JP2014115175A - Automatic adjustment device, and method for co2 sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an error from superposing on a COconcentration measurement value after correction.SOLUTION: An automatic adjustment device includes: a COconcentration measurement value acquisition unit 120 for acquiring a COconcentration measurement value from a COsensor which measures COconcentration in control object space; a parameter storage unit 122 for storing an opening/closing instruction parameter of an outside air damper at the time of automatic adjustment of the COsensor; a damper control unit 121 for introducing outside air to the control object space by controlling opening of the outside air damper according to a condition regulated by the opening/closing instruction parameter when an automatic adjustment needs to be executed, and for closing the outside air damper when the COconcentration measurement value is within a range of a reference value ±α continuously for a certain period of time; and a COsensor drift correction unit 124 for replacing a baseline with the reference value, with a minimum value of the COconcentration measurement value during the period from the start of the automatic adjustment to the closing of the outside air damper being the baseline.

Description

The present invention relates to an automatic adjustment apparatus and method for correcting the drift of a CO ₂ sensor.

When people live their daily lives, CO ₂ is generated day and night. For example, it also occurs by breathing. For this reason, when there is no person who is the source of CO _{2 in} the building, the atmospheric concentration of 400 ppm is set as the minimum value by ventilation with the outside air. In a CO ₂ sensor such as a solid electrolytic type that measures the concentration of CO ₂ , a deviation due to a drift (time-dependent change) of up to 150 ppm / year occurs due to optical factors of the detection element. Conventionally, calibration with a CO ₂ zero ppm gas was manually performed every year to reset the drift amount of the CO ₂ sensor.

Calibration with CO ₂ zero ppm gas has the advantage that it can be reliably calibrated and adjusted, but has the problem of being complicated and costly. Therefore, an automatic adjustment function (Automatic Baseline Correction) for correcting the minimum value of the CO ₂ concentration within a predetermined time (period) sampled by the CO ₂ sensor to the atmospheric concentration (400 ppm) has become widespread (Patent Document 1, (See Non-Patent Document 1 and Non-Patent Document 2).

JP-A-11-14583

“Duct insertion type CO 2 sensor CDE”, [online], SLEIKE Co., Ltd., [December 4, 2012 search], Internet <http: // www. three-k. biz / pdf / CDE-J. pdf # search> "Large CO2 Display Model 4018", [online], Tsuruga Electric Co., Ltd., [December 4, 2012 search], Internet <http: // www. tsuruga. co. jp / products / 4018 / index. html>

According to the conventional method, in an environment where the airtightness of the building is high or people are stationed for 24 hours, CO ₂ continues to be generated, and the CO ₂ concentration in the building is close to the atmospheric concentration. It may not decrease. Under such circumstances, if the minimum value of the CO ₂ concentration is corrected by the automatic adjustment function, an error may be superimposed on the measured value of the CO ₂ concentration. For example, in an environment where the minimum concentration is reduced only to 600 ppm, 600 ppm is set to 400 ppm by the automatic adjustment function, so that an error of −200 ppm occurs in the measured value of the CO ₂ concentration after adjustment.

The present invention has been made to solve the above problems, and provides an automatic adjustment apparatus and method for a CO ₂ sensor capable of preventing an error from being superimposed on a corrected CO ₂ concentration measurement value. For the purpose.

Automatic adjusting apparatus of CO ₂ sensor of the present invention, a CO ₂ concentration measurement value acquisition means for acquiring a CO ₂ concentration measurement value from the CO ₂ sensor for measuring the CO ₂ concentration in the control target space, automatic adjustment of the CO ₂ sensor Parameter storage means for preliminarily storing the open / close instruction parameter of the external air damper at the time, and when the automatic adjustment is to be executed according to a predetermined adjustment schedule, the opening degree of the external air damper according to the condition defined by the open / close instruction parameter When the outside air is introduced into the space to be controlled and the measured CO ₂ concentration is within the range of the reference value ± α (α is a predetermined value) continuously for a certain time, the outside air damper is The damper control means for closing, and the minimum value of the measured CO ₂ concentration during the period from the start of the automatic adjustment to the closing of the outside air damper is taken as a baseline, and this baseline CO ₂ sensor drift correction means for performing drift correction that replaces the reference value with the reference value.
In addition, one configuration example of the CO ₂ sensor automatic adjustment device according to the present invention further includes an open time of the external air damper from the start of the automatic adjustment until the external air damper is closed, and a CO immediately before the automatic adjustment starts. ₂ Based on the measured concentration value and the measured CO ₂ concentration value during the period from the start of the automatic adjustment until the outside air damper is closed, the measured CO ₂ concentration value is within the range of the reference value ± α for a certain period of time. And a parameter setting means for updating the opening / closing instruction parameter so as to satisfy the condition that the value decreases until the value reaches.

The automatic adjustment method of the CO ₂ sensor of the present invention, a CO ₂ concentration measurement value acquisition step of acquiring the CO ₂ concentration measurements from CO ₂ sensor for measuring the CO ₂ concentration in the control object space, a predetermined adjustment When the automatic adjustment is to be performed according to a schedule, the opening degree of the outside air damper is controlled according to the conditions specified by the opening / closing instruction parameter stored in advance in the parameter storage means, the outside air is introduced into the control target space, A damper control step for closing the outside air damper when the measured CO ₂ concentration value is within a range of a reference value ± α (α is a predetermined value) continuously for a predetermined time; and the outside air damper from the start of the automatic adjustment. CO ₂ sensor drift that performs drift correction to replace the baseline with the minimum value of the measured CO ₂ concentration during the period until the closure of the baseline. And a correction step.

According to the present invention, when the automatic adjustment of the CO ₂ sensor is to be executed, the opening degree of the outside air damper is controlled according to the conditions defined by the open / close instruction parameter, and outside air is actively introduced into the controlled space, and the CO ₂ concentration Since the measured value is continuously within the range of the reference value ± α for a certain period of time, it is possible to prevent errors from being superimposed on the corrected CO ₂ concentration measured value, and to ensure the accuracy of automatic adjustment. Can be increased.

Further, in the present invention, the open time of the outside air damper from the start of the automatic adjustment until the outside air damper is closed, the measured CO ₂ concentration immediately before the start of the automatic adjustment, and the time from the start of the automatic adjustment until the outside air damper is closed. By updating the open / close instruction parameter based on the measured CO ₂ concentration value during the period, the open / close instruction parameter is set so that the measured CO ₂ concentration value falls within the range of the reference value ± α for a certain period of time. Can learn.

It is a block diagram which shows the structure of the air-conditioning control system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the controller which concerns on embodiment of this invention. It is a flowchart illustrating the operation of the automatic adjusting apparatus during automatic adjustment to correct the drift of the CO ₂ sensor in the embodiment of the present invention. It is a figure which shows the example of recording of the data recorded on the parameter setting part in embodiment of this invention.

[Principle of the Invention]
In the present invention, the outside air damper is fully opened at a predetermined cycle for a certain period of time so that the outside air is taken in for a certain period of time, and then the minimum value of the CO ₂ concentration measured by the CO ₂ sensor is determined as the atmospheric concentration (400 ppm). ) Modified. In the present invention, the open time of the outside air damper is learned, and the measured CO ₂ concentration is reduced to the atmospheric concentration.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an air conditioning control system according to an embodiment of the present invention. The air conditioning control system includes an air conditioner 1, an outside air damper 2 that controls the amount of outside air OA introduced into the air conditioner 1, and a return air that controls the amount of return air RA returned from the controlled space 11 into the air conditioner 1. The damper 3, the cold water valve 4 that controls the amount of cold water sent to the cold water coil of the air conditioner 1, the hot water valve 5 that controls the amount of hot water sent to the hot water coil of the air conditioner 1, and the humidifier of the air conditioner 1 A humidifying valve 6 for controlling the amount of cold water or hot water, an air supply temperature sensor 7 for measuring the temperature of the air (supply air SA) sent from the air conditioner 1, and an indoor temperature sensor 8 for measuring the temperature of the control target space 11. A CO ₂ sensor 9 that measures the CO ₂ concentration in the controlled space 11, a humidity sensor 10 that measures the humidity in the controlled space 11, and a controller 12 that controls the dampers 2, 3 and the valves 3, 4, 5. And VAV (Variable Air Volume) Consisting of knit 13. The air conditioner 1 includes a filter 14, a cold water coil 15 that cools air, a hot water coil 16 that heats air, a humidifier 17, and a fan 18 that sends the cooled or heated air.

  Next, the operation of the air conditioning control system of FIG. 1 will be briefly described. The cold water coil 15 of the air conditioner 1 cools the outside air OA and the return air RA with cold water supplied from a heat exchanger (not shown) via the cold water valve 4. The hot water coil 16 of the air conditioner 1 heats the outside air OA and the return air RA with hot water supplied from the heat exchanger via the hot water valve 5. Further, the cold water or hot water sent out from the heat exchanger is supplied to the humidifier 17 through the humidification valve 6. The humidifier 17 controls the humidity of the supply air SA cooled or heated by the coils 15 and 16 by creating a water spray state. The supply air SA cooled or heated by the coils 15 and 16 and humidified by the humidifier 17 is sent out to the control target space 11 by the fan 18. Part of the air in the control target space 11 is returned to the air conditioner 1 as return air RA.

The supply air temperature sensor 7 measures the temperature of the supply air SA sent out from the air conditioner 1. The indoor temperature sensor 8 measures the temperature of the control target space 11, the CO ₂ sensor 9 measures the CO ₂ concentration of the control target space 11, and the humidity sensor 10 measures the humidity of the control target space 11. The controller 12 controls the opening degree of the valves 4 and 5 so that the temperature of the supply air SA matches a predetermined supply air temperature setting value. Further, the controller 12 controls the opening degree of the outside air damper 2 so that the CO ₂ concentration in the control target space 11 coincides with a predetermined CO ₂ concentration set value. Furthermore, the controller 12 controls the opening degree of the humidifying valve 6 so that the humidity of the control target space 11 coincides with a predetermined humidity set value.

  The VAV unit 13 calculates a required air volume of the control target space 11 so that the temperature of the control target space 11 coincides with a predetermined indoor temperature setting value, and a damper ( The opening degree (not shown) is controlled. The controller 12 calculates the total required air volume value of the entire system from the required air volume values sent from the plurality of VAV units 13, obtains the fan rotation speed according to the total required air volume value, The air conditioner 1 is controlled so that it becomes.

The building management method related to the air conditioning control system as described above stipulates that the CO ₂ concentration should be 1000 ppm or less when measured six times a year. Hereinafter, an automatic adjustment device for correcting the drift of the CO ₂ sensor 9 will be described.
FIG. 2 is a block diagram showing the configuration of the controller 12. The controller 12 includes a CO ₂ concentration measurement value acquisition unit 120 for acquiring the CO ₂ concentration measurements from CO ₂ sensor 9, the damper control unit 121 for controlling the damper 2,3, outside air at the time of automatic adjustment of CO ₂ sensor 9 A parameter storage unit 122 that stores the opening / closing instruction parameter of the damper 2 in advance, a parameter setting unit 123 that updates the opening / closing instruction parameter, a CO ₂ sensor drift correction unit 124 that performs drift correction of the CO ₂ sensor 9, and an air supply temperature sensor 7 and a measurement value acquisition unit 125 that acquires measurement values from the humidity sensor 10, and a valve control unit 126 that controls the valves 4, 5, and 6. The CO ₂ concentration measurement value acquisition unit 120, the damper control unit 121, the parameter storage unit 122, the parameter setting unit 123, and the CO ₂ sensor drift correction unit 124 constitute an automatic adjustment device.

  Since the control of the outside air damper 2 at the normal time by the damper control unit 121 and the control of the valves 4, 5, and 6 at the normal time by the valve control unit 126 are as described above, detailed description is omitted.

FIG. 3 is a flowchart showing the operation of the automatic adjustment device during automatic adjustment for correcting the drift of the CO ₂ sensor 9.
When the damper control unit 121 is to perform automatic adjustment according to a predetermined adjustment schedule (for example, a schedule that is executed once a year and on January 1) (YES in step S1 in FIG. 3), parameters The opening degree of the outside air damper 2 is controlled in accordance with the open / close instruction parameters of the outside air damper 2 stored in the storage unit 122 (opening time, opening degree, etc. of the outside air damper 2), and automatic adjustment is started (step S2 in FIG. 3). At the time of automatic adjustment, the opening degree of the outside air damper 2 is normally set to 100% (fully open). Thus, outside air is introduced from the outside air damper 2 to the controlled space 11 through the air conditioner 1, and the CO ₂ concentration in the controlled space 11 is reduced.

Parameter setting unit 123, the automatic adjustment is started, the opening time of the outside air damper 2 is opened, the CO ₂ concentration measured value acquisition unit 120 records the CO ₂ concentration measurements to obtain (Figure 3 step S3 ).
When the measured CO ₂ concentration value falls within the range of atmospheric concentration (400 ppm) ± α (α is a predetermined allowable value) (YES in step S4 in FIG. 3), the damper control unit 121 turns the outside air damper 2 on. Close (step S5 in FIG. 3). If the measured value of CO ₂ concentration does not fall within the range of the atmospheric concentration (400 ppm) ± α for a certain period of time despite the elapse of the open time of the outside air damper 2 specified by the open / close instruction parameter, The open time of the outside air damper 2 is extended until the measured CO ₂ concentration is continuously within the range of the atmospheric concentration (400 ppm) ± α for a certain period of time.

When the outside air damper 2 is closed, the CO ₂ sensor drift correcting unit 124 uses the minimum value of the measured CO ₂ concentration during the period from the start of automatic adjustment until the outside air damper 2 is closed as a baseline, and this baseline is used as a reference value. Drift correction is performed to replace the atmospheric concentration value (400 ppm) (step S6 in FIG. 3). Thereafter, the measured CO ₂ concentration sampled by the CO ₂ sensor 9 is handled on the assumption that the baseline determined at the time of this drift correction is 400 ppm.

Finally, the parameter setting unit 123 sets the open time of the outside air damper 2 from the start of automatic adjustment until the outside air damper 2 is closed, the measured CO ₂ concentration immediately before the start of automatic adjustment, and the outside air from the start of automatic adjustment. Based on the minimum value of the measured CO ₂ concentration during the period until the damper 2 is closed, the open / close instruction parameter in the parameter storage unit 122 is updated as necessary (step S7 in FIG. 3).

FIG. 4 is a diagram illustrating a recording example of data recorded in the parameter setting unit 123. In the example of FIG. 4, the open time of the outside air damper 2 from the start of the automatic adjustment until the outside air damper 2 is closed, the measured CO ₂ concentration immediately before the start of the automatic adjustment, and the outside air damper 2 from the start of the automatic adjustment. The difference between the minimum value of the measured CO ₂ concentration value in the period until closing and the minimum value of the measured CO ₂ concentration value and the minimum measured CO ₂ concentration value is recorded.

For example, in the example of October 25, 2011 or October 7, 2012, when the outside air damper 2 is opened for 2 hours, the measured CO ₂ concentration falls to a range of 400 ppm ± α (for example, 10 ppm). Therefore, if the open time of the outside air damper 2 defined by the opening / closing instruction parameter is 2 hours, it is not necessary to update the opening / closing instruction parameter. On the other hand, in the example of April 20, 2012, it can be seen that it takes 2 hours and 20 minutes for the measured CO ₂ concentration to fall to the range of 400 ppm ± α. Therefore, when the open time of the outside air damper 2 defined by the open / close instruction parameter is 2 hours, it is understood that this open time is not sufficient. Therefore, the parameter setting unit 123 updates the opening time and the opening degree of the outside air damper 2 defined by the opening / closing instruction parameter. In this example, the open time may be 2 hours and 20 minutes.

In this way, the parameter setting unit 123 sets the open / close instruction parameter of the parameter storage unit 122 so as to satisfy the condition that the measured CO ₂ concentration decreases continuously for a certain period of time until it falls within the range of the atmospheric concentration (400 ppm) ± α. Update. In the next automatic adjustment, the updated opening / closing instruction parameter is used. Note that the recording example in FIG. 4 is an example, and an average value of the number of people in the room may be recorded.

As described above, in the present embodiment, when the automatic adjustment of the CO ₂ sensor 9 is to be executed, the opening degree of the outside air damper 2 is controlled according to the conditions defined by the open / close instruction parameter, and the outside air is supplied to the control target space 11. Since the CO ₂ concentration measurement value is continuously within the range of the atmospheric concentration ± α for a certain period of time, it is possible to prevent errors from being superimposed on the corrected CO ₂ concentration measurement value. This can increase the certainty of automatic adjustment. In the present embodiment, the open / close instruction parameter can be learned so that the measured value of CO ₂ concentration decreases continuously for a certain period of time until it falls within the range of the atmospheric concentration ± α.

  The controller 12 of the present embodiment can be realized by a computer having a CPU (Central Processing Unit), a storage device, and an external interface, and a program for controlling these hardware resources. In such a computer, a program for realizing the automatic adjustment method of the present invention is provided in a state of being recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card. The CPU writes the program read from the recording medium to the storage device, and executes the processing of the present embodiment according to the program stored in the storage device.

The present invention can be applied to a technique for correcting the drift of the CO ₂ sensor.

1 ... air conditioner, 2 ... outdoor air damper, 3 ... return air dampers, 4 ... cold water valve, 5 ... hot water valve, 6 ... humidifying valve, 7 ... supply air temperature sensor, 8 ... indoor temperature sensor, 9 ... CO ₂ sensor, 10 ... humidity sensor, 11 ... control target space, 12 ... controller, 13 ... VAV unit, 14 ... filter, 15 ... cold water coil, 16 ... hot water coil, 17 ... humidifier, 18 ... fan, 120 ... CO ₂ concentration measurements acquisition unit, 121 ... damper control unit, 122 ... parameter storage unit, 123 ... parameter setting unit, 124 ... CO ₂ sensor drift correction unit, 125 ... measured value acquisition unit, 126 ... valve control section.

Claims (4)

And the CO ₂ concentration measured value acquisition means for acquiring a CO ₂ concentration measurement value from the CO ₂ sensor for measuring the CO ₂ concentration in the control object space,
Parameter storage means for storing in advance an open / close instruction parameter of an outside air damper during automatic adjustment of the CO ₂ sensor;
When the automatic adjustment is to be executed according to a predetermined adjustment schedule, the opening degree of the outside air damper is controlled according to the condition defined by the opening / closing instruction parameter, the outside air is introduced into the control target space, and the CO ₂ Damper control means for closing the outside air damper when the concentration measurement value is within the range of the reference value ± α (α is a predetermined value) continuously for a certain time;
CO ₂ sensor drift correction means for performing drift correction by taking the minimum value of the measured CO ₂ concentration during the period from the start of the automatic adjustment until the outside air damper is closed as a baseline, and replacing the baseline with the reference value. An automatic adjustment device for a CO ₂ sensor, comprising: The automatic adjustment device for a CO ₂ sensor according to claim 1,
Further, the open time of the outside air damper from the start of the automatic adjustment until the outside air damper is closed, the measured CO ₂ concentration immediately before the start of the automatic adjustment, and the outside air damper is closed from the start of the automatic adjustment. The above open / close instruction parameter is updated so as to satisfy the condition that the measured CO ₂ concentration decreases until it falls within the range of the reference value ± α for a certain period of time based on the measured CO ₂ concentration during the period up to An apparatus for automatically adjusting a CO ₂ sensor, comprising parameter setting means for performing And the CO ₂ concentration measured value acquisition step of acquiring the CO ₂ concentration measurements from CO ₂ sensor for measuring the CO ₂ concentration in the control object space,
When the automatic adjustment is to be executed according to a predetermined adjustment schedule, the opening degree of the outside air damper is controlled according to the conditions defined by the opening / closing instruction parameter stored in advance in the parameter storage means, and the outside air is A damper control step of closing the outside air damper when the measured CO ₂ concentration value is within a range of a reference value ± α (α is a predetermined value) continuously for a predetermined time;
A CO ₂ sensor drift correction step for performing drift correction by taking the minimum value of the measured CO ₂ concentration during the period from the start of the automatic adjustment until the outside air damper is closed as a baseline, and replacing the baseline with the reference value. A method for automatically adjusting a CO ₂ sensor, comprising: The method for automatically adjusting a CO ₂ sensor according to claim 3,
Further, the open time of the outside air damper from the start of the automatic adjustment until the outside air damper is closed, the measured CO ₂ concentration immediately before the start of the automatic adjustment, and the outside air damper is closed from the start of the automatic adjustment. The above open / close instruction parameter is updated so as to satisfy the condition that the measured CO ₂ concentration decreases until it falls within the range of the reference value ± α for a certain period of time based on the measured CO ₂ concentration during the period up to A method for automatically adjusting a CO ₂ sensor, comprising a parameter setting step.

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