Wet film humidification control method and device for double-cold-source type fresh air dehumidifier

Abstract

The invention relates to the technical field of dehumidifiers, in particular to a double-cold-source type fresh air dehumidifier wet film humidification control method and device. The dehumidifier receives the starting-up signal and judges whether the mode is a heating and humidifying mode or not; when the dehumidifier is in the heating and humidifying 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 through a PID control algorithm, and the heating function of the reheating coil is controlled; and when the air outlet temperature reaches the set target air outlet temperature, PID control adjustment is stopped. The problem of accurate control of the actual air outlet temperature of the dehumidifier in the heating and humidifying mode in winter is solved; the energy consumption is reduced; and the hot water flow of the running coil in winter is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of dehumidifiers, and in particular to a wet film humidification control method and device for a dual-cold-source fresh air dehumidifier. Background Art

[0002] In traditional dual-cold source fresh air dehumidifiers, under winter conditions, after the fresh air is heated by the surface cooler heat exchanger, there is no wet film to humidify the fresh air. When it is sent into the indoor environment, the user experience is dry and the comfort level is poor.

[0003] In recent years, most manufacturers have adopted the method of adding a wet film after the evaporator to humidify the fresh air to achieve the purpose of increasing the humidity of the outlet air; however, this method will reduce the actual outlet air temperature, and the user experience of the air sent into the room will be cool and the comfort level will be poor; therefore, some manufacturers have added electric auxiliary heating to the air outlet section to reheat the supply air, but this method has high energy consumption; in addition, under winter heating conditions, 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 reheating coil.

[0004] Therefore, in order to improve the accuracy of the actual outlet air temperature in the winter heating and humidification operation mode of the dual-cold source fresh air dehumidifier, 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-cold source fresh air dehumidifier. Summary of the invention

[0005] In view of the shortcomings of the existing methods, the present invention solves the problem of accurately controlling the actual air outlet temperature of the dehumidifier in the winter heating and humidification mode; and reduces energy consumption and increases the hot water flow rate of the coil in winter operation.

[0006] The technical solution adopted by the present invention is: a dual cold source fresh air dehumidifier wet film humidification control method comprises the following steps:

[0007] Step 1: Trigger the dehumidifier start signal;

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

[0009] Step 3: When the dehumidifier is in the heating and humidifying 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;

[0010] As a preferred implementation manner of the present invention, the initial opening is a user-defined value.

[0011] As a preferred embodiment of the present invention, when the dehumidifier is not in the heating and humidifying mode, the first water flow valve is opened 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] As a preferred embodiment of the present invention, adjusting the opening of the second water flow valve by using a PID control algorithm includes:

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

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

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

[0017] 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;

[0018] Step 422: 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;

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

[0020] Step 43, calculating the opening of the second water flow valve using a PID control algorithm;

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

[0022] Calculate the output value P, the formula is:

[0023]

[0024] Calculate the opening of the second water flow valve using the formula:

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

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

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

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

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

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

[0031] Beneficial effects of the present invention:

[0032] 1. Use PID control algorithm to accurately control the temperature of fresh air after humidification in winter, reduce energy waste and meet users' comfort needs;

[0033] 2. The wet film humidification structure of the dehumidifier is reasonably designed. By adding a second water flow valve control, the hot water flow of the heating coil is effectively increased, thereby improving the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0036] Among them, 1. the first water flow valve; 2. the second water flow valve; 3. the plate heat exchanger; 4. the electronic expansion valve; 5. the compressor; 6. the filter section; 7. the pre-cooling coil; 8. the evaporator; 9. the wet film section; 10. the reheat coil; 11. the supply air temperature sensor; 12. the supply air fan. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and embodiments. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore it only shows the components related to the present invention.

[0038] like Figure 1 As shown, a dual cold source fresh air dehumidifier wet film humidification control method comprises the following steps:

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

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

[0041] Step 3: When the dehumidifier is in the heating and humidifying mode, the first water flow valve 1 is closed, the second water flow valve 2 is opened, and the second water flow valve is opened to the initial opening degree P0; otherwise, the dehumidifier is not in the heating and humidifying mode, the first water flow valve 1 is opened, 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 P0, the opening 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 of the second water flow valve 2 is adjusted by using a PID control algorithm so that the outlet air temperature reaches and remains at the target outlet air temperature, including:

[0044] Step 41: The unit detects the outlet air temperature T every Δt. out , and calculate T out and the set target air outlet temperature T outs The absolute value of the temperature difference ΔT;

[0045] Step 42: Set the control parameter K in the PID control algorithm according to 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 )<q, the control parameter K p <a; when ΔT(t)-ΔT(t-1)<r, the control parameter K i <b,K d >c;

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

[0050] The value range of the set temperature difference q is 2°C to 10°C; the value range of the adjustment parameter r is 0.5°C to 1°C;

[0051] Assume q = 5°C, r = 0.8°C;

[0052] If the temperature difference ΔT(t) ≥ 5°C, 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; at the same time, 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 ΔT(t)-ΔT(t-1 increases, the Ki value increases, K d The value decreases;

[0053] If the temperature difference ΔT(t) is less than 5°C, 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; at the same time, when the temperature difference change ΔT(t)-ΔT(t-1) is less than 0.8℃, the Ki value is less than 0.5, and K d Value>0.03; by K p , K i , K d The dynamic correction of the coefficient effectively avoids the occurrence of system oscillation.

[0054] Step 43, using the PID control algorithm to calculate the opening of the second water flow valve 2;

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

[0056]

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

[0058] Substitute the output value P into formula (2) to calculate the opening of the second water flow valve 2. The formula is:

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

[0060] In the embodiment of the present invention, the user sets the target air outlet temperature to 36°C, and the initial detected air outlet temperature is 10°C. At this time, ΔT ( t ) and ΔT ( t ) -ΔT ( t-1 ) 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, and these parameters are substituted into formula (1) to obtain the output value P of 156.26; Substitute the P value into formula (2) to calculate the opening degree P of the second water flow valve 2 s is 100%; the opening of the second water flow valve 2 is adjusted to a fully open state to achieve rapid regulation of the water flow rate, promote the increase in the outlet air temperature, and ultimately reach a predetermined target outlet air temperature.

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

[0062] Dual cold source fresh air dehumidifier wet film humidification control system, including:

[0063] Compressor 5, filter section 6, precooling coil 7, evaporator 8, wet film section 9, reheat coil 10, air supply fan 12, electronic expansion valve 5, first water flow valve 1, second water flow valve 2 and air supply temperature sensor 11; under winter heating and humidification conditions, the first water flow valve 1 is closed to avoid hot water diversion; the second water flow valve 2 configured in front of the water inlet pipe of the reheat coil 10 is used to adjust the high-temperature water flow entering the reheat coil 10 during heating and humidification; after the hot coil 10, the air supply temperature sensor 11 is installed in front of the air supply fan 12 to detect the actual air supply temperature, and the PID control algorithm is used to control the opening of the second water flow valve 2 so that the actual air supply temperature reaches and maintains the target air supply temperature.

[0064] In summer cooling and dehumidification conditions, water flow valve 1 is fully opened and water flow valve 2 is closed to avoid cold water diversion;

[0065] Working principle:

[0066] When the dehumidifier is running in the heating and humidification mode, the mixed air is filtered out impurities and harmful substances by the filter section 6 to obtain purified mixed air. The purified mixed air exchanges heat with the pre-cooling coil 7, and the air temperature increases. Then it is humidified in the wet film section 9. The moisture content of the mixed air after humidification is significantly improved, but the air temperature is significantly reduced. The lower humid air mixed air exchanges heat in the reheat coil 10, and the temperature is increased. The opening of the second water flow valve 2 is calculated by the PID control algorithm, and the high-temperature water flow through the second water flow valve 2 is intelligently adjusted, so as to achieve the actual air outlet temperature. Accurate control, energy saving and comfort.

[0067] Under the refrigeration and dehumidification conditions, the second water flow valve 2 is closed, the first water flow valve 1 is fully opened, and the wet film section is closed.

[0068] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A dual cold source fresh air dehumidifier wet film humidification control method, characterized in that: The following steps are involved: Step 1: Trigger the dehumidifier start signal; Step 2: The dehumidifier receives a power-on signal and determines whether it is in heating and humidification mode; Step 3: When the dehumidifier is in the heating and humidifying 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; 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; Step 5: When the outlet air temperature reaches the set target outlet air temperature, stop PID control adjustment.

2. The wet film humidification control method of the dual cold source fresh air dehumidifier according to claim 1 is characterized in that: Using the PID control algorithm to adjust the opening of the second water flow valve includes: Step 41: Calculate the outlet air temperature T at each Δt period. out and the set target air outlet temperature T outs The absolute value of the temperature difference ΔT; Step 42: for ΔT(t) and ΔT(t)-ΔT(t-1), control parameter K p , K i and K d Make judgments; Step 43: Calculate the opening of the second water flow valve using a PID control algorithm.

3. The wet film humidification control method of the dual cold source fresh air dehumidifier according to claim 2 is characterized in that: Step 42 specifically includes: 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; Step 422, when ΔT(t) < q, control parameter K p <a; when ΔT(t) - ΔT(t - 1) < r, control parameter K i < b, K d > c; Among them, q is the set temperature difference; r, a, b, c are constants.

4. The wet film humidification control method of the dual cold source fresh air dehumidifier according to claim 3 is characterized in that: Step 43 includes: Calculate the output value P, the formula is: Calculate the opening of the second water flow valve using the formula: P s =max[0,min(100,P)]×100% (2) Among them, ΔT(t) is the temperature difference at time t, ΔT(i) is the temperature difference at time i, and ΔT(t-1) is the temperature difference at time t-1.

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

6. The wet film humidification control method of a dual cold source fresh air dehumidifier according to claim 1, characterized in that: When the dehumidifier is not in the heating and humidifying mode, the first water flow valve is opened and the second water flow valve is closed.

7. A device using the dual cold source fresh air dehumidifier wet film humidification control method according to any one of claims 1 to 6, characterized in that: include: A compressor, a filter section, a precooling coil, an evaporator, a wet film section, a reheat coil, an air supply fan, an electronic expansion valve, a first water flow valve, a second water flow valve and an air supply temperature sensor, wherein a second water flow valve is installed at the water inlet end in front of the reheat coil, and the opening of the second water flow valve is adjusted to adjust the high-temperature water flow entering the reheat coil during heating and humidification.

8. Double cold source fresh air dehumidifier wet film humidification control system, characterized in that: include: a memory for storing instructions executable by a processor; A processor, used to execute instructions to implement the wet-film humidification control method for a dual-cold-source fresh air dehumidifier as described in any one of claims 1-6.

9. A computer readable medium storing a computer program code, characterized in that: When the computer program code is executed by a processor, the wet-film humidification control method for a dual-cold-source fresh air dehumidifier is implemented as described in any one of claims 1 to 6.

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