttled and decompressed. The electronic expansion valve adjusts the refrigerant flow in real time according to the detected superheat of evaporation or supercooling of condensation. This control is more flexible and efficient.

Please continue to refer to FIG. 1. In one embodiment, the compressor branch includes a first compressor branch 110 and a second compressor branch 120 connected in parallel with each other. The first compressor branch 110 is provided with a first compressor 111, and the second compressor branch 120 is provided with a second compressor 121, and the displacement of the first compressor 111 is greater than the first The displacement of the second compressor 121.

Optionally, the first compressor 111 is a scroll compressor with a large displacement or a centrifugal compressor with a large displacement. The second compressor 121 is a rotor compressor with a small displacement. The rotor compressor may be a fixed-plate rotor compressor or a sliding-plate rotor compressor. As shown in FIG. 2 or FIG. 4, when the load of the air conditioning system is small, the second compressor branch 120 communicates and the first compressor branch 110 closes. It can effectively utilize the advantages of small displacement and small output of the rotor compressor. Rotor compressors have a smaller displacement, and when operating at 10 Hz, the refrigerant displacement of a compressor with a smaller displacement is less. In this case, the cooling capacity output by the air conditioner is lower, and the power consumption is also smaller. For the case where the room temperature is 26°C and the user sets the temperature at 25°C, the heat load (cooling demand) in the room is relatively small, and the air conditioner The output can be satisfied with a small cooling capacity. On the one hand, it avoids frequent room temperature fluctuations caused by the large output of the air conditioner. On the other hand, the output of the air conditioner is smaller and the power is smaller, and the operation is more energy-efficient. As shown in FIG. 3 or FIG. 5, when the load of the air conditioning system is large, the first compressor branch 110 and the second compressor branch 120 are both in communication. Through the combination of a small-displacement rotor compressor and a large-displacement scroll compressor, the output of the unit under low load can be reduced, the room temperature fluctuation is smaller, and the comfort is higher. The introduction of a large-displacement scroll compressor can effectively reduce the number of multiple small-displacement rotor compressors, which reduces the number of compressors and improves the reliability of system operation. In an air conditioning system with two compressors connected in parallel, the number of compressors and the frequency of operation are adjusted according to the user's cooling capacity or heating demand. From small output to large output, the usual control is: first turn on the first small displacement The compressor works from low frequency to medium and high frequency, and then turn on the second large displacement compressor to work. This time, the two compressors work at the same time and increase from low frequency to maximum frequency at the same time. Therefore, in the dual-press system, the design of large and small compressors is more conducive to reducing the output of the air conditioner under low load.

In one of the embodiments, the first compressor branch 110 is provided with a first control valve capable of controlling its on-off, and the second compressor branch 120 is provided with a control valve capable of controlling its on-off Second control valve. This is the control device and control method of the air-conditioning system of the present application that can control the on-off of the two branches of the compressor unit 100. Of course, the on-off branch can also be achieved by starting and stopping the compressor, but the compressor is frequently used for a long time. Start and stop will affect the service life of the compressor.

Optionally, both the first control valve and the second control valve are solenoid valves. This is an optional structure and type of control valves for the two control branch channels in the air-conditioning system of the present application, which can achieve precise, precise, convenient and quick control.

Please refer to FIGS. 2 to 5, the air conditioning system further includes a four-way valve 500. The first port 510 of the four-way valve 500 communicates with the exhaust port of the compressor unit 100, the second port 520 of the four-way valve 500 communicates with the outdoor heat exchanger 200, and the four-way valve 500 The third port 530 is connected to the intake port of the compressor unit 100, and the fourth port 540 of the four-way valve 500 is connected to the indoor heat exchanger 400.

As shown in FIGS. 2 and 3, when the air conditioning system is operating in a cooling mode, the first port 510 of the four-way valve 500 communicates with the second port 520 of the four-way valve 500, the four-way valve 500 The third port 530 of the valve 500 communicates with the fourth port 540 of the four-way valve 500. The high-temperature and high-pressure refrigerant gas discharged from the compressor unit 100 is connected to the outdoor heat exchanger 200 through the four-way valve 500. The flow device 300 reduces the temperature and pressure to a low-temperature and low-pressure refrigerant liquid. After absorbing heat through the indoor heat exchanger 400, the low-temperature and low-pressure liquid evaporates into a low-temperature and low-pressure refrigerant gas. After the gas-liquid separator 600 separates the gas and liquid, it enters the suction port of the compressor unit 100 and enters the next cycle. When the refrigeration cycle is low, determine the output of the outdoor unit according to the cooling demand or heat load of the indoor unit in the system, and determine whether to turn on the compressor 111 or compressor 121. When the load is high, the two compressors At the same time put into operation. There are many ways to determine the size of the load. The conventional scheme is based on the outdoor ambient temperature, the indoor ambient temperature, and the temperature set by the user. Under cooling conditions, the higher the outdoor temperature, the higher the indoor temperature. , The lower the temperature set by the user, the greater the load, otherwise, the smaller the load. The size of the load can reflect the size of user needs.

As shown in FIGS. 4 and 5, when the air conditioning system is operating in the heating mode, the first port 510 of the four-way valve 500 communicates with the fourth port 540 of the four-way valve 500. The second port 520 of the port valve 500 communicates with the third port 530 of the four-way valve 500. The high-temperature and high-pressure refrigerant gas discharged from the compressor unit 100 is connected to the indoor heat exchanger 400 through the four-way valve 500. The refrigerant releases heat from the high-temperature and high-pressure gas in the indoor heat exchanger 400 to condense into a normal-temperature and high-pressure refrigerant liquid, The flow device 300 reduces the temperature and pressure to a low-temperature and low-pressure refrigerant liquid. After absorbing heat through the outdoor heat exchanger 200, the low-temperature and low-pressure liquid evaporates into a low-temperature and low-pressure refrigerant gas. After the gas-liquid separator 600 separates the gas and liquid, it enters the suction port of the compressor unit 100 and enters the next cycle.

Referring to FIGS. 2 to 5, the air-conditioning system further includes a gas-liquid separator 600. The gas-liquid separator 600 is disposed between the four-way valve 500 and the air inlet of the compressor unit 100. The gas-liquid separator 600 is to achieve the separation of refrigerant gas and liquid, and to avoid damage to the compressor due to the large amount of liquid refrigerant in the compressor suction. Generally, the gas-liquid separator 600 is used in the design of large-capacity air conditioners. Because the larger the air conditioner, the more refrigerant is charged, and when operating at low load, the required amount of circulating refrigerant is small, and the liquid is returned. The possibility is greater, and the addition of the gas-liquid separator 600 can improve the reliability of the system.

Please refer to FIG. 1 to FIG. 5, an embodiment of the present application provides a control method of an air-conditioning system, the control method adopts the air-conditioning system as shown in any one of the above technical solutions, the method includes: according to the air-conditioning system For the actual load size, choose to open the compressor branch corresponding to the load.

When the load demand is small, the small displacement compressor branch is opened, that is, the second compressor branch 120 is opened. When the load demand is large, a large displacement compressor branch is opened, that is, the first compressor branch 110 or both the first compressor branch 110 and the second compressor branch 120 are opened. By using the aforementioned air-conditioning system and adopting the above-mentioned control means, it is possible to select a small-displacement compressor to turn on under a small load and turn off a large-displacement compressor branch, so that the air-conditioning system meets the requirements of the indoor environment with lower power consumption Heating or cooling requirements effectively reduce power consumption and save energy. It can achieve lower unit output under low load, less room temperature fluctuation and higher comfort. To meet the actual needs of cooling or heating in different loads of the indoor environment, to achieve the user's target temperature and the role of cooling or heating. The above air-conditioning system can also start a small-displacement compressor to run at a higher frequency under a small load, which can not only meet the user's cooling or heating needs, but also reduce power consumption, and can also increase the compressor's oil return strength. , To meet the oil return requirements of the compressor, thereby reducing the wear of the compressor, extending the life of the compressor, and improving the operational reliability of the air conditioning system. The control method of the above air-conditioning system can also control at least one other compressor to still be able to normally start running when a single compressor fails, which can meet the air-conditioning use requirements in an emergency.

In one of the embodiments, when the compressor branch includes a first compressor branch 110 and a second compressor branch 120 connected in parallel with each other, when the actual load of the air conditioning system is small, the second compression is turned on For the engine branch 120, when the actual load of the air conditioning system is large, both the first compressor branch 110 and the second compressor branch 120 are opened.

In one embodiment, when the air-conditioning system has the four-way valve 500, as shown in FIGS. 4 and 5, when the air-conditioning system needs heating, the first of the four-way valve 500 is controlled The port 510 communicates with the fourth port 540, and the second port 520 communicates with the third port 530. As shown in FIGS. 3 and 4, when cooling by an air conditioning system is required, the first port 510 of the four-way valve 500 is controlled to communicate with the second port 520, the third port 530 and the fourth Port 540 is connected. Through the above-mentioned control means and steps when the four-way valve 500 is provided, the switching control of the four-way valve 500 can enable the air conditioning system to achieve the purpose and effect of heating or cooling to meet the needs of users or actual conditions.

The above air-conditioning system includes a compressor unit, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger. The compressor unit, the outdoor heat exchanger, the throttle device, and the indoor heat exchanger form a circulation circuit. The compressor unit includes at least two compressor branches parallel to each other, at least one compressor is provided on each compressor branch, and the total displacement of the compressors on any two of the compressor branches different. According to the size of the required cooling or heating load, different compressor displacement compressor branches are selected to be connected to open the compressor with the corresponding compressor displacement when the indoor environment is under small load, medium load and large load demand. The branch circuit can meet the actual demand for cooling or heating of different loads in the indoor environment and reach the user's target temperature and cooling or heating demand. For example, when the air conditioning system is running at low load, open the small-displacement compressor branch and close the large-displacement compressor branch, so that the air-conditioning system can meet the heating or cooling needs of the indoor environment with lower power consumption. Realize lower unit output under low load, less room temperature fluctuation, higher comfort, effectively reduce power consumption, save energy and improve energy efficiency of air conditioning system; and when the air conditioning system is running at high load, At the same time, the large-displacement compressor branch and the small-displacement compressor branch are opened to meet the actual demands of high-load cooling or heating in the indoor environment.

The technical features of the above-mentioned embodiments can be arbitrarily combined. To simplify the description, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered within the scope of this description.

The above-mentioned embodiments only express several implementation manners of the present application, and their descriptions are more specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those of ordinary skill in the art, without departing from the concept of the present application, a number of modifications and improvements can also be made, which all fall within the protection scope of the present application. Therefore, the protection scope of the patent of this application shall be subject to the appended claims.

Claims

An air-conditioning system is characterized by comprising a compressor unit (100), an outdoor heat exchanger (200), a throttle device (300) and an indoor heat exchanger (400):

The compressor unit (100), the outdoor heat exchanger (200), the throttle device (300) and the indoor heat exchanger (400) form a circulation circuit;

The compressor unit (100) includes at least two compressor branches connected in parallel with each other, at least one compressor is provided on each compressor branch, wherein any two compressor branches The total displacement is different.
The air conditioning system according to claim 1, wherein the compressor branch includes a first compressor branch (110) and a second compressor branch (120) connected in parallel to each other, the first compressor A first compressor (111) is provided on the branch (110), a second compressor (121) is provided on the second compressor branch (120), and the displacement of the first compressor (111) Greater than the displacement of the second compressor (121).
The air conditioning system according to claim 2, wherein the first compressor (111) is a scroll compressor, and the second compressor (121) is a rotor compressor.
The air-conditioning system according to claim 2, characterized in that a first control valve capable of controlling its on-off is provided on the first compressor branch (110), and the second compressor branch ( 120) A second control valve capable of controlling its on-off is provided.
The air-conditioning system according to claim 4, wherein the first control valve and the second control valve are both solenoid valves.
The air-conditioning system according to any one of claims 1 to 5, further comprising a four-way valve (500), the first port (510) of the four-way valve (500) and the compressor unit ( 100) The exhaust port communicates, the second port (520) of the four-way valve (500) communicates with the outdoor heat exchanger (200), and the third port (530) of the four-way valve (500) Communicating with the air inlet of the compressor unit (100), and the fourth port (540) of the four-way valve (500) communicates with the indoor heat exchanger (400), wherein,

The first port (510) of the four-way valve (500) communicates with the second port (520) of the four-way valve (500), and the third port (530) of the four-way valve (500) communicates with all The fourth port (540) of the four-way valve (500) communicates;

or,

The first port (510) of the four-way valve (500) communicates with the fourth port (540) of the four-way valve (500), and the second port (520) of the four-way valve (500) communicates with all The third port (530) of the four-way valve (500) communicates.
The air-conditioning system according to claim 6, further comprising a gas-liquid separator (600), the gas-liquid separator (600) is disposed between the four-way valve (500) and the compressor unit (100) ) Between the air intakes.
The air-conditioning system according to claim 1, wherein the throttle device (300) is a thermal expansion valve or an electronic expansion valve.
A control method for an air-conditioning system, characterized in that the control method uses the air-conditioning system according to any one of claims 1 to 8, and the method includes: according to the actual load of the air-conditioning system, select Compressor branch with corresponding load.
The control method according to claim 9, wherein when the compressor branch includes a first compressor branch (110) and a second compressor branch (120) connected in parallel to each other, when the air conditioner When the actual load of the system is small, the second compressor branch (120) is turned on. When the actual load of the air conditioning system is large, the first compressor branch (110) and the second compressor branch (120) ) Are turned on.
The control method according to claim 9, characterized in that, when the air conditioning system has the four-way valve (500), when heating of the air-conditioning system is required, the control of the four-way valve (500) is controlled The first port (510) communicates with the fourth port (540), and the second port (520) communicates with the third port (530);

When cooling of the air conditioning system is required, the first port (510) of the four-way valve (500) is controlled to communicate with the second port (520), the third port (530) and the fourth port (540) Connected.