JP2006057902A - Temperature and humidity controller and control method for heater thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature and humidity controller and a control method for a heater by the temperature and humidity controller, capable of suppressing an overshoot of dry-bulb temperature even when increasing rise speed of the dry-bulb temperature and wet-bulb temperature. <P>SOLUTION: This temperature and humidity controller mainly has a test bath, an air heating heater 12, a humidifying heater 13a, an evaporator, a fan, a dry-bulb temperature sensor 16, a wet-bulb temperature sensor 17, and a controller 18. The controller 18 is provided with an air heating heater control part 18h predicting whether the dry-bulb temperature overshoots target dry-bulb temperature when keeping the air heating heater 12 operating when operating the air heating heater 12 at high output, and turns off output of the air heating heater 12 when predicting that it overshoots. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a temperature / humidity control device capable of appropriately adjusting the inside of a sealed test tank to a predetermined temperature and a predetermined humidity, and a heater control method using the temperature / humidity control device.

  Generally, a temperature / humidity control device that can appropriately adjust the inside of a sealed test tank to a predetermined temperature or a predetermined humidity as an environmental test device for examining material characteristics (such as the occurrence of rust) in different environments. Are known. Such a temperature and humidity control apparatus mainly includes a dry bulb temperature sensor, a wet bulb temperature sensor, an air heater, a humidifier heater, a cooler, and a controller. Here, the dry bulb temperature sensor is for detecting the dry bulb temperature in the test chamber (air temperature: temperature measured by a dry bulb thermometer having a dry heat-sensitive part). Is for detecting the wet bulb temperature in the test tank (temperature measured by a wet bulb thermometer having a heat sensitive part wrapped with a damp cloth). The air heater is for raising the dry bulb temperature by heating air, and the humidifier heater is for raising the wet bulb temperature by boiling and evaporating the water in the humidifying pan. The cooler is for lowering the dry bulb temperature and the wet bulb temperature.

  In such a temperature / humidity control device, the test is performed by appropriately controlling the air heater and the humidifier heater so that the measured values of the dry bulb temperature and the wet bulb temperature detected by each sensor reach the respective target values. The inside of the tank is controlled to a predetermined temperature and humidity. However, in order to raise the wet bulb temperature described above, the water in the humidifying pan must be boiled and the temperature of the moisture in the cloth that wraps the heat sensitive part must be raised. While the temperature rises and falls quickly in response to fluctuations in the output of the heater (responsiveness is fast), the wet bulb temperature rises and falls only after a specified delay time has elapsed even if the output of the humidifying heater fluctuates. No (slow responsiveness). Therefore, for example, even if the air heater and the humidifier heater are simultaneously operated at the maximum output when the dry bulb temperature and the wet bulb temperature are substantially the same value in the initial state, the dry bulb temperature first reaches the target value. A phenomenon occurs in which the wet bulb temperature reaches the target value later. In view of this, the temperature and humidity control apparatus employs various control methods in consideration of such a phenomenon.

  As a general method, the dry bulb temperature is controlled by controlling the air heater based on the measured value of the dry bulb temperature sensor and its target value. Separately, the measured value of the wet bulb temperature sensor is used. There is a method of controlling the wet bulb temperature by controlling the humidifying heater based on the target value and the target value. In this method, as shown in FIG. 4, with respect to the dry bulb temperature that has previously reached the target value, the dry bulb temperature is maintained at the target value by appropriately PID-controlling the output of the air heater after reaching the target value. As for the wet bulb temperature that rises late (hereinafter also referred to as “maintenance control”), the wet bulb temperature is maintained and controlled by appropriately PID-controlling the output of the humidifier heater after reaching the vicinity of the target value. It has been broken.

  However, if the wet bulb temperature is weakened by the PID control after the wet bulb temperature reaches the target value in this way, the wet bulb temperature does not decrease unless a predetermined delay time has elapsed as described above. This causes a problem that the wet bulb temperature exceeds the target value (hereinafter referred to as “overshoot”). At this time, if the target value of the dry bulb temperature is close to the target value of the wet bulb temperature, the amount of heat from the humidifying heater for raising the wet bulb temperature also raises the dry bulb temperature. The ball temperature sometimes overshoots. Furthermore, even when the overheated wet bulb temperature, etc. is lowered and returned to the target value, a phenomenon (undershoot) occurs that causes the measured value to fall below the target value, so the wet bulb temperature etc. is fairly stable at the target value. In some cases, so-called hunting occurs.

  As a control method for such a problem, conventionally, as shown in FIG. 5, PID control is performed on the humidifying heater long before the wet bulb temperature reaches the target value, thereby reducing the rising speed of the wet bulb temperature. A technique for suppressing overshoot is known (see Patent Document 1). In this method, if the wet bulb temperature overshoots, the output of the humidifying heater is forcibly turned off, and then PID control with a small P constant is performed to suppress undershoot and hunting. It can also be suppressed.

JP-A-5-66045

  By the way, in the above-described technique, regarding the control of the air heater, the air heater is operated at the maximum output until the dry bulb temperature reaches the target value, and after reaching the target value, the output of the air heater is performed by PID control. The control is such that the dry bulb temperature is maintained at the target value by raising and lowering. Therefore, as shown in FIG. 6, when the rising speed of the dry bulb temperature and the wet bulb temperature is increased, a high output immediately after shifting from the operating state of the maximum output of the air heater to the maintenance control and the maximum of the humidifier heater When combined with the output, the heater as a whole has a large output, the large output (heat amount) greatly affects the dry bulb temperature, and as a result, there is a problem that the dry bulb temperature significantly overshoots.

  Therefore, in the present invention, a temperature / humidity control device and a heater control method using the temperature / humidity control device that can suppress the overshoot of the dry bulb temperature even when the dry bulb temperature and the rising speed of the wet bulb temperature are increased. The purpose is to provide.

  The invention according to claim 1 of the present invention that solves the above-mentioned problems includes a test tank formed of a heat insulating material, dry bulb temperature detecting means for detecting a dry bulb temperature in the test tank, and the test tank. A wet bulb temperature detecting means for detecting the wet bulb temperature, an air heater that contributes to an increase in the dry bulb temperature, a humidifier heater that contributes to an increase in the wet bulb temperature or the dry bulb temperature, and the dry bulb temperature or In order to set the wet bulb temperature to a predetermined target dry bulb temperature or target wet bulb temperature, the air heater or the humidifier heater is initially controlled to operate at a high output, and the dry bulb temperature or When the wet bulb temperature reaches the target dry bulb temperature or the target wet bulb temperature, the heater control means controls to maintain the dry bulb temperature or the wet bulb temperature at the target dry bulb temperature or the wet bulb temperature. And the high output Overshoot predicting means for predicting that the dry bulb temperature will overshoot from the target dry bulb temperature if the air heater is kept running when the air heater is being operated; and When the chute predicting means predicts that the overshoot will occur, the output of the air heater is decreased more rapidly than the immediately preceding output, so that both the dry bulb temperature and the wet bulb temperature are mainly produced only by the output of the humidifier heater. And overshoot suppressing means for suppressing the overshoot.

  Here, “high output” refers to an output that is appropriately set to increase the dry bulb temperature and wet bulb temperature at a predetermined speed in the initial stage, and maintenance control that is performed when each temperature reaches a target value. An output higher than the output at the time. Specifically, the high output corresponds to the maximum output of the heater, for example, 90% of the maximum output.

  According to the first aspect of the present invention, for example, when both the air heater and the humidifier heater are operated at the maximum output so that the dry bulb temperature and the wet bulb temperature in the test tank reach the respective target values quickly, The temperature and the wet bulb temperature each rise at a rapid rise rate. In this way, while the air heater is operated at the maximum output, it is always predicted by the overshoot prediction means whether or not the dry bulb temperature will overshoot from the target dry bulb temperature after a predetermined time. And if it is predicted that overshooting will occur by this overshoot predicting means, the output of the air heater is suddenly dropped by the overshoot suppressing means, for example, so as to be turned off, and thereafter only the output of the humidifying heater is output. As a result, the dry bulb temperature and the wet bulb temperature rise. For this reason, the rising speed of the dry bulb temperature or the like becomes moderate, and the overshoot such as the dry bulb temperature or the like is suppressed. That is, according to the present invention, the amount of heat of the entire heater (the amount of heat of the air heater + the amount of heat of the humidifying heater) can be reduced considerably before the rapidly rising dry bulb temperature reaches the target dry bulb temperature. When the bulb temperature reaches the target dry bulb temperature, the rising speed of the dry bulb temperature is reduced, and overshoot can be suppressed.

The invention according to claim 2 is the temperature and humidity control device according to claim 1, wherein the overshoot predicting means includes a difference between the dry bulb temperature and the wet bulb temperature, the target dry bulb temperature, and the Overshoot is predicted based on the difference in dry bulb temperature.
Further, the invention according to claim 3 is the temperature and humidity control device according to claim 1, wherein the overshoot predicting means includes a difference between the target dry bulb temperature and the dry bulb temperature, and a target wet bulb temperature. And overshoot based on the difference between the wet bulb temperatures.

  According to the invention described in claim 2 or claim 3, since the dry bulb temperature and wet bulb temperature, which are actually measured values, are referred to, overshoot can be accurately predicted.

  The invention according to claim 4 is the temperature / humidity control device according to claim 2, wherein the target dry bulb temperature and the target wet bulb temperature are set to substantially the same value. When the difference between the dry bulb temperature and the wet bulb temperature and the difference between the target dry bulb temperature and the dry bulb temperature are substantially equal, it is predicted that an overshoot will occur.

  Here, “substantially the same value” means that the difference between the target dry bulb temperature and the target wet bulb temperature is in the range of 0 to 5.0 ° C. Further, “when substantially equal” means that the difference ΔT1 between the dry bulb temperature and the wet bulb temperature and the difference ΔT2 between the target dry bulb temperature and the dry bulb temperature are within a range of 0 to 5.0 ° C. It means that there is.

  According to the invention described in claim 4, when the difference between the dry bulb temperature and the wet bulb temperature and the difference between the target dry bulb temperature and the dry bulb temperature are substantially equal, for example, by stopping the air heater. Then, the dry bulb temperature and wet bulb temperature can be increased at a good rate only with the humidifying heater, and when the dry bulb temperature becomes close to the target dry bulb temperature, the output of the humidifying heater is gradually weakened. By simply performing simple control, it is possible to satisfactorily maintain the dry bulb temperature and suppress the overshoot of the wet bulb temperature.

  The temperature and humidity control device according to claim 5 is the temperature and humidity control device according to claim 4, wherein the overshoot predicting means determines the difference between the dry bulb temperature and the wet bulb temperature to determine the heat of the temperature and humidity control device. A difference between the dry bulb temperature and the wet bulb temperature is corrected by adding a correction constant set according to the magnitude of inertia.

  According to the fifth aspect of the present invention, the difference between the dry bulb temperature and the wet bulb temperature is corrected in consideration of the thermal inertia of the temperature and humidity control device, so that the timing at which the output of the air heater is suddenly dropped can be accurately determined. Since it can be determined, suppression of overshoot can be further improved.

  Invention of Claim 6 is the heater control method by the temperature-humidity control apparatus of Claim 1, Comprising: The high output operation process which operates the said air heating heater and the said humidification heater by high output, In the high power operation process, an overshoot prediction process for predicting whether or not the dry bulb temperature will overshoot from the target dry bulb temperature if the air heater is continuously operated at a high output, and the overshoot prediction In the process, when it is predicted that overshooting will occur, the output of the air heater is decreased more rapidly than the previous output, so that both the dry bulb temperature and the wet bulb temperature are moderated mainly by only the output of the humidifier heater. And an overshoot suppressing step for suppressing overshoot.

  According to the sixth aspect of the present invention, for example, in order to make the dry bulb temperature and the wet bulb temperature in the test tank reach the respective target values quickly, both the air heater and the humidifier heater at the maximum output in the high output operation process. When operated, the dry bulb temperature and wet bulb temperature each rise at a rapid rate of rise. During this high power operation process, it is always predicted whether or not the dry bulb temperature will overshoot from the target dry bulb temperature after a lapse of a predetermined time (overshoot prediction process). In this overshoot prediction step, if it is predicted that overshoot will occur, the output of the air heater is turned off, for example, and then the dry bulb temperature and wet bulb temperature rise only by the output of the humidifier heater. Therefore, the rising speed of the dry bulb temperature becomes moderate, and the overshoot of the dry bulb temperature is suppressed (overshoot suppression step).

  According to the first aspect of the present invention, even when the air bulb heater and the like are operated at a high output to increase the dry bulb temperature and the wet bulb temperature, the overshoot prediction means causes the dry bulb temperature to increase. If it is predicted that overshoot will occur, the output of the air heater will be suddenly reduced by the overshoot suppression means, and the rising speed of the dry bulb temperature will be slowed down. Can do.

  According to the invention described in claim 2 or claim 3, since the dry bulb temperature and wet bulb temperature, which are actually measured values, are referred to, overshoot can be accurately predicted.

  According to the invention described in claim 4, when the difference between the dry bulb temperature and the wet bulb temperature and the difference between the target dry bulb temperature and the dry bulb temperature are substantially equal, for example, by stopping the air heater. Then, the dry bulb temperature and wet bulb temperature can be increased at a good rate only with the humidifying heater, and when the dry bulb temperature becomes close to the target dry bulb temperature, the output of the humidifying heater is gradually weakened. By simply performing simple control, it is possible to satisfactorily maintain the dry bulb temperature and suppress the overshoot of the wet bulb temperature.

  According to the fifth aspect of the present invention, the difference between the dry bulb temperature and the wet bulb temperature is corrected in consideration of the thermal inertia of the temperature and humidity control device, so that the timing at which the output of the air heater is suddenly dropped can be accurately determined. Since it can be determined, suppression of overshoot can be further improved.

  According to the sixth aspect of the present invention, even when the rising speed of the dry bulb temperature and the wet bulb temperature is increased by the high output operation step, the overshoot prediction step performed during the dry bulb temperature and the wet bulb temperature is performed. Is predicted to overshoot, the process proceeds to the overshoot suppression process, the output of the air heater is suddenly reduced, and the rising speed of the dry bulb temperature becomes slow. Can be suppressed.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is an explanatory view showing a temperature / humidity control device according to the present embodiment, FIG. 2 is a block diagram showing details of the control device of FIG. 1, and FIG. And a graph showing changes in dry bulb temperature or wet bulb temperature.

  As shown in FIG. 1, the temperature / humidity control apparatus 10 includes a test tank 11, an air heater 12, a humidifier 13, an evaporator 14, a blower 15, a dry bulb temperature sensor (dry bulb temperature detecting means) 16, and a wet bulb temperature. A sensor (wet bulb temperature detecting means) 17 and a control device 18 are mainly provided. In the test tank 11, the outer frame 11a and the partition wall 11b are both formed of a heat insulating material, and the internal space is partitioned into the air-conditioning room R1 and the test room R2 by the partition wall 11b.

  The air conditioning chamber R1 is provided with the air heater 12, the humidifier 13, the evaporator 14, and the blower 15. The test chamber R2 is provided with the dry bulb temperature sensor 16 and the wet bulb temperature sensor 17. It has been. In addition, the air conditioning room R1 and the test room R2 communicate with each other through the vent holes 11c and 11d formed in the upper part and the lower part of the partition wall 11b.

The air heater 12 heats the air in the test tank 11, thereby contributing to an increase in the dry bulb temperature.
The humidifier 13 boils water in a humidifying pan (not shown) and contributes to an increase in wet bulb temperature or dry bulb temperature, and the water boiled by the humidifier heater 13a is used as steam in the air conditioning room R1. It is mainly composed of a steam divergence portion 13b that diverges inside.

The evaporator 14 is cooled by the refrigerant of the cooler 14a, and contributes to air cooling and water vapor liquefaction (dehumidification).
The blower 15 sends out the air heated or cooled in the air conditioning room R1 from the upper ventilation port 11c into the test room R2, and sucks the air in the test room R2 from the lower ventilation hole 11d, so that the test chamber 11 Air is circulated inside.
The dry bulb temperature sensor 16 is a sensor that detects the dry bulb temperature in the test chamber R2, and the wet bulb temperature sensor 17 is a sensor that detects the wet bulb temperature in the test chamber R2.

  As shown in FIG. 2, the control device 18 includes a bath dry bulb temperature setter 18a, a bath humidity setter 18b, a target dry bulb temperature output calculator 18c, a target wet bulb temperature output calculator 18d, and a dry bulb temperature difference. It mainly includes a calculation unit 18e, a wet bulb temperature difference calculation unit 18f, an actually measured temperature difference calculation unit 18g, an air heater control unit 18h, and a humidification heater control unit 18i. The tank dry bulb temperature setter 18a and the tank humidity setter 18b are for the user to set the dry bulb temperature and humidity in the test tank 11 to desired values. In addition, as such a setting device, a touch panel, a keyboard, etc. are employ | adopted, for example.

  The target dry bulb temperature output calculating unit 18c determines the dry bulb temperature set by the in-tank dry bulb temperature setting unit 18a as the target dry bulb temperature Ttdry, and the target dry bulb temperature Ttdry is supplied to the dry bulb temperature difference calculating unit 18e. It has a function to output.

  The target wet bulb temperature output calculation unit 18d calculates the target wet bulb temperature Ttwet based on the dry bulb temperature set by the tank dry bulb temperature setter 18a and the humidity set by the tank wet bulb setter 18b. The target wet bulb temperature Ttwet has a function of outputting to the wet bulb temperature difference calculating unit 18f. In the present embodiment, the target dry bulb temperature Ttdry and the target wet bulb temperature Ttwet are set to substantially the same value. Specifically, the difference between these temperatures is in the range of 0 to 5.0 ° C. It is set to become.

  The dry bulb temperature difference calculation unit 18e is configured to output the target dry bulb temperature Ttdry output from the target dry bulb temperature output calculation unit 18c, the actual dry bulb temperature detected by the dry bulb temperature sensor 16 (T1dry shown in FIG. 3), and the like. The difference α is calculated, and the calculation result (difference α) is output to the air heater control unit 18h.

  The wet bulb temperature difference calculation unit 18f is configured to output the target wet bulb temperature Ttwet output from the target wet bulb temperature output calculation unit 18d, the actual wet bulb temperature detected by the wet bulb temperature sensor 17 (such as T1wet shown in FIG. 3), and the like. The difference β is calculated, and the calculation result is output to the humidifying heater control unit 18i.

  The measured temperature difference calculation unit 18g calculates a difference γ between the measured dry bulb temperature (T1dry, etc.) detected by the dry bulb temperature sensor 16 and the measured wet bulb temperature (T1wet, etc.) detected by the wet bulb temperature sensor 17, The calculation result is output to the air heater controller 18h. In the following description, the measured dry bulb temperature or the measured wet bulb temperature is also simply referred to as the dry bulb temperature or the wet bulb temperature for convenience.

  The air heater controller 18h is based on the signal (difference α) output from the dry bulb temperature difference calculator 18e and the signal (difference γ) output from the measured temperature difference calculator 18g. It has a function of controlling 12 outputs. Specifically, when the difference α is larger than the value obtained by adding the correction constant a such as thermal inertia to the difference γ, the air heater control unit 18h operates the air heater 12 at the maximum output, and α = Γ + a When the air heater 12 is continuously operated at the maximum output, the dry bulb temperature is predicted (determined) to overshoot, and the air heater 12 is turned off (stopped). have. Here, the air heater controller 18h, the dry bulb temperature difference calculator 18e, and the actually measured temperature difference calculator 18g in the present embodiment correspond to “overshoot predicting means” in the claims, and are controlled by the air heater. The part 18h corresponds to “overshoot suppressing means and heater control means” in the claims.

  The correction constant a can be obtained by estimating or mapping with reference to the heat generation and the outside air temperature of the temperature / humidity control device 10. The air heater controller 18h operates the air heater 12 that has been stopped again when the wet bulb temperature reaches the target wet bulb temperature Ttwet, and controls the dry bulb temperature by performing PID control. It also has a function of maintaining the target dry bulb temperature Ttdry (see FIG. 3). Furthermore, α and γ + a need only be approximately equal, and the difference between α and γ + a may be in the range of 0 to 5.0 ° C.

  The humidifying heater control unit 18i has a function of controlling the output of the humidifying heater 13a based on a signal (difference β) output from the wet bulb temperature difference calculating unit 18f. Specifically, the humidifying heater control unit 18i operates the humidifying heater 13a at the maximum output until the difference β reaches a predetermined value (a value obtained by subtracting T2wet from Ttwet shown in FIG. 3), and the difference β becomes the predetermined value. Has a function of gradually decreasing the output of the humidifying heater 13a. The humidifying heater control unit 18i also has a function of maintaining the wet bulb temperature at the target wet bulb temperature Ttwet by performing PID control of the humidifier heater 13a when the wet bulb temperature reaches the target wet bulb temperature Ttwet. ing. Here, the humidifying heater control unit 18i in the present embodiment corresponds to “heater control means” in the claims.

  Next, a method for controlling the heaters 12 and 13a by the temperature and humidity control apparatus 10 according to the present embodiment will be described. In this embodiment, the temperature of water in the humidifying pan (not shown) is set so that the dry bulb temperature in the initial stage is relatively higher than the wet bulb temperature and the wet bulb temperature rises immediately. The description will be made on the assumption that the temperature has been heated to near the boiling point.

  When the operation of the temperature / humidity control device 10 is started, as shown in FIG. 3, first, the heaters 12 and 13a are both operated at the maximum output, and the dry bulb temperature and the wet bulb temperature rise at a relatively fast speed. (High power operation process). In this high-power operation process, the above-described air heater controller 18h (see FIG. 2) always corrects the difference α between the target dry bulb temperature and the dry bulb temperature and the difference γ between the dry bulb temperature and the wet bulb temperature. By determining whether or not the sum of the constant a is equal, it is predicted whether or not the dry bulb temperature will overshoot (overshoot prediction step).

  When it is determined by the air heater control section 18h that the difference α between the target dry bulb temperature and the dry bulb temperature is equal to the difference γ between the dry bulb temperature and the wet bulb temperature plus the correction constant a (time t1). ), The air heater 12 is turned off by the air heater controller 18h (overshoot suppressing step). When the air heater 12 is turned off in this way, the dry bulb temperature rises only by the surplus amount of heat from the humidifying heater 13a, so that the rising speed becomes slow and the humidifying heater 13a A part of the amount of heat is used to increase the dry bulb temperature, so that the wet bulb temperature increases at a slower speed.

  Thereafter, when the wet bulb temperature reaches T2wet (time t2), the output of the humidifying heater 13a is gradually decreased by the humidifying heater control unit 18i. As a result, the rising speed of the dry bulb temperature is further relaxed in the vicinity of the target dry bulb temperature Ttdry, and the rising speed of the wet bulb temperature is further loosened, so that the dry bulb temperature and the wet bulb temperature do not overshoot. The ball temperature Ttdry and the target wet bulb temperature Ttwet will be reached. When the wet bulb temperature reaches the target wet bulb temperature Ttwet after the dry bulb temperature (time t3), the air heater 12 and the humidifier heater 13a are appropriately controlled so that the dry bulb temperature and the wet bulb temperature are the target values. Will be maintained.

According to the above, the following effects can be obtained in the present embodiment.
Even when the air heater 12 is operated at the maximum output to increase the dry bulb temperature and the wet bulb temperature, the air heater controller 18h predicts that the dry bulb temperature will overshoot. Since the output of the air heater 12 is stopped and the rising speed of the dry bulb temperature becomes slow, overshoot of the dry bulb temperature can be suppressed.

Since the air heater controller 18h refers to the dry bulb temperature and wet bulb temperature, which are actually measured values, overshoot can be predicted with high accuracy.
When it is predicted that overshooting will occur, the output of the air heater 12 is stopped, and thereafter, only the humidifying heater 13a needs to be controlled, and the control can be simplified.

  When the value obtained by adding the correction constant a to the difference γ between the dry bulb temperature and the wet bulb temperature is equal to the difference α between the target dry bulb temperature and the dry bulb temperature, the air heater 12 is stopped, and thereafter It is possible to increase the dry bulb temperature and the wet bulb temperature at a good speed by only operating the humidifier heater 13a only at the maximum output, and gradually reduce the output of the humidifier heater 13a when the wet bulb temperature reaches T2wet. By simply performing simple control, the dry bulb temperature can be maintained and the wet bulb temperature overshoot can be suppressed satisfactorily.

  By correcting the difference between the dry bulb temperature and the wet bulb temperature in consideration of the thermal inertia of the temperature / humidity control device 10, the timing for stopping the air heater 12 can be determined with high accuracy, so that overshoot can be suppressed. Further improvement can be achieved.

In addition, this invention is implemented in various forms, without being limited to the said embodiment.
In the present embodiment, the air heater 12 is turned off when it is predicted that an overshoot of the dry bulb temperature will occur. However, the present invention is not limited to this. For example, the air heater 12 is aired when an overshoot is predicted to occur. What is necessary is just to drop rapidly the output of the heater 12 to 50% or less of the output just before. However, it is preferable to turn off the air heater 12 as in the present embodiment because the speed of increasing each temperature can be relaxed to the maximum.

  In the present embodiment, overshoot is predicted based on the target dry bulb temperature Ttdry and the dry bulb temperature difference α and the dry bulb temperature and wet bulb temperature difference γ, but the present invention is not limited to this, for example, The overshoot may be predicted based on the difference α between the target dry bulb temperature Ttdry and the dry bulb temperature and the difference β between the target wet bulb temperature Ttwet and the wet bulb temperature. Even if such data (α, β) is referred to, overshoot can be predicted by determining whether the ratio α / β of these data (α, β) has reached a predetermined value, for example. Based on the prediction result, the same control as in this embodiment can be performed. In this case, the value of the predetermined value used for overshoot prediction can include a correction constant a such as thermal inertia similar to the present embodiment.

  In the present embodiment, the air heater 12 is controlled based on the dry bulb temperature or the wet bulb temperature (actual value) detected by the dry bulb temperature sensor 16 or the wet bulb temperature sensor 17, but the present invention is not limited to this. For example, the air heater 12 may be controlled according to time. For example, as shown in FIG. 3, when the temperature / humidity controller 10 starts operating, if there is a predetermined temperature difference Tdw between the dry bulb temperature and the wet bulb temperature, the heaters 12 and 13a are operated at the maximum output. In the meantime, the air heater controller 18h is made to determine whether or not the time t1 has elapsed, thereby predicting whether or not overshooting will occur. When the time t1 elapses, the air heater 12 is turned off, and when the time t2 elapses thereafter, the output of the humidifying heater 13a is decreased. Further, when the time t3 has elapsed, both the heaters 12 and 13a are shifted to maintenance control. Note that the times t1 to t3 for switching the outputs of the heaters 12 and 13a can be obtained in advance by experiments, simulations, etc., and the times t1 to t3 thus obtained are the dry bulb temperature as an initial condition, By creating a map corresponding to the wet bulb temperature, each heater 12, 13a can be controlled according to each time t1 to t3.

It is explanatory drawing which shows the temperature / humidity control apparatus which concerns on this embodiment. It is a block diagram which shows the detail of the control apparatus of FIG. It is a graph which shows the control method of each heater by a temperature / humidity control apparatus, and the change of dry bulb temperature or wet bulb temperature. It is a graph which shows the control method of the conventional common heater. It is a graph which shows the conventional method which suppresses the overshoot of wet-bulb temperature or dry-bulb temperature by controlling the output of a humidification heater. It is a graph which shows the problem which arises when the raising speed of dry bulb temperature and wet bulb temperature is made quick.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Temperature / humidity control apparatus 11 Test tank 12 Air heater 13 Humidifier 13a Humidifier 13b Steam diffuser 14 Evaporator 14a Cooler 15 Blower 16 Dry bulb temperature sensor 17 Wet bulb temperature sensor 18 Controller 18a 18b Target dry bulb temperature output calculation unit 18d Target wet bulb temperature output calculation unit 18e Dry bulb temperature difference calculation unit 18f Wet bulb temperature difference calculation unit 18g Actual temperature difference calculation unit 18h Air heater control unit 18i Humidification heater controller

Claims (6)

A test chamber formed of thermal insulation;
Dry bulb temperature detection means for detecting the dry bulb temperature in the test chamber;
Wet bulb temperature detecting means for detecting the wet bulb temperature in the test chamber;
An air heater that contributes to an increase in the dry bulb temperature;
A humidifying heater that contributes to an increase in the wet bulb temperature or the dry bulb temperature;
In order to set the dry bulb temperature or wet bulb temperature to a predetermined target dry bulb temperature or target wet bulb temperature, the air heater or the humidifier heater is initially controlled to operate at a high output, When the dry bulb temperature or the wet bulb temperature reaches the target dry bulb temperature or the target wet bulb temperature, the dry bulb temperature or the wet bulb temperature is maintained at the target dry bulb temperature or the wet bulb temperature. Heater control means for controlling;
Overshoot predicting means for predicting that the dry bulb temperature will overshoot from the target dry bulb temperature if the air heater is kept running when the air heater is operated at the high output. When,
When the overshoot predicting means predicts that overshoot will occur, the output of the air heater is dropped more rapidly than the previous output, so that the dry bulb temperature and the wet bulb temperature mainly by only the output of the humidifier heater. The temperature / humidity control device is characterized by comprising overshoot suppressing means that gently raises both of them to suppress overshoot. The temperature and humidity control apparatus according to claim 1,
The overshoot predicting means predicts overshoot based on the difference between the dry bulb temperature and the wet bulb temperature, and the difference between the target dry bulb temperature and the dry bulb temperature. . The temperature and humidity control apparatus according to claim 1,
The overshoot predicting means predicts overshoot based on the difference between the target dry bulb temperature and the dry bulb temperature, and the difference between the target wet bulb temperature and the wet bulb temperature. . The temperature and humidity control device according to claim 2, wherein the target dry bulb temperature and the target wet bulb temperature are set to substantially the same value.
The overshoot predicting means predicts an overshoot when a difference between the dry bulb temperature and the wet bulb temperature and a difference between the target dry bulb temperature and the dry bulb temperature are substantially equal. Temperature and humidity control device. The temperature and humidity control device according to claim 4,
The overshoot prediction means adds the correction constant set according to the magnitude of the thermal inertia of the temperature and humidity control device to the difference between the dry bulb temperature and the wet bulb temperature, thereby obtaining the dry bulb temperature and A temperature and humidity control device that corrects the difference in wet bulb temperature. A heater control method using the temperature and humidity control apparatus according to claim 1,
A high-power operation step of operating the air heater and the humidifying heater at a high output;
In the high output operation step, an overshoot prediction step for predicting whether or not the dry bulb temperature will overshoot from the target dry bulb temperature if the air heater is kept operating at a high output as it is,
In the overshoot prediction step, when it is predicted that overshoot will occur, the dry bulb temperature and wet bulb temperature are mainly determined only by the output of the humidifying heater by dropping the output of the air heater more rapidly than the previous output. An overshoot suppressing step of suppressing both overshoots by slowly raising both of the above, and a heater control method using a temperature and humidity control device.

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