WO2021233465A1

WO2021233465A1 - Control method for air conditioning unit, and air conditioning unit

Info

Publication number: WO2021233465A1
Application number: PCT/CN2021/099545
Authority: WO
Inventors: 王书森; 张捷; 王铁伟; 邓善营
Original assignee: 青岛海尔空调电子有限公司; 青岛海尔空调器有限总公司; 海尔智家股份有限公司
Priority date: 2020-10-22
Filing date: 2021-06-11
Publication date: 2021-11-25
Also published as: CN112303826A; CN112303826B

Abstract

The present invention belongs to the technical field of air conditioning, and specifically relates to a control method for an air conditioning unit, and an air conditioning unit. The present invention aims to solve the problem that during the operation process of an air conditioning unit, when the load of an indoor unit suddenly fluctuates, a compressor is subjected to a surge because same cannot normally increase and reduce a load in a timely manner, and the operation stability of the compressor is affected, such that even a compressor bearing fails. With regards to this aim, in the present invention, an actual air suction pressure value of a compressor, an actual air discharge pressure value of the compressor and an actual bearing offset of the compressor are determined; and then, a load balance valve arranged between an air suction end and an air discharge end of the compressor is selectively controlled on the basis of a determination result, and at the same time, compressor energy adjustment is performed cooperatively. Therefore, in terms of the load change to an indoor unit, a load balance valve is adjusted by means of the method, and compressor energy adjustment is performed, so as to adaptively adjust the operation state of a compressor, thereby solving the problem that the compressor is subjected to a surge, and the operation stability of the compressor is affected, such that even a compressor bearing fails.

Description

Control method of air-conditioning unit and air-conditioning unit

Technical field

The invention belongs to the technical field of air conditioners, and specifically relates to a control method of an air conditioner unit and an air conditioner unit.

Background technique

The single-cooling air-conditioning unit is an air-conditioning unit that can only be used for refrigeration, and it has a wide range of applications in the edible fungus breeding industry and cold storage and other fields.

In the refrigerant circulation route of a single-cooling air conditioning unit, the exhaust port of the compressor communicates with the first end of the outdoor condenser, and the second end of the outdoor condenser communicates with the first end of the user-side evaporator through a throttling device. The second end of the user-side evaporator is in communication with the suction port of the compressor. In the working process of the single-cooling air conditioning unit, through the repeated compression of the refrigerant by the compressor and the repeated throttling of the refrigerant by the throttling device, the circulating flow of the refrigerant realizes that the outdoor condenser releases heat to the outdoor environment and the user side The purpose of the evaporator to absorb indoor heat. At the same time, single-cooling air conditioning units generally include multiple indoor units. Each indoor unit is equipped with a user-side evaporator and a fan. The fan draws indoor hot air into the indoor unit and exchanges it with the user-side evaporator. Heat, and then blow the cold air into the room after the temperature is lowered, so as to achieve the purpose of cooling the room.

However, during the operation of the single-cooling air-conditioning unit, the number of indoor units turned on and the adjustment of the fan speed in the indoor unit will reduce the load of the indoor unit. When the total load of the indoor unit fluctuates suddenly, if the control is not good for the compressor "Surge" phenomenon is prone to occur, which affects the stability of compressor operation and even causes compressor bearing failure problems. It is easier when the operating pressure ratio (the ratio of the actual discharge pressure of the compressor to the actual suction pressure of the compressor) is high. problem appear.

Correspondingly, a new control method of an air conditioning unit and an air conditioning unit are needed in the art to solve the above-mentioned problems.

Summary of the invention

In order to solve the problem of the compressor "surging" when the load of the indoor unit suddenly fluctuates during the operation of the existing air conditioning unit, which affects the stability of the compressor operation and even causes the compressor bearing failure, the present invention provides A control method of an air conditioning unit and an air conditioning unit.

First, this embodiment provides a control method of an air conditioning unit. In the refrigerant circulation route of the air conditioning unit, the exhaust port of the compressor communicates with the first end of the outdoor condenser, and the second end of the outdoor condenser is The first end of the user-side evaporator is communicated with the first end of the user-side evaporator through a throttling device, and the second end of the user-side evaporator is communicated with the suction port of the compressor; the air conditioning unit is also provided with a load balance valve, so The first end of the load balance valve is connected to the refrigerant pipeline between the exhaust port of the compressor and the first end of the outdoor condenser, and the second end of the load balance valve is connected to the compressor The suction port is connected; the control method includes: obtaining the actual suction pressure value of the compressor, the actual discharge pressure value, the actual inlet pressure value of the outdoor condenser, and the actual bearing offset of the compressor; judging the actual suction pressure Whether the air pressure value is within a reasonable suction pressure range determined based on the set suction pressure value, determine whether the actual exhaust pressure value is greater than the actual inlet air pressure value, and determine whether the actual bearing offset is less than the set value Offset; the load balance valve is selectively controlled based on the judgment result.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, in the step of "selectively controlling the load balance valve based on the result of the judgment", if the actual suction pressure value is located in the Within the reasonable suction pressure range, while the actual exhaust pressure value is greater than the actual inlet air pressure value and the actual bearing offset is less than the set offset, the current opening of the load balance valve is maintained And/or, if the actual suction pressure value is greater than the maximum reasonable suction pressure value within the reasonable suction pressure range, while the actual exhaust pressure value is greater than the actual inlet air pressure value and the actual bearing If the offset is less than the set offset, the load balance valve is reduced by the set adjustment range based on the current opening; and/or, if any of the following conditions is met, the load The balance valve increases the setting adjustment range on the basis of the current opening: Condition 1: The actual suction pressure value is less than the minimum reasonable suction pressure value within the reasonable suction pressure range; Condition 2: The actual exhaust pressure value The air pressure value is less than or equal to the actual inlet air pressure value; condition 3: the actual bearing offset is greater than or equal to the set offset.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, in the step of "selectively controlling the load balance valve based on the judgment result", each time the load balance valve is reduced or increased After setting the adjustment range and waiting for the set interval time, re-execute the step "Judging whether the actual suction pressure value is within the reasonable suction pressure range determined based on the set suction pressure value, and then judging the actual exhaust pressure Whether the value is greater than the actual inlet air pressure value, determine whether the actual bearing offset is less than the set offset", and selectively control the load balance valve based on the new determination result.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, the set adjustment range and the set interval time are both based on the pressure of the actual exhaust pressure value and the actual suction pressure value. The ratio is determined.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, the setting rule of the setting adjustment range is: increasing with the increase of the pressure ratio; and/or, the setting interval The time setting rule is: increase with the increase of the pressure ratio.

As a preferred technical solution of the above-mentioned control method provided in this embodiment, the control method further includes: if the actual suction pressure difference between the actual suction pressure value and the maximum reasonable suction pressure value When it is less than the first preset suction pressure difference, the set interval time after the load balance valve decreases the set adjustment range next time is greater than the setting after the load balance valve decreases the set adjustment range this time Intervals.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, the determination rule of the reasonable suction pressure range is: the larger the pressure ratio of the actual exhaust pressure value to the actual suction pressure value, Then, the difference between the maximum reasonable suction pressure value, the minimum reasonable suction pressure value and the set suction pressure value within the reasonable suction pressure range is also larger.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, when the load balancing valve is selectively controlled based on the judgment result, if the load balancing valve is currently in the closed state, the The control method further includes: obtaining the current energy value of the compressor; determining the first energy value to be energized of the compressor based on the actual suction pressure value, the set suction pressure value, and the current energy value; The pressure ratio of the actual discharge pressure value to the actual suction pressure value determines the minimum energy value of the compressor; when the first energy value to be assigned is less than the minimum energy value, the minimum energy value is assigned to the compressor The compressor is assigned; when the first energy value to be energized is greater than or equal to the minimum energy value, the compressor is assigned according to the first energy to be energized.

As a preferred technical solution of the above-mentioned control method provided by this embodiment, when the load balancing valve is selectively controlled based on the judgment result, if the load balancing valve is currently in an open state, the The control method further includes: obtaining the current energy value of the compressor; determining the maximum load ratio of the compressor based on the current opening degree of the load balancing valve; based on the current energy value, the maximum load ratio, and the actual suction pressure Value and the maximum reasonable suction pressure value within the reasonable suction pressure range to calculate the energy adjustment value of the compressor; determine the minimum energy of the compressor based on the pressure ratio of the actual discharge pressure value to the actual suction pressure value Value; based on the minimum energy value and the energy adjustment value to determine the second energy value to be assigned to the compressor; when the second energy value to be assigned is less than the minimum energy value, according to the minimum energy value assignment The compressor is assigned; when the second energy value to be energized is greater than or equal to the minimum energy value, the compressor is assigned according to the second energy to be energized.

In addition, the present invention also provides an air-conditioning unit. In the refrigerant circulation route of the air-conditioning unit, the exhaust port of the compressor communicates with the first end of the outdoor condenser, and the second end of the outdoor condenser passes through the joint. The flow device is in communication with the first end of the user-side evaporator, the second end of the user-side evaporator is in communication with the suction port of the compressor, the air conditioning unit is also provided with a load balancing valve, and the load balancing The first end of the valve is connected to the refrigerant pipeline between the discharge port of the compressor and the first end of the outdoor condenser; the second end of the load balance valve is connected to the suction port of the compressor The air conditioning unit is also provided with a pressure detecting element for detecting the actual suction pressure value, the actual exhaust pressure value or the actual inlet pressure value of the outdoor condenser of the compressor, and is provided with a pressure detecting element for detecting the compressor Offset detection element for the actual bearing offset; the air-conditioning unit also includes a memory, a processor, and a control program of the air-conditioning unit stored in the memory and running on the processor, and the control of the air-conditioning unit When the program is executed by the processor, the steps of the air conditioning unit control method as in any of the above technical solutions are realized.

According to the control method of the air conditioning unit and the air conditioning unit of the present invention, by judging whether the actual suction pressure value of the compressor is within a reasonable suction pressure range determined based on its set suction pressure value, and judging the actual discharge of the compressor Whether the pressure value is greater than the actual inlet air pressure value of the outdoor condenser, and determine whether the actual bearing offset of the compressor is less than the set offset, and then set it between the suction end and the discharge end of the compressor based on the judgment result The load balance valve is selectively controlled, and at the same time, the compressor's assigned energy can be adjusted comprehensively through the load balance valve state, the actual suction pressure, and the set suction pressure. In this way, according to the load change of the indoor unit, the ratio of the discharge pressure to the suction pressure of the compressor can be adjusted adaptively by adjusting the load balance valve and the assigned energy of the compressor, so as to avoid the "surge" phenomenon of the compressor and its influence The stability of the compressor operation even causes the problem of compressor bearing failure. At the same time, in this control process, the control is performed only by detecting the relevant parameters in the outdoor unit. There is no need to detect the number of indoor units and the indoor temperature, etc., and the complicated communication lines are reduced, which is beneficial to ensure the control of the air-conditioning unit. Simplify the structure of the air conditioning unit under the premise of the effect.

In addition, according to the control method of the air conditioning unit and the air conditioning unit of the present invention, when the load balance valve is adjusted, it is also based on the actual suction pressure value, the maximum reasonable suction pressure value within the reasonable suction pressure range, and the current compressor The energy value, etc. determines the energy value to be assigned to the compressor. In this way, in response to the load change of the indoor unit, the energy value of the compressor during operation is correspondingly reduced, thereby avoiding the waste of energy during the operation of the air-conditioning unit, and ultimately improving the operating efficiency of the air-conditioning unit.

Description of the drawings

Hereinafter, the control method of the air conditioning unit and the air conditioning unit of the present invention will be described with reference to the accompanying drawings. In the attached picture:

Figure 1 is a schematic diagram of the structure of the air conditioning unit of this embodiment;

Fig. 2 is a schematic flow chart of the control method of the air conditioning unit of this embodiment.

List of reference signs

1- Compressor; 11- Check valve; 12- Load balance valve; 13- First pressure sensor; 14- Second pressure sensor; 15- Third pressure sensor; 16- Bypass solenoid valve; 17- Bypass expansion valve;

2- outdoor condenser; 21- thermal expansion valve; 22- solenoid valve;

3- User side evaporator;

4-gas-liquid separator; 5-reservoir; 51-electric ball valve; 52-cooling expansion valve.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention, and are not intended to limit the protection scope of the present invention. For example, although this embodiment describes the control method of the air conditioning unit by taking the load balancing valve connected to the two ends of the compressor's discharge port and suction port as an example, this connection relationship is not static and does not deviate from it. Under the conditions of the principles of the present invention, those skilled in the art can make adjustments as needed to adapt to specific applications. For example, in an air-conditioning unit equipped with a gas-liquid separator, the end of the load balancing valve used to connect the compressor suction port can also be connected to the inlet of the gas-liquid separator, that is, one end of the load balancing valve is indirectly connected to the compressor For example, under the premise that a one-way valve is provided at the exhaust port of the compressor, the end of the load balance valve connected to the exhaust port of the compressor can also be connected to the outlet of the one-way valve.

It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The term of the indicated direction or positional relationship is based on the direction or positional relationship shown in the drawings, which is only for ease of description, and does not indicate or imply that the device or element must have a specific orientation, be configured and operated in a specific orientation Therefore, it cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

In addition, it should be noted that, in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, they can be fixed or fixed. It is a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those skilled in the art, the specific meaning of the above-mentioned terms in the present invention can be understood according to specific circumstances.

In order to solve the above-mentioned problems in the prior art, that is, in order to solve the problem of the existing air-conditioning unit in the operation process, when the load of the indoor unit suddenly fluctuates, the compressor will "surge", which will affect the stability of the compressor operation. It even causes the problem of compressor bearing failure. The present invention provides a control method of an air conditioning unit and an air conditioning unit.

This embodiment aims to combine the magnetic levitation compressor + evaporative condenser (or shell and tube type, fin type condenser) + thermal expansion valve (or electronic expansion valve) + indoor multiple air coolers combined system form and tube Road configuration, this combination form is used, and it solves the problem of the sudden fluctuation of the load of the indoor unit during the operation of this combination form, which causes the compressor to be too late to load and reduce the load, which affects the stability of the compressor operation. It even caused the problem of compressor bearing failure. For this purpose, this embodiment judges the actual suction pressure value of the compressor, the actual discharge pressure value of the compressor, and the actual bearing offset, and then compares the values provided at the suction end and the discharge end of the compressor based on the judgment result. The load balance valve between them is selectively controlled while cooperating with compressor energy adjustment. In this way, in response to the load change of the indoor unit, the load balance valve and compressor energy adjustment are adjusted by this method to adaptively adjust the operating state of the compressor, so as to avoid the "surge" phenomenon of the compressor and the impact on the operation of the compressor. Stability can even cause problems with compressor bearing failures. Therefore, this combination mode can be applied to edible fungus breeding and other similar scenarios, and the energy-saving efficiency of the system can be improved.

In the edible fungus breeding industry, the direct refrigeration mode of one compressor with multiple indoor units mentioned in this embodiment is the first, especially the magnetic levitation compressor (oil-free) is applied to this refrigeration system. At present, most of the chillers produce low-temperature cold water, and the cold water exchanges heat at the end of the room. This type of direct expansion air conditioning system with one or two compressors and an indoor unit in a room, but they are systems with oil. The advantages of the magnetic levitation compressor of this embodiment: the oil-free system has a good heat exchange effect, is easy to maintain, has low noise, and partially meets the high energy efficiency of operation.

First of all, as shown in Figure 1 is an air conditioning unit provided by this embodiment. In the refrigerant circulation route of the air conditioning unit, the exhaust port of the compressor 1 communicates with the first end of the outdoor condenser 2, and the outdoor condenser 2 The second end of the user-side evaporator 3 communicates with the first end of the user-side evaporator 3 through a throttling device (such as the thermal expansion valve 21 in Fig. 1), and the second end of the user-side evaporator 3 communicates with the suction port of the compressor 1, The air conditioning unit is also provided with a load balancing valve 12, the first end of the load balancing valve 12 is connected to the refrigerant pipeline between the exhaust port of the compressor 1 and the first end of the outdoor condenser 2; the first end of the load balancing valve 12 The two ends are connected with the suction port of the compressor 1; the air conditioning unit is also provided with a pressure detection element for detecting the actual suction pressure value, the actual discharge pressure value of the compressor 1, or the actual inlet pressure value of the outdoor condenser 2, and An offset detecting element for detecting the actual bearing offset of the compressor 1 is provided; those skilled in the art can understand that the above-mentioned air conditioning unit also includes some other well-known structures, such as a processor, a controller, a memory, etc., where the memory Including but not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory or registers, etc. Processors include but are not limited to CPLD/FPGA, DSP, ARM processor, MIPS processor, etc. In order to unnecessarily obscure the embodiments of the present disclosure, these well-known structures are not shown in the drawings. Among them, the control program of the air-conditioning unit described later in this embodiment is stored in the memory and can be run on the processor. The control program of the air-conditioning unit is executed by the processor to realize the air-conditioning unit of any of the following embodiments. The steps of the control method.

Exemplarily, in the air conditioning unit shown in FIG. 1, the compressor 1 is a magnetic levitation compressor. Since the magnetic levitation compressor does not need to use lubricating oil, it avoids the influence of lubricating oil on the heat exchange efficiency of the air-conditioning unit and reduces the air-conditioning unit. Maintenance costs.

In order to prevent the refrigerant from flowing back to the compressor 1 through the discharge port of the compressor 1 when the compressor 1 is stopped or other unexpected situations, a check valve 11 is also connected to the discharge port of the compressor 1. 11 is set to allow only the refrigerant to flow from the discharge port of the compressor 1 to the outdoor condenser 2 through the one-way valve 11. In this case, the first end of the load balancing valve 12 may be connected to the outlet end of the one-way valve 11 indirectly with the exhaust port of the compressor 1.

In this embodiment, a bypass solenoid valve 16 and a bypass expansion valve 17 are connected in parallel between the inlet end of the one-way valve 11 and the inlet end of the gas-liquid separator 4. By adjusting the bypass solenoid valve 16 and the bypass expansion valve 17 To reduce the pressure ratio in the air conditioning unit (that is, the ratio of the actual discharge pressure to the actual suction pressure), and then assist the compressor 1 to start and stop.

In order to prevent the compressor 1 from "inhaling liquid", that is, sucking the liquid refrigerant into the compressor 1, causing the compressor 1 to experience liquid hammer and damaging the compressor 1, a gas-liquid separator 4 can also be provided on the suction port of the compressor 1. In this case, the second end of the load balance valve 12 may be connected to the inlet of the gas-liquid separator 4 to indirectly communicate with the suction port of the compressor 1.

In this embodiment, a reservoir 5 is also connected between the second end of the outdoor condenser 2 and the first end of the user-side evaporator 3. The reservoir 5 is used to store the high-pressure liquid refrigerant from the outdoor condenser 2. Without causing the liquid refrigerant to flood the inner surface of the outdoor condenser 2, it can also make the heat transfer area of the outdoor condenser 2 play a full role, and adjust and stabilize the circulation of the refrigerant in order to adapt to changes in working conditions. At the same time, it also acts as a liquid seal. Prevent high-pressure gas refrigerant from fleeing into the low-pressure system pipeline.

In this embodiment, the air conditioning unit shown in Figure 1 includes a plurality of user-side evaporators 3, and each user-side evaporator 3 is connected with a throttling device at the inlet. The throttling device in Figure 1 is thermal The expansion valve 21, in addition, the throttling device can also be an electronic expansion valve. At the same time, after the air conditioning unit is shut down, in order to ensure that the refrigerant in the refrigerant circulation pipeline stops flowing, a solenoid valve 22 is installed before the thermal expansion valve 21, and an electric ball valve 51 is installed between the outlet of the accumulator 5 and the solenoid valve 22. .

In this embodiment, the second end of the outdoor condenser 2 (at the outlet end of the accumulator 5 in FIG. 1) is also communicated with the refrigerant inlet of the gas-liquid separator 4 through a cooling expansion valve 52. In this way, when the high temperature in the gas-liquid separator 4 causes the suction superheat of the compressor 1 to be large, the outdoor condenser 2 can be connected to the gas-liquid separator 4, so that the liquid in the outdoor condenser 2 The refrigerant passes through the cooling expansion valve 52 and enters the gas-liquid separator 4 to vaporize, reducing the temperature inside the gas-liquid separator 4. It is understandable that by setting a temperature sensor on the suction port of the compressor 1, the exhaust temperature of the gas-liquid separator 4 can be detected, and the saturation temperature difference between the exhaust gas temperature of the gas-liquid separator 4 and the internal pressure of the liquid separator 4 The value is the degree of superheat to determine whether the inside of the gas-liquid separator 4 needs to be cooled.

At the same time, the second end of the outdoor condenser 2 is also in communication with the cooling inlet of the compressor 1; and the compressor 1 is equipped with a temperature sensor and an electric control valve. In this way, when the temperature sensor in the compressor 1 detects that the temperature of the compressor 1 is high, the electric control valve can be used to connect the outdoor condenser 2 with the cooling inlet of the compressor 1, so that the liquid in the outdoor condenser 2 The refrigerant enters the compressor 1 to vaporize, thereby reducing the temperature inside the compressor 1.

In this embodiment, a first pressure sensor 13 for detecting the actual inlet air pressure value of the outdoor condenser 2 is provided between the outlet end of the one-way valve 11 and the first end of the outdoor condenser 2. At the exhaust port of the compressor 1 A second pressure sensor 14 used to detect the actual discharge pressure value of the compressor 1 is provided at the inlet end of the check valve 11, and a useful pressure sensor 14 is provided between the suction port of the compressor 1 and the discharge port of the gas-liquid separator 4. The third pressure sensor 15 to detect the actual suction pressure value of the compressor 1.

Then, in conjunction with the air-conditioning unit in FIG. 1, this embodiment provides a method for controlling the air-conditioning unit. In the refrigerant circulation route of the air-conditioning unit, the exhaust port of the compressor 1 and the first end of the outdoor condenser 2 The second end of the outdoor condenser 2 communicates with the first end of the user-side evaporator 3 through a throttling device, and the second end of the user-side evaporator 3 communicates with the suction port of the compressor 1; There is a load balancing valve 12, the first end of the load balancing valve 12 is connected to the refrigerant pipeline between the discharge port of the compressor 1 and the first end of the outdoor condenser 2, and the second end of the load balancing valve 12 is connected to the compressor The suction port of 1 is connected; as shown in Figure 2, the control method of the air conditioning unit includes:

S1. Obtain the actual suction pressure value, the actual discharge pressure value of the compressor 1, the actual inlet pressure value of the outdoor condenser 2, and the actual bearing offset of the compressor 1.

Exemplarily, in conjunction with the air conditioning unit in FIG. 1, the actual suction pressure value, actual discharge pressure value, and outdoor condensation of the compressor 1 can be obtained through the first pressure sensor 13, the second pressure sensor 14, and the third pressure sensor 15. The actual inlet air pressure value of the compressor 2; and the compressor 1 generally has its own offset detection element to detect the actual bearing offset.

S2. Determine whether the actual suction pressure value is within the reasonable suction pressure range determined based on the set suction pressure value, determine whether the actual exhaust pressure value is greater than the actual inlet air pressure value, and determine whether the actual bearing offset is less than the set deviation Shift.

Exemplarily, in the existing magnetic levitation compressor, the suction pressure value can be directly input through the touch screen of the compressor 1. The set offset of the bearing of the compressor 1 is the maximum offset when the compressor 1 is working normally, and this value is generally obtained according to the factory parameters of the compressor 1. It should be noted that after the load balance valve 12 is adjusted to a certain extent, it takes a certain time to achieve the air pressure balance of each part of the air conditioning unit. Therefore, when judging whether the actual bearing offset is less than the set offset, if the compression is obtained If the actual bearing offset of the machine 1 is greater than or equal to the set offset, the parameter can be obtained again after 5 seconds to ensure that the bearing offset has stabilized when the load balance valve 12 is adjusted.

S3. The load balance valve 12 is selectively controlled based on the judgment result.

According to the control method of the air-conditioning unit and the air-conditioning unit of this embodiment, it is determined whether the actual suction pressure value of the compressor 1 is within a reasonable suction pressure range determined based on the set suction pressure value, and the compressor 1 Whether the actual discharge pressure value is greater than the actual inlet air pressure value of the outdoor condenser 2, and determine whether the actual bearing offset of compressor 1 is less than the set offset, and then based on the result of the determination to set at the suction end of compressor 1 The load balance valve 12 between and the exhaust end is selectively controlled. In this way, in response to the load change of the indoor unit, the load balance valve 12 is adjusted by this method to adaptively change the ratio of the discharge pressure to the suction pressure of the compressor 1, so as to avoid the "surge" phenomenon of the compressor 1, and Avoid affecting the stability of the operation of the compressor 1 and even causing the bearing failure of the compressor 1. At the same time, in this control process, the control purpose can be achieved only by detecting the relevant parameters in the outdoor unit. There is no need to detect the number of indoor units and indoor temperature, etc., and reduce the complex communication lines, which is beneficial to ensure the air conditioning Simplify the structure of the air conditioning unit under the premise of the control effect of the unit.

It can be understood that although this embodiment is described by setting one compressor 1 as an example, the provision of two or more compressors 1 in the air conditioning unit according to actual needs by those skilled in the art still belongs to this embodiment. Describe the scope.

As a preferred implementation of the above-mentioned control method provided in this embodiment, in step S3 "selectively control the load balance valve 12 based on the result of the judgment":

1) If the actual suction pressure value is within the reasonable suction pressure range, and the actual discharge pressure value is greater than the actual inlet air pressure value and the actual bearing offset is less than the set offset, it indicates that there is no surge in compressor 1. There is no need to adjust the load balancing valve 12, and the current opening degree of the load balancing valve 12 is maintained.

2) If the actual suction pressure value is greater than the maximum reasonable suction pressure value within the reasonable suction pressure range, it means that it is necessary to reduce the load balance valve opening to reduce the bypass energy, and at the same time increase the compressor assignment energy to reduce the actual suction pressure. At the same time, the actual exhaust pressure value is greater than the actual inlet air pressure value and the actual bearing offset is less than the set offset, then the load balance valve 12 is reduced by the set adjustment range based on the current opening.

3) If any of the following conditions are met, increase the setting adjustment range of the load balance valve 12 on the basis of the current opening: Condition 1: The actual suction pressure value is less than the minimum reasonable suction within the reasonable suction pressure range The pressure value means that it is necessary to increase the opening of the load balance valve to increase the bypass energy, and reduce the assigned energy of the compressor to increase the actual suction pressure; Condition 2: The actual discharge pressure value is less than or equal to the actual inlet pressure value; Condition 3: The actual bearing offset is greater than or equal to the set offset.

In summary, the control method of the air conditioning unit provided in this embodiment controls the load balance valve 12 according to the specific working conditions of the compressor 1 to ensure that the actual suction pressure is maintained to the set suction pressure. At the same time, make preparations to prevent surge in the vicinity, thereby avoiding the problem of compressor 1 surge and the stable operation of the air-conditioning unit.

As a preferred implementation of the above-mentioned control method provided by this embodiment, in step S3 "selectively control the load balance valve 12 based on the judgment result", each time the load balance valve 12 is reduced or increased After setting the adjustment range and waiting for the set interval, re-execute the step "Judging whether the actual suction pressure value is within the reasonable suction pressure range determined based on the set suction pressure value, and judging whether the actual exhaust pressure value is greater than the actual inlet The air pressure value is used to determine whether the actual bearing offset is less than the set offset", and the load balance valve 12 is selectively controlled based on the new determination result.

It is understandable that when the ratio of the actual discharge pressure to the actual suction pressure of the compressor 1 is adjusted by the load balance valve 12, the load balance valve 12 needs to be adjusted multiple times, and the two adjacent adjustments need to be adjusted at a certain interval. Time to ensure that the operating parameters of the air conditioning unit can be obtained after the last adjustment and stability, so that the effective adjustment of the load balance valve 12 can be realized.

As a preferred implementation of the above-mentioned control method provided by this embodiment, the set adjustment range and the set interval time are determined based on the pressure ratio of the actual exhaust pressure value and the actual intake pressure value.

It can be understood that the greater the deviation of the pressure ratio between the actual exhaust pressure value and the actual intake pressure value from the reasonable range, the greater the amplitude of this adjustment to achieve the effective adjustment of the load balance valve 12; If the pressure ratio between the air pressure value and the actual suction pressure value deviates from a reasonable range, the amplitude of this adjustment needs to be reduced accordingly in order to realize the effective adjustment of the load balance valve 12. That is, the setting rule for setting the adjustment range is: increase with the increase of the pressure ratio.

At the same time, it can be understood that the larger the adjustment range of the load balancing valve 12 last time, the more time it takes for the air conditioning unit to reach equilibrium. Therefore, the setting rule for the set interval time is: increase with the increase of the pressure ratio. Big.

In addition, it should be noted that when the actual suction pressure value is very close to the maximum reasonable suction pressure value or the minimum reasonable suction pressure value (the difference between the first preset suction pressure and the second preset suction pressure is used below ), when adjusting the load balance valve 12, a cautious method needs to be taken to avoid adjustment errors, so the set interval time can be appropriately extended at this time.

Therefore, as a preferred implementation of the above-mentioned control method provided by this embodiment, the control method further includes: if the actual suction pressure difference between the actual suction pressure value and the maximum reasonable suction pressure value is less than the first When the suction pressure difference is preset, the set interval time after the load balance valve 12 reduces the set adjustment range next time is greater than the set interval time after the load balance valve 12 reduces the set adjustment range this time.

As a preferred implementation of the above-mentioned control method provided in this embodiment, the determination rule of the reasonable suction pressure range is: the greater the pressure ratio of the actual exhaust pressure value to the actual suction pressure value, the reasonable suction pressure range The greater the difference between the maximum reasonable suction pressure value, the minimum reasonable suction pressure value and the set suction pressure value within.

It is understandable that the greater the pressure ratio between the actual exhaust pressure value and the actual suction pressure value, the larger the actually allowable adjustment range of the load balance valve 12 is, so it is reasonable to determine based on the set suction pressure value at this time. The suction pressure range is also relatively large, and such a setting can ensure reasonable adjustment of the load balance valve 12.

As a preferred implementation of the above-mentioned control method provided by this embodiment, when the load balancing valve 12 is selectively controlled based on the judgment result, if the load balancing valve 12 is currently in the closed state, the control method further includes : Obtain the current energy value of compressor 1; determine the first energy value to be assigned to compressor 1 based on the actual suction pressure value, the set suction pressure value and the current energy value; based on the actual discharge pressure value and the actual suction pressure The pressure ratio of the value determines the minimum energy value of compressor 1; when the first energy value to be assigned is less than the minimum energy value, compressor 1 is assigned according to the minimum energy value assignment; when the first energy value to be assigned is greater than or equal to the minimum energy value When the value is set, the compressor 1 is assigned a value according to the first energy to be energized.

Exemplarily, the current energy value of the compressor 1 can be directly fed back from the compressor 1. When the load balance valve 12 is currently closed, that is, the air conditioning unit is running relatively smoothly, the reasonable energy value of the compressor 1 (ie The formula for determining the first to-be-energized value of the compressor 1 is also relatively simple. For example, when the load balance valve 12 is currently closed, the first energy value to be energized of the compressor 1 = the current energy value of the compressor + (the actual suction pressure value-the set suction pressure value) × K ₃ + D ₂ ; Among them, K ₃ , D ₂ are the factory parameters related to the structure of the air conditioning unit, which are measured through experiments before leaving the factory.

As a preferred implementation of the above-mentioned control method provided by this embodiment, when the load balancing valve 12 is selectively controlled based on the judgment result, if the load balancing valve 12 is currently in an open state, the control method is still Including: obtaining the current energy value of compressor 1; determining the maximum load ratio of compressor 1 based on the current opening of the load balance valve 12; based on the current energy value, maximum load ratio, actual suction pressure value and reasonable suction pressure range Calculate the energy adjustment value of compressor 1 based on the maximum reasonable suction pressure value; determine the minimum energy value of compressor 1 based on the pressure ratio between the actual discharge pressure value and the actual suction pressure value; determine the compression based on the minimum energy value and the energy adjustment value The second energy value to be assigned to the engine 1; when the second energy value to be assigned is less than the minimum energy value, the compressor 1 is assigned according to the minimum energy value assignment; when the second energy value to be assigned is greater than or equal to the minimum energy value, The compressor 1 is assigned according to the second energy to be energized.

Exemplarily, the minimum energy value of the compressor 1 = (actual discharge pressure of the compressor/actual suction pressure of the compressor) × K+R, where, according to the actual discharge pressure of the compressor and the actual suction pressure of the compressor For the ratio of air pressure, the corresponding parameters K and R are determined by looking up the table by looking up the table.

Compressor's energy adjustment value = Min{current energy value, maximum load ratio-K ₁ (current energy value-maximum load ratio)} + (actual suction pressure value-the maximum reasonable suction pressure value within the reasonable suction pressure range )×K ₂ +D;

Among them, K ₁ and K ₂ are the factory parameters related to the structure of the air conditioning unit, which are measured through experiments before leaving the factory; maximum load ratio = 100%-load balance valve 12 opening * load balance valve 12 ratio setting/10; D is the correction value, which can be obtained through experiments.

The second energy value to be assigned=(minimum energy value of the compressor+energy adjustment value of the compressor)/2+D ₁ , D ₁ is a preset correction value.

It should be noted that with regard to the setting of the above parameters, due to the differences in the values of different air conditioning units, and the same air conditioning unit under different working conditions, some of the parameter values are different, so the specific size of the above parameters is no longer limited. Description, but this does not prevent those skilled in the art from being able to perform normal implementation on the basis of the description of this embodiment.

According to the control method of the air conditioning unit and the air conditioning unit of this embodiment, when the load balancing valve 12 is adjusted, it is also based on the actual suction pressure value, the maximum reasonable suction pressure value within the reasonable suction pressure range, and the compressor 1 The current energy value and the like determine the energy value of the compressor 1 to be energized. In this way, in response to the load change of the indoor unit, the energy value of the compressor 1 during operation is correspondingly reduced, thereby avoiding the waste of energy during the operation of the air-conditioning unit, and ultimately improving the operating efficiency of the air-conditioning unit. According to the experimental results, after adopting the above-mentioned control method of the air-conditioning unit of this embodiment, the electric energy saved by the air-conditioning unit can reach 40%-50%.

Of course, the above-mentioned alternative implementations, as well as alternative implementations and preferred implementations, can also be used in cross-coordination, so as to combine new implementations to be suitable for more specific application scenarios.

It should be noted that although the detailed steps of the method of the present invention are described in detail above, those skilled in the art can combine, split and exchange the order of the above steps without departing from the basic principles of the present invention. The modified technical solution does not change the basic idea of the present invention, and therefore also falls within the protection scope of the present invention. For example, when obtaining the actual suction pressure value of compressor 1, the actual discharge pressure value, the actual inlet pressure value of outdoor condenser 2, and the actual bearing offset of compressor 1, they can be obtained at the same time or within a reasonable time. For example, determine whether the actual suction pressure value is within the reasonable suction pressure range determined based on the set suction pressure value, determine whether the actual exhaust pressure value is greater than the actual inlet air pressure value, and determine the actual bearing offset When it is less than the set offset, it can be judged at the same time or one after the other.

Those skilled in the art should understand that the control method of the air conditioning unit provided in this embodiment can be stored as a program in a computer readable storage medium. The storage medium includes a number of instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute some steps of the methods in the various embodiments of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code .

In addition, those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments means that they are protected by the present invention. Within the scope and form different embodiments. For example, in the claims of the present invention, any one of the claimed embodiments can be used in any combination.

So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, those skilled in the art will readily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

A control method of an air-conditioning unit. In the refrigerant circulation route of the air-conditioning unit, the exhaust port of the compressor communicates with the first end of an outdoor condenser, and the second end of the outdoor condenser communicates with the user through a throttling device. The first end of the side evaporator is in communication, and the second end of the user-side evaporator is in communication with the suction port of the compressor; the feature is that the air conditioning unit is also provided with a load balance valve, and the load balance The first end of the valve is connected to the refrigerant pipeline between the discharge port of the compressor and the first end of the outdoor condenser, and the second end of the load balance valve is connected to the suction port of the compressor Connected; the control method includes:

Obtain the actual suction pressure value of the compressor, the actual discharge pressure value, the actual inlet pressure value of the outdoor condenser, and the actual bearing offset of the compressor;

Determine whether the actual suction pressure value is within a reasonable suction pressure range determined based on the set suction pressure value, determine whether the actual exhaust pressure value is greater than the actual inlet air pressure value, and determine the actual bearing offset Whether the amount is less than the set offset;

The load balancing valve is selectively controlled based on the judgment result.
The control method according to claim 1, wherein in the step of "selectively controlling the load balance valve based on the result of the judgment",

If the actual suction pressure value is within the reasonable suction pressure range, while the actual exhaust pressure value is greater than the actual inlet air pressure value and the actual bearing offset is less than the set offset, Maintain the current opening of the load balancing valve; and/or,

If the actual suction pressure value is greater than the maximum reasonable suction pressure value within the reasonable suction pressure range, at the same time the actual exhaust pressure value is greater than the actual inlet air pressure value and the actual bearing offset is less than all The set offset, then the load balance valve is reduced by the setting adjustment range based on the current opening; and/or,

If any of the following conditions is met, the load balance valve will be increased to set the adjustment range based on the current opening:

Condition 1: The actual suction pressure value is less than the minimum reasonable suction pressure value within the reasonable suction pressure range;

Condition 2: The actual exhaust pressure value is less than or equal to the actual inlet air pressure value;

Condition 3: The actual bearing offset is greater than or equal to the set offset.
The control method according to claim 2, wherein in the step of "selectively controlling the load balance valve based on the judgment result", each time the load balance valve is set to decrease or increase After adjusting the range and waiting for the set interval, re-execute the step "Judging whether the actual suction pressure value is within the reasonable suction pressure range determined based on the set suction pressure value, and judging whether the actual exhaust pressure value is greater than According to the actual inlet air pressure value, it is determined whether the actual bearing offset is less than the set offset", and the load balance valve is selectively controlled based on the new determination result.
The control method according to claim 3, wherein the set adjustment range and the set interval time are both determined based on the pressure ratio of the actual exhaust pressure value and the actual suction pressure value .
The control method according to claim 4, wherein the setting rule of the setting adjustment range is: increasing with the increase of the pressure ratio; and/or,

The setting rule of the set interval time is: increase with the increase of the pressure ratio.
The control method according to claim 3, wherein the control method further comprises:

If the actual suction pressure difference between the actual suction pressure value and the maximum reasonable suction pressure value is less than the first preset suction pressure difference, the load balance valve is set to decrease next time The set interval time after the adjustment range is greater than the set interval time after the load balance valve reduces the set adjustment range this time.
The control method according to claim 1, wherein the determination rule of the reasonable suction pressure range is: the greater the pressure ratio of the actual exhaust pressure value to the actual suction pressure value, the The greater the difference between the maximum reasonable suction pressure value, the minimum reasonable suction pressure value and the set suction pressure value within the reasonable suction pressure range.
The control method according to claim 1, wherein when the load balancing valve is selectively controlled based on the judgment result, if the load balancing valve is currently closed, the control method further include:

Get the current energy value of the compressor;

Determining the first energy value to be energized of the compressor based on the actual suction pressure value, the set suction pressure value and the current energy value;

Determining the minimum energy value of the compressor based on the pressure ratio of the actual discharge pressure value to the actual suction pressure value;

When the first energy value to be assigned is less than the minimum energy value, the compressor is assigned according to the minimum energy value assignment; when the first energy value to be assigned is greater than or equal to the minimum energy value , Assigning a value to the compressor according to the first energy to be energized.
The control method according to claim 1, wherein when the load balancing valve is selectively controlled based on the judgment result, if the load balancing valve is currently in an open state, the control method further include:

Get the current energy value of the compressor;

Determining the maximum load ratio of the compressor based on the current opening of the load balancing valve;

Calculating the energy adjustment value of the compressor based on the current energy value, the maximum load ratio, the actual suction pressure value, and the maximum reasonable suction pressure value within the reasonable suction pressure range;

Determining the minimum energy value of the compressor based on the pressure ratio of the actual discharge pressure value to the actual suction pressure value;

Determining a second energy value to be energized of the compressor based on the minimum energy value and the energy adjustment value;

When the second energy value to be assigned is less than the minimum energy value, the compressor is assigned according to the minimum energy value assignment; when the second energy value to be assigned is greater than or equal to the minimum energy value , Assigning a value to the compressor according to the second energy to be energized.
An air-conditioning unit, characterized in that, in the refrigerant circulation route of the air-conditioning unit, the exhaust port of the compressor communicates with the first end of the outdoor condenser, and the second end of the outdoor condenser is connected to the first end of the outdoor condenser through a throttling device. The first end of the user-side evaporator is in communication, and the second end of the user-side evaporator is in communication with the suction port of the compressor, characterized in that:

The air conditioning unit is also provided with a load balancing valve, and the first end of the load balancing valve is connected to the refrigerant pipeline between the exhaust port of the compressor and the first end of the outdoor condenser; The second end of the load balancing valve is in communication with the suction port of the compressor;

The air conditioning unit is also provided with a pressure detecting element for detecting the actual suction pressure value, actual exhaust pressure value or the actual inlet air pressure value of the outdoor condenser of the compressor, and is provided with a pressure detecting element for detecting the actual pressure value of the compressor. Offset detection element for bearing offset;

The air-conditioning unit also includes a memory, a processor, and a control program of the air-conditioning unit stored on the memory and running on the processor. The control program of the air-conditioning unit is executed by the processor as The steps of the control method of the air conditioning unit described in any one of 1 to 9 are required.