A wet membrane humidification control method and device for a dual cold source fresh air dehumidifier

Abstract

The present application relates to the technical field of dehumidifier, especially to a double cold source fresh air dehumidifier wet membrane humidification control method and device, comprising triggering a dehumidifier start signal; the dehumidifier receives the start signal, judges whether it is a heating and humidification mode; when the dehumidifier is in the heating and humidification mode, the first water flow valve is closed, the second water flow valve is opened, and the second water flow valve is opened to the initial opening degree; the opening degree of the second water flow valve is adjusted by using the PID control algorithm to control the heating function of the reheating coil; when the outlet air temperature reaches the set target outlet air temperature, the PID control adjustment is stopped. The present application solves the problem of accurate control of actual outlet air temperature of the dehumidifier in the heating and humidification mode in winter; and reduces energy consumption and increases the hot water flow of the operating coil in winter.

Description

Technical Field

[0001] This invention relates to the field of dehumidifier technology, and in particular to a method and device for controlling the humidification of a dual-cold-source fresh air dehumidifier with wet film. Background Technology

[0002] Traditional dual-source dehumidifiers for fresh air supply, when operating in winter, heat the fresh air through the surface cooler heat exchanger, but without a wet film to humidify the fresh air, resulting in a dry feeling and poor comfort when delivered indoors.

[0003] In recent years, most manufacturers have adopted the method of adding a wet film after the evaporator to humidify the fresh air and achieve the purpose of increasing the humidity of the outlet air. However, this method will reduce the actual outlet air temperature, and users will feel a cold sensation when the air is delivered into the room, resulting in poor comfort. Therefore, some manufacturers add electric auxiliary heating in the outlet section to reheat the supply air, but this method has high energy consumption. In addition, under the winter heating condition, a large part of the hot water of the traditional dual cold source fresh air dehumidifier is still diverted to the plate heat exchanger of the refrigeration system, resulting in insufficient hot water flow to the surface cooling coil and reheat coil.

[0004] Therefore, in order to improve the accuracy of the actual outlet air temperature of the dual-source fresh air dehumidifier in winter heating and humidification mode, while reducing energy consumption and increasing the hot water flow of the coil in winter operation, it is necessary to optimize the existing wet film humidification structure and control method of the dual-source fresh air dehumidifier. Summary of the Invention

[0005] To address the shortcomings of existing methods, this invention solves the problem of accurately controlling the actual outlet air temperature in the winter heating and humidification mode of dehumidifiers; and reduces energy consumption while increasing the hot water flow rate of the coil during winter operation.

[0006] The technical solution adopted in this invention is: a method for controlling the humidification of a dual-cold-source fresh air dehumidifier using a wet film, comprising the following steps:

[0007] Step 1: Trigger the dehumidifier's power-on signal;

[0008] Step 2: The dehumidifier receives the power-on signal and determines whether it is in heating and humidification mode;

[0009] Step 3: When the dehumidifier is in heating and humidification mode, the first water flow valve is closed, the second water flow valve is opened, and the second water flow valve is opened to its initial opening degree.

[0010] In a preferred embodiment of the present invention, the initial opening degree is a custom value.

[0011] In a preferred embodiment of the present invention, if the dehumidifier is not in heating and humidification mode, the first water flow valve is open and the second water flow valve is closed.

[0012] Step 4: Use the PID control algorithm to adjust the opening of the second water flow valve to control the heating function of the reheat coil.

[0013] In a preferred embodiment of the present invention, adjusting the opening degree of the second water flow valve using a PID control algorithm includes:

[0014] Step 41: Calculate the outlet air temperature T at each Δt interval. out With the set target outlet air temperature T outs The absolute value of the temperature difference ΔT;

[0015] Step 42, for ΔT ( t ) and ΔT ( t ) -ΔT ( t-1 ) The control parameter K in the PID control algorithm p K i and K d Make a judgment;

[0016] In a preferred embodiment of the present invention, step 42 specifically includes:

[0017] Step 421, when ΔT ( t ) When ≥q, the control parameter K p ≥a; when ΔT ( t ) -ΔT ( t-1 ) When ≥r, the control parameter K i ≥b, K d ≤c;

[0018] Step 422, when ΔT ( t ) When q < q, the control parameter K p <a; when ΔT ( t ) -ΔT ( t-1 ) When <r, the control parameter K i <b, K d >c;

[0019] Where q is the set temperature difference; r, a, b, and c are constants.

[0020] Step 43: Calculate the opening degree of the second water flow valve using the PID control algorithm;

[0021] In a preferred embodiment of the present invention, step 43 includes:

[0022] The formula for calculating the output value P is:

[0023]

[0024] The opening degree of the second water flow valve is calculated using the following formula:

[0025] P s =max[0,min(100,P)]×100% (2)

[0026] Where, ΔT ( t ) Let ΔT be the temperature difference at time t. ( i ) Let ΔT be the temperature difference at time i. ( t-1 ) Let t be the temperature difference at time t-1.

[0027] Step 5: When the outlet air temperature reaches the set target outlet air temperature, stop the PID control adjustment;

[0028] As a preferred embodiment of the present invention, the apparatus for the wet film humidification control method of the dual-source fresh air dehumidifier includes: a compressor, a filter section, a precooling coil, an evaporator, a wet film section, a reheat coil, a blower, an electronic expansion valve, a first water flow valve, a second water flow valve, and a blower temperature sensor. The second water flow valve is installed at the water inlet end before the reheat coil, and the opening of the second water flow valve is adjusted to regulate the flow rate of high-temperature water entering the reheat coil during heating and humidification.

[0029] As a preferred embodiment of the present invention, the dual-source fresh air dehumidifier wet film humidification control system includes: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the dual-source fresh air dehumidifier wet film humidification control method.

[0030] As a preferred embodiment of the present invention, a computer-readable medium storing computer program code implements a wet film humidification control method for a dual-cold-source fresh air dehumidifier when executed by a processor.

[0031] The beneficial effects of this invention are:

[0032] 1. Utilize PID control algorithm to precisely regulate the temperature of fresh air supplied after humidification in winter, reducing energy waste and meeting users' comfort needs;

[0033] 2. The dehumidifier has a reasonable wet film humidification structure design. By adding a second water flow valve, the hot water flow rate of the heating coil is effectively increased, thereby improving the heat exchange efficiency. Attached Figure Description

[0034] Figure 1 This is a flowchart of the wet film humidification control method for the dual-cold-source fresh air dehumidifier of the present invention;

[0035] Figure 2 This is a schematic diagram of the wet film humidification control system for the dual-cold-source fresh air dehumidifier of the present invention;

[0036] Among them, 1. First water flow valve; 2. Second water flow valve; 3. Plate heat exchanger; 4. Electronic expansion valve; 5. Compressor; 6. Filter section; 7. Precooling coil; 8. Evaporator; 9. Wet film section; 10. Reheat coil; 11. Supply air temperature sensor; 12. Supply air fan. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments. The drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0038] like Figure 1 As shown, a method for controlling the humidification of a dual-source fresh air dehumidifier using a wet film includes the following steps:

[0039] Step 1: Trigger the start signal of the dual-source fresh air dehumidifier (referred to as dehumidifier);

[0040] Step 2: The dehumidifier receives the power-on signal and determines whether it is in heating and humidification mode;

[0041] Step 3: When the dehumidifier is in heating and humidification mode, the first water flow valve 1 is closed and the second water flow valve 2 is opened, and the second water flow valve is opened to the initial opening degree P0; otherwise, when the dehumidifier is not in heating and humidification mode, the first water flow valve 1 is open and the second water flow valve 2 is closed.

[0042] Step 4: After the second water flow valve 2 is opened to the initial opening degree P0, the opening degree of the second water flow valve 2 is adjusted using the PID control algorithm to control the heating function of the reheat coil 10.

[0043] The opening degree of the second water flow valve 2 is adjusted using a PID control algorithm to ensure that the outlet air temperature reaches and remains at the target outlet air temperature, including:

[0044] Step 41: Measure the outlet air temperature T of the unit every Δt time interval. out And calculate T out With the set target outlet air temperature T outs The absolute value of the temperature difference ΔT;

[0045] Step 42: Set the control parameter K in the PID control algorithm based on ΔT(t) and ΔT(t)-ΔT(t-1). p K i and K d ;

[0046] Step 42 specifically includes:

[0047] Step 421: When ΔT(t)≥q, the control parameter K p ≥a; When ΔT(t)-ΔT(t-1)≥r, the control parameter K i ≥b, K d ≤c;

[0048] Step 422, when ΔT( t When q < q, the control parameter K p <a; When ΔT(t)-ΔT(t-1)<r, the control parameter K i <b, K d >c;

[0049] Where q is the set temperature difference; r, a, b, and c are constants, a > b > c, and a, b, and c are all ≥ 0;

[0050] The temperature difference q is set to a range of 2℃ to 10℃; the adjustment parameter r is set to a range of 0.5℃ to 1℃.

[0051] Let q = 5℃ and r = 0.8℃;

[0052] If the temperature difference ΔT(t) ≥ 5℃, then the proportionality coefficient K p K should be satisfied p ≥2, and as the temperature difference ΔT(t) increases, K p The value increases accordingly; simultaneously, when the temperature difference change ΔT(t) - ΔT(t-1) ≥ 0.8℃, the integral coefficient K... i K should be satisfied i ≥0.5, differential coefficient K d K should be satisfied d ≤0.03, and as the temperature difference change ΔT(t)-ΔT(t-1) increases, the Ki value increases, K d The value decreases;

[0053] If the temperature difference ΔT(t) < 5℃, then the proportionality coefficient K p K should be satisfied p <2, and as the temperature difference ΔT(t) decreases, K p The value decreases accordingly; simultaneously, when the temperature difference change ΔT(t) - ΔT(t-1) < 0.8℃, the Ki value < 0.5, and K d Value > 0.03; through K p K i K d The dynamic correction of the coefficients effectively avoids system oscillations.

[0054] Step 43: Calculate the opening degree of the second water flow valve 2 using the PID control algorithm;

[0055] The output value P is calculated using the PID control algorithm, and the formula is:

[0056]

[0057] Where, ΔT ( t ) Let ΔT be the temperature difference at time t. ( i ) Let ΔT be the temperature difference at time i. ( t-1 ) Let t be the temperature difference at time t-1.

[0058] Substituting the output value P into formula (2), the opening degree of the second water flow valve 2 is calculated using the following formula:

[0059] P s =max[0,min(100,P)]×100% (2)

[0060] In this embodiment of the invention, the user sets the target outlet air temperature to 36°C, and the initially detected outlet air temperature is 10°C. At this time, ΔT ( t ) and ΔT ( t ) -ΔT ( t-1 ) The temperature is 26℃; according to the set PID control algorithm parameters, the proportional coefficient K p =5. Integral coefficient K i =1, differential coefficient K d =0.01, substituting these parameters into formula (1), the output value P is calculated to be 156.26; substituting the value of P into formula (2), the opening degree P of the second water flow valve 2 is calculated. s If the value is 100%, then the opening of the second water flow valve 2 is adjusted to the fully open state to achieve rapid adjustment of water flow, promote the increase of air outlet temperature, and finally reach the predetermined target air outlet temperature.

[0061] Step 5: When the outlet air temperature reaches the set target outlet air temperature, stop the PID control adjustment.

[0062] The dual-source cold air dehumidifier wet film humidification control system includes:

[0063] The system includes a compressor 5, a filter section 6, a precooling coil 7, an evaporator 8, a wet film section 9, a reheat coil 10, a blower 12, an electronic expansion valve 5, a first water flow valve 1, a second water flow valve 2, and a blower temperature sensor 11. During winter heating and humidification, the first water flow valve 1 is closed to prevent hot water diversion. The second water flow valve 2, installed before the water inlet pipe of the reheat coil 10, regulates the flow rate of high-temperature water entering the reheat coil 10 during heating and humidification. A blower temperature sensor 11 is installed after the reheat coil 10 and before the blower 12 to detect the actual blower temperature. A PID control algorithm is used to control the opening of the second water flow valve 2, ensuring that the actual blower temperature reaches and maintains the target blower temperature.

[0064] In summer cooling and dehumidification mode, water flow valve 1 is fully open and water flow valve 2 is closed to prevent cold water from flowing out.

[0065] Working principle:

[0066] When the dehumidifier is operating in heating and humidification mode, the mixed air passes through the filter section 6 to filter impurities and harmful substances, resulting in purified mixed air. The purified mixed air exchanges heat with the precooling coil 7, increasing the air temperature, and then proceeds to the wet film section 9 for humidification. The moisture content of the humidified mixed air is significantly increased, but the air temperature is significantly reduced. The lower humidity air mixed air exchanges heat with the reheat coil 10, increasing the temperature. The opening of the second water flow valve 2 is calculated by the PID control algorithm, and the high-temperature water flow rate through the second water flow valve 2 is intelligently adjusted to achieve precise control of the actual outlet air temperature, achieving the goal of energy saving and comfort.

[0067] In refrigeration and dehumidification mode, the second water flow valve 2 is closed, the first water flow valve 1 is fully open, and the wet film section is closed.

[0068] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for controlling the humidification of a dual-cold-source fresh air dehumidifier using a wet film, characterized in that, Includes the following steps: Step 1: Trigger the dehumidifier's power-on signal; Step 2: The dehumidifier receives the power-on signal and determines whether it is in heating and humidification mode; Step 3: When the dehumidifier is in heating and humidification mode, the first water flow valve is closed, the second water flow valve is opened, and the second water flow valve is opened to its initial opening degree. Step 4: Use the PID control algorithm to adjust the opening of the second water flow valve to control the heating function of the reheat coil. Adjusting the opening of the second water flow valve using a PID control algorithm includes: Step 41, each Calculate the outlet air temperature T within time t. out With the set target outlet air temperature T outs absolute value of temperature difference T; Step 42, for and Control parameter K p K i and K d Make a judgment; Step 42 specifically includes: Step 421, when T When ≥q, the control parameter K p ≥a; when When ≥r, the control parameter K i ≥b, K d ≤c; Step 422, when T When q < q, the control parameter K p <a; when When <r, the control parameter K i <b, K d >c; Where q is the set temperature difference; r, a, b, and c are constants; Step 43: Calculate the opening degree of the second water flow valve using the PID control algorithm; Step 5: When the outlet air temperature reaches the set target outlet air temperature, stop the PID control adjustment.

2. The wet film humidification control method for a dual-cold-source fresh air dehumidifier according to claim 1, characterized in that, Step 43 includes: The formula for calculating the output value P is: （1） The opening degree of the second water flow valve is calculated using the following formula: P s =max[0,min(100,P)] 100% (2) in, Let be the temperature difference at time t. Let t be the temperature difference at time t-1.

3. The wet film humidification control method for a dual-cold-source fresh air dehumidifier according to claim 1, characterized in that, The initial opening is a custom value.

4. The wet film humidification control method for a dual-cold-source fresh air dehumidifier according to claim 1, characterized in that, If the dehumidifier is not in heating and humidification mode, the first water flow valve will be open and the second water flow valve will be closed.

5. An apparatus employing the wet film humidification control method for a dual-cold-source fresh air dehumidifier according to any one of claims 1-4, characterized in that, include: The system includes a compressor, a filter section, a precooling coil, an evaporator, a wet film section, a reheat coil, a blower, an electronic expansion valve, a first water flow valve, a second water flow valve, and a blower temperature sensor. The second water flow valve is installed at the water inlet before the reheat coil. Adjusting the opening of the second water flow valve is used to regulate the flow rate of high-temperature water entering the reheat coil during heating and humidification.

6. A dual-cold-source fresh air dehumidifier wet film humidification control system, characterized in that, include: Memory is used to store instructions that can be executed by the processor; A processor for executing instructions to implement the wet film humidification control method for a dual-source fresh air dehumidifier as described in any one of claims 1-4.

7. A computer-readable medium storing computer program code, characterized in that, The computer program code, when executed by a processor, implements the wet film humidification control method for a dual-cold-source fresh air dehumidifier as described in any one of claims 1-4.

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