WO2021223612A1

WO2021223612A1 - Vrf air-conditioning system and control method therefor, and control device

Info

Publication number: WO2021223612A1
Application number: PCT/CN2021/089752
Authority: WO
Inventors: 崔国栋; 王海胜; 陈聪; 褚运通
Original assignee: 青岛海尔空调电子有限公司; 海尔智家股份有限公司
Priority date: 2020-06-19
Filing date: 2021-04-26
Publication date: 2021-11-11
Also published as: CN111878961A

Abstract

Provided are a control system and method for a VRF air conditioner, and a control device. The control method comprises: measuring the temperature of output water at a water outlet; and according to the temperature of output water, adjusting the opening degree of a first throttling component and/or a second throttling component, and preferentially adjusting the opening degree of the second throttling component under the condition where the temperature of output water can be adjusted by adjusting the opening degree of the first throttling component or the opening degree of the second throttling component. According to the present invention, a VRF air-conditioning system can meet the air-conditioning requirements of an indoor heat exchanger on one hand, and can supply hot water to an external water consumption terminal on the other hand. Moreover, the second throttling component is set to be a throttling component which is adjusted preferentially, such that the temperature of output water can be adjusted in a more timely manner.

Description

VRF air conditioning system and its control method and control device

Technical field

The present invention relates to the field of air treatment technology, in particular to a VRF air conditioning system and its control method and control device.

Background technique

Air conditioners usually have a cooling mode and a heating mode. The refrigerant can be circulated in the circuit formed by the compressor-condenser-throttling component (for example, an electronic expansion valve or capillary tube, etc.)-evaporator-compressor. The space provides cold or heat, thereby lowering or raising the temperature of the indoor space. The switching between cooling mode and heating mode is accomplished by switching the four-way valve. Specifically, the flow path of the refrigerant in the circuit is switched by the four-way valve, so that when the air conditioner is in the cooling mode, the indoor heat exchanger is the evaporator and the outdoor heat exchanger is the condenser, and when the air conditioner is in the heating mode At that time, the indoor heat exchanger is a condenser and the outdoor heat exchanger is an evaporator.

VRF (Variable Refrigerant Flow, variable refrigerant flow) air conditioning systems usually include an indoor side and a hot water side. The indoor side mainly adjusts the temperature/humidity of the air in the indoor space through the circulation of refrigerant in the corresponding loop. On the other side, the temperature of the hot water supplied to the water terminal is mainly adjusted by the circulation of the refrigerant in the corresponding circuit. By distributing the refrigerant in the two circuits, the VRF air-conditioning system can meet the demands of the indoor side and the hot water side at the same time. For VRF air-conditioning systems, especially when the indoor side is in the cooling mode (such as summer), how to effectively recover the condensed waste heat while ensuring that the hot water side is provided with hot water up to the standard temperature? How to better solve this problem On a technical issue, there is still room for improvement.

Correspondingly, a new technical solution is needed in this field to solve the above-mentioned problems.

Summary of the invention

technical problem

In view of this, the technical problem to be solved by the present invention is to provide a VRF air conditioning system and its control method and control device that can effectively recover the condensation waste heat on the indoor side while ensuring the provision of hot water up to the standard to the hot water side.

solution

The first aspect of the present invention provides a control method of a VRF air-conditioning system. The VRF air-conditioning system includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, a heat storage device, a four-way valve, and a throttling component. The thermal device includes a water storage container, an intermediate heat exchanger is arranged in the water storage container, the water storage container has a water outlet, the throttling assembly includes a first throttling component and a second throttling component, the compression The machine, the outdoor heat exchanger, the first throttling component, and the indoor heat exchanger form a first refrigerant circuit, the compressor, the intermediate heat exchanger, the second throttling component, and the The indoor heat exchanger forms a second refrigerant circuit, and the control method includes: detecting the temperature of the outlet water at the outlet; adjusting the temperature of the first throttling component and/or the second throttling component according to the outlet water temperature The opening degree, and in the case that the outlet water temperature can be adjusted by adjusting the opening degrees of the first throttle member and the second throttle member, the opening degree of the second throttle member is adjusted preferentially.

With such an arrangement, the VRF air conditioning system of the present invention can meet the indoor air conditioning requirements on the one hand, and supply hot water to the water terminal on the hot water side on the other hand. In addition, by setting the second throttling component as a throttling component that is adjusted preferentially, the temperature of the outlet water can be adjusted in a more timely manner.

Regarding the above-mentioned control method of the VRF air conditioning system, in a possible implementation, the four-way valve has four sides C, D, E, and S. When the CD side of the four-way valve is connected, and the ES side is connected, , Through the circulation of the refrigerant in the first refrigerant circuit composed of the compressor→outdoor heat exchanger→first throttling component→indoor heat exchanger→compressor, so that the indoor side where the indoor heat exchanger is located obtains the cooling capacity. The refrigerant circulates in the second refrigerant circuit composed of the compressor → the intermediate heat exchanger → the second throttling component → the indoor heat exchanger → the compressor so that the heat storage device can at least supply hot water to the hot water side through the water outlet , Said "according to the outlet water temperature, adjust the opening degree of the first throttle component and/or the second throttle component, and adjust the opening degree of the first throttle component and the second throttle component When the temperature of the outlet water can be adjusted, the “priority adjustment of the opening degree of the second throttling component” includes: reducing the opening degree of the second throttling component when the outlet water temperature is greater than the required target outlet temperature.

By preferentially reducing the opening degree of the second throttle member, it is possible to reduce the circulating refrigerant participating in the second refrigerant circuit at the first time, so that the rate of increase of the outlet water temperature can be suppressed.

Regarding the above-mentioned control method of the VRF air-conditioning system, in a possible implementation manner, the “decreasing the opening of the second throttle component when the outlet water temperature is greater than the required target outlet temperature” includes: Simultaneously or after decreasing the opening degree of the second throttle member, the opening degree of the first throttle member is increased.

Through the joint adjustment of the first throttle component and the second throttle component, on the one hand, it can seek to restrain the rising speed of the outlet water temperature, and on the other hand, it can also adjust the two refrigerant circuits through the redistribution of the refrigerant. The total amount of refrigerant in the room, so as to ensure the cooling effect of the indoor side.

Regarding the control method of the above-mentioned VRF air-conditioning system, in a possible implementation manner, “at the same time or after the opening of the second throttling component is reduced, the opening of the first throttling component is increased” It includes: during at least a part of the adjustment period, the increase in the opening degree of the first throttle member is greater than the decrease in the opening degree of the second throttle member.

Through this setting, on the one hand, it is ensured that the temperature of the hot water provided to the external user terminal is not too high. However, in this process, the cooling effect on the indoor side will be enhanced to a certain extent.

The reason for adopting such a treatment method is that compared with thermal shock, the increase in the cooling capacity caused by the increase in the circulation of the refrigerant in the cooling mode has a relatively small effect on the body feeling of the indoor users. Therefore, this setting can To curb the rate of increase in the temperature of the outlet water faster.

Regarding the above-mentioned control method of the VRF air conditioning system, in a possible implementation, the “during at least part of the adjustment period, the increase in the opening degree of the first throttle component is greater than the decrease in the opening degree of the second throttle component. "Small amount" includes: when the outlet water temperature is greater than the first set temperature, reducing the opening degree of the second throttling member and increasing the opening degree of the first throttling member to the maximum; wherein, the first throttling member The set temperature is greater than the required target outlet temperature.

With this arrangement, in the case where the outlet water temperature is too high, the outlet water temperature can be adjusted quickly. If it is assumed that the required target outlet water temperature is 55°C, the first set temperature can be a certain value between 75-85°C (for example, 75°C).

After that, the rising rate of the outlet water temperature will gradually decrease. As the water terminal uses water (removing hot water) and the external water source replenishes water (adding cold water), the outlet water temperature will eventually decrease, such as in the outlet water. When the temperature is less than or equal to the first set temperature (but still greater than the required target outlet temperature), the opening of the first throttle can be appropriately reduced to meet the hot water quality of the water terminal on the hot water side and the indoor side at the same time There are two requirements for the cooling effect. It is understandable that, at this time, it is still necessary to ensure that the rising speed of the outlet water temperature shows a downward trend. Therefore, the opening degree of the second throttle component still needs to be smaller than the original opening degree before adjustment, and the opening degree of the first throttle component is still It needs to be greater than the original opening before adjustment.

By dividing the adjustment process into two or more stages with urgency and urgency, for example, the adjustment of the first throttle component is divided into a large adjustment in the first stage and a small adjustment thereafter. In addition, the adjustment for the reduction of the opening degree of the second throttle component can also be divided into different stages, such as the overall reduction relative to the opening degree before the adjustment, but the degree of reduction can be changed. For example, when the outlet water temperature is less than or equal to the aforementioned first set temperature, since the water temperature is no longer too high, the distribution of the refrigerant needs to be continued by the second refrigerant circuit under the premise of ensuring that the outlet water temperature should continue to decrease. Share. However, since the outlet water temperature is greater than the first set temperature, the opening of the second throttle component has been reduced. At this stage, you can refer to the actual outlet temperature reduction progress, the hot water demand of the water terminal, and the makeup water temperature. And other factors, you can choose to continue to reduce the opening of the second throttle or keep the opening of the second throttle at the end of the first stage basically unchanged.

Regarding the above-mentioned control method of the VRF air conditioning system, in a possible implementation, after the step of “decreasing the opening of the second throttle component when the outlet water temperature is greater than the required target outlet temperature”, so The control method includes: reducing the opening degree of the first throttle member to a reference opening degree and increasing the opening degree of the second throttle member to the maximum when the outlet water temperature is less than the second set temperature; according to For the outlet water temperature, PID adjustment is performed on the opening degrees of the first throttle component and the second throttle component; wherein the second set temperature is less than the required target outlet water temperature.

Through this setting, a starting state of PID adjustment after the temperature of the outlet water is adjusted to not over-temperature is given. Based on PID adjustment, the VRF air conditioning system can jointly adjust the temperature of the indoor air and the hot water demanded by the water terminal on the hot water side. It should be noted that the reference opening is a low value set by the VRF air conditioning system with a small opening.

For the above-mentioned control method of the VRF air conditioning system, in a possible implementation manner, a water mixing valve is arranged between the water outlet of the water storage device and the water terminal, and the water mixing valve is also connected to an external water source.

With this arrangement, the external water source and the hot water in the water storage device are mixed (preliminarily cooled) at the mixing valve and then supplied to the water terminal. Under the same temperature of the water outlet, the position of the mixing valve is adjusted The temperature of the hot water supplied to the water terminal can be changed.

Regarding the control method of the above-mentioned VRF air-conditioning system, in a possible implementation, the heat storage device further includes a solar heat storage module, so that the heat obtained from the intermediate heat exchanger and/or the solar heat storage module can be transferred to hot water. Hot water is provided on the side.

Through such a setting, the hot water side can obtain hot water whose temperature reaches the standard by actively supplementing heat.

A second aspect of the present invention provides a VRF air-conditioning system. The VRF air-conditioning system includes a control module, wherein the control module is used to execute the control method of any one of the foregoing VRF air-conditioners.

It is understandable that the VRF air conditioning system has all the technical effects of the aforementioned control method of the VRF air conditioning system, which will not be repeated here.

A third aspect of the present invention provides a control device, the control device includes a memory and a processor, wherein the memory stores a program capable of executing the control method of the VRF air-conditioning system according to any one of the foregoing, wherein, The processor can call the program and execute the control method of any one of the foregoing VRF air conditioning systems.

It is understandable that the control device has all the technical effects of the aforementioned control method of the VRF air-conditioning system, which will not be repeated here.

Description of the drawings

The present invention will be described below with reference to the drawings. In the attached picture:

Figure 1 shows a schematic structural diagram of a VRF air conditioning system according to an embodiment of the present invention;

Figure 2 shows a schematic structural diagram of a heat storage device in a VRF air conditioning system according to an embodiment of the present invention;

Fig. 3 shows a schematic flow chart 1 of a control method of a VRF air-conditioning system according to an embodiment of the present invention;

FIG. 4 shows a second schematic flowchart of a control method of a VRF air conditioning system according to an embodiment of the present invention;

FIG. 5 shows the third flowchart of the control method of the VRF air conditioning system according to an embodiment of the present invention; and

Fig. 6 shows a fourth flowchart of a control method of a VRF air-conditioning system according to an embodiment of the present invention.

List of reference signs:

1. Compressor; 2. Four-way valve; 3. Outdoor heat exchanger; 4. Indoor heat exchanger; 51. Electronic expansion valve PMV-C; 52. Electronic expansion valve PMV-Q; 6. Gas-liquid separator; 7. Oil return device; 8. Heat storage device; 81. Water storage container; 811. Water outlet; 812. Water inlet; 82. Intermediate heat exchanger; 83. Solar heat storage module; 9. Water mixing valve; 10. Water terminal.

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.

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" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

1 and 2, FIG. 1 shows a schematic structural diagram of a VRF air conditioning system according to an embodiment of the present invention, and FIG. 2 shows a schematic structural diagram of a heat storage device in a VRF air conditioning system according to an embodiment of the present invention. As shown in Figures 1 and 2, the VRF air conditioning system mainly includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an indoor heat exchanger 4, a throttling component, and a heat storage device 8. The heat storage device 8 includes a heat storage device. Thermal module and water storage container 81. As an example, the heat storage device 8 includes a box body, a heat storage module is provided below the box body and a water storage container 81 above the box body, and the heat storage module is a solar thermal storage module 83. The water storage container 81 is provided with an intermediate heat exchanger 82, the four-way valve 2 has four sides C, D, E, and S. The throttle assembly includes a first throttle component and a second throttle component. In this embodiment , The first throttling component and the second throttling component are both electronic expansion valves, where the first throttling component is an electronic expansion valve PMV-C 51 (hereinafter referred to as PMV-C), and the second throttling component is an electronic expansion valve PMV-Q 52 (hereinafter referred to as PMV-Q).

Among them, the structure of the hot water side is mainly:

The water storage container 81 has a water outlet 811 and a water inlet 812. On the one hand, an external water source (tap water) can supply water to the water terminal 10 through the water outlet 811, and on the other hand, can supply water to the water storage container 81 through the water inlet 812. Specifically, after the hot water in the water storage container 81 flows out through the water outlet 811, it is first mixed with cold water provided by an external water source, and then supplied to the water terminal 10 on the hot water side. In order to adjust the temperature of the hot water obtained by the water terminal 10 more flexibly, a mixing valve 9 for adjusting the mixing ratio is arranged at the mixing place.

Based on the above-mentioned structure of the hot water side, the adjustment of the temperature of the hot water of the water terminal 10 can theoretically be achieved by "the position of the mixing valve 9 is constant, only by adjusting the temperature standard of the water outlet", and "the temperature standard of the water outlet is constant". , It can be obtained only by adjusting the position of the water mixing valve 9" and "combined adjusting the temperature standard of the water outlet and the position of the water mixing valve 9". However, because the position of the mixing valve is fixed, the existence of the mixing valve is of little significance, so the latter two adjustment schemes are usually used.

Among them, the structure of the indoor side is mainly:

The C side of the four-way valve 2 is connected to the first side of the outdoor heat exchanger 3 and the first side of the intermediate heat exchanger 82 respectively, and the second side of the outdoor heat exchanger 3 is connected to the first side of the indoor heat exchanger 4 And PMV-C is arranged on the pipeline between the two, the second side of the intermediate heat exchanger 82 is connected to the first side of the indoor heat exchanger 4 and PMV-Q is arranged on the pipeline between the two, the indoor heat exchanger The second side of the heater 4 is connected to the E side of the four-way valve 2, and the S side of the four-way valve 2 is connected to the air return port of the compressor 1, and a gas-liquid separator 6 is arranged between the two. The air port is connected to the D side of the four-way valve 2 and an oil return 7 is arranged between the two.

Based on the above-mentioned indoor side structure, and taking as an example, the adjustment of the temperature of the hot water of the water terminal 10 on the hot water side is obtained by "the temperature standard of the water outlet is constant and only by adjusting the position of the mixing valve 9". Let's explain the operation mode of the VRF air conditioning system.

When the VRF air conditioning system is in the cooling mode, the CD side of the four-way valve 2 is connected, and the ES side is connected. Compressor 1→outdoor heat exchanger 3→PMV-C→indoor heat exchanger 4→compressor 1 forms the first refrigerant circuit , So that the indoor side where the indoor heat exchanger 4 is located obtains cold capacity, compressor 1→intermediate heat exchanger 82→PMV-Q→indoor heat exchanger 4→compressor 1 forms a second refrigerant circuit, so that the heat storage The device 8 can provide hot water to the user terminal through the water outlet.

When the VRF air conditioning system is in the cooling mode, the high temperature and high pressure refrigerant carries the waste heat transferred from the indoor side for heat recovery, thereby providing hot water (such as domestic hot water) to the water terminal 10 on the hot water side. Taking into account the performance of the heat storage device itself and the experience of the water terminal, a reasonable temperature is usually limited to the hot water in the water storage container 81, which is recorded here as the required target water outlet temperature.

The VRF air conditioning system of the present invention includes a control module, and a temperature sensor is installed at the water outlet of the water storage container 81. The temperature sensor detects the temperature of the outlet water of the water storage container 81 and transmits the detected temperature of the outlet water to the control module. The control module is used to implement the following control method, so that the hot water at the water outlet of the water storage container can fall back as soon as possible when it deviates from the required target water outlet temperature.

In the description of the present invention, "module" and "processor" may include hardware, software, or a combination of both. A module can include hardware circuits, various suitable sensors, communication ports, and memory, and can also include software parts, such as program codes, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. The processor has data and/or signal processing functions. The processor can be implemented in software, hardware, or a combination of the two. The non-transitory computer-readable storage medium includes any suitable medium that can store program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, and so on.

Those skilled in the art can understand that all or part of the process in the method of the above-mentioned embodiment of the present invention can also be completed by instructing relevant hardware through a computer program, and the computer program can be stored in a computer readable In the storage medium, when the computer program is executed by the processor, the steps of the foregoing method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file, or some intermediate forms. The computer-readable medium may include: any entity or device, medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory, random access memory, and electrical carrier signal that can carry the computer program code. , Telecommunications signals and software distribution media, etc. It should be noted that the content contained in the computer-readable medium can be appropriately added or deleted according to the requirements of the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to the legislation and patent practice, the computer-readable medium Does not include electrical carrier signals and telecommunication signals.

Further, it should be understood that since the setting of the control module is only to illustrate the functional units of the system of the present invention, the physical device corresponding to the control module may be the processor itself, or a part of the software or hardware in the processor. Or part of the combination of software and hardware. Therefore, the number of control modules is only illustrative.

Those skilled in the art can understand that the control module can be adaptively split. The specific disassembly of the control module will not cause the technical solution to deviate from the principle of the present invention. Therefore, the technical solutions after the disassembly will fall within the protection scope of the present invention.

Referring to FIG. 3, FIG. 3 shows a first schematic flowchart of a control method of a VRF air conditioning system according to an embodiment of the present invention. As shown in Figure 3, the control method of the VRF air conditioning system includes the following steps:

When the VRF air-conditioning system is in the cooling mode, obtain the temperature of the outlet water at the water outlet 811 of the water storage container detected by the temperature sensor;

Adjust the opening degree of PMV-C and/or PMV-Q according to the outlet water temperature, and adjust the PMV-Q first in the case that the adjustment of the outlet water temperature can be achieved by adjusting the opening degree of PMV-C and PMV-Q. Opening.

When the VRF air-conditioning system meets the indoor air conditioning requirements and the hot water conditioning requirements on the hot water side, PMV-Q is set as a throttling component with priority adjustment, and when a countermeasure strategy for cooling medium adjustment is given for temperature adjustment, it can Realize the adjustment of the outlet water temperature more timely.

Referring to FIG. 4, FIG. 4 shows a second flowchart of a control method of a VRF air conditioning system according to an embodiment of the present invention. As shown in FIG. 4, in a possible implementation manner, the control method of the VRF air conditioning system further includes the following steps:

In the case where the outlet water temperature is greater than the required target outlet water temperature, the opening degree of PMV-Q is preferably reduced. In order to ensure the temperature of the indoor air, the opening degree of PMV-C is increased while or after the opening degree of PMV-Q is decreased. As in a preferred embodiment, after reducing the opening degree of PMV-Q by 10-20 s, the opening degree of PMV-C is increased. PMV-Q's first response strategy can make the adjustment of the outlet water temperature feedback in the first time.

For the step of “increasing the opening degree of PMV-C while or after reducing the opening degree of PMV-Q”, in order to ensure the rapid realization of temperature adjustment, in a possible implementation manner, at least During a part of the adjustment period, the increase in the opening degree of PMV-C is greater than the decrease in the opening degree of PMV-Q. As in a preferred embodiment, the increase in the opening of PMV-C is greater than the decrease in the opening of PMV-Q by not less than 10p. The countermeasures of reserving a short-term priority adjustment space for the hot water side can make the outlet water temperature more effective.

However, the starting point of the control logic of "the increase in the opening degree of PMV-C is greater than the decrease in opening degree of PMV-Q" is to add cooling capacity to the outlet water temperature. Therefore, considering the indoor side experience, PMV -The state where the increase in the opening of C is greater than the decrease in the opening of PMV-Q cannot last too long, such as the state where the increase in the opening of PMV-C is generally greater than the decrease in the opening of PMV-Q The duration should not be more than 3min.

Referring to FIG. 5, FIG. 5 shows a third flowchart of a control method of a VRF air conditioning system according to an embodiment of the present invention. As shown in Fig. 5, in a possible implementation manner, the step of “increasing the opening degree of PMV-C while or after decreasing the opening degree of PMV-Q” further includes:

Assuming that the required target outlet temperature is 55°C, the state where the outlet temperature is higher than the required target outlet temperature is divided into two stages. The first stage is the stage where the outlet temperature is greater than the first set temperature (for example, the first set temperature is 75°C), the second stage is the stage where the outlet water temperature is greater than or equal to the required target outlet temperature to less than or equal to the first set temperature.

Among them, in the above-mentioned first stage, the control method of the VRF air-conditioning system is: turn off the opening degree of PMV-Q to the standby reference opening degree (such as 24p), and increase the opening degree of PMV-C to fully open at the same time;

Among them, in the above-mentioned second stage, the control method of the VRF air-conditioning system is: appropriately open the opening of PMV-Q, such as 5-10p, while appropriately closing the opening of PMV-C, such as continuing to maintain After the opening of PMV-C is fully opened for 10s, the opening of PMV-C should be reduced by 5-10p accordingly. After that, PID adjustment is performed on PMV-C and PMV-Q according to the difference between the outlet water temperature and the required target outlet temperature to ensure the overall performance of the VRF air conditioning system.

Referring to FIG. 6, FIG. 6 shows a fourth flowchart of a control method of a VRF air conditioning system according to an embodiment of the present invention. As shown in Figure 6, the control method of the VRF air conditioning system further includes the following steps:

In the case where the outlet water temperature is less than the required target outlet temperature (for example, the outlet water temperature can be directly compared with the required target outlet temperature, or the outlet water temperature can be compared with a certain set temperature less than the required target outlet temperature), first Increase the opening of PMV-Q to fully open and close the small PMV-C to the standby reference opening (such as 24pls);

After that, take this state as the starting point, and perform PID adjustment on the opening of PMV-C and PMV-Q according to the difference between the outlet water temperature and the required target outlet temperature to ensure the overall performance of the VRF air conditioning system.

The above part is the control method to ensure that the outlet water temperature can meet the standard when the VRF air conditioning system is in the cooling mode.

When the VRF air conditioning system is in heating mode, the DE side of the four-way valve 2 is connected, and the CS side is connected. Compressor 1→indoor heat exchanger 4→PMV-C→outdoor heat exchanger 3→compressor 1 forms the first The refrigerant circuit makes the indoor side of the indoor heat exchanger 4 get heat. Compressor 1→indoor heat exchanger 4→PMV-Q→intermediate heat exchanger 82→compressor 1 forms a second refrigerant circuit. At this time, The heat of the heat storage device 8 to provide hot water to the water terminal on the hot water side through the water outlet comes from the heat stored by the heat storage device 8 itself. At the same time, the second refrigerant circuit, while inputting low-pressure and low-temperature refrigerant to the intermediate heat exchanger 82 of the heat storage device 8, can absorb the heat of the heat storage device 8 for forced heat exchange, thereby increasing the refrigerant at the suction port of the compressor 1. In this way, the indoor heat exchanger 4 can obtain more heat by increasing the refrigerant circulation of the compressor 1 in the circuit.

In this case, the opening degree of PMV-Q can be controlled according to the temperature difference between the refrigerant inlet and the refrigerant outlet of the intermediate heat exchanger, such as increasing the opening degree of PMV-Q when the difference is greater than a certain threshold (such as 1°C) , That is, the indoor heat exchanger 4 obtains more heat through the circulation of the refrigerant. When the difference is less than the threshold, it is considered that the effect of forced heat exchange is not obvious. At this time, PMV-Q can be appropriately reduced or even turned off. The specific way of increasing or decreasing the opening degree of PMV-Q can be PID control according to the specific difference. In the cooling mode, the heat to provide hot water to the outside mainly comes from the heat storage device 8. In order to prevent affecting the basic demand of the water terminal 10 on the hot water side, when the temperature at the water outlet is lower than 25°C, regardless of the difference Whether it is greater than the aforementioned threshold, PMV-Q is selected to be turned off, and active temperature compensation is performed by turning on reserved heat replenishment measures such as auxiliary electric heating to ensure the basic demand of the water terminal 10 on the hot water side.

It should be pointed out that although the various steps are described in a specific sequence in the above embodiments, those skilled in the art can understand that in order to achieve the effects of the present invention, different steps do not have to be executed in this order. It can be executed simultaneously (in parallel) or in other order, or some steps can be omitted, and these changes are all within the protection scope of the present invention.

It should be noted that although the above specific control method is taken as an example for introduction, those skilled in the art can understand that the present invention should not be limited to this. In fact, users can flexibly adjust related steps, parameters in steps and other elements according to actual application scenarios and other situations.

So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to 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 a VRF air conditioning system, characterized in that the VRF air conditioning system includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, a heat storage device, a four-way valve and a throttle component,

The heat storage device includes a water storage container, an intermediate heat exchanger is arranged in the water storage container, and the water storage container has a water outlet,

The throttle assembly includes a first throttle component and a second throttle component,

The compressor, the outdoor heat exchanger, the first throttle component, and the indoor heat exchanger form a first refrigerant circuit,

The compressor, the intermediate heat exchanger, the second throttling component, and the indoor heat exchanger form a second refrigerant circuit,

The control method includes:

Detecting the water outlet temperature at the water outlet;

Adjust the opening degree of the first throttle component and/or the second throttle component according to the outlet water temperature, and

In the case that the temperature of the outlet water can be adjusted by adjusting the opening degrees of the first throttle member and the second throttle member, the opening degree of the second throttle member is adjusted preferentially.
The control method according to claim 1, wherein the four-way valve has four sides C, D, E, and S,

When the CD side of the four-way valve is connected and the ES side is connected, the refrigerant circulates in the first refrigerant circuit composed of the compressor → outdoor heat exchanger → first throttle component → indoor heat exchanger → compressor. So that the indoor side where the indoor heat exchanger is located obtains the cooling capacity,

Through the circulation of the refrigerant in the second refrigerant circuit composed of the compressor → the intermediate heat exchanger → the second throttling component → the indoor heat exchanger → the compressor, the heat storage device can at least provide heat to the hot water side through the water outlet water,

The "According to the outlet water temperature, adjust the opening of the first throttle member and/or the second throttle member, and adjust the opening of the first throttle member and the second throttle member can be In the case of realizing the adjustment of the outlet water temperature, the priority of adjusting the opening of the second throttle component" includes:

In the case where the outlet water temperature is greater than the required target outlet water temperature, the opening of the second throttle component is reduced.
The control method according to claim 2, wherein the “decreasing the opening of the second throttle component when the outlet water temperature is greater than the required target outlet temperature” includes:

Simultaneously or after decreasing the opening degree of the second throttle member, the opening degree of the first throttle member is increased.
The control method according to claim 3, wherein the "increasing the opening of the first throttle member while or after reducing the opening of the second throttle member" includes:

During at least a part of the adjustment, the increase in the opening degree of the first throttle member is greater than the decrease in the opening degree of the second throttle member.
The control method according to claim 4, wherein the “during at least a part of the adjustment period, the increase in the opening degree of the first throttle member is greater than the decrease in the opening degree of the second throttle member” includes :

In the case that the outlet water temperature is greater than the first set temperature, reduce the opening degree of the second throttle component and increase the opening degree of the first throttle component to the maximum;

Wherein, the first set temperature is greater than the required target outlet water temperature.
The control method according to claim 2, characterized in that, after the step of “decreasing the opening of the second throttling member in the case where the outlet water temperature is greater than the required target outlet temperature”, the control method comprises :

In the case that the outlet water temperature is less than the second set temperature, reducing the opening degree of the first throttle member to the reference opening degree and increasing the opening degree of the second throttle member to the maximum;

Perform PID adjustment on the opening degrees of the first throttle component and the second throttle component according to the outlet water temperature;

Wherein, the second set temperature is less than the required target outlet water temperature.
The control method according to any one of claims 1 to 6, wherein a water mixing valve is arranged between the water outlet of the water storage device and the water terminal, and the water mixing valve is also connected to an external water source Pass.
The control method according to any one of claims 1 to 6, wherein the heat storage device further comprises a solar heat storage module, so that the heat obtained from the intermediate heat exchanger and/or the solar heat storage module is transferred to Hot water is provided on the hot water side.
A VRF air conditioning system, characterized in that the VRF air conditioning system includes a control module, and the control module can execute the control method of the VRF air conditioning system according to any one of claims 1 to 8.
A control device, characterized in that it comprises a memory and a processor,

Wherein, the memory is used to store a computer program;

Wherein, the processor can call the program and execute the control method of the VRF air conditioning system according to any one of claims 1 to 8.