JP2959188B2 - Air quality control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air quality control system for detecting the condition of air quality and controlling an air conditioner, a ventilator, an air purifier or a combination thereof based on the detection signal.

[0002]

2. Description of the Related Art In recent years, the degree of hermeticity of buildings, such as office buildings, has been improved in general houses, and high efficiency of cooling and heating and energy saving have been achieved. However, on the other hand, the accumulation of carbon dioxide and various odors generated by various human activities has been promoted, and the indoor air quality has deteriorated, resulting in a problem of harm to health and increased discomfort. Various air conditioners, ventilators, or air purifiers have been introduced to cope with such a situation.

[0003]

However, the conventional air conditioner, ventilator or air purifier only performs operation control according to initially set conditions, and performs control corresponding to the actual air quality. It was almost impossible. SUMMARY OF THE INVENTION It is an object of the present invention to solve this problem and perform accurate and detailed air quality control corresponding to a change in actual air quality.

[0004]

Means for Solving the Problems The present invention, detection means for detecting the Air Quality, temperature, detection means for detecting the humidity, more causes of change in the air quality of an output from the air-<br/> disposition detecting means changing the air quality environment by the specific and signal processing means having a row of cormorants function determines the degree of change, and processed signals
Air conditioning apparatus for ventilation apparatus, control means for controlling the air cleaning apparatus or device that is complexed thereof
Wherein the sensing means, air quality control system characterized by having a function of detecting at least background odor, human occupancy, and air quality of the three elements of smoking
It is a non.

[0005]

According to the present invention, the cause of the change in air quality is specified by the output from the air quality detection means, the degree of change in the air quality is determined, and the change in air quality is accurately detected by correcting the temperature and humidity. As a result, fine air quality control can be performed.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, 1 is an air quality detecting means for detecting air quality, 2 is a temperature and humidity detecting means for detecting temperature and humidity,
Reference numeral 3 denotes a signal processing unit having a function of performing air quality judgment on the output of the air quality detection unit and correcting temperature and humidity, and 4 denotes an air conditioner, a ventilator, an air purifier or the like based on the processed signal. The control means 5 for controlling these combined devices is an air conditioner, a ventilation device, an air cleaning device or a combined device thereof. In this embodiment, the background odor, human occupancy, and smoking are made into three elements constituting air quality, and a semiconductor alcohol sensor (hereinafter, referred to as an organic solvent) which is sensitive to organic solvents as air quality detecting means.
An alcohol sensor), a solid electrolyte carbon dioxide sensor (hereinafter simply referred to as a carbon dioxide sensor) and a semiconductor carbon monoxide sensor (hereinafter simply referred to as a carbon monoxide sensor) were used. A ceramic thermistor and a humidity sensor were used as temperature and humidity detecting means. The signal processing means has a function of specifying the cause of a change in air quality based on an output from the air quality detection means and a function of determining the degree of change in air quality. In addition, the discomfort of the air quality is easily affected by the temperature and the humidity, and the characteristics of the gas sensor are inevitably changed to some extent by the temperature and the humidity. Therefore, the signal processing means has a function of correcting temperature and humidity.

[0007] The cause of the change in air quality can be relatively easily achieved by using a gas sensor that selectively detects a specific gas component that causes the change in air quality. On the other hand, the degree of change in air quality can be easily determined by monitoring the output of the sensor. When the sensor output reaches a preset value derived in advance from the correspondence between the air quality and the level of discomfort (degree of discomfort), an operation signal of an air conditioner or the like is sent to the control means. The degree of discomfort of the air quality can be determined by a method such as a report test, and the correspondence between the degree of discomfort and the sensor output can be obtained relatively easily. Therefore, it is also possible to subdivide the sensor output level according to the degree of air quality discomfort and to perform fine control corresponding to the degree of change in air quality.

Next, the operation of the system of the embodiment will be described based on experimental results. In the present embodiment, an SnO ₂ -based alcohol sensor is used as a sensor for detecting the state of background odor, and a NA sensor is used as a gas sensor for detecting a human occupancy state.
A SICON-based carbon dioxide sensor and a SnO ₂ -based carbon monoxide sensor were used as sensors for detecting the state of smoking.
Similar effects can be obtained by using a SnO ₂ -based hydrogen sensor as a sensor for detecting the state of smoking. The measurement was performed by providing a room of about 1.5 × 2 × 2.2 m provided with an air conditioner having a ventilation and air cleaning function (hereinafter, simply referred to as an air conditioner). The sensor was mounted on a wall about 2 m from the floor. Depending on the contents of the experiment, the air conditioner was operated for a predetermined time immediately before the measurement so that the air quality in the measurement chamber was almost constant for each measurement, and the experiment was performed so that the output of each sensor at that time became the reference level in the measurement atmosphere. Conditions have been set. Therefore, the output of the alcohol sensor at this time indicates the reference level of the background odor.

FIG. 2 shows a change in the output of each sensor when one person enters the measurement room. The temperature of the measuring chamber is about 20
The temperature and humidity were set at about 60% RH. After a while, the output of the carbon dioxide sensor began to change, and the output tended to increase with the passage of time.
After this, the output of the alcohol sensor tended to increase little by little. On the other hand, almost no change was observed in the output of the carbon monoxide sensor. Utilizing these characteristics, the output pattern of the carbon dioxide sensor detects that the air quality has changed due to the presence of a human (entering the room).
In addition, the degree of change in air quality can be determined based on the output of the carbon dioxide sensor. At the same time, the state of the background odor at this time can be determined by the output of the alcohol sensor in a state including the odor component generated by the presence of a person.

FIG. 3 shows a change in the output pattern of each sensor when another person enters the room where one person is present. The temperature and humidity conditions were set the same as above. The broken lines show the output change when one person stays in the room. The output of the carbon dioxide sensor changes remarkably in response to the increase in the number of people. By utilizing this characteristic, it is possible to detect a change in the magnitude of the load (the number of people) and perform air quality control corresponding to the speed and degree of the temporal change in air quality based on this information. In this case as well, a slight change in the background odor level appears in the output pattern of the alcohol sensor. In this case, the output of the carbon monoxide sensor hardly changes.

FIG. 4 shows a change in output of each sensor when the occupant starts smoking. The temperature and humidity conditions are the same as above. When smoking was detected, the output of the carbon monoxide sensor increased rapidly. By using this output characteristic, it is possible to specify that the cause of the change in air quality is smoking, and to determine the degree thereof. Since the carbon dioxide concentration does not increase significantly due to smoking, only a slight change is observed in the output of the carbon dioxide sensor. A slight change was also observed in the output of the alcohol sensor, because a small amount of aldehyde or the like generated by smoking was detected. This can be treated as a change in the state of the background odor due to smoking.
Note that the broken line in the figure is the output characteristic when smoking is not performed.

FIG. 5 shows a case where the temperature and humidity of the atmosphere are 20 ° C.-40% RH (a: solid line) at the time of smoking detection.
75% RH (b: dashed line), and 20 ° C.-40%
The output curves of the carbon monoxide sensor under the respective conditions when the temperature and humidity are corrected at a temperature of 30 ° C. to 75% RH based on RH (c: dashed line) are shown. It is clear that if the temperature and humidity conditions are different, the response characteristics of the gas sensor change considerably and affect the determination of air quality.However, by performing temperature and humidity correction, this effect can be almost eliminated, and the air quality can be reduced. The reliability of the control system can be improved. Although not shown,
Correction processing can be similarly performed for the temperature and humidity dependence of the outputs of the carbon dioxide sensor and the alcohol sensor. In addition to sensor characteristics, air quality discomfort as a sensation
Affected by humidity. In this case, since the correlation between the degree of discomfort and the temperature and humidity can be obtained in advance, the correction can be made relatively easily by performing signal processing using a microcomputer.

Based on the results of these experiments, a simple air quality control system was constructed using the above sensors. Since the temperature of the measurement chamber was 20 ± 5 ° C. and the humidity was 55 ± 10% RH, a temperature and humidity correction process was performed with reference to 20 ° C.-55% RH. The timing for issuing a signal for operating the air conditioner and the operation mode were set as follows. If it is determined from the sensor output pattern that the cause of the air quality change is due to being in a room, the operation signal of the ventilation mode is output when the output of the carbon dioxide sensor reaches a level equivalent to 1000 ppm of carbon dioxide concentration, and the ventilation mode is set for a certain time. Drive. If it is determined that the cause of the air quality change is smoking, the operation signal of the air cleaning mode is issued when the output of the carbon monoxide sensor becomes 1.5 times the reference level, and the output is at the level immediately before the detection. The operation is continued for a certain time after returning to. As for the background odor, an operation signal in the air cleaning mode is issued when the output of the alcohol sensor becomes 1.2 times the reference level, and the operation is continued for a certain time even after the output returns to the level immediately before the detection.

If the smoking and the background change are detected at the same time, smoking is given priority, and if they are detected one after another, the operation signal of the air conditioner is issued with priority given to the previously detected cause of change. . In addition, when the occupancy and smoking or background fluctuation are detected at the same time or at the same time, the operation signals of the respective modes are output when the output reaches the respective set value. The air quality determination output level was determined from the relationship between the air quality discomfort level and the sensor output characteristics in the reference state (20 ° C.-55% RH). In each case, the operation capacity of the air conditioner in each operation mode was constant.

FIG. 6 shows that one person enters the measurement room and
Changes in air quality when smoking for a certain period of time and continuing to stay in the room
Output of each sensor when the air conditioner is automatically operated according to
It is a force pattern. Carbon dioxide sensor occupies the room, monoxide
Carbon sensor smoking, alcohol sensor back
Ground level is detected, and the sensor output
When the air conditioner reaches the detection setting level
Operation, the air quality in the measurement room returns to the initial level.
The appearance is appearing. Detailed operation of the system based on the diagram
This will be described in detail. First, time t₀One human enters the measurement room
The output of the carbon dioxide sensor that detected the occupancy was slightly delayed
Begins to increase at time t₁Is the occupancy detection setting level (V_AReached)
At the same time, a ventilation mode operation signal of the air conditioner is issued. So
The air conditioner operates for a predetermined time and the air quality returns to the initial state.
The output of the carbon dioxide sensor decreases as it returns
You. Time t_TwoWhen the ventilation mode operation of the air conditioner ends with
The carbon dioxide sensor detects the occupancy again and the output starts increasing.
Confuse. At this time, the output of the carbon dioxide sensor
Time t before the level is reached_ThreeThe occupants started smoking in
Therefore, the carbon monoxide sensor detects this and
Begins to increase. The output of the carbon monoxide sensor is at time t_Fourso
Smoking detection setting level (V_B) And based on this information
Signal of the air conditioner in the air cleaning mode
Is activated. Note that time t_FourWith the alcohol sensor
The force is also set to the background change detection level (V_C) Reached
But with a predetermined control algorithm
Accordingly, signal processing is performed with priority given to smoking. And slightly
Time t late_FiveSets the CO2 sensor to the occupancy detection setting level.
The air conditioner ventilation mode operation signal is issued.
Operation in ventilation mode in addition to air purification mode operation.
Start. Then, the air purification mode operation is performed at time t.₆Then,
Air mode operation at time t₇To end each. During this time
Air conditioner is in air cleaning mode because occupants have stopped smoking
Time t when operation was stopped ₆After that, it is triggered by the occupants' breathing
The carbon dioxide produced causes changes in air quality,
Carbon sensor output increases to reach occupancy detection set level
Time t₈The ventilation mode operation signal of the air conditioner
Start driving. Note that, in this experiment,
Kgland odor reduced by ventilation mode operation of air conditioner
The alcohol sensor output was smoked
At other times, the detection level was not reached.

As described above, the air quality control system according to the present embodiment accurately detects changes in air quality, controls the operation of the air conditioner based on the information, and controls the air quality to a certain level that does not cause discomfort. It was found to have the function of maintaining.

The present invention is not limited to the above embodiment. In the embodiment, SnO _{2 is} used as the air quality detecting means.
-Based semiconductor alcohol sensor, carbon monoxide sensor and N
Although the case where the ASICON-based solid electrolyte carbon dioxide sensor is used has been described, the present invention is not limited to this, and various gas sensors having different materials and principles can be used.
Further, even if the cause of the change in air quality is the same, it is also possible to change the type of gas to be detected to another one and use a sensor suitable for that. In addition, in the embodiment, the case where three kinds of gas sensors corresponding to three kinds (occupancy, smoking, background) are used and the cause of the change of the air quality is described. It is also possible to perform more finely controlled air quality by increasing the types of odor components to be performed.

The air quality control system according to the present invention can be basically configured by using a number of gas sensors according to the type of cause of air quality. However, the system can be made more compact by using a composite gas sensor hybridized on one chip instead of using a large number of single gas sensors in combination. Also,
A single gas sensor responsive to multiple gases can be used to identify multiple causes of air quality changes. In this case, for example, the microcomputer stores in advance the different response characteristics of the same sensor with respect to each gas type that specifies the cause of the change, and compares the response characteristics with the actual response characteristics of the sensor to relatively easily determine the change in air quality. The cause can be specified.

On the other hand, not limited to the gas sensor, it is also possible to use detection means according to the purpose and scale, such as optical gas detection means and chemical gas detection means. The temperature and humidity detecting means are not limited to the embodiment, and various detecting means can be used without departing from the gist of the invention.

Further, in the embodiment, the case where the intermittent operation control of the air conditioner is performed so that the air quality does not exceed a certain unpleasant level has been described. However, the air conditioner and the like are controlled so that the air quality is always maintained at a constant level. The control can be performed more finely. That is, the output level of the air quality detection means is subdivided, and a control signal corresponding to the change of the air quality level is issued to finely change the operation capability of the air conditioner or the like, so that the air quality level falls within a substantially constant range. Can be maintained. It is also effective to use a method such as fuzzy control. Further, according to the cause of the change in the air quality, the air quality control can be optimally performed by selectively using or combining the ventilation mode, the air cleaning mode, and the like. In addition, when performing operation control that gives continuous or discontinuous changes to the temperature and humidity conditions of the atmosphere with time, it is possible to make corrections in consideration of the unpleasantness of air quality and the temperature and humidity characteristics of the sensor characteristics. Optimum control of air quality becomes possible.

[0021]

As described above, by using the air quality control system according to the present invention, the cause of the change in the air quality is specified and the degree of the change is determined. It can control and maintain the air quality at a comfortable level.

[Brief description of the drawings]

FIG. 1 is a block diagram of an air quality control system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an output pattern of a sensor that detects an occupancy.

FIG. 3 is an output pattern diagram of a sensor corresponding to a change in occupancy load.

FIG. 4 is an output pattern diagram of a sensor that detects smoking.

FIG. 5 is a diagram showing the influence of temperature and humidity on smoking detection characteristics.

FIG. 6 is an explanatory diagram of the operation of the air quality control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air quality detection means 2 Temperature and humidity detection means 3 Signal processing means 4 Control means 5 Air conditioner etc.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F24F 11/02

Claims (6)

(57) [Claims] 1. A detecting means for detecting air quality, a detecting means for detecting temperature and humidity, and a function of specifying a cause of a change in air quality and judging a degree of the change based on an output from the air quality detecting means. signal processing means, and the processed signal conditioning device for varying the air quality environment, the ventilator, e Bei control means for controlling the air cleaning apparatus or device that is complexed thereof, said sensing means , At least background odor, human
Detecting air quality with three factors of occupancy and smoking
An air quality control system characterized by having functions . 2. The air quality control system according to claim 1, wherein the air quality detection means has a function of detecting air quality having three factors including background odor, presence of a person, and smoking. 3. The air quality detecting means uses a sensor for detecting organic solvents, and the signal processing means has a function of judging a state of background odor based on an output signal from the sensor. 2. The air quality control system according to 1. 4. An air quality detecting means, wherein a sensor for detecting carbon dioxide is used, and said signal processing means has a function of judging a human occupancy state based on an output signal from said sensor. 2. The air quality control system according to 1. 5. A method according to claim 1, wherein a sensor for detecting hydrogen or carbon monoxide is used as the air quality detecting means, and the signal processing means has a function of judging a smoking state based on an output signal from the sensor. 2. The air quality control system according to 1. 6. The air quality control system according to claim 1, wherein the signal processing means has a function of correcting the temperature and humidity with respect to the output from the air quality detection means.