A multi-connected heat medium quantity uniform distribution control system and method

Abstract

The application provides a multi-connected heat medium quantity uniform distribution control system and method, which comprises: a heat exchange module for heat exchanging the medium and indoor air; a control module connected with the heat exchange module for uniformly controlling the distribution of the medium; an operation valve arranged on a main gas pipe and a main liquid pipe; a first indoor unit and a second indoor unit, both connected with the control module through the main gas pipe and connected with the heat exchange module through the main liquid pipe for heat exchanging with the medium to realize heating of indoor space; a filter arranged on the main liquid pipe branch for removing impurities in the medium; and a supercooling coil for dissipating heat in high-temperature and high-pressure medium discharged by the compressor to outdoor air to condense the medium into liquid. The application can ensure uniform distribution of the medium among multiple indoor units by adjusting the electronic expansion valve, and can significantly improve the heating effect of each indoor unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent control, in particular to a multi-connected heat medium quantity uniform distribution control system and method. BACKGROUND

[0002] With the progress of science and technology and the improvement of people's living standards, multi-connected air conditioning systems have been widely used in the market due to their flexibility and energy saving. However, in actual use, multi-connected air conditioning systems have some problems in heating mode, especially the poor heating effect caused by uneven distribution of refrigerant and the refrigerant noise problem, which seriously affects the user experience and the overall efficiency of the system.

[0003] In a multi-connected air conditioning system, one outdoor unit is connected to multiple indoor units, and the high-temperature and high-pressure refrigerant gas discharged by the compressor is transported to each indoor unit through the main pipe and the branch pipe. However, due to the different lengths of the pipes connected to each indoor unit and the height difference of the indoor unit installation positions, uneven distribution of refrigerant often occurs. This uneven distribution not only reduces the heating effect of some indoor units, greatly reducing user experience, but also causes noise when the refrigerant flows due to insufficient subcooling, i.e. the so-called "refrigerant noise", further affecting the comfort of use. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a multi-connected heat medium quantity uniform distribution control system and method, which can ensure uniform distribution of refrigerant between multiple indoor units by adjusting the electronic expansion valve, and significantly improve the heating effect of each indoor unit.

[0005] To solve the above technical problems, the technical solution of the present application is as follows:

[0006] In a first aspect, a multi-connected heat medium quantity uniform distribution control system comprises:

[0007] A heat exchange module for heat exchange between refrigerant and indoor air;

[0008] A control module connected to the heat exchange module for uniform control of refrigerant distribution;

[0009] An operating valve provided on the main gas pipe and the main liquid pipe;

[0010] A first indoor unit and a second indoor unit, both connected to the control module through the main gas pipe and connected to the heat exchange module through the main liquid pipe, for heat exchange with the refrigerant to achieve heating of the indoor space;

[0011] A filter provided on the main liquid pipe branch for removing impurities in the refrigerant;

[0012] The overcooling coil dissipates heat in the high-temperature and high-pressure refrigerant discharged by the compressor to the outdoor air, so that the refrigerant is condensed into a liquid.

[0013] Further, the heat exchange module comprises several heat exchangers, one end of the heat exchanger is connected with the overcooling pipe, the other end is connected with the control module; the overcooling pipe is connected with the outdoor electronic expansion valve, filters are arranged on both sides of the outdoor electronic expansion valve, one end of the outdoor electronic expansion valve is connected with the heat exchange module through the filter, the other end is connected with the overcooling coil and the third outdoor electronic expansion valve of the overcooling coil through the filter.

[0014] Further, the control module comprises:

[0015] a four-way valve;

[0016] a gas-liquid separator connected with the four-way valve;

[0017] a compressor connected with the gas-liquid separator;

[0018] an oil separator, one end of which is connected with the compressor, the bottom of the oil separator is connected with a filter, and the filter is connected with the overcooling coil, the oil separator is connected with the gas-liquid separator through the filter and the two overcooling coils, and the two overcooling coils are connected in parallel, one end of one of the overcooling coils is provided with a control valve;

[0019] an oil separator, one end of which is connected with the compressor, the bottom of the oil separator is connected with a filter, and the filter is connected with the overcooling coil, the oil separator is connected with the gas-liquid separator through the filter and the overcooling coil;

[0020] a one-way valve connected with the oil separator, and the one-way valve is provided with a valve together with the oil separator;

[0021] a high-pressure sensor, one end of which is connected with the one-way valve, and the other end is connected with the four-way valve.

[0022] Further, the first indoor unit comprises a first distributor assembly and a first indoor electronic expansion valve, the first distributor assembly is connected with the main gas pipe through a first gas pipe branch; the first indoor electronic expansion valve is provided with filters on both sides, one end of the first indoor electronic expansion valve is connected with the first distributor assembly through the filter, and the other end is connected with a first liquid branch pipe through the filter, and the first liquid branch pipe is connected with the main liquid pipe.

[0023] The second indoor unit comprises a second distributor assembly and a second indoor electronic expansion valve, the second distributor assembly is connected with the main gas pipe through a second gas pipe branch; the second indoor electronic expansion valve is provided with filters on both sides, one end of the second indoor electronic expansion valve is connected with the second distributor assembly through the filter, and the other end is connected with a second liquid branch pipe through the filter, and the second liquid branch pipe is connected with the main liquid pipe.

[0024] Further, the first indoor unit and the second indoor unit are connected with the overcooling coil through the main liquid pipe; the overcooling coil is connected with the outdoor electronic expansion valve; the four-way valve is connected with the overcooling coil and connected with the third outdoor electronic expansion valve through the overcooling coil; the third outdoor electronic expansion valve is provided with a filter at one end and connected with the filter of the outdoor electronic expansion valve through the filter.

[0025] Further, the first indoor unit and the second indoor unit are configured with temperature sensors for detecting the temperature at the outlet of the indoor heat exchanger.

[0026] In a second aspect, a multi-split air conditioner hot refrigerant quantity uniform distribution control method is provided, which controls the operation conditions according to the refrigerant distribution among the indoor units, comprising:

[0027] The indoor unit is set to an outdoor heating mode, the outdoor heating mode includes non-refrigeration defrosting, non-defrosting control and non-heating oil return control, and it is confirmed that all indoor unit components in the temperature control open state have been continuously operated for at least 5 minutes, wherein the indoor unit components include a first indoor unit (10) and a second indoor unit (11);

[0028] After all the temperature control open indoor units are continuously operated for 5 minutes, when the high pressure detected by the high pressure sensor is greater than 2.5 MPa, the difference between the maximum value and the minimum value of the temperature sensor of the heat exchanger in all the temperature control open indoor units is ≥5℃, and this condition is continuously met for 10 minutes, and a signal is collected every minute during this period, to obtain the operation conditions for the refrigerant distribution uniform control among the indoor units, wherein the broadcast parameter temperature is adjusted by the difference between the maximum value and the minimum value of the temperature sensor, the adjustment interval is 3-10℃, and the unit is 1℃; the number of temperature control open indoor units is ≥2, and at least 50% of the total capacity of the indoor units is in the on state;

[0029] Further, according to the refrigerant distribution among the indoor units, the operation conditions are uniformly controlled to obtain the refrigerant distribution uniform control method among the indoor units, comprising:

[0030] According to the operation conditions of the refrigerant distribution uniform control among the indoor units, the valve opening degree of the electronic expansion valve of the indoor unit is adjusted, so that the adjusted valve opening degree is ≥100; and according to the valve opening degree, the difference between the maximum value and the minimum value of the temperature sensor is maintained to maintain a certain refrigerant flow, so as to obtain the uniform distribution content of the refrigerant among the indoor units;

[0031] According to the uniform distribution content of the refrigerant among the indoor units, the exit conditions are set, including defrosting control start, compressor shutdown, number of temperature control open indoor units change and only one temperature control open indoor unit operation.

[0032] Further, the operation conditions of the refrigerant distribution uniform control of the whole machine include:

[0033] Setting the four-way valve to open, the compressor running time > 10 minutes; after the defrosting control ends, start timing from the four-way valve opening again, full 10 minutes; and after the warm house oil return control ends, also start timing from the four-way valve opening again, full 10 minutes;

[0034] Set the indoor unit to outdoor heating mode, and confirm that all indoor unit components in temperature control open state have been continuously running for at least 5 minutes;

[0035] After all temperature control open indoor units have been running for 5 minutes, when the high pressure sensor detects a high pressure greater than 2.5MPa, the difference between the maximum and minimum values of the temperature sensor of the heat exchanger in all temperature control open indoor units ≥5℃, the EEV of the indoor unit =470; the difference between the set temperature and the temperature value of the temperature control open indoor unit >15℃, and the difference between the temperature difference and the set temperature >20℃ for 5min, to obtain the operating conditions of the whole machine refrigerant uniform distribution control.

[0036] Further, according to the operating conditions of the whole machine refrigerant uniform distribution control, the operating conditions of the whole machine refrigerant uniform distribution control are realized, including:

[0037] According to the operating conditions of the whole machine refrigerant uniform distribution control, the target high pressure is changed to 3.15MPa, and the target superheat degree of the outdoor unit is reduced to 1.5℃, to realize the uniform distribution of the whole machine system refrigerant;

[0038] According to the uniform distribution of the whole machine system refrigerant, the exit conditions are set, including defrosting control start, compressor shutdown, number of temperature control open indoor units changes, warm house oil return control and temperature difference ≤15℃ from set temperature.

[0039] The above scheme of the present application at least includes the following beneficial effects:

[0040] By adjusting the indoor electronic expansion valve, the uniform distribution of refrigerant among multiple indoor units can be ensured. By increasing the compressor frequency and increasing the opening degree of the outdoor electronic expansion valve, not only the uniform distribution of refrigerant among the whole machine is helped, but also the supercooling degree of each indoor unit is increased. By fine adjustment of each main component in the multi-split system, including the indoor electronic expansion valve and the outdoor electronic expansion valve, and adjustment of the compressor frequency, through accurate control of the key components in the multi-split system, the problem of uneven distribution of refrigerant is solved, and the refrigerant sound is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a kind of multi-split system heating refrigerant uniform distribution control system diagram provided by the embodiment of the present application.

[0042] Figure 2A valve aperture is 1.8mm, the front and back pressure difference is 0.98MPa, and the flow curve diagram of different valve steps is provided in the multi-connected heat medium quantity uniform distribution control system.

[0043] 1, heat exchange module; 2, gas-liquid separator; 3, compressor; 4, control module; 5, oil separator; 6, check valve; 7, high pressure sensor; 8, four-way valve; 9, operating valve; 10, first indoor unit; 11, second indoor unit; 12, outdoor electronic expansion valve; 13, heat exchanger; 14, filter; 15, subcooling pipe; 16, subcooling coil; 17, third outdoor electronic expansion valve; 101, first indoor electronic expansion valve; 102, first distributor assembly; 1101, second indoor electronic expansion valve; 1102, second distributor assembly; 18, control valve. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present disclosure will be described below in greater detail with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0045] As Figure 1 shown, the embodiments of the present application propose a multi-connected heat medium quantity uniform distribution control system, comprising:

[0046] The heat exchange module 1 is used for heat exchange between the refrigerant and indoor air.

[0047] The control module 4 is connected with the heat exchange module 1, and is used for uniform control of the distribution of the refrigerant.

[0048] The operating valve 9 is arranged on the main gas pipe and the main liquid pipe.

[0049] The first indoor unit 10 and the second indoor unit 11 are both connected with the control module 4 through the main gas pipe, and are both connected with the heat exchange module 1 through the main liquid pipe, and are used for heat exchange with the refrigerant to realize heating of the indoor space.

[0050] The filter 14 is arranged on the main liquid pipe branch, and is used for removing impurities in the refrigerant.

[0051] The subcooling coil 16 dissipates heat in the high-temperature and high-pressure refrigerant discharged by the compressor to outdoor air, so that the refrigerant is condensed into a liquid.

[0052] In the embodiment of the present application, the design of the heat exchange module 1 enables efficient heat exchange between the refrigerant and indoor air, which helps to quickly adjust the indoor temperature. The presence of the control module 4 enables the system to achieve uniform distribution control of the refrigerant between indoor units and the entire system. The operation of the valves 9 on the main gas pipe and the main liquid pipe can easily control the flow of refrigerant by adjusting these valves. The first indoor unit 10 and the second indoor unit 11 are connected to the control module 4 and the heat exchange module 1 through an optimized connection method, which ensures efficient heat exchange with the refrigerant. The filter 14 is installed on the main liquid pipe branch, which effectively removes impurities in the refrigerant. The design of the subcooling coil 16 enables the heat in the high-temperature and high-pressure refrigerant discharged by the compressor to be efficiently dissipated to the outdoor air, achieving rapid condensation of the refrigerant. This helps to reduce the temperature pressure of the system and improve the operating efficiency.

[0053] In a preferred embodiment of the present application, the heat exchange module 1 includes several heat exchangers 13, one end of which is connected to the subcooling pipe 15, and the other end is connected to the control module 4. The subcooling pipe 15 is connected to the outdoor electronic expansion valve 12, and the outdoor electronic expansion valve 12 is provided with filters 14 on both sides. The outdoor electronic expansion valve 12 is connected to the heat exchange module 1 through the filter 14 on one side, and is connected to the subcooling coil 16 and the third outdoor electronic expansion valve 17 of the subcooling coil on the other side.

[0054] In the embodiment of the present application, the heat exchange module 1 contains multiple heat exchangers 13, which increases the surface area of heat exchange, thereby improving the heat exchange efficiency between the refrigerant and indoor air. The connection design of the subcooling pipe 15 and the heat exchanger 13, as well as the precise control of the outdoor electronic expansion valve 12, enables the refrigerant to be fully subcooled before entering the indoor unit, improving the refrigeration effect and reducing energy loss during transmission. The filters 14 are installed on both sides of the outdoor electronic expansion valve 12, which can effectively remove impurities in the refrigerant and protect the heat exchanger 13 and other system components from the effects of impurities. Through reasonable layout and connection design, as well as precise control of the subcooling coil 16 and the outdoor electronic expansion valve 17, the entire system can operate stably under various environmental conditions, providing continuous and efficient refrigeration or heating effect.

[0055] In a specific embodiment of the present application, the heat exchange module 1 comprises two heat exchangers 13, which are connected with the supercooling pipe 15 at one end, allowing the refrigerant flowing from the supercooling pipe 15 to directly enter the heat exchanger 13 for heat exchange; the other end of the heat exchanger 13 is connected with the control module 4. The control module 4 is responsible for regulating the distribution of refrigerant, ensuring that each heat exchanger 13 can obtain the appropriate amount of refrigerant to achieve efficient heat exchange. The supercooling pipe 15 is directly connected with the outdoor electronic expansion valve 12 for accurately adjusting the flow and pressure of the refrigerant, and the filter 14 is arranged on both sides of the outdoor electronic expansion valve 12. The main function of the filter 14 is to remove impurities in the refrigerant, protecting the subsequent components (such as the heat exchanger 13 and the supercooling coil pipe 16) from being contaminated and damaged. One end of the filter 14 is connected between the outdoor electronic expansion valve 12 and the heat exchange module 1, ensuring that the refrigerant entering the heat exchange module 1 is pure, and the other end of the filter 14 is connected between the outdoor electronic expansion valve 12 and the supercooling coil pipe 16, also playing a role in purifying the refrigerant. The supercooling coil pipe 16 is connected with the outdoor electronic expansion valve 12, and the supercooling coil pipe 16 is also equipped with a special outdoor electronic expansion valve 17 for controlling the flow and pressure of the refrigerant during the supercooling process, ensuring that the supercooling effect reaches the best.

[0056] In a preferred embodiment of the present application, the control module 4 comprises:

[0057] a four-way valve 4;

[0058] a gas-liquid separator 2 connected with the four-way valve 4;

[0059] a compressor 3 connected with the gas-liquid separator 2;

[0060] an oil separator 5, one end of which is connected with the compressor 3, the bottom of the oil separator 5 is connected with the filter 14, and the filter 14 is connected with the supercooling coil pipe 16, the oil separator 5 is connected with the gas-liquid separator 2 through the filter 14 and two supercooling coil pipes 16, and the two supercooling coil pipes 16 are connected in parallel, and one end of one of the supercooling coil pipes 16 is provided with a control valve 18;

[0061] a one-way valve 6 connected with the oil separator 5, and the one-way valve 6 and the oil separator 5 are provided with a valve;

[0062] a high-pressure sensor 7, one end of which is connected with the one-way valve 6, and the other end of which is connected with the four-way valve 4.

[0063] In the embodiment of the present application, through the control of the four-way valve 4, the system can realize the quick switching of the refrigeration and heating modes, and improve the energy conversion efficiency. At the same time, the gas-liquid separator 2 ensures that the refrigerant entering the compressor 3 is gaseous, preventing liquid refrigerant from causing damage to the compressor, thereby prolonging the service life of the compressor and improving its energy efficiency. The design of the oil separator 5 enables the lubricating oil in the refrigerant discharged from the compressor 3 to be effectively separated, ensuring the recovery and reuse of lubricating oil, and also preventing the contamination of other parts of the system by oil. The filter 14 connected at the bottom of the oil separator 5 removes impurities and small particles in the refrigerant, ensuring that the refrigerant entering the subcooling coil 16 is pure. The one-way valve 6 prevents reverse flow of the refrigerant, ensuring safe operation of the system. At the same time, the valve control between the oil separator 5 makes the refrigerant flow more flexible and controllable, and the high-pressure sensor 7 monitors the pressure change of the system in real time and feeds back the signal to the control system.

[0064] In the specific embodiment of the present application, the four-way valve 4 is directly connected with the gas-liquid separator 2, the main gas pipe, the high-pressure sensor 7 and the heat exchange module 1. The connection of the four-way valve 4 with the gas-liquid separator 2 ensures that the refrigerant recovered from the system can smoothly enter the gas-liquid separator 2 for separation. The gas-liquid separator 2 is connected between the four-way valve 4 and the compressor 3, and its main function is to separate the refrigerant before it enters the compressor 3, ensuring that only gaseous refrigerant enters the compressor. The compressor 3 is the power source of the air conditioning system, responsible for compressing the refrigerant, increasing its temperature and pressure. The inlet of the compressor 3 is connected with the gas-liquid separator 2, ensuring that only pure gaseous refrigerant is sucked in. The outlet of the compressor 3 is connected with the oil separator 5, sending the compressed high-temperature and high-pressure refrigerant into the oil separator 5. One end of the oil separator 5 is connected with the outlet of the compressor 3, receiving the high-temperature and high-pressure refrigerant and lubricating oil mixture. The bottom of the oil separator 5 is connected with two subcooling coils 16 through a filter 14. One of the subcooling coils 16 is provided with a control valve 18 for adjusting according to the system flow. The other end of the subcooling coil 16 is connected with the gas-liquid separator 2, forming a circulation. The one-way valve 6 is connected between the oil separator 5 and the high-pressure sensor 7, preventing reverse flow of the refrigerant. A valve is provided between the one-way valve 6 and the oil separator 5 to control the flow of the refrigerant. The high-pressure sensor 7 is used to monitor the high-pressure side pressure of the system. One end of the high-pressure sensor 7 is connected with the one-way valve 6, receiving high-pressure refrigerant from the compressor 3. The other end of the high-pressure sensor 7 is connected with the four-way valve 4, forming a closed-loop control system, which adjusts the working state of the four-way valve 4 according to the pressure change.

[0065] In a preferred embodiment of the present application, the first indoor unit 10 comprises a first distributor assembly 102 connected to the main gas pipe through a first gas pipe branch, and a first indoor electronic expansion valve 101. The first indoor electronic expansion valve 101 is provided with filters 14 on both sides. One end of the first indoor electronic expansion valve 101 is connected to the first distributor assembly 102 through a filter 14, and the other end is connected to a first liquid pipe branch through a filter 14. The first liquid pipe branch is connected to the main liquid pipe.

[0066] The second indoor unit 11 comprises a second distributor assembly 1102 connected to the main gas pipe through a second gas pipe branch, and a second indoor electronic expansion valve 1101. The second indoor electronic expansion valve 1101 is provided with filters 14 on both sides. One end of the second indoor electronic expansion valve 1101 is connected to the second distributor assembly 1102 through a filter 14, and the other end is connected to a second liquid pipe branch through a filter 14. The second liquid pipe branch is connected to the main liquid pipe.

[0067] In the embodiment of the present application, the first indoor unit 10 and the second indoor unit 11 both adopt similar modular designs, including distributor assemblies and electronic expansion valves, and other key components. The distributor assembly can ensure uniform and efficient distribution of refrigerant inside the indoor unit. The indoor electronic expansion valve can accurately control the flow and pressure of the refrigerant to adapt to changes in the indoor environment. The filters 14 provided on both sides of the indoor electronic expansion valve can effectively remove impurities and particulate matter from the refrigerant, keeping the system clean. The modular design and clear connection layout make the first indoor unit and the second indoor unit easier to maintain and manage.

[0068] In a specific embodiment of the present application, the distributor assembly 102 is a key component of the first indoor unit 10, responsible for the distribution and regulation of refrigerant. The distributor assembly 102 is connected to the main gas pipe through a first gas pipe branch. In this way, gaseous refrigerant transported from the main gas pipe can enter the first distributor assembly 102 and then be distributed to various parts of the indoor unit. One end of the first indoor electronic expansion valve 101 is connected to the first distributor assembly 102 through a filter 14. Liquid refrigerant flowing out of the first distributor assembly 102 can be filtered by the filter 14 and then enter the first indoor electronic expansion valve 101. The other end of the first indoor electronic expansion valve 101 is also provided with a filter 14 and connected to the first liquid pipe branch through this filter. The liquid refrigerant adjusted by the first indoor electronic expansion valve 101 will be filtered again and then flow into the main liquid pipe through the first liquid pipe branch.

[0069] In another embodiment of the present application, the second distributor assembly 1102 is similar to the first distributor assembly 102 in the first indoor unit. The second distributor assembly 1102 is connected to the main gas pipe through a second gas pipe branch, so as to receive the gaseous refrigerant delivered from the main gas pipe. One end of the second indoor electronic expansion valve 1101 is connected to the second distributor assembly 1102 through a filter 14, so as to receive the liquid refrigerant flowing out of the distributor assembly. The other end of the second indoor electronic expansion valve 1101 is also connected to the second liquid pipe through a filter 14. The adjusted liquid refrigerant will be filtered and then flow back to the main liquid pipe through the second liquid pipe.

[0070] In a preferred embodiment of the present application, the first indoor unit 10 and the second indoor unit 11 are connected to the supercooling coil 16 through the main liquid pipe; the supercooling coil 16 is connected to the outdoor electronic expansion valve 12; the four-way valve 4 is connected to the supercooling coil 16 and the third outdoor electronic expansion valve 17 through the supercooling coil 16; one end of the third outdoor electronic expansion valve 17 is provided with a filter 14, and the filter 14 is connected to the filter 14 of the outdoor electronic expansion valve 12.

[0071] In an embodiment of the present application, the first indoor unit 10 and the second indoor unit 11 are directly connected to the supercooling coil 16 through the main liquid pipe, so that the refrigerant flowing back from the indoor unit can be quickly cooled again through the supercooling coil; the supercooling coil 16 is connected to the outdoor electronic expansion valve 12, allowing accurate control of the refrigerant flow during supercooling; the connection of the four-way valve 4 to the supercooling coil 16 allows the system to flexibly switch between different operating modes (such as cooling and heating); the filter 14 is provided at one end of the third outdoor electronic expansion valve 17 and connected to the filter 14 of the outdoor electronic expansion valve 12, forming a double filtration system.

[0072] In an embodiment of the present application, the first indoor unit 10 and the second indoor unit 11 are connected to the supercooling coil 16 through the main liquid pipe. The output end of the supercooling coil 16 is connected to the outdoor electronic expansion valve 12. After the liquid refrigerant is cooled by the supercooling coil 16, it will flow into the outdoor electronic expansion valve 12. One connection port of the four-way valve 4 is connected to the supercooling coil 16 and to the third outdoor electronic expansion valve 17 through the supercooling coil 16. The four-way valve 4 allows the refrigerant to flow through the supercooling coil 16 and the outdoor electronic expansion valve 17 according to the operating mode (cooling or heating) of the system. One end of the third outdoor electronic expansion valve 17 is provided with a filter 14. The filter 14 is also connected to the filter 14 of the outdoor electronic expansion valve 12 through a pipe.

[0073] In a preferred embodiment of the present application, temperature sensors are arranged in the first indoor unit 10 and the second indoor unit 11 to detect the temperature at the outlet of the indoor unit heat exchanger.

[0074] In the embodiments of the present application, the temperature sensor can monitor the temperature at the outlet of the heat exchanger in real time, thereby ensuring that the air temperature provided by the indoor unit is consistent with the set temperature. By accurately sensing the indoor temperature, the air conditioning system can more intelligently adjust the cooling or heating power, and the real-time monitoring function of the temperature sensor helps to prevent the indoor unit from overheating or overcooling. Once an abnormal temperature is detected, the system can immediately respond. By responding to temperature changes in a timely manner, the air conditioning system can avoid damage to the equipment caused by extreme temperatures, thereby prolonging the service life of the equipment.

[0075] A multi-split heat medium quantity uniform distribution control method, according to the refrigerant distribution between indoor units, to uniformly control the operating conditions, comprising:

[0076] The indoor unit is set to an outdoor heating mode, the outdoor heating mode includes non-refrigeration defrosting, non-defrosting control and non-heating oil return control, and it is confirmed that all indoor unit components in the temperature control open state have been continuously operated for at least 5 minutes, wherein the indoor unit components include a first indoor unit 10 and a second indoor unit 11;

[0077] After all the temperature control open indoor units have been continuously operated for 5 minutes, when the high pressure detected by the high pressure sensor is greater than 2.5 MPa, the difference between the maximum and minimum values of the temperature sensor of the heat exchanger in all the temperature control open indoor units is ≥5℃, and this condition is continuously met for 10 minutes, and a signal is collected every minute during this period to obtain the operating conditions for uniform control of refrigerant distribution between indoor units, wherein the broadcast code parameter temperature is adjusted by the difference between the maximum and minimum values of the temperature sensor, the adjustment interval is 3-10℃, and the unit is 1℃; the number of indoor units in the temperature control open state is ≥2, and at least 50% of the total capacity of the indoor units is in the on state;

[0078] In the embodiments of the present application, by accurately controlling the operating mode and response conditions of the indoor unit, the system can more efficiently utilize energy. In non-refrigeration defrosting, non-defrosting control and non-heating oil return control and other modes, the system can avoid unnecessary energy consumption; by monitoring the data of the high pressure sensor and the indoor unit heat exchanger temperature sensor, the system can more accurately grasp the distribution of refrigerant among the indoor units. By setting specific operating conditions and parameters such as high pressure threshold and temperature sensor temperature difference, the system can respond promptly in abnormal situations to avoid equipment damage or performance degradation. By accurately controlling the temperature and operating mode of the indoor unit, the system can provide a more comfortable and stable indoor environment for the user. By collecting and analyzing the operating data of the indoor unit components, the system can achieve more intelligent management.

[0079] In a preferred embodiment of the present application, according to the refrigerant distribution between indoor units, the operating conditions are uniformly controlled to obtain a method for uniform control of refrigerant distribution between indoor units, comprising:

[0080] According to the operation condition of the indoor unit refrigerant distribution uniform control, the electronic expansion valve opening degree of the indoor unit is adjusted, so that the adjusted valve opening degree ≥100; and according to the difference between the maximum value and the minimum value of the high pressure and the temperature sensor temperature, a certain refrigerant flow is maintained, so as to obtain the uniform distribution of the refrigerant between the indoor units.

[0081] According to the uniform distribution of the refrigerant between the indoor units, the exit condition is set, including the defrosting control start, the compressor shutdown, the change of the number of indoor units with temperature control open, and only one indoor unit with temperature control open.

[0082] In the embodiment of the application, by adjusting the indoor valve opening degree, the refrigerant can be more evenly distributed between the indoor units. When the system detects that the difference between the maximum value and the minimum value of the high pressure and the temperature sensor temperature reaches the set condition, timely adjustment of the valve opening degree can quickly change the refrigerant flow, so that the system reaches a stable state more quickly. By precisely controlling the valve opening degree and the refrigerant flow, the system can meet the user's needs while minimizing energy consumption and refrigerant waste. This helps to reduce operating costs and achieve more environmentally friendly and energy-saving air conditioning operation. Reasonable valve opening degree adjustment and exit condition setting can avoid damage to the system due to excessive pressure or temperature fluctuations, thereby prolonging the service life of the equipment. At the same time, this also reduces the frequency of maintenance and replacement of parts, thereby reducing maintenance costs. By ensuring the uniform distribution of refrigerant and timely response to temperature changes, a more comfortable and stable indoor environment is provided.

[0083] In a preferred embodiment of the application, the operation condition of the whole machine refrigerant distribution uniform control includes:

[0084] The calculation of the four-way valve opening and the compressor running time is set to be >10 minutes; after the defrosting control ends, the timing starts again from the four-way valve opening, and it is full 10 minutes; and after the warm house oil return control ends, the timing also starts again from the four-way valve opening, and it is full 10 minutes;

[0085] The indoor unit is set to outdoor warm house mode, and it is confirmed that all indoor unit components in the temperature control open state have been continuously operated for at least 5 minutes;

[0086] After all the indoor units with temperature control open have been continuously operated for 5 minutes, when the high pressure detected by the high pressure sensor is greater than 2.5 MPa, the difference between the maximum value and the minimum value of the temperature sensor temperature of the heat exchanger in all the indoor units with temperature control open is ≥5℃, the valve opening degree EEV of the indoor unit is 470; the difference between the set temperature and the temperature value of the indoor unit with temperature control open is >15℃, and the difference between the temperature difference and the set temperature is >20℃ for 5 minutes, to obtain the operation condition of the whole machine refrigerant distribution uniform control.

[0087] In the embodiments of the present application, by precisely controlling the opening time of the four-way valve and the running time of the compressor, the system can operate more efficiently. Ensuring that the compressor works in the best state, avoiding unnecessary energy consumption and wear and tear, thus improving the overall efficiency. After the defrosting control and the warm house oil return control end, start timing from the four-way valve opening again, ensure that the system has enough time to stabilize and recover. By setting specific operating conditions, such as the high pressure detected by the high pressure sensor being greater than 2.5 MPa, and the difference between the maximum and minimum values of the heat exchanger temperature sensor, the system can more accurately control the distribution of refrigerant between various indoor units. By monitoring and controlling multiple key parameters, such as indoor unit valve opening, temperature difference, etc., the system can respond promptly in abnormal situations, avoiding equipment damage or performance degradation. This helps to enhance the stability and reliability of the system, reducing the likelihood of failure. By precisely controlling the temperature and refrigerant distribution of indoor units, the system can provide users with a more comfortable and stable indoor environment.

[0088] In a preferred embodiment of the present application, the operating conditions for achieving uniform refrigerant distribution control of the entire system include:

[0089] According to the operating conditions for achieving uniform refrigerant distribution control of the entire system, the target high pressure is changed to 3.15 MPa, and the outdoor unit target superheat is reduced to 1.5℃, to achieve uniform distribution of refrigerant in the entire system.

[0090] According to the content of uniform distribution of refrigerant in the entire system, the exit conditions are set, including defrosting control start, compressor shutdown, number of indoor units with temperature control opening changes, warm house oil return control, and difference between temperature difference and set temperature ≤15℃.

[0091] In the embodiments of the present application, by changing the target high pressure to 3.15 MPa, the system can operate at a higher pressure, which helps to improve heat exchange efficiency, thus achieving better refrigeration or heating effect under the same energy consumption. At the same time, reducing the outdoor unit target superheat to 1.5℃ can reduce unnecessary energy consumption and improve overall energy efficiency. By setting carefully designed exit conditions, such as defrosting control start and compressor shutdown, the system can respond promptly when encountering potential problems or abnormal situations, avoiding equipment damage or performance degradation. By adjusting the target high pressure and superheat, the system can better control the flow and distribution of refrigerant, ensuring that each indoor unit can obtain the required amount of refrigerant, which helps to achieve more uniform temperature control, improve the utilization efficiency of refrigerant, and reduce waste.

[0092] Figure 2 The flow curve diagram for different valve steps of the electronic expansion valve, with a pressure difference of 0.98 MPA and medium being air. If this electronic expansion valve is used in a refrigerant system, because the pressure difference before and after the valve body is different, the medium is different, and the flow is also different, but the trend is the same.

[0093] Number of pulses Flow rate 0 0 10 0 20 0.23 30 3.62 40 5.49 50 6.74 60 8.1 70 9.43 80 10.65 90 11.91 100 13.26 125 16.12 150 18.83 175 21.74 200 24.12 250 28.82 300 33.27 350 37.17 400 40.6 450 43.62 500 46.36

[0094] The above describes the preferred embodiments of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which should also be considered as the protection scope of the present application.

Claims

1. A method for controlling uniform distribution of a heat-source refrigerant amount in a multi-connected system, characterized by, The application relates to a multi-connected heat medium quantity uniform distribution control system. The system comprises: a heat exchange module (1) for heat exchange between the heat medium and indoor air; a control module (4) connected with the heat exchange module (1) for uniform control of the distribution of the heat medium; an operation valve (9) arranged on a main gas pipe and a main liquid pipe; a first indoor unit (10) and a second indoor unit (11) both connected with the control module (4) through the main gas pipe and connected with the heat exchange module (1) through the main liquid pipe for heat exchange with the heat medium to realize heating of an indoor space; a filter (14) arranged on the main liquid pipe branch for removing impurities in the heat medium; a supercooling coil (16) for dissipating heat in high-temperature and high-pressure heat medium discharged by a compressor to outdoor air so that the heat medium is condensed into liquid; the control module (4) comprises: a four-way valve (8); a gas-liquid separator (2) connected with the four-way valve (8); a compressor (3) connected with the gas-liquid separator (2); an oil separator (5) connected with the compressor (3) at one end; a high-pressure sensor (7) connected with a one-way valve (6) at one end and connected with the four-way valve (8) at the other end; the first indoor unit (10) comprises a first distributor assembly (102) and a first indoor electronic expansion valve (101); the second indoor unit (11) comprises a second distributor assembly (1102) and a second indoor electronic expansion valve (1101); temperature sensors are arranged in the first indoor unit (10) and the second indoor unit (11) for detecting the temperature at the outlet of an indoor unit heat exchanger; the operation conditions of the indoor unit heat medium distribution uniform control include: setting the indoor unit to an outdoor heating mode, the outdoor heating mode comprising non-refrigeration defrosting, non-defrosting control and non-heating oil return control, and confirming that all indoor unit components in a temperature control open state have continuously operated for at least 5 minutes, wherein the indoor unit components include the first indoor unit (10) and the second indoor unit (11); after all the indoor units in the temperature control open state continuously operate for 5 minutes, when the high pressure detected by the high-pressure sensor is greater than 2.5 MPa, the difference between the maximum value and the minimum value of the temperature sensor of the heat exchanger in all the indoor units in the temperature control open state is greater than or equal to 5 DEG C, and the condition is continuously satisfied for 10 minutes, signals are collected every minute during the 10 minutes to obtain the operation conditions of the indoor unit heat medium distribution uniform control, wherein the maximum value and the minimum value of the temperature sensor are used to adjust the temperature of a dial code parameter, the adjustment interval is 3-10 DEG C, and the unit is 1 DEG C; the number of indoor units in the temperature control open state is greater than or equal to 2, and at least 50% of the total capacity of the indoor units is in the open state; according to the operation conditions of the indoor unit heat medium distribution uniform control, an indoor unit heat medium distribution uniform control method is obtained, which comprises: according to the operation conditions of the indoor unit heat medium distribution uniform control, the valve opening degree of the electronic expansion valve of the indoor unit is adjusted so that the adjusted valve opening degree is greater than or equal to 100, and the high pressure and the difference between the maximum value and the minimum value of the temperature sensor are maintained to maintain a certain heat medium flow, so that the indoor unit heat medium is uniformly distributed. According to the uniform distribution of the refrigerant between the indoor units, the exit condition is set, including defrost control start, compressor shutdown, the number of indoor units with temperature control start changing and only one indoor unit with temperature control start running.

2. The control method of claim 1, wherein The heat exchange module (1) comprises several heat exchangers (13), one end of the heat exchanger (13) is connected with the supercooling pipe (15), the other end is connected with the control module (4); the supercooling pipe (15) is connected with the first outdoor electronic expansion valve (12), both sides of the first outdoor electronic expansion valve (12) are provided with filters (14), one end of the first outdoor electronic expansion valve (12) is connected with the heat exchange module (1) through the filter (14), the other end is connected with the supercooling coil pipe (16) and the third outdoor electronic expansion valve (17) of the supercooling coil pipe.

3. The control method of claim 2, wherein The bottom of the oil separator (5) is connected with the filter (14), and the filter (14) is connected with the supercooling coil pipe (16), the oil separator (5) is connected with the gas-liquid separator (2) through the filter (14) and two supercooling coil pipes (16), and the two supercooling coil pipes (16) are connected in parallel, one end of one of the supercooling coil pipes (16) is provided with a control valve (18); the one-way valve (6) is connected with the oil separator (5).

4. The control method of claim 3, wherein The first distributor assembly (102) is connected with the main gas pipe through the first gas pipe branch; the first indoor electronic expansion valve (101) is provided with filters (14) on both sides, one end of the first indoor electronic expansion valve (101) is connected with the first distributor assembly (102) through the filter (14), the other end is connected with the first liquid branch pipe through the filter (14), and the first liquid branch pipe is connected with the main liquid pipe; The second distributor assembly (1102) is connected with the main gas pipe through the second gas pipe branch; the second indoor electronic expansion valve (1101) is provided with filters (14) on both sides, one end of the second indoor electronic expansion valve (1101) is connected with the second distributor assembly (1102) through the filter (14), the other end is connected with the second liquid branch pipe through the filter (14), and the second liquid branch pipe is connected with the main liquid pipe.

5. The control method of claim 4, wherein The first indoor unit (10) and the second indoor unit (11) are connected with the supercooling coil pipe (16) through the main liquid pipe; the cooling coil pipe (16) is connected with the first outdoor electronic expansion valve (12); the four-way valve (8) is connected with the supercooling coil pipe (16) and connected with the third outdoor electronic expansion valve (17) through the supercooling coil pipe (16); one end of the third outdoor electronic expansion valve (17) is provided with a filter (14), and the filter (14) is connected with the filter (14) of the first outdoor electronic expansion valve (12).

6. The control method of claim 5, wherein The operation conditions of the whole machine refrigerant distribution uniform control include: Setting the calculation four-way valve opening, the compressor running time > 10 minutes; after the defrost control ends, the four-way valve is opened again, and the timing is started, and it is full 10 minutes; and after the greenhouse oil return control ends, the four-way valve is opened again, and the timing is started, and it is full 10 minutes; The indoor unit is set to outdoor greenhouse mode, and it is confirmed that all indoor unit components in the temperature control start state have been continuously running for at least 5 minutes; After all temperature control on indoor units continuously run for 5 minutes, when the high pressure detected by the high pressure sensor is greater than 2.5 MPa, the difference between the maximum and minimum values of the temperature sensor of the heat exchanger in all temperature control on indoor units is greater than or equal to 5 DEG C, the valve opening EEV of the indoor unit is 470, the difference between the set temperature and the temperature value of the temperature control on indoor unit is greater than 15 DEG C, and the difference between the temperature difference and the set temperature is greater than 20 DEG C for 5 minutes, the operating conditions for obtaining uniform refrigerant distribution control of the whole machine are obtained.

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