WO2017202198A1

WO2017202198A1 - Multi-split system and method for controlling heating throttling element thereof

Info

Publication number: WO2017202198A1
Application number: PCT/CN2017/083654
Authority: WO
Inventors: 罗彬�; 李元阳
Original assignee: 广东美的暖通设备有限公司; 美的集团股份有限公司
Priority date: 2016-05-23
Filing date: 2017-05-09
Publication date: 2017-11-30
Also published as: CN106016457B; EP3467390A1; CN106016457A; EP3467390B1; EP3467390A4

Abstract

A method for controlling a heating throttling element (35) in a multi-split system comprises: obtaining a target gas discharge pressure of a compressor, or a saturation temperature corresponding to the target gas discharge pressure (S1); controlling the compressor according to the target gas discharge pressure or the saturation temperature corresponding to the target gas discharge pressure to enable the compressor to operate stably, obtaining a high pressure and an intermediate pressure of a bypass device (30) after operation of the compressor becomes stable, and calculating a pressure difference between the high pressure and the intermediate pressure (S2); and obtaining a target pressure difference between the high pressure and the intermediate pressure of the bypass device (30), and adjusting an opening degree of the heating throttling element (35) according to the pressure difference and the target pressure difference. A multi-split system applying the method for controlling the heating throttling element is also disclosed.

Description

Multi-line system and control method thereof for heating and throttling element

Technical field

The invention relates to the technical field of air conditioners, in particular to a control method of a heating throttling element in a multi-line system and a multi-line system.

Background technique

The multi-line system has four modes: pure cooling, pure heating, main cooling, and main heating. Among them, the main cooling mode and the main heating mode can simultaneously utilize the system's condensation heat and evaporation heat to achieve simultaneous cooling and heating, which greatly improves the system energy efficiency.

During the operation of the multi-line system, the high-pressure gas of the high-pressure pipe of the outdoor unit enters the heating indoor unit, and after the heating indoor unit releases heat, it expands into a low-pressure gas through the electronic expansion valve and returns to the outdoor unit. The opening degree of the electronic expansion valve will affect the flow rate of the refrigerant entering the heating indoor unit, and also adjust the condensation temperature of the heating indoor unit. The proper opening degree will make the heating indoor unit have both higher refrigerant flow rate and also Higher condensation temperature, which results in higher heat production.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, an object of the present invention is to provide a control method for a heating throttling element in a multi-line system, which adjusts the opening degree of the heating throttling element by the pressure difference between the high and medium pressures of the flow dividing device, so as to The on-line system not only meets the liquid discharge requirements, but also has good performance and energy efficiency during heating, especially during partial load heating, and improves the user experience.

Another object of the present invention is to provide a non-transitory computer readable storage medium.

Yet another object of the present invention is to provide a multi-line system.

To achieve the above object, an embodiment of the present invention provides a method for controlling a heating throttle element in a multi-line system, the multi-line system including an outdoor unit, a flow dividing device, and a plurality of indoor units, the outdoor unit including a compressor, the flow dividing device comprising a first heat exchanger, a second heat exchanger and a heating throttle element, an outlet of the first heat exchange flow path of the first heat exchanger and the second heat exchanger An inlet of the first heat exchange passage is in communication, and an outlet of the second heat exchange passage of the second heat exchanger is in communication with an inlet of the second heat exchange passage of the first heat exchanger, A heating throttling element is disposed between an outlet of the first heat exchange passage of the second heat exchanger and an inlet of the second heat exchange passage of the second heat exchanger, the method comprising the steps of: Obtaining a target exhaust pressure of the compressor or a saturation temperature corresponding to the target exhaust pressure; controlling the compressor according to the target exhaust pressure or a saturation temperature corresponding to the target exhaust pressure to make The compressor is running stably and after the compressor is running stably Take the high pressure and intermediate pressure shunt device, and calculating the high-pressure and the pressure difference between the pressure in the pressure; high and obtaining the shunt device a target pressure difference between the pressure and the medium pressure, and adjusting the opening of the heating and throttling element according to the pressure difference and the target pressure difference.

According to the control method of the heating throttling element in the multi-line system according to the embodiment of the present invention, first, the target exhaust pressure of the compressor or the saturation temperature corresponding to the target exhaust pressure is acquired, and then corresponding to the target exhaust pressure or the target exhaust pressure. The saturation temperature controls the compressor to stabilize the compressor, and obtains the high pressure and medium pressure of the flow dividing device after the compressor is stably operated, and calculates the pressure difference between the high pressure and the medium pressure, and finally obtains The target pressure difference between the high pressure and the medium pressure of the flow dividing device, and the opening of the heating throttle element is adjusted according to the pressure difference and the target pressure difference, so that the multi-line system is heated, especially It is a part load heating system that not only meets the liquid discharge requirements, but also has good performance and energy efficiency to improve the user experience.

According to an embodiment of the present invention, adjusting the opening degree of the heating and throttling element according to the pressure difference value and the target pressure difference value, comprising: if the pressure difference value is greater than the target pressure difference value And controlling the opening degree of the heating and throttling element; if the pressure difference is smaller than the target pressure difference, the opening degree of the heating and throttling element is controlled.

According to an embodiment of the present invention, after adjusting the opening degree of the heating and throttling element, the method further includes: determining whether the pressure difference value is equal to the target pressure difference value, and determining the current state of the compressor Whether the saturation temperature corresponding to the exhaust pressure is greater than or equal to a saturation temperature corresponding to the target exhaust pressure of the compressor, and determining whether the operating frequency of the compressor is greater than or equal to the maximum frequency; if the pressure difference is equal to the target pressure The difference, or the saturation temperature corresponding to the current exhaust pressure of the compressor is greater than or equal to a saturation temperature corresponding to the target exhaust pressure of the compressor, or the operating frequency of the compressor is greater than or equal to the maximum frequency, then controlling The opening of the heating and throttling element remains unchanged.

According to an embodiment of the present invention, if the pressure difference is not equal to the target pressure difference, the saturation temperature corresponding to the current exhaust pressure of the compressor is less than the saturation temperature corresponding to the target exhaust pressure of the compressor. And the operating frequency of the compressor is less than the maximum frequency, the operating frequency of the compressor is adjusted, and the opening degree of the heating and throttling element is adjusted according to the adjusted operating frequency of the compressor .

According to an embodiment of the invention, the multi-line system operates in a heating mode, a main heating mode or a main cooling mode.

To achieve the above object, the present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program, the program being implemented by the processor to implement the control method of the heating throttling element in the multi-line system described above .

The non-transitory computer readable storage medium of the embodiment of the present invention adjusts the heating throttling element according to the pressure difference between the high and medium pressures of the flow dividing device by performing the above-described control method of the heating throttling element in the multi-line system The degree of opening is such that when the multi-line system is heated, especially when partially loaded, it can meet the liquid discharge requirements, has good performance and energy efficiency, and improves the user experience.

In order to achieve the above object, another embodiment of the present invention provides a multi-line system, including: an outdoor unit, the outdoor unit includes a compressor, a plurality of indoor units, a flow dividing device, and the flow dividing device includes a first heat exchange a second heat exchanger and a heating and throttling element, wherein an outlet of the first heat exchange passage of the first heat exchanger is in communication with an inlet of the first heat exchange passage of the second heat exchanger, An outlet of the second heat exchange passage of the second heat exchanger is in communication with an inlet of the second heat exchange passage of the first heat exchanger, and the heating throttle element is disposed at the second exchange Between the outlet of the first heat exchange flow path of the heat exchanger and the inlet of the second heat exchange flow path of the second heat exchanger; a control module for obtaining a target exhaust pressure of the compressor Or the saturation temperature corresponding to the target exhaust pressure, and controlling the compressor according to the target exhaust pressure or a saturation temperature corresponding to the target exhaust pressure to stabilize the compressor, and Obtaining the high pressure and pressure of the flow dividing device after the compressor is stably operated Pressing pressure, the control module calculates a pressure difference between the high pressure and the medium pressure, and acquires a target pressure difference between the high pressure and the medium pressure of the flow dividing device, and according to the The pressure difference and the target pressure difference adjust the opening of the heating throttle element.

According to the multi-line system of the embodiment of the present invention, the control module first acquires the target exhaust pressure of the compressor or the saturation temperature corresponding to the target exhaust pressure, and performs the compressor on the compressor according to the target exhaust pressure or the saturation temperature corresponding to the target exhaust pressure. Control to stabilize the compressor and obtain the high pressure and medium pressure of the flow dividing device after the compressor is stably operated. Then, the control module calculates the pressure difference between the high pressure and the medium pressure, and obtains the high pressure of the flow dividing device. The target pressure difference between the pressure and the medium pressure, and the opening of the heating throttle element according to the pressure difference and the target pressure difference, so that the multi-line system is heated, especially the partial load system When it is hot, it can meet the drainage requirements, but also has good performance and energy efficiency.

According to an embodiment of the present invention, the control module adjusts the opening degree of the heating and throttling element according to the pressure difference value and the target pressure difference value, wherein if the pressure difference is greater than Determining the target pressure difference, the control module performing a small control on the opening of the heating throttle element; if the pressure difference is less than the target pressure difference, the control module is The opening of the thermal throttling element is controlled by an increase.

According to an embodiment of the present invention, after the adjustment of the opening degree of the heating and throttling element, the control module further determines whether the pressure difference is equal to the target pressure difference, and determines the compression. Whether the saturation temperature corresponding to the current exhaust pressure of the machine is greater than or equal to a saturation temperature corresponding to the target exhaust pressure of the compressor, and determining whether the operating frequency of the compressor is greater than or equal to the maximum frequency, and the pressure difference is equal to The target pressure difference, or a saturation temperature corresponding to a current exhaust pressure of the compressor, is greater than or equal to a saturation temperature corresponding to a target exhaust pressure of the compressor, or an operating frequency of the compressor is greater than or equal to the maximum At the frequency, the opening of the heating and throttling element is controlled to remain unchanged.

According to an embodiment of the present invention, if the pressure difference is not equal to the target pressure difference, the saturation temperature corresponding to the current exhaust pressure of the compressor is less than the saturation temperature corresponding to the target exhaust pressure of the compressor. And said The operating frequency of the compressor is less than the maximum frequency, and the control module adjusts the operating frequency of the compressor, and adjusts the opening degree of the heating and throttling element according to the adjusted operating frequency of the compressor. .

DRAWINGS

1 is a block diagram showing the structure of a multi-line system according to an embodiment of the present invention.

2 is a flow chart of a method of controlling a heating throttle element in a multiple-line system in accordance with an embodiment of the present invention.

3 is a flow chart of a method of controlling a heating throttle element in a multiple-line system in accordance with one embodiment of the present invention.

Reference numerals: outdoor unit 10, a plurality of indoor units 20, a flow dividing device 30, a gas-liquid separator 31, a first heat exchanger 32, a second heat exchanger 33, a first throttle element 34, and a heating throttle element 35.

detailed description

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

A multi-line system and a method of controlling the same of the heating and throttling element according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

In an embodiment of the present invention, the multi-line system includes an outdoor unit, a flow dividing device, and a plurality of indoor units, the outdoor unit includes a compressor, and the flow dividing device includes a first heat exchanger, a second heat exchanger, and a heating throttle element. An outlet of the first heat exchange passage of the first heat exchanger is in communication with an inlet of the first heat exchange passage of the second heat exchanger, and an outlet of the second heat exchange passage of the second heat exchanger is first exchanged An inlet of the second heat exchange passage of the heat exchanger is in communication, and the heating throttle element is disposed at an inlet of the first heat exchange passage of the second heat exchanger and an inlet of the second heat exchange passage of the second heat exchanger between.

Specifically, as shown in FIG. 1 , the multi-line system includes an outdoor unit 10 , a plurality of indoor units 20 , and a flow dividing device 30 . The outdoor unit 10 includes a compressor (not specifically shown), and the flow dividing device 30 includes gas and liquid. The separator 31, the first heat exchanger 32, the second heat exchanger 33, the first throttle element 34, and the heating throttle element 35.

The first end of the gas-liquid separator 31 is connected to one end of the outdoor unit 10. The second end of the gas-liquid separator 31 is in communication with the inlet of the first heat exchange passage of the first heat exchanger 32, and the first throttle element 34 is disposed at the first heat exchange passage of the first heat exchanger 32. The outlet is between the inlet of the first heat exchange passage of the second heat exchanger 33. The heating throttle element 35 is disposed between the outlet of the first heat exchange passage of the second heat exchanger 33 and the inlet of the second heat exchange passage of the second heat exchanger 33, and the second heat exchanger 33 The outlet of the second heat exchange flow path is in communication with the inlet of the second heat exchange flow path of the first heat exchanger 32, and the outlet of the second heat exchange flow path of the first heat exchanger 32 is respectively connected to the other end of the outdoor unit 10 One end of the refrigeration indoor unit is connected. Refrigeration indoor unit The other end is in communication with the outlet of the first heat exchange path of the second heat exchanger 33, and the third end of the gas-liquid separator 31 is connected to one end of the heating indoor unit, and the other end of the heating indoor unit is second The inlets of the first heat exchange passages of the heat exchanger 33 are in communication. Wherein, the first throttle element and the heating throttle element may be electronic expansion valves, and the first heat exchanger and the second heat exchanger may be plate heat exchangers.

In the case of multi-line system heating (including multi-line system operation in heating mode, main heating mode or main cooling mode), especially under partial load heating, if the opening of the heating throttling element is too small, then The pressure difference between the inlet and outlet of the heating indoor unit (ie, the pressure difference ΔP=Ps1-Ps2 between the high pressure Ps1 and the intermediate pressure Ps2 of the flow dividing device) becomes smaller, and the refrigerant flow rate and flow rate entering the heating indoor unit are both Reducing, at this time, because the indoor temperature of the heating indoor unit is usually low, there is a chance of liquid storage in the heating chamber, and the outlet temperature of the heating indoor unit is lowered, thereby causing the heating capacity to be attenuated, so measures need to be taken Excess liquid in the heating indoor unit is drained. At the same time, the smaller inlet and outlet pressure difference will not only cause the subcooling degree of the heating indoor unit to be too large, but also cause the pre-valve subcooling degree of the heating throttling element SCm2=Tps2-Tm2 (where Tps2 is the middle of the diverting device) The saturation temperature corresponding to the pressure value, that is, the saturation temperature corresponding to the pre-valve pressure value of the heating throttling element, and Tm2 is the pre-valve temperature value of the heating throttling element) is relatively high.

If the opening degree of the heating throttling element is too large, the pressure difference between the inlet and outlet of the heating indoor unit will become large, and the flow rate and flow rate of the refrigerant entering the heating indoor unit will increase, although the heating indoor unit at this time The liquid storage is not easy to occur, but the outlet supercooling degree of the heating indoor unit is too small, and the pre-chamber subcooling degree SCm2 of the heating and throttling element is too small, and there may be gas in front of the valve, resulting in system instability. At the same time, the opening of the heating throttling element is too large, which will cause the operating frequency of the compressor to increase, the energy efficiency of the system to be lowered, and the high pressure may not rise, and the exhaust superheat of the compressor may be relatively low.

If the heating element does not have liquid accumulation, the opening of the heating throttling element is relatively small. At this time, the exhaust superheat of the compressor is relatively high, the high pressure is relatively high, and the operating frequency of the compressor is relatively low. The system can be very efficient. Therefore, by controlling the pressure difference ΔP=Ps1-Ps2 between the reasonable high pressure Ps1 and the medium pressure Ps2, the system can meet the liquid discharge requirements and have good heating and energy efficiency performance.

2 is a flow chart of a method of controlling a heating throttle element in a multiple-line system in accordance with an embodiment of the present invention. As shown in FIG. 2, the control method of the heating throttling element in the multi-line system includes the following steps:

S1: Obtain a target exhaust pressure of the compressor or a saturation temperature corresponding to the target exhaust pressure.

S2, controlling the compressor according to the target exhaust pressure or the saturation temperature corresponding to the target exhaust pressure to stabilize the compressor, and obtaining the high pressure and the intermediate pressure of the flow dividing device after the compressor is stably operated, and calculating the high pressure The difference in pressure from the medium pressure.

Specifically, when the multi-line system is operated in the heating mode, the main heating mode, or the main cooling mode, the exhaust pressure Pc of the compressor is obtained in real time through a pressure sensor disposed at an exhaust port of the compressor, or is acquired After the exhaust pressure Pc of the compressor, the saturation temperature Tc corresponding to the exhaust pressure is acquired based on the exhaust pressure Pc. Then, according to the exhaust pressure Pc of the compressor (or the saturation temperature Tc corresponding to the exhaust pressure) and the target exhaust pressure Pcs (or the target exhaust pressure) The difference between the saturation temperatures Tcs) is PI (Proportional Integral) adjustment of the operating frequency of the compressor to obtain the new compressor discharge pressure Pc (or exhaust pressure) after the compressor is stably operated. Corresponding saturation temperature Tc), and high pressure pressure Ps1 and intermediate pressure Ps2 of the flow dividing device. Wherein, the high pressure Ps1 can be obtained by a pressure sensor disposed at the outlet of the first heat exchange path of the first heat exchanger of the flow dividing device, and the medium pressure Ps2 can be passed through the first change of the second heat exchanger. Pressure sensor detection at the inlet of the heat flow path is obtained.

S3, obtaining a target pressure difference between the high pressure and the medium pressure of the flow dividing device, and adjusting the opening of the heating throttle element according to the pressure difference and the target pressure difference.

It should be noted that the target pressure difference ΔPs is the pressure difference between the high pressure and the medium pressure of the flow dividing device obtained by the experimental verification, and the target pressure difference ΔPs is generally small. It can guarantee the system refrigerant flow rate and meet the high pressure value.

According to an embodiment of the invention, the opening of the heating throttle element is adjusted according to the pressure difference value and the target pressure difference, including: if the pressure difference is greater than the target pressure difference, opening the heating throttle element The degree is controlled by the small adjustment; if the pressure difference is smaller than the target pressure difference, the opening degree of the heating throttle element is controlled.

That is, the heating throttle is performed on the premise that the compressor is adjusted to obtain the exhaust pressure Pc of the new compressor (or the saturation temperature Tc corresponding to the exhaust pressure), and the high pressure Ps1 and the intermediate pressure Ps2. From the initial opening degree, the element performs PI adjustment based on the pressure difference ΔP between the high pressure pressure Ps1 and the intermediate pressure Ps2 and the target pressure difference ΔPs.

If ΔP > ΔPs, the opening degree of the heating and throttling element is kept small, and at this time, the exhaust pressure Pc of the compressor (or the saturation temperature Tc corresponding to the exhaust pressure) rises, and ΔP becomes small as the flow rate decreases.

If ΔP < ΔPs, the opening degree of the heating throttle element is increased, and at this time, the exhaust pressure Pc of the compressor (or the saturation temperature Tc corresponding to the exhaust pressure) is lowered, and ΔP is increased due to an increase in the flow rate.

According to an embodiment of the present invention, after adjusting the opening degree of the heating throttle element, the method further comprises: determining whether the pressure difference is equal to the target pressure difference, and determining whether the saturation temperature corresponding to the current exhaust pressure of the compressor is And greater than or equal to the saturation temperature corresponding to the target exhaust pressure of the compressor, and determining whether the operating frequency of the compressor is greater than or equal to the maximum frequency; if the pressure difference is equal to the target pressure difference, or the saturation temperature corresponding to the current exhaust pressure of the compressor is greater than When the saturation temperature corresponding to the target exhaust pressure of the compressor is equal, or the operating frequency of the compressor is greater than or equal to the maximum frequency, the opening of the control heating throttle element remains unchanged.

If the pressure difference is not equal to the target pressure difference, the saturation temperature corresponding to the current exhaust pressure of the compressor is less than the saturation temperature corresponding to the target exhaust pressure of the compressor, and the operating frequency of the compressor is less than the maximum frequency, then the compressor The operating frequency is adjusted, and the opening of the heating throttle element is adjusted according to the adjusted operating frequency of the compressor.

Specifically, after adjusting the opening degree of the heating throttle element, it is also determined whether ΔP=ΔPs, and Pc≥Pcs (or Tc≥Tcs) or the compressor is already full. If ΔP=ΔPs, or ΔP≠ΔPs but Pc≥Pcs (or Tc≥Tcs), or ΔP≠ΔPs but the compressor is already full, the opening of the control heating throttle element remains unchanged; otherwise, the compression is adjusted first. The operating frequency of the machine, and re-adjust the opening of the heating throttling element until the above conditions are met. It indicates that the system has reached a steady state, and the opening degree of the heating throttling element can be stabilized under the opening degree, thereby ensuring that the system performance and energy efficiency can be better under heating, especially partial load heating.

In order to make the present invention more clearly understood by those skilled in the art, FIG. 3 is a flowchart of a method of controlling a heating throttle element in a multiple-line system according to a specific example of the present invention.

As shown in FIG. 3, the control method of the heating throttling element in the multi-line system may include the following steps:

S101, the current opening degree of the heating throttle element.

S102, the operating frequency of the compressor is adjusted according to the difference between the exhaust pressure Pc (or the saturation temperature Tc corresponding to the exhaust pressure) and the target exhaust pressure Pcs (or the saturation temperature Tcs corresponding to the target exhaust pressure). A new exhaust pressure Pc (or a saturation temperature Tc corresponding to the exhaust pressure), a high pressure Ps1, and a medium pressure Ps2 are obtained.

S103, performing PI adjustment on the opening degree of the heating throttle element according to the difference between the pressure difference ΔP and the target pressure difference ΔPs.

S104, if ΔP>ΔPs, the opening degree of the small heating and throttling element is turned off.

S105, if ΔP < ΔPs, the opening of the heating element is opened.

S106, it is judged whether ΔP=ΔPs is satisfied, and Pc≥Pcs (or Tc≥Tcs) or the compressor is already full. If yes, go to step S107; if no, go back to step S101.

S107, the heating throttling element is stabilized at the opening, and the system is stable.

In summary, the control method of the heating throttling element in the multi-line system according to the embodiment of the present invention first acquires the target exhaust pressure of the compressor or the saturation temperature corresponding to the target exhaust pressure, and then according to the target exhaust pressure or The saturation temperature corresponding to the target exhaust pressure controls the compressor to stabilize the compressor, and obtains the high pressure and medium pressure of the flow dividing device after the compressor is stably operated, and calculates the pressure between the high pressure and the medium pressure. Difference, finally obtaining the target pressure difference between the high pressure and the medium pressure of the flow dividing device, and rapidly adjusting the opening of the heating throttle element according to the pressure difference and the target pressure difference, so as to make the multi-line system In the heating, especially when the partial load is heated, it can meet the liquid discharge requirements, and has good performance and energy efficiency to improve the user experience.

In addition, the present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program that, when executed by the processor, implements the control method of the heating throttling element in the multi-line system described above.

1 is a block diagram showing the structure of a multi-line system according to an embodiment of the present invention. As shown in FIG. 1, the multi-line system includes an outdoor unit 10, a plurality of indoor units 20, a flow dividing device 30, and a control module (not specifically shown in the drawings).

Wherein, the outdoor unit 10 includes a compressor (not specifically shown), and the flow dividing device 30 includes a first heat exchanger 32, a second heat exchanger 33 and a heating and throttling element 35, the outlet of the first heat exchange passage of the first heat exchanger 32 is in communication with the inlet of the first heat exchange passage of the second heat exchanger 33, and the second exchange The outlet of the second heat exchange passage of the heat exchanger 33 is in communication with the inlet of the second heat exchange passage of the first heat exchanger 32, and the first heat exchange of the heating throttle element 35 at the second heat exchanger 33 is provided. The outlet of the flow path is between the inlet of the second heat exchange flow path of the second heat exchanger 33.

a control module, wherein the control module is configured to acquire a target exhaust pressure of the compressor or a saturation temperature corresponding to the target exhaust pressure, and control the compressor according to the target exhaust pressure or a saturation temperature corresponding to the target exhaust pressure to stabilize the compressor Running, and obtaining the high pressure and the intermediate pressure of the flow dividing device 30 after the compressor is stably operated, the control module calculates the pressure difference between the high pressure and the medium pressure, and obtains the high pressure and the medium pressure of the flow dividing device 30. The target pressure difference between the two, and the opening of the heating and throttling element 35 are adjusted according to the pressure difference and the target pressure difference. Wherein, the target pressure difference is obtained by experimental verification to obtain a pressure difference between the high pressure and the medium pressure of the flow dividing device in the absence of liquid accumulation, and the target pressure difference is generally small to ensure system refrigerant flow. And meet the value of high pressure.

According to an embodiment of the invention, the control module adjusts the opening degree of the heating throttle element according to the pressure difference value and the target pressure difference, wherein if the pressure difference is greater than the target pressure difference, the control module controls the heating The opening degree of the throttle element 35 is controlled to be small; if the pressure difference is smaller than the target pressure difference, the control module controls the opening of the heating throttle element 35 to be increased.

Specifically, when the multi-line system heating (including the multi-line system operating in the heating mode, the main heating mode, or the main cooling mode), especially under partial load heating, the control module first passes through the exhaust gas disposed in the compressor. The pressure sensor at the mouth acquires the exhaust pressure Pc of the compressor in real time, or acquires the saturation temperature Tc corresponding to the exhaust pressure based on the exhaust pressure Pc after acquiring the exhaust pressure Pc of the compressor. Then, the control module compares the difference between the exhaust pressure Pc of the compressor (or the saturation temperature Tc corresponding to the exhaust pressure) and the target exhaust pressure Pcs (or the saturation temperature Tcs corresponding to the target exhaust pressure) to the compressor. The operating frequency is subjected to PI adjustment to obtain a new compressor discharge pressure Pc (or a saturation temperature Tc corresponding to the exhaust pressure), and a high pressure pressure Ps1 and an intermediate pressure Ps2 of the flow dividing device 30 after the compressor is stably operated. Wherein, the high pressure Ps1 can be detected by a pressure sensor disposed at the outlet of the first heat exchange path of the first heat exchanger 32 of the flow dividing device 30, and the medium pressure Ps2 can be passed through the second heat exchanger 33. A pressure sensor at the inlet of the first heat exchange flow path is detected.

Under the premise that the compressor is adjusted to obtain the exhaust pressure Pc of the new compressor (or the saturation temperature Tc corresponding to the exhaust pressure), and the high pressure pressure Ps1 and the intermediate pressure Ps2, the control module according to the high pressure Ps1 and the middle The pressure difference ΔP between the pressures Ps2 and the target pressure difference ΔPs are PI-adjusted from the initial opening degree by the heating throttle element 35.

If ΔP>ΔPs, the control module controls the opening degree of the heating throttle element 35 to be small, at which time the exhaust pressure Pc of the compressor (or the saturation temperature Tc corresponding to the exhaust pressure) rises, and the flow rate decreases, ΔP Become smaller.

If ΔP < ΔPs, the control module controls the opening degree of the heating throttle element 35 to be large, at which time the discharge pressure Pc of the compressor (or the saturation temperature Tc corresponding to the exhaust pressure) is decreased, and ΔP is increased due to the flow rate. Become bigger.

According to an embodiment of the present invention, after the control module adjusts the opening degree of the heating throttle element 35, it also determines Determining whether the pressure difference is equal to the target pressure difference, and determining whether the saturation temperature corresponding to the current exhaust pressure of the compressor is greater than or equal to the saturation temperature corresponding to the target exhaust pressure of the compressor, and determining whether the operating frequency of the compressor is greater than or equal to the maximum Frequency, and when the pressure difference is equal to the target pressure difference, or the saturation temperature corresponding to the current exhaust pressure of the compressor is greater than or equal to the saturation temperature corresponding to the target exhaust pressure of the compressor, or the operating frequency of the compressor is greater than or equal to the maximum frequency The opening of the control heating throttle element 35 remains unchanged.

If the pressure difference is not equal to the target pressure difference, the saturation temperature corresponding to the current exhaust pressure of the compressor is less than the saturation temperature corresponding to the target exhaust pressure of the compressor, and the operating frequency of the compressor is less than the maximum frequency, the control module compresses The operating frequency of the machine is adjusted, and the opening degree of the heating throttle element 35 is adjusted according to the operating frequency of the adjusted compressor.

Specifically, after adjusting the opening degree of the heating throttle element 35, the control module further determines whether there is ΔP=ΔPs, and Pc≥Pcs (or Tc≥Tcs) or the compressor is already full. If ΔP = ΔPs, or ΔP ≠ ΔPs but Pc ≥ Pcs (or Tc ≥ Tcs), or ΔP ≠ ΔPs but the compressor is already full, the control module controls the opening of the heating throttle element 35 to remain unchanged; otherwise, The control module first adjusts the operating frequency of the compressor, and re-adjusts the opening degree of the heating throttle element 35 until the above condition is satisfied, indicating that the system has reached a steady state, and the opening degree of the heating throttle element 35 can be stabilized at the opening degree. In order to ensure that the system can be better under the heating, especially under partial load heating, the performance and energy efficiency of the system can be better.

In the description of the present invention, it is to be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" or "second" may include at least one of the features, either explicitly or implicitly. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless specifically defined otherwise.

In the present invention, the terms "installation", "connected", "connected", "fixed" and the like shall be understood broadly, and may be either a fixed connection or a detachable connection, unless explicitly stated and defined otherwise. , or integrated; can be mechanical or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction of two elements, unless otherwise specified Limited. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification, as well as features of various embodiments or examples, may be combined and combined.

Any process or method description in the flowcharts or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logic function or process. And the scope of the preferred embodiments of the invention includes additional implementations, in which the functions may be performed in a substantially simultaneous manner or in an opposite order depending on the functions involved, in the order shown or discussed. It will be understood by those skilled in the art to which the embodiments of the present invention pertain.

The logic and/or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be embodied in any computer readable medium, Used in conjunction with, or in conjunction with, an instruction execution system, apparatus, or device (eg, a computer-based system, a system including a processor, or other system that can fetch instructions and execute instructions from an instruction execution system, apparatus, or device) Or use with equipment. For the purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport a program for use in an instruction execution system, apparatus, or device, or in conjunction with the instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections (electronic devices) having one or more wires, portable computer disk cartridges (magnetic devices), random access memory (RAM), Read only memory (ROM), erasable editable read only memory (EPROM or flash memory), fiber optic devices, and portable compact disk read only memory (CDROM). In addition, the computer readable medium may even be a paper or other suitable medium on which the program can be printed, as it may be optically scanned, for example by paper or other medium, followed by editing, interpretation or, if appropriate, other suitable The method is processed to obtain the program electronically and then stored in computer memory.

It should be understood that portions of the invention may be implemented in hardware, software, firmware or a combination thereof. In the above-described embodiments, multiple steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware and in another embodiment, it can be implemented by any one or combination of the following techniques well known in the art: discrete with logic gates for implementing logic functions on data signals Logic circuits, application specific integrated circuits with suitable combinational logic gates, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative, It is to be understood that the invention is susceptible to variations, modifications, alterations and variations of the embodiments described herein.

Claims

A control method for a heating throttling element in a multi-line system, characterized in that the multi-line system includes an outdoor unit, a flow dividing device and a plurality of indoor units, the outdoor unit includes a compressor, and the shunt device includes a heat exchanger, a second heat exchanger and a heating and throttling element, an outlet of the first heat exchange passage of the first heat exchanger and an inlet of the first heat exchange passage of the second heat exchanger Connected, the outlet of the second heat exchange passage of the second heat exchanger is in communication with the inlet of the second heat exchange passage of the first heat exchanger, and the heating throttle element is disposed at Between the outlet of the first heat exchange passage of the second heat exchanger and the inlet of the second heat exchange passage of the second heat exchanger, the method comprises the steps of:

Obtaining a target exhaust pressure of the compressor or a saturation temperature corresponding to the target exhaust pressure;

Controlling the compressor according to the target exhaust pressure or a saturation temperature corresponding to the target exhaust pressure to stably operate the compressor, and acquiring a high voltage of the shunt device after the compressor is stably operated Pressure and medium pressure, and calculating a pressure difference between the high pressure and the medium pressure;

Obtaining a target pressure difference between the high pressure and the intermediate pressure of the flow dividing device, and adjusting an opening of the heating and throttling element according to the pressure difference and the target pressure difference.
The method of controlling a heating throttle element in a multiple-line system according to claim 1, wherein the opening of the heating throttle element is adjusted according to the pressure difference value and the target pressure difference ,include:

If the pressure difference is greater than the target pressure difference, the opening of the heating and throttling element is controlled to be small;

If the pressure difference is smaller than the target pressure difference, the opening degree of the heating and throttling element is adjusted.
The control method of the heating and throttling element in the multi-line system according to claim 1 or 2, further comprising: after adjusting the opening degree of the heating and throttling element, further comprising:

Determining whether the pressure difference is equal to the target pressure difference, and determining whether a saturation temperature corresponding to a current exhaust pressure of the compressor is greater than or equal to a saturation temperature corresponding to a target exhaust pressure of the compressor, and determining a Whether the operating frequency of the compressor is greater than or equal to the maximum frequency;

If the pressure difference is equal to the target pressure difference, or the saturation temperature corresponding to the current exhaust pressure of the compressor is greater than or equal to a saturation temperature corresponding to the target exhaust pressure of the compressor, or the compressor When the operating frequency is greater than or equal to the maximum frequency, the opening of the heating and throttling element is controlled to remain unchanged.
A method of controlling a heating throttle element in a multiple-line system according to claim 3, wherein if said pressure difference is not equal to said target pressure difference, said compressor's current exhaust pressure corresponds to The saturation temperature is less than a saturation temperature corresponding to the target exhaust pressure of the compressor, and the operating frequency of the compressor is less than the maximum frequency, the operating frequency of the compressor is adjusted, and according to the adjusted compressor Operating frequency versus the heating throttling The opening of the component is adjusted.
The method of controlling a heating throttle element in a multiple-line system according to any one of claims 1 to 4, wherein the multi-line system operates in a heating mode, a main heating mode, or a main cooling mode. .
A multi-line system, characterized in that it comprises:

An outdoor unit, the outdoor unit including a compressor;

Multiple indoor units;

a flow dividing device comprising a first heat exchanger, a second heat exchanger and a heating throttling element, an outlet of the first heat exchange flow path of the first heat exchanger and the second heat exchanger An inlet of the first heat exchange passage is in communication, and an outlet of the second heat exchange passage of the second heat exchanger is in communication with an inlet of the second heat exchange passage of the first heat exchanger, a heating throttle element disposed between an outlet of the first heat exchange passage of the second heat exchanger and an inlet of the second heat exchange passage of the second heat exchanger;

a control module, configured to acquire a target exhaust pressure of the compressor or a saturation temperature corresponding to the target exhaust pressure, and according to the target exhaust pressure or a saturation temperature corresponding to the target exhaust pressure Controlling the compressor to stabilize the compressor, and obtaining high pressure and medium pressure of the flow dividing device after the compressor is stably operated, the control module calculating the high pressure and the a pressure difference between the intermediate pressures, and a target pressure difference between the high pressure and the medium pressure of the flow dividing device, and the heating according to the pressure difference and the target pressure difference The opening of the throttle element is adjusted.
The multi-line system according to claim 6, wherein the control module adjusts the opening degree of the heating and throttling element according to the pressure difference value and the target pressure difference, wherein

If the pressure difference is greater than the target pressure difference, the control module performs a small control on the opening of the heating and throttling element;

If the pressure difference is less than the target pressure difference, the control module controls the opening of the heating throttle element.
The multi-line system according to claim 6 or 7, wherein the control module further determines whether the pressure difference is equal to the target after adjusting the opening degree of the heating and throttling element a pressure difference value, and determining whether a saturation temperature corresponding to a current exhaust pressure of the compressor is greater than or equal to a saturation temperature corresponding to a target exhaust pressure of the compressor, and determining whether the operating frequency of the compressor is greater than or equal to a maximum frequency And wherein the pressure difference is equal to the target pressure difference, or the saturation temperature corresponding to the current exhaust pressure of the compressor is greater than or equal to a saturation temperature corresponding to the target exhaust pressure of the compressor, or the compression When the operating frequency of the machine is greater than or equal to the maximum frequency, the opening of the heating and throttling element is controlled to remain unchanged.
The multiple-line system according to claim 8, wherein if the pressure difference is not equal to the target pressure difference, a saturation temperature corresponding to a current exhaust pressure of the compressor is less than a target of the compressor Exhaust pressure Corresponding saturation temperature, and the operating frequency of the compressor is less than the maximum frequency, the control module adjusts an operating frequency of the compressor, and performs heating according to an adjusted operating frequency of the compressor The opening of the throttle element is adjusted.
The method of controlling a heating throttle element in a multiple-line system according to any one of claims 6 to 9, wherein the multi-line system operates in a heating mode, a main heating mode, or a main cooling mode. .
A non-transitory computer readable storage medium having stored thereon a computer program, wherein the program is executed by a processor to implement a heating section in a multi-line system according to any one of claims 1-5 The control method of the flow component.