Air conditioner frequency adjusting method and system based on connecting pipe

Abstract

An air conditioner frequency adjusting method based on a connecting pipe comprises the following steps that S1, pressure sensors are installed at an inlet and an outlet of an evaporator, and first liquid pressure at the inlet of the evaporator is obtained through the pressure sensors; s2, whether the first liquid pressure is larger than a pressure threshold value or not is judged, if the first liquid pressure is larger than the pressure threshold value, the current liquid temperature in the input connecting pipe is obtained, and an adjusting coefficient is obtained based on the length and diameter of the input connecting pipe and the liquid temperature; and S3, the power of the current air conditioner outdoor unit is adjusted based on the adjusting coefficient. And the power of the air conditioner outdoor unit is adjusted based on the adjusting coefficient, so that the power of the air conditioner outdoor unit can be kept within a certain working interval, and the indoor temperature can be kept stable and comfortable. The problems that the refrigerating effect is reduced or energy consumption is increased due to the fact that the pressure of the evaporator is too high are solved, and therefore the use experience of a user is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning regulation, and in particular to an air conditioning frequency regulation method and system based on a connecting pipe. Background Art

[0002] The connecting pipes between the indoor and outdoor units of the air conditioner include an input connecting pipe and an output connecting pipe. The output connecting pipe is responsible for bringing the refrigerant placed in the indoor unit to the outdoor unit outside to complete the condensation. After the condensation is completed, it will become a high-pressure liquid and re-enter the indoor unit through the input connecting pipe to form a circulating refrigeration system.

[0003] Because the air conditioning system is affected by the user's actual installation environment during installation, the length of the connecting pipes between the internal and external units is not the same. When the user uses a larger power to operate or start the air conditioner, due to the short length of the input connecting pipe, there is not enough space for the liquid to flow and dissipate heat. At the same time, a large amount of liquid will block the input connecting pipe, affecting the normal flow of the refrigerant, and ultimately affecting the efficiency and performance of the air conditioning system. Therefore, a method that can balance the length of the connecting pipe and the air conditioning frequency is urgently needed. Summary of the invention

[0004] In view of the above-mentioned defects, the purpose of the present invention is to propose an air-conditioning frequency adjustment method and system based on a connecting pipe, so as to solve the problem that the power of the existing air-conditioning outdoor unit is fixed and the power cannot be self-adjusted due to the different lengths of the connecting pipe.

[0005] To achieve this purpose, the present invention adopts the following technical solution: an air conditioning frequency adjustment method based on a connecting pipe, comprising the following steps:

[0006] Step S1: installing pressure sensors at the inlet and outlet of the evaporator, and obtaining a first liquid pressure at the inlet of the evaporator through the pressure sensors;

[0007] Step S2: determining whether the first liquid pressure is greater than a pressure threshold, and if so, obtaining the current liquid temperature in the input connecting pipe, and obtaining a regulation coefficient based on the length and diameter of the input connecting pipe and the liquid temperature;

[0008] Step S3: adjusting the power of the current air conditioner outdoor unit based on the adjustment coefficient.

[0009] Preferably, the step of obtaining the adjustment coefficient based on the length and diameter of the quantity connecting pipe and the liquid temperature in step S2 is as follows:

[0010] Determine the gas phase coefficient of the current condensate based on the liquid temperature;

[0011] Obtaining a second liquid pressure at an outlet of the evaporator, obtaining a pressure difference between the first liquid pressure and the second liquid pressure, and obtaining a current flow rate of the condensate fluid based on the pressure difference and the gas phase coefficient;

[0012] Predicting a first total pressure drop in the current pipeline according to the length and diameter of the input connecting pipe and the flow rate of the condensate fluid;

[0013] The ratio between the standard total pressure drop and the first total pressure drop is used as the adjustment coefficient.

[0014] Preferably, the formula for obtaining the flow rate of the current condensate fluid based on the pressure difference and the gas phase coefficient is as follows:

[0015]

[0016] Where Δp is the pressure difference, ρ mix =αρ1+(1-α)ρ2, α is the gas phase coefficient, ρ1 and ρ2 are the density of the condensate fluid when it is vaporized and the density when it is liquefied, respectively;

[0017] The formula for obtaining the first total pressure drop is as follows:

[0018]

[0019] Where f is the pipeline friction factor, L is the length of the input connecting pipe, D is the diameter of the input connecting pipe, v is the flow rate of the condensate fluid, and K is the resistance coefficient.

[0020] Preferably, the specific steps of step S3 are as follows:

[0021] The adjustment coefficient, the length of the input connection pipe, and the diameter are input into the PID controller to obtain the operating frequency of the outdoor unit when the condenser flows smoothly into the evaporator as the first frequency;

[0022] The current operating frequency of the external machine is obtained as the second operating frequency, and it is determined whether the frequency difference between the first operating frequency and the second operating frequency is less than the first frequency threshold. If so, the power of the external machine is not adjusted, and step S1 is executed again after a preset time.

[0023] If the frequency difference is greater than the first frequency threshold and less than the second frequency threshold, the power of the outdoor unit is adjusted to the first frequency;

[0024] If the frequency difference is greater than the second frequency threshold, the lowest operating frequency is used as the power of the air conditioner outdoor unit, and when the first liquid pressure is lower than or equal to the pressure threshold, the power of the outdoor unit is adjusted to the first frequency.

[0025] Preferably, the formula for obtaining the first frequency is as follows:

[0026]

[0027] Where Kp, Ki, Kd are the gains of the PID controller, μ is the adjustment coefficient, and sum error The difference between the total pressure drop in the input pipeline and the standard total pressure after adjusting the frequency for the outdoor unit.

[0028] An air conditioning frequency adjustment system based on a connecting pipe, characterized in that the air conditioning frequency adjustment method based on a connecting pipe is used, comprising a pressure sensing module, a data processing module and an adjustment module;

[0029] The pressure sensing module is used to install pressure sensors at the inlet and outlet of the evaporator, and obtain the first liquid pressure at the inlet of the evaporator through the pressure sensor;

[0030] The data processing module is used to determine whether the first liquid pressure is greater than a pressure threshold, and if so, to obtain the liquid temperature in the current input connecting pipe, and to obtain the adjustment coefficient based on the length and diameter of the input connecting pipe and the liquid temperature;

[0031] The adjustment module is used to adjust the power of the current air conditioner outdoor unit based on the adjustment coefficient.

[0032] Preferably, the data processing module includes a gas phase coefficient acquisition submodule, a flow rate acquisition submodule, a first total pressure drop acquisition submodule and an adjustment coefficient acquisition submodule;

[0033] The gas phase coefficient acquisition submodule is used to determine the gas phase coefficient of the current condensate based on the liquid temperature;

[0034] The flow rate acquisition submodule is used to acquire the second liquid pressure at the outlet of the evaporator, acquire the pressure difference between the first liquid pressure and the second liquid pressure, and acquire the flow rate of the current condensate fluid based on the pressure difference and the gas phase coefficient;

[0035] The first total pressure drop acquisition submodule is used to predict the first total pressure drop in the current pipeline according to the length and diameter of the input connecting pipe and the flow rate of the condensate fluid;

[0036] The regulation coefficient acquisition submodule is used to use the ratio between the standard total pressure drop and the first total pressure drop as the regulation coefficient.

[0037] Preferably, the adjustment module includes a frequency acquisition submodule and an adjustment submodule;

[0038] The frequency acquisition submodule is used to input the adjustment coefficient, the length of the input connection pipe, and the diameter input value into the PID controller to obtain the operating frequency of the external unit when the condenser flows smoothly into the evaporator as the first frequency;

[0039] The regulating submodule is used to obtain the current operating frequency of the external machine as the second operating frequency, and determine whether the frequency difference between the first operating frequency and the second operating frequency is less than the first frequency threshold. If so, the power of the external machine is not adjusted, and the pressure sensing module is called again after a preset time.

[0040] If the frequency difference is greater than the first frequency threshold and less than the second frequency threshold, the power of the outdoor unit is adjusted to the first frequency;

[0041] If the frequency difference is greater than the second frequency threshold, the lowest operating frequency is used as the power of the air conditioner outdoor unit, and when the first liquid pressure is lower than or equal to the pressure threshold, the power of the outdoor unit is adjusted to the first frequency.

[0042] One of the above technical solutions has the following advantages or beneficial effects: in the present invention, the adjustment coefficient of the condensate fluid being able to smoothly pass through the evaporator is obtained by inputting the length, diameter and liquid temperature of the connecting pipe, and then the power of the air conditioner outdoor unit is adjusted based on the adjustment coefficient, so that the power of the air conditioner outdoor unit can be maintained in a certain working range, so that the indoor temperature can be kept stable and comfortable. The problems such as reduced refrigeration effect or increased energy consumption caused by excessive evaporator pressure are avoided, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a flow chart of an embodiment of the method of the present invention.

[0044] Figure 2 It is a schematic diagram of the structure of an embodiment of the system of the present invention. DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0046] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] like Figures 1-2 As shown, a method for adjusting the frequency of an air conditioner based on a connecting pipe comprises the following steps:

[0049] Step S1: installing pressure sensors at the inlet and outlet of the evaporator, and obtaining a first liquid pressure at the inlet of the evaporator through the pressure sensors;

[0050] Step S2: determining whether the first liquid pressure is greater than a pressure threshold, and if so, obtaining the current liquid temperature in the input connecting pipe, and obtaining a regulation coefficient based on the length and diameter of the input connecting pipe and the liquid temperature;

[0051] Step S3: adjusting the power of the current air conditioner outdoor unit based on the adjustment coefficient.

[0052] In some installation environments, due to the short length of the input connecting pipe, there is not enough space for liquid to flow and dissipate heat. At the same time, a large amount of liquid will block the input connecting pipe, affecting the normal flow of refrigerant and ultimately affecting the efficiency and performance of the air-conditioning system.

[0053] To this end, in the present invention, pressure sensors are installed at the inlet and outlet of the evaporator respectively. When the first pressure at the inlet of the evaporator is greater than the pressure threshold, it indicates that there is a condensate flow obstruction. The reason for the condensate flow obstruction is that the temperature of the condensate is high, and there is a gas-liquid coexistence in the input connecting pipe, which affects the overall density of the condensate fluid. The flow of the condensate is ultimately affected. At this time, it may be necessary to appropriately reduce the power of the air conditioner outdoor unit to reduce the temperature of the condensate entering the input connecting pipe, so that the condensate fluid can flow smoothly into the generator, so that the efficiency and performance of the air conditioning system can be maintained normal. In the present invention, the adjustment coefficient of the condensate fluid that can smoothly pass through the evaporator is obtained by the length, diameter and liquid temperature of the input connecting pipe, and then the power of the air conditioner outdoor unit is adjusted based on the adjustment coefficient, so that the power of the air conditioner outdoor unit can be maintained in a certain working range, so that the indoor temperature can be kept stable and comfortable. The problems such as reduced refrigeration effect or increased energy consumption caused by excessive evaporator pressure are avoided, thereby improving the user experience.

[0054] Preferably, the step of obtaining the adjustment coefficient based on the length and diameter of the quantity connecting pipe and the liquid temperature in step S2 is as follows:

[0055] Determine the gas phase coefficient of the current condensate based on the liquid temperature;

[0056] Obtaining a second liquid pressure at an outlet of the evaporator, obtaining a pressure difference between the first liquid pressure and the second liquid pressure, and obtaining a current flow rate of the condensate fluid based on the pressure difference and the gas phase coefficient;

[0057] Predicting a first total pressure drop in the current pipeline according to the length and diameter of the input connecting pipe and the flow rate of the condensate fluid;

[0058] The ratio between the standard total pressure drop and the first total pressure drop is used as the adjustment coefficient.

[0059] After the condensed gas is processed by the expansion valve of the external unit, it will become a low-temperature and low-pressure liquid. However, due to the high power of the external unit, the liquid pressure and temperature before the expansion valve processing are too high. After being output by the expansion valve, not all condensed liquid will become liquid, and part of the gas will be output at this time. Since the output gas part is related to the temperature, the relationship between the liquid temperature and the gas volume at the inlet of the input connecting pipe in the laboratory can be collected multiple times to obtain the corresponding gas phase coefficient (the ratio of gas to liquid). Since the condensate processing equipment (expansion valve, condenser) is the same for the same air conditioner, the relationship between the corresponding temperature and the gas phase coefficient can be found according to the style of the air conditioner. Then, the flow rate of the condensate fluid in the pipeline is obtained according to the variant of the Bernoulli equation and the continuity equation. There is no need to use an additional flow rate sensor to obtain the flow rate, which simplifies the control cost of the air conditioner.

[0060] After obtaining the flow rate of the condensate, a pressure drop model is established based on the improved Churchill equation. The first total pressure drop in the current pipeline is predicted by the length and diameter of the connecting pipe and the flow rate of the condensate fluid; and the first total pressure drop is the pressure drop at which the current condensate fluid can flow smoothly to the evaporator. The standard total pressure drop is the pressure drop at which the condensate fluid can flow smoothly to the evaporator when it is all liquid. The ratio between the two total pressure drops can immediately tell the current coefficient ratio that needs to be adjusted. According to the adjustment coefficient, the power of the external unit is adjusted to drive the condensate fluid to enter the evaporator smoothly, ensuring the efficiency and performance of the air conditioning system.

[0061] Preferably, the formula for obtaining the flow rate of the current condensate fluid based on the pressure difference and the gas phase coefficient is as follows:

[0062]

[0063] Where Δp is the pressure difference, ρ mix=αρ1+(1-α)ρ2, α is the gas phase coefficient, ρ1 and ρ2 are the density of the condensate fluid when it is vaporized and the density when it is liquefied, respectively;

[0064] The formula for obtaining the first total pressure drop is as follows:

[0065]

[0066] Where f is the pipeline friction factor, L is the length of the input connecting pipe, D is the diameter of the input connecting pipe, v is the flow rate of the condensate fluid, and K is the resistance coefficient.

[0067] Preferably, the specific steps of step S3 are as follows:

[0068] The adjustment coefficient, the length of the input connection pipe, and the diameter are input into the PID controller to obtain the operating frequency of the outdoor unit when the condenser flows smoothly into the evaporator as the first frequency;

[0069] The current operating frequency of the external machine is obtained as the second operating frequency, and it is determined whether the frequency difference between the first operating frequency and the second operating frequency is less than the first frequency threshold. If so, the power of the external machine is not adjusted, and step S1 is executed again after a preset time.

[0070] If the frequency difference is greater than the first frequency threshold and less than the second frequency threshold, the power of the outdoor unit is adjusted to the first frequency;

[0071] If the frequency difference is greater than the second frequency threshold, the lowest operating frequency is used as the power of the air conditioner outdoor unit, and when the first liquid pressure is lower than or equal to the pressure threshold, the power of the outdoor unit is adjusted to the first frequency.

[0072] The first frequency threshold is a dead zone control set by the present invention to avoid excessive power adjustment with too small adjustment range. Avoid frequent adjustment of the power of the external unit, thereby causing instability of the system. When the frequency difference is less than the second frequency threshold and greater than the first frequency threshold, the power of the external unit is directly adjusted to the first frequency. When the frequency difference is greater than the second frequency threshold, it indicates that the difference between the first frequency and the second frequency is too large. Even if the working frequency of the external unit is adjusted to the first frequency, the condensate fluid cannot smoothly enter the evaporator in a short time, which will cause continuous adjustment of the system. For this reason, when the frequency difference is greater than the second frequency threshold, the lowest working frequency will be used as the power of the air conditioner external unit to avoid excessive heating and pressurization of the condenser within a certain period of time, so that the first liquid pressure can drop rapidly. When the first liquid pressure is lower than or equal to the pressure threshold, the power of the external unit is adjusted back to the first frequency to speed up the working efficiency of the air conditioner so that the air conditioner can meet the user's cooling needs.

[0073] Preferably, the formula for obtaining the first frequency is as follows:

[0074]

[0075] Where Kp, Ki, Kd are the gains of the PID controller, μ is the adjustment coefficient, and sum error The difference between the total pressure drop in the input pipeline and the standard total pressure after adjusting the frequency for the outdoor unit.

[0076] An air conditioning frequency adjustment system based on a connecting pipe, characterized in that the air conditioning frequency adjustment method based on a connecting pipe is used, comprising a pressure sensing module, a data processing module and an adjustment module;

[0077] The pressure sensing module is used to install pressure sensors at the inlet and outlet of the evaporator, and obtain the first liquid pressure at the inlet of the evaporator through the pressure sensor;

[0078] The data processing module is used to determine whether the first liquid pressure is greater than a pressure threshold, and if so, to obtain the liquid temperature in the current input connecting pipe, and to obtain the adjustment coefficient based on the length and diameter of the input connecting pipe and the liquid temperature;

[0079] The adjustment module is used to adjust the power of the current air conditioner outdoor unit based on the adjustment coefficient.

[0080] Preferably, the data processing module includes a gas phase coefficient acquisition submodule, a flow rate acquisition submodule, a first total pressure drop acquisition submodule and an adjustment coefficient acquisition submodule;

[0081] The gas phase coefficient acquisition submodule is used to determine the gas phase coefficient of the current condensate based on the liquid temperature;

[0082] The flow rate acquisition submodule is used to acquire the second liquid pressure at the outlet of the evaporator, acquire the pressure difference between the first liquid pressure and the second liquid pressure, and acquire the flow rate of the current condensate fluid based on the pressure difference and the gas phase coefficient;

[0083] The first total pressure drop acquisition submodule is used to predict the first total pressure drop in the current pipeline according to the length and diameter of the input connecting pipe and the flow rate of the condensate fluid;

[0084] The regulation coefficient acquisition submodule is used to use the ratio between the standard total pressure drop and the first total pressure drop as the regulation coefficient.

[0085] Preferably, the adjustment module includes a frequency acquisition submodule and an adjustment submodule;

[0086] The frequency acquisition submodule is used to input the adjustment coefficient, the length of the input connection pipe, and the diameter input value into the PID controller to obtain the operating frequency of the external unit when the condenser flows smoothly into the evaporator as the first frequency;

[0087] The regulating submodule is used to obtain the current operating frequency of the external machine as the second operating frequency, and determine whether the frequency difference between the first operating frequency and the second operating frequency is less than the first frequency threshold. If so, the power of the external machine is not adjusted, and the pressure sensing module is called again after a preset time.

[0088] If the frequency difference is greater than the first frequency threshold and less than the second frequency threshold, the power of the outdoor unit is adjusted to the first frequency;

[0089] If the frequency difference is greater than the second frequency threshold, the lowest operating frequency is used as the power of the air conditioner outdoor unit, and when the first liquid pressure is lower than or equal to the pressure threshold, the power of the outdoor unit is adjusted to the first frequency.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0091] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for adjusting the frequency of an air conditioner based on a connecting pipe, characterized in that: The steps include: Step S1: installing pressure sensors at the inlet and outlet of the evaporator, and obtaining a first liquid pressure at the inlet of the evaporator through the pressure sensors; Step S2: determining whether the first liquid pressure is greater than a pressure threshold, and if so, obtaining the current liquid temperature in the input connecting pipe, and obtaining a regulation coefficient based on the length and diameter of the input connecting pipe and the liquid temperature; Step S3: adjusting the power of the current air conditioner outdoor unit based on the adjustment coefficient.

2. The air conditioning frequency adjustment method based on the connecting pipe according to claim 1, characterized in that: The steps of obtaining the adjustment coefficient based on the length and diameter of the quantity connecting pipe and the liquid temperature in step S2 are as follows: Determine the gas phase coefficient of the current condensate based on the liquid temperature; Obtaining a second liquid pressure at an outlet of the evaporator, obtaining a pressure difference between the first liquid pressure and the second liquid pressure, and obtaining a current flow rate of the condensate fluid based on the pressure difference and the gas phase coefficient; Predicting a first total pressure drop in the current pipeline according to the length and diameter of the input connecting pipe and the flow rate of the condensate fluid; The ratio between the standard total pressure drop and the first total pressure drop is used as the adjustment coefficient.

3. The air conditioning frequency adjustment method based on the connecting pipe according to claim 2 is characterized in that: The formula for obtaining the flow rate of the current condensate fluid based on the pressure difference and the gas phase coefficient is as follows: Where Δp is the pressure difference, ρ mix =αρ1+(1-α)ρ2, α is the gas phase coefficient, ρ1 and ρ2 are the density of the condensate fluid when it is vaporized and the density when it is liquefied, respectively; The formula for obtaining the first total pressure drop is as follows: Where f is the pipeline friction factor, L is the length of the input connecting pipe, D is the diameter of the input connecting pipe, v is the flow rate of the condensate fluid, and K is the resistance coefficient.

4. The air conditioning frequency adjustment method based on the connecting pipe according to claim 1, characterized in that: The specific steps of step S3 are as follows: The adjustment coefficient, the length of the input connection pipe, and the diameter are input into the PID controller to obtain the operating frequency of the outdoor unit when the condenser flows smoothly into the evaporator as the first frequency; The current operating frequency of the external machine is obtained as the second operating frequency, and it is determined whether the frequency difference between the first operating frequency and the second operating frequency is less than the first frequency threshold. If so, the power of the external machine is not adjusted, and step S1 is executed again after a preset time. If the frequency difference is greater than the first frequency threshold and less than the second frequency threshold, the power of the outdoor unit is adjusted to the first frequency; If the frequency difference is greater than the second frequency threshold, the lowest operating frequency is used as the power of the air conditioner outdoor unit, and when the first liquid pressure is lower than or equal to the pressure threshold, the power of the outdoor unit is adjusted to the first frequency.

5. The method for adjusting the frequency of an air conditioner based on a connecting pipe according to claim 4, characterized in that: The formula for obtaining the first frequency is as follows: Where Kp, Ki, Kd are the gains of the PID controller, μ is the adjustment coefficient, and sum error The difference between the total pressure drop in the input pipeline and the standard total pressure after adjusting the frequency for the outdoor unit.

6. An air conditioning frequency adjustment system based on a connecting pipe, characterized in that: The method for adjusting the frequency of an air conditioner based on a connecting pipe according to any one of claims 1 to 5 comprises a pressure sensing module, a data processing module and an adjusting module; The pressure sensing module is used to install pressure sensors at the inlet and outlet of the evaporator, and obtain the first liquid pressure at the inlet of the evaporator through the pressure sensor; The data processing module is used to determine whether the first liquid pressure is greater than a pressure threshold, and if so, to obtain the liquid temperature in the current input connecting pipe, and to obtain the adjustment coefficient based on the length and diameter of the input connecting pipe and the liquid temperature; The adjustment module is used to adjust the power of the current air conditioner outdoor unit based on the adjustment coefficient.

7. The air conditioning frequency adjustment system based on the connecting pipe according to claim 6, characterized in that: The data processing module includes a gas phase coefficient acquisition submodule, a flow rate acquisition submodule, a first total pressure drop acquisition submodule and an adjustment coefficient acquisition submodule; The gas phase coefficient acquisition submodule is used to determine the gas phase coefficient of the current condensate based on the liquid temperature; The flow rate acquisition submodule is used to acquire the second liquid pressure at the outlet of the evaporator, acquire the pressure difference between the first liquid pressure and the second liquid pressure, and acquire the flow rate of the current condensate fluid based on the pressure difference and the gas phase coefficient; The first total pressure drop acquisition submodule is used to predict the first total pressure drop in the current pipeline according to the length and diameter of the input connecting pipe and the flow rate of the condensate fluid; The regulation coefficient acquisition submodule is used to use the ratio between the standard total pressure drop and the first total pressure drop as the regulation coefficient.

8. The air conditioning frequency adjustment system based on the connecting pipe according to claim 6, characterized in that: The adjustment module includes a frequency acquisition submodule and an adjustment submodule; The frequency acquisition submodule is used to input the adjustment coefficient, the length of the input connection pipe, and the diameter input value into the PID controller to obtain the operating frequency of the external unit when the condenser flows smoothly into the evaporator as the first frequency; The regulating submodule is used to obtain the current operating frequency of the external machine as the second operating frequency, and determine whether the frequency difference between the first operating frequency and the second operating frequency is less than the first frequency threshold. If so, the power of the external machine is not adjusted, and the pressure sensing module is called again after a preset time. If the frequency difference is greater than the first frequency threshold and less than the second frequency threshold, the power of the outdoor unit is adjusted to the first frequency; If the frequency difference is greater than the second frequency threshold, the lowest operating frequency is used as the power of the air conditioner outdoor unit, and when the first liquid pressure is lower than or equal to the pressure threshold, the power of the outdoor unit is adjusted to the first frequency.

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