JP3966441B2 - Air conditioning apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air-conditioning control apparatus having a heat exchanger coil and a vaporizing humidifier, and in particular, to a method and a method for controlling temperature and humidity at the same time using the vaporization cooling effect of the vaporizing humidifier .
[0002]
[Related background]
Conventionally, control of room temperature by an air conditioner using this type of air conditioning method has an outside air damper, a cold water coil, and a hot water coil, and is performed, for example, by PID control of the outside air damper, the cold water valve, and the hot water valve. On the other hand, in the above air conditioner, indoor (return air) humidity control is often performed by using a humidifying valve and a vaporizing humidifier to control the vaporizing humidifier on / off.
[0003]
[Problems to be solved by the invention]
However, in such an air conditioner, cooling using a cold water coil uses cold water generated by a refrigerator, which is a cold heat source, and the refrigerator uses gas and electricity. It is not preferable.
The present invention utilizes an evaporative cooling effect of an evaporative humidifier that uses clean water for cooling, an air conditioner that can reduce consumption of gas and electricity in a cold heat source, and can protect the global environment, and An object is to provide such a method.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, an air conditioner having a heat exchanging coil and a humidifier and simultaneously performing temperature control by heat exchange and humidity control by humidification in the humidifier is provided downstream of the humidifier. A humidity sensor that is installed in the air supply passage on the side and measures the humidity accompanying the supply air; a valve that adjusts the amount of water supplied to the humidifier; and one of the supply air temperature, the room temperature, and the return air temperature. The control output of evaporative cooling is obtained from any one of P, PI, and PID from the temperature sensor to be measured, the control set temperature (temperature set value), and the measured temperature (measured temperature), and the valve is operated. and a control unit, particularly in the control device determines a control gain corresponding to the process gain with determining the process gain of evaporative cooling from the relationship between the temperature and humidity of air passing through the air supply passage, this decision Wherein P, PI, is characterized in that so as to correct the control parameters of the PID by the control gain was.
[0005]
In addition, the air conditioner according to the present invention uses the P, PI, or PID based on the control set temperature and the actually measured temperature in order to positively use the evaporative cooling effect of the humidifier. A second control output for evaporative cooling is obtained from the measured humidity from the humidity sensor and the humidity saturation limit characteristic obtained in advance, and the minimum value of the first control output and the second control output is obtained. According to the control output, the amount of water supplied to the humidifier is adjusted by operating the valve, and the control set temperature and the actually measured temperature are matched .
Preferably, the valve comprises a proportional valve whose valve opening is adjusted or a two-position valve which is time-proportional controlled, and is used for proportional control of the amount of water supplied to the humidifier .
[0007]
Further, in the present invention, for example, the third control output is obtained by using any one of P, PI, and PID from the control set humidity (humidity set value) and the measured humidity of the room or the return air. A valve that adjusts the amount of water supplied to the humidifier by the control output of the maximum value of the control output and the third control output is operated so that the control set temperature coincides with the actually measured temperature. A reduction in the evaporative cooling effect when the atmospheric humidity is high is prevented, and the opening degree of the humidifying valve is controlled.
[0008]
In the present invention, the air conditioning method includes an outside air cooling step in which temperature control is performed by outside air, a vaporization cooling step in which temperature control is performed by the vaporization cooling effect according to any one of claims 3 to 6, and heat exchange in a chilled water coil. It consists of a chilled water cooling process that performs temperature control, and the cooling control is performed so that the control set temperature and the measured temperature coincide with each other in the priority order of the process order, thereby reducing energy costs and improving the environmental aspect. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of an air conditioning control method and apparatus according to the present invention will be described with reference to the drawings of FIGS.
FIG. 1 is a configuration diagram of an air conditioning system using an air conditioning control method according to the present invention. In the figure, an air conditioner 10 includes a cooling coil 12 supplied with cold water from a cold heat source (not shown) via a cold water valve 11, a heating coil 14 supplied with hot water from a hot heat source (not shown) via a hot water valve 13, It has a humidifier 16 to which clean water is supplied from a water tap (not shown) through a humidifying valve 15, an air supply fan 17, a return air fan 18, and dampers 19 to 21 for outside air, return air, and exhaust. Configured. The cold water, for example, reaches the cold water valve 11 from a cold heat source through a pump, is supplied to the cooling coil 12, and then returns to the cold heat source again. The hot water reaches, for example, a hot water valve 13 from a heat source through a pump, is supplied to the heating coil 14, and then returns to the heat source again. Moreover, the above-mentioned clean water reaches the humidification valve 15 from, for example, tap water, is supplied to the humidifier 16, and unnecessary clean water is discharged.
[0010]
The opening operation of the cold water valve 11, the hot water valve 13, and the humidification valve 15 including the dampers 19 to 21 and proportional valves is controlled by the control device 22, and the supply air blown out by the supply air fan 17 is the air conditioner 10. The return air supplied from the inside through the air supply duct 23 to the room and taken in by the return air fan 18 is supplied from the room through the return air duct 26 into the air conditioner 10.
[0011]
The air supply duct 23 is provided with a temperature sensor 24 for detecting the temperature of the supply air supplied from the air conditioner 10 and a humidity sensor 25 for detecting the humidity of the supply air. The humidity sensor 27 for detecting the humidity of the return air taken in from the room is attached, and the control device 22 is given the humidity setting value of the return air from the room, and the actually measured humidity is inputted from the humidity sensor 27. Yes. The control device 22 is provided with the temperature setting value and humidity setting value of the supply air from the air conditioner 10, and the actually measured temperature and the actually measured humidity are input from the temperature sensor 24 and the humidity sensor 27.
[0012]
Meanwhile, the captured outside air into the air conditioner 10 is supplied to the room, also the portion of the air return air from the room, is discharged from the outside air duct 28 through an exhaust damper 21, the return air Is recirculated to the air supply side of the air conditioner 10 through the return air damper 20. The return air returned by the recirculation is mixed with the outside air taken in from the outside air duct 29 via the outside air damper 19 at a predetermined ratio.
[0013]
In addition, an integrated temperature / humidity sensor 30 for detecting the temperature and humidity of the outside air taken in is attached to the outside air duct 29, and is used to enable / disable the outside air cooling.
In the present invention, any one of P, PI, and PID of coil cooling, coil heating, evaporative cooling, and outside air cooling is used from the temperature setting value, measured value, and control parameter of any one of supply air, indoor air, and return air. A control output is obtained, and the cold water valve 11, the hot water valve 13, the humidification valve 15 and the dampers 19 to 21 are controlled by this control output, and the temperature set value and the actually measured value are matched. Further, in the present invention, the control output is obtained by using any one of the indoor (return air) humidity P, PI, and PID from the humidity setting value of the room or the return air, the actual measurement value, and the control parameter. The humidification valve 15 is controlled by the control output so that the humidity set value and the actually measured value are matched. That is, the amount of water flowing to the cooling coil 12, the amount of water flowing to the heating coil 14, the amount of water flowing to the humidifier 16, the outside air intake amount, the return air amount, the exhaust amount, and the like are controlled.
[0014]
In the present embodiment, as an example, the control output is obtained from the temperature setting value of the supply air, the actual measurement value, and the PID control parameter using the PID of the coil cooling, evaporative cooling, and the outside air cooling. Then, the humidifying valve 15 and each of the dampers 19 to 21 are controlled, and a control output is obtained from the humidity setting value of the return air, the actual measurement value, and the PID control parameter using the PID of the return air humidity. A case of controlling the above will be described.
[0015]
Furthermore, in the present embodiment, from the viewpoint of energy cost and environment, the control device 22 performs temperature control during cooling in the order of priority of outside air cooling, vaporization cooling using a humidifier, and heat exchange using a chilled water coil. When the cooling is necessary, the outside air damper 19 is first opened, the humidification valve 15 is opened after the opening is completed, and the cold water valve 11 is further opened. However, when the outside air cannot be cooled due to the outside air and the indoor air condition (for example, high temperature and high humidity or low temperature and low humidity), that is, when the temperature and humidity detected by the temperature / humidity sensor 30 are high temperature and high humidity from a certain set value. In the case of low temperature and low humidity conditions, the outside air cooling is not performed.
[0016]
However, when the air humidity at the inlet of the humidifier 16 approaches a saturated state, the amount of evaporated water decreases, the cooling effect is lost, the amount of drainage from the humidifier 16 increases, and water is also wasted. Therefore, evaporative cooling in such a state is not a good idea. Therefore, in this embodiment, the saturation state of the supply air is determined based on the relative humidity of the supply air. That is, the limit opening degree of the humidification valve 15 at the time of supply air saturation is calculated from the supply air humidity by the supply air humidity limit opening degree table shown in FIG. When the opening degree of the humidifying valve 15 shown in the above table reaches the limit opening degree with respect to the actually measured humidity of the supply air, the cold water valve 11 is opened as shown in the control state transition diagram of FIG. FIG. 3 is an example of the proportional operation. When integration and differentiation operations are applied, each line shifts or deviates in the middle.
[0017]
Next, a detailed control operation will be described using a flowchart showing a control process of the control device 22 of FIG. When cooling is necessary, the control device 22 first determines whether or not the outside air can be cooled based on the outside air conditions (the outside air temperature and the outside air humidity detected by the temperature / humidity sensor 30) (step 101). The lock is released, and calculation is performed using the outside air cooling PID from the temperature setting value of the supply air input using the outside air cooling PID, the actually measured temperature, and the PID control parameter of the outside air damper 19 (step 102). An outside air damper instruction output indicating the opening degree of the outside air damper, which is an output, is obtained, and the opening degree control of the outside air damper 19 is performed by the outside air damper instruction output.
[0018]
In the above opening degree control, the minimum opening degree and the maximum opening degree of the outside air damper are set in advance, and when the outside air damper reaches the maximum opening degree or the outside air cooling is impossible due to the outside air condition. In step 101, it is determined whether evaporative cooling is possible from the temperature setting value and the actually measured temperature of the supply air. Here, when evaporative cooling is possible, calculation is performed based on the actually measured temperature of the supply air input using the evaporative cooling PID, the temperature setting value, and the PID control parameter of the humidifying valve 15 (step 103), and the control output. A humidifying valve instruction output indicating the opening degree of the humidifying valve is obtained, and the humidifying valve instruction output is performed.
[0019]
By the way, the process gain of evaporative cooling (cooling effect on the amount of supplied water) varies greatly depending on the humidity of the air passing through the humidifier 16. For example, evaporative cooling effect is large in low-humidity air, but evaporative cooling effect is small in high-humidity air. The fluctuation of the process gain can be read from the known air diagram shown in FIG. 5. For example, when considering how the cooling effect of air having a temperature of 25 ° C. changes as an example, the humidifier 16 is 80%. Considering the humidifying ability up to the relative humidity (hereinafter referred to as “% RH”), when the air at the inlet of the humidifier is 40% RH, the cooling effect is about 6-7 ° C. On the other hand, at 70% RH, the temperature difference decreases to about 1.5 ° C. For such a large process gain change, if the control gain is constant, temperature control with good response cannot be realized.
[0020]
Therefore, in the present embodiment, stable control can be realized by storing the air diagram data in the control device and automatically correcting the gain of the evaporative cooling control in accordance with the supply air humidity. FIG. 6 is a correction diagram showing an example of gain correction. Similarly, the process gain of evaporative cooling varies depending on the passing air volume and the inlet dry bulb temperature. Therefore, if the control gain is corrected based on these values, the controllability can be further improved.
[0021]
Further, a supply air humidity limit opening degree table is created in the control device 22 in order to determine the saturation state of the supply air (see FIG. 2). The control device 22 obtains a humidifying valve instruction output indicating the opening degree of the humidifying valve, which is a control output, from the actually measured humidity of the supply air and the supply air humidity limit opening degree table (step 104), and performs the humidifying valve instruction output. .
With respect to the humidifying valve instruction output obtained from the evaporative cooling PID and the supply air humidity limit opening table, the control device 22 selects any one of the minimum values of the humidifying valve instruction output (step 105). Here, when the output from the evaporative cooling PID is smaller, the output is selected. When the output from the supply air humidity limit opening table is smaller, the state is being limited. Is output, and the interlock of the coil cooling PID is released by the interlock determination in step 101, and the process proceeds to temperature control by heat exchange in the cold water coil using the coil cooling PID.
[0022]
Further, the control device 22 performs calculation based on the actually measured humidity of the return air, the humidity setting value, and the PID control parameter of the humidifying valve that are input using a predetermined indoor (return air) humidity PID (step 106). A humidifying valve instruction output indicating the opening of the humidifying valve as an output is obtained, and the humidifying valve instruction output is performed.
In response to the humidifying valve instruction output from the evaporative cooling PID selected by the minimum value selection and the humidifying valve instruction output from the indoor (return air) humidity PID, the control device 22 outputs any one of the maximum values of the humidifying valve instruction output. A selection is made (step 107). Here, when the output from the evaporative cooling PID is larger, the output is selected. When the output from the indoor (return air) humidity PID is larger, the humidifier is controlled by temperature control. Since the humidity is controlled, the output indicating that the humidification is being performed is output, the interlock of the coil cooling PID is released by the interlock determination in step 101, and the cold water coil using the coil cooling PID is used. Shift to temperature control by heat exchange.
[0023]
And the control apparatus 22 operates the humidification valve 15 by the humidification valve instruction | indication output selected by maximum value selection. Further, the control device 22 determines that the temperature control using the evaporative cooling PID does not function when the state output is in the limit in step 105 or when the state output is in the humidifying state in step 107. Using the coil cooling PID, a calculation is performed based on the actual temperature of the supply air, the temperature setting value, and the PID control parameter of the chilled water valve 11 (step 108), and a chilled water valve instruction indicating the opening degree of the chilled water valve 11 as a control output. An output is obtained, and the opening degree of the chilled water valve is controlled by the chilled water valve instruction output.
[0024]
As described above, in the present embodiment, the evaporative cooling effect of the humidifier is used, the humidification valve instruction output is obtained from the temperature set value and the actually measured temperature using the evaporative cooling PID, and the opening degree control of the humidification valve is performed. Thus, the temperature control of the air conditioner is performed, so that it is possible to efficiently perform the temperature control that is inexpensive and does not adversely affect the environment due to natural energy.
Moreover, in this embodiment, since temperature control is performed according to the priority order of the outside air cooling, the evaporative cooling in the humidifier, and the thermal effect of the chilled water coil, the energy cost can be reduced and the environment can be improved.
[0025]
In addition, although the humidification valve 15 which concerns on this embodiment was comprised with the proportional valve, this invention is not limited to this, For example, it is also possible to comprise with an opening-and-closing two-position type valve. In this case, the control device 22 can proportionally control the amount of clean water supplied to the humidifier by performing time proportional control (duty control) on the humidification valve.
The present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention.
[0026]
【The invention's effect】
As described above, in the present invention, the evaporative cooling effect of the humidifier that uses clean water is positively utilized for cooling temperature control, and evaporative cooling is performed using any of evaporative cooling P, PI, and PID. Since the control output is obtained and the humidification valve is proportionally controlled by the control output to match the control set temperature and the actually measured temperature, consumption of gas and electricity at the cold heat source can be reduced, and the global environment can be protected. it can.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an air conditioning system using an air conditioning control method according to the present invention.
FIG. 2 is a view showing a supply air humidity limit opening table showing a relationship between supply air humidity and a limit opening of a humidifying valve;
FIG. 3 is a control state transition diagram showing transition of each control state performed by the air conditioner.
FIG. 4 is a flowchart showing a control process of the control device shown in FIG. 1;
FIG. 5 is an air diagram for reading process gain variation.
FIG. 6 is a correction diagram showing an example of gain correction.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Air conditioner 11 Cold water valve 12 Cooling coil 13 Hot water valve 14 Heating coil 15 Humidifier valve 16 Humidifier 17, 18 Fan 19-21 Damper 22 Controller 23, 26, 28, 29 Duct 24 Temperature sensor 25, 27 Humidity sensor 30 Temperature Humidity sensor

Claims (7)

In an air conditioner having a heat exchange coil and a humidifier, and simultaneously performing temperature control by heat exchange and humidity control by humidification in the humidifier,
A humidity sensor that is installed in an air supply passage on the downstream side of the humidifier and measures the humidity associated with the air supply;
A valve for adjusting the amount of water supplied to the humidifier;
A temperature sensor that actually measures either the supply air temperature, the room temperature, or the return air temperature;
A control device for operating the valve to obtain a control output of evaporative cooling in the humidifier using any one of P, PI, and PID from the control set temperature and the temperature actually measured by the temperature sensor;
Further, the control device obtains a process gain of evaporative cooling from the relationship between the temperature and humidity of the air passing through the air supply passage, determines a control gain corresponding to the process gain, and determines the P, An air-conditioning apparatus comprising means for correcting PI and PID control parameters . In an air conditioner that has a coil for heat exchange and a humidifier, and simultaneously performs temperature control by heat exchange and humidity control by humidification in the humidifier,
A humidity sensor that is installed in an air supply passage on the downstream side of the humidifier and measures the humidity associated with the air supply;
A valve for adjusting the amount of water supplied to the humidifier;
A temperature sensor that actually measures either the supply air temperature, the room temperature, or the return air temperature;
From the control set temperature and the actually measured temperature, the first control output of evaporative cooling is obtained using any one of P, PI, and PID, and from the actually measured humidity from the humidity sensor and the previously obtained humidity saturation limit characteristic. A control device for obtaining a second control output of evaporative cooling and operating the valve with a control output of a minimum value of the first control output and the second control output;
An air conditioner comprising: The air conditioner according to claim 1 or 2 , wherein the valve is a proportional valve or a two-position valve that is controlled in proportion to time. In an air conditioning method for controlling the measured values of temperature and humidity to be close to the set values using a heat exchange coil and a humidifier installed in the air supply passage ,
P from the actually measured control temperature setting temperature, PI, obtains a first control output of the evaporative cooling using any of PID, adjusting the amount of water of water supplied to the humidifier by the first control output Operate the valve to
The process gain of the evaporative cooling is determined from the relationship between the temperature and humidity of the air passing through the air supply passage, and a control gain corresponding to the process gain is determined. Based on the determined control gain, the P, PI, and PID are determined. An air conditioning method comprising correcting a control parameter . Using a heat exchange coil installed in the air supply passage humidifier, the air conditioner method of controlling so as to approach a set value the measured values of the adjustment to the temperature and humidity of the supply water to the humidifier,
A first control output of evaporative cooling is obtained from any one of P, PI, and PID from the control set temperature and the actually measured temperature, and
A second control output of evaporative cooling is obtained from the measured humidity from the humidity sensor installed in the air supply passage on the downstream side of the humidifier and the humidity saturation limit characteristic obtained in advance.
Air conditioning method characterized by operating the valve for adjusting the amount of water water supplied to the humidifier by controlling the output of the minimum value of the second control output and said first control output. In an air conditioning method that uses a heat exchange coil and a humidifier installed in an air supply passage to adjust the amount of water supplied to the humidifier and control the measured values of temperature and humidity to approach set values,
A first control output of evaporative cooling is obtained from any one of P, PI, and PID from the control set temperature and the actually measured temperature, and
A second control output of evaporative cooling is obtained from the measured humidity from the humidity sensor installed in the air supply passage on the downstream side of the humidifier and the humidity saturation limit characteristic obtained in advance.
Furthermore, the third control output of evaporative cooling is obtained from either the control set humidity and the measured humidity of the room or return air using either P, PI, or PID.
Wherein with the first selecting control output and the control output of the minimum value of the second control output, the humidifier by controlling the output of the maximum value among the third control output and the control output selected An air conditioning method characterized by operating a valve for adjusting the amount of water supplied to the water. In an air conditioning method for controlling the measured values of temperature and humidity to be close to the set values using a heat exchange coil and a humidifier installed in the air supply passage ,
An outside air cooling step in which temperature control is performed by outside air, a vaporization cooling step in which temperature control is performed by a vaporization cooling effect in the humidifier by the air conditioning method according to any one of claims 4 to 6, and the heat exchange coil . and a cold water cooling step of controlling the temperature by the heat exchanger,
An air conditioning method, characterized in that temperature control is performed so that the control set temperature and the measured temperature coincide with each other in the priority order of the outside air cooling step, the vaporization cooling step, and the cold water cooling step .

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