Defrosting control system applied to live AI fin

Abstract

The invention discloses a defrosting control system applied to a live AI fin, and relates to the technical field of refrigeration, heat pump industry and air source heat pump unit defrosting systems, and the defrosting control system comprises an evaporator inlet air moisture content calculation module, an evaporator exhaust air moisture content calculation module, an evaporator frosting amount calculation module and a defrosted amount calculation module; according to the method, the frosting amount of unit mass air passing through fins of the evaporator is calculated according to the inlet / exhaust air moisture content difference value of the evaporator; according to the integral principle, the frosting amount of the current evaporator is calculated in a real-time accumulation mode, and when the frosting amount reaches a preset value, namely, the defrosting condition is met, defrosting is started; the current defrosted amount is calculated in real time in the defrosting process, and when the defrosted amount reaches the preset value of the frosting amount, defrosting is finished; accurate defrosting is realized; the problems of false defrosting and incomplete defrosting of a traditional air source heat pump are solved; and the heating performance and the comprehensive energy efficiency ratio of the air source heat pump are further improved.

Description

Technical Field

[0001] The present invention relates to the refrigeration and heat pump industries and the technical field of defrosting systems for air source heat pump units, and in particular to a real-time AI fin defrosting control system. Background Art

[0002] When the air source heat pump is operating under heating conditions, especially at low ambient temperatures, the fin evaporator needs to absorb a large amount of low-grade heat from the outdoor atmosphere and discharge air at a lower temperature. During this process, the water vapor in the humid air will frost on the surface of the fins when it comes into contact with the low-temperature heat exchange fins. The fin frosting is a negative feedback operation. Once the fins begin to frost, it will worsen and seriously affect the heating effect of the air source heat. The heat pump host cooling (heating) system must be defrosted tangentially.

[0003] Traditional defrosting technology sets the conditions for entering and exiting defrosting based on parameters such as ambient temperature, fin temperature, and operating time. This technology ignores the key parameter of air humidity, and the relative humidity in the atmosphere is different in different geographical regions, or at different times in the same region, or even at different times on the same day. Traditional defrosting technology ignores the impact of air temperature and humidity on the fin frosting rate, resulting in deviations in determining the time to enter and exit defrosting, especially in ultra-low ambient temperatures. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a real-time AI fin defrost control system in response to the shortcomings of the background technology, which solves the problems of false defrosting and incomplete defrosting under traditional defrosting technology; and further improves the heating performance of the air source heat pump and the comprehensive energy efficiency ratio.

[0005] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions:

[0006] A real-time AI fin defrosting control system includes an evaporator inlet air humidity calculation module, an evaporator exhaust air humidity calculation module, an evaporator frost amount calculation module, and a defrosted amount calculation module; the frost amount per unit mass of air passing through the evaporator fins is calculated by the evaporator inlet / exhaust air humidity difference; the current evaporator frost amount is accumulated and calculated in real time by the integration principle, and when the frost amount reaches a preset value, the defrosting condition is met and defrosting begins; the current defrosted amount is calculated in real time during defrosting, and when the defrosted amount reaches the preset value of the frost amount, the defrosting ends; and precise defrosting is achieved;

[0007] Among them, the evaporator inlet air humidity calculation module is used to detect the temperature and relative humidity of the evaporator inlet air in real time through the temperature and humidity sensor on the evaporator inlet side, and calculate the absolute humidity value of the evaporator inlet wet air;

[0008] The evaporator exhaust air humidity calculation module is used to detect the temperature and relative humidity of the evaporator exhaust air in real time through the temperature and humidity sensor on the evaporator exhaust side, and calculate the absolute humidity value of the evaporator exhaust wet air;

[0009] The evaporator frost amount calculation module is used to calculate the current evaporator frost amount in real time by integrating the principle;

[0010] The defrosted amount calculation module is used to calculate the heat released by the fin evaporator during the tangential defrosting operation of the system in real time through the integral principle.

[0011] As a further preferred solution of the present invention applied to a real-time AI fin defrost control system,

[0012] Defrost entry conditions: Frost amount > set defrost amount;

[0013] Defrost exit condition: defrosted amount > set defrost amount;

[0014] As a further preferred solution of the present invention applied to the real-time AI fin defrost control system, the evaporator frost amount calculation module specifically calculates as follows:

[0015] Frost amount = ∫ the difference in moisture content between the inlet and outlet of the evaporator × the air mass flow rate through the fin evaporator × time.

[0016] As a further preferred solution of the present invention applied to the real-time AI fin defrosting control system, the specific calculation of the heat release of the fin is as follows:

[0017] Fin heat release = ∫ enthalpy difference of refrigerant passing through the inlet and outlet of the fin × mass flow rate of refrigerant in the refrigeration system × time;

[0018] The defrosted amount is calculated as follows:

[0019] Defrosted amount = heat released by fins / heat required to melt unit mass of frost.

[0020] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0021] The present invention is an AI fin defrost control system applied to real-time defrosting, comprising an evaporator inlet air moisture content calculation module, an evaporator exhaust air moisture content calculation module, an evaporator frost amount calculation module, and a defrosted amount calculation module; the frost amount per unit mass of air passing through the evaporator fins is calculated by the evaporator inlet / exhaust air moisture content difference; the current evaporator frost amount is accumulated and calculated in real time by the integration principle, and when the frost amount reaches a preset value, the defrosting condition is met and defrosting begins; during defrosting, the current defrosted amount is calculated in real time, and when the defrosted amount reaches the preset value of the frost amount, the defrosting ends; precise defrosting is achieved; the present invention solves the problems of false defrosting and incomplete defrosting of traditional air source heat pumps; and further improves the heating performance and comprehensive energy efficiency ratio of air source heat pumps. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a functional flow chart of the real-time AI fin defrost control of the present invention;

[0024] Figure 2 This is a flow chart of the system initialization module of the present invention;

[0025] Figure 3 This is a flow chart of the frosting amount calculation module of the present invention;

[0026] Figure 4 This is a flow chart of the cumulative defrost heating module of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] A real-time AI fin defrost control technology is disclosed, comprising an evaporator inlet air moisture content calculation module, an evaporator exhaust air moisture content calculation module, an evaporator frost amount calculation module, and a defrosted amount calculation module.

[0029] The present invention calculates the amount of frost per unit mass of air passing through the evaporator fins by the difference in humidity of the evaporator inlet / exhaust air. The current amount of frost on the evaporator is calculated in real time by the integration principle. When the amount of frost reaches a preset value, the defrosting condition is met and defrosting begins. The defrosting calculates the current amount of defrost in real time. When the amount of defrost reaches the preset value of the amount of frost, the defrosting ends. Accurate defrosting is achieved.

[0030] The evaporator inlet air moisture content calculation module detects the temperature and relative humidity of the evaporator inlet air in real time through the evaporator inlet side temperature and humidity sensor, and calculates the absolute moisture content value of the evaporator inlet wet air in the unit of: g / kg dry air;

[0031] The evaporator inlet air moisture content calculation module detects the temperature and relative humidity of the evaporator exhaust air in real time through the evaporator exhaust side temperature and humidity sensor, and calculates the absolute moisture content value of the evaporator exhaust wet air in units of: g / kg dry air;

[0032] The evaporator frost amount calculation module calculates the current evaporator frost amount in real time and cumulatively through the integration principle.

[0033] Frost amount (g) = ∫ the difference in moisture content between the inlet and outlet of the evaporator (g / kg dry air) × the mass flow rate of air passing through the fin evaporator (kg / min) × time (min);

[0034] The defrosted amount calculation module calculates the heat (j) released by the finned evaporator (the condenser in this case) in real time through the integration principle during the tangential defrosting operation of the system.

[0035] Fin heat release (j) = ∫ enthalpy difference of refrigerant passing through the inlet and outlet of the fin (j / kg) × mass flow rate of refrigerant in the refrigeration system (kg / min) × time (min);

[0036] Defrosted amount (g) = heat released by fins (j) / heat required to melt unit mass of frost (j / g).

[0037] The present invention calculates the amount of frost per unit mass of air passing through the evaporator fins by using the difference in moisture content of the evaporator inlet / exhaust air. The current amount of frost on the evaporator is calculated cumulatively in real time by using the principle of integration. When the amount of frost reaches a preset value, the defrosting condition is met and defrosting begins. During the defrosting process, the current amount of defrost is calculated in real time. When the amount of defrost reaches the preset value of the amount of frost, the defrosting ends. Accurate defrosting is achieved. The present invention solves the problems of false defrosting and incomplete defrosting in traditional air source heat pumps. The heating performance and comprehensive energy efficiency ratio of air source heat pumps are further improved.

[0038] The specific embodiments are as follows: Figure 1As shown, a method for real-time AI fin defrosting control includes a system initialization module for the first power-on, a program start, and a check whether it is the first power-on. If it is the first power-on, the system is initialized. If it is not the first power-on and has been initialized, it is determined whether it is in the defrosting state. If it is in the defrosting state, it goes to the defrosted amount calculation module to calculate the current cumulative amount of frost that has been removed, and then the defrosted amount and the defrosting amount setting value are judged. If the condition is met, the defrosting is exited. Otherwise, the cycle continues; if it is not in the defrosting state, the frost amount calculation module is run, and the current total frost amount is calculated by integration, and then the frost amount and the defrosting amount setting value are judged. If the condition for entering the defrosting is met, defrosting is performed, and then the program ends.

[0039] like Figure 2 As shown, the program starts to power on, first the system main clock is divided, each peripheral frequency is selected, the watchdog clock selection is initialized, then the GPIO is initialized to configure the pins used by the MCU, the IO input and output direction and the initial value of the IO, then the ADC is initialized to configure the ADC peripheral parameters, specify the corresponding multiplexed IO pins, reset the ADC, turn on the ADC, then the PIT is initialized to initialize the timer division configuration and the recommended clock unit, then the EEPROM is initialized to initialize the data storing the global variables of the program, then the parameters of the frost amount calculation module are initialized, and then the parameters of the defrosted amount calculation module are initialized.

[0040] like Figure 3 As shown, the program starts, and the timer is used to determine whether the collection cycle time is reached. If not, wait. If the collection cycle is reached, the evaporator inlet air humidity content calculation, evaporator exhaust air humidity content calculation, evaporator exhaust air density calculation are performed, and the above results are input to the cumulative humidity content calculation module, and finally the current real-time frost amount is calculated.

[0041] like Figure 4 As shown, the program starts and uses the timer to determine whether the collection cycle time is reached. If not, it waits. If the collection cycle is reached, the compressor exhaust port enthalpy is calculated from the compressor exhaust temperature, and the condensation outlet enthalpy is calculated from the evaporator (condensation at this time) fin coil temperature. Combined with the compressor exhaust volume and the compressor operating frequency, the fin heat release is calculated cumulatively, and then the cumulative defrost amount is calculated.

[0042] Although 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 appended claims and their equivalents.

Claims

1. A real-time AI fin defrost control system, characterized by: It includes an evaporator inlet air humidity calculation module, an evaporator exhaust air humidity calculation module, an evaporator frost amount calculation module, and a defrost amount calculation module; the frost amount per unit mass of air passing through the evaporator fins is calculated through the difference in humidity of the evaporator inlet / exhaust air; Through the principle of integration, the current frost amount of the evaporator is calculated in real time. When the frost amount reaches the preset value, the defrosting condition is met and defrosting begins. During defrosting, the current defrosted amount is calculated in real time. When the defrosted amount reaches the preset value, defrosting ends. Achieve precise defrosting; Among them, the evaporator inlet air humidity calculation module is used to detect the temperature and relative humidity of the evaporator inlet air in real time through the temperature and humidity sensor on the evaporator inlet side, and calculate the absolute humidity value of the evaporator inlet wet air; The evaporator exhaust air humidity calculation module is used to detect the temperature and relative humidity of the evaporator exhaust air in real time through the temperature and humidity sensor on the evaporator exhaust side, and calculate the absolute humidity value of the evaporator exhaust wet air; The evaporator frost amount calculation module is used to calculate the current evaporator frost amount in real time by integrating the principle; The defrosted amount calculation module is used to calculate the heat released by the fin evaporator during the tangential defrosting operation of the system in real time through the integral principle.

2. The AI ​​fin defrost control system for real-time use according to claim 1, characterized in that: Defrost entry conditions: Frost amount > set defrost amount; Defrost exit condition: defrost amount > set defrost amount.

3. The AI ​​fin defrost control system for real-time use according to claim 1, characterized in that: The evaporator frost amount calculation module specifically calculates as follows: Frost amount = ∫ the difference in moisture content between the inlet and outlet of the evaporator × the air mass flow rate through the fin evaporator × time.

4. The AI ​​fin defrost control system for real-time use according to claim 1, characterized in that: The specific calculation of the heat release of the fin is as follows: Fin heat release = ∫ enthalpy difference of refrigerant passing through the inlet and outlet of the fin × mass flow rate of refrigerant in the refrigeration system × time; The defrosted amount is calculated as follows: Defrosted amount = heat released by fins / heat required to melt unit mass of frost.

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