KR20230138725A - Hydrogen gas sensor apparatus with heater function humidity sensor and deterioration corrtecting method thereof - Google Patents

Abstract

A method for correcting deterioration of a hydrogen gas sensor device provided with a heater function humidity sensor of the present invention is a deterioration correction method for a hydrogen gas sensor device that applies temperature and humidity compensation and has a heater function humidity sensor, comprising the steps of: comparing a first hydrogen gas measurement value and a predetermined reference value after power is applied to the hydrogen gas sensor device; heating the humidity sensor for a predetermined time if the first hydrogen gas measurement value is not higher than the reference value; and obtaining a hydrogen gas measurement value of the hydrogen sensor module after the predetermined time has elapsed. According to the present invention, a standard has been established to enable the heater of the humidity sensor by distinguishing between VOC poisoning and durability deterioration.

Description

Hydrogen gas sensor device with heater function humidity sensor and deterioration correction method {HYDROGEN GAS SENSOR APPARATUS WITH HEATER FUNCTION HUMIDITY SENSOR AND DETERIORATION CORRTECTING METHOD THEREOF}

The present invention relates to a method for correcting deterioration of a hydrogen gas sensor device using a humidity sensor deterioration correction logic using a heater function.

In general, the outlook for fossil fuels is not bright. Recently, with the emergence of new large energy consumers such as China and India, the use period based on reserves is expected to shorten. Accordingly, research is being conducted worldwide to replace fossil fuels with hydrogen energy.

Hydrogen energy is receiving attention as a storage medium for various alternative energies to address energy supply and demand problems.

Hydrogen is being researched globally as a clean energy source, and is currently being used in various fields such as fuel cells and internal combustion engines, and its consumption is expected to increase in fields such as fuel cell vehicles and power generation within a few years.

However, hydrogen has a high flash point and has the property of exploding when its concentration exceeds a certain level, so the need for a hydrogen sensor that can detect hydrogen leakage in the process of handling hydrogen is becoming important.

On the other hand, facilities such as storage facilities for chemicals and/or radioactive products, geothermal drilling, warehouse sites and industrial tanks may be at risk of hydrogen emissions associated with the stored products, which are explosive and hazardous to human health. You may be placed in an environment that is harmful to you. There is also a need to control risks in the above-mentioned fields and to preventively detect any hydrogen emissions that may occur.

In particular, fuel electric vehicles (FCEV), which are expected to have the widest use of hydrogen energy, rely heavily on hydrogen sensors mounted on the fuel cell stack to increase energy efficiency and stability.

Accordingly, as a hydrogen sensor that detects leaks of hydrogen gas, for example, a sensor using an electrical method that utilizes the change in electrical conductivity of metal when hydrogen is adsorbed on metal such as platinum or palladium, a sensor using an oxide semiconductor type and a gas MOSFET, etc. Sensors using electrochemical methods and sensors using optical methods to detect hydrogen leaks using light have been developed.

Among them, in the case of a hydrogen detection sensor of the heat conduction type, which has excellent cost efficiency, that is, economic efficiency, the heat conduction value due to the hydrogen concentration in the atmosphere is affected by changing depending on the temperature / humidity value in the atmosphere. It is applied to determine hydrogen concentration by compensating for the heat conduction value.

In the case of automotive relative humidity sensors applied to compensate for the heat conduction type hydrogen detection sensor, a method using a desiccant is generally used. When a desiccant is used, durability deterioration occurs due to long-term use, making it difficult to measure relative humidity. It will have an impact. Additionally, if the desiccant is poisoned by VOC, etc., the relative humidity sensor may be poisoned and deteriorated.

In particular, hydrogen gas sensors for automobiles are inevitably located in closed spaces where large amounts of VOCs are collected in certain installation environments, and in this case, conventional humidity sensors are poisoned by VOCs and cannot accurately measure relative humidity. .

A VOC poisoned humidity sensor can be restored to normal by adding a heater function to the humidity sensor. Therefore, humidity sensors that include a heater function are being released recently. However, in order to recover from VOC poisoning using the heater function, it is impossible to detect the hydrogen concentration at the installation location for at least a few seconds, or several minutes at the most, so the heat function cannot be used continuously in the usual use area.

Figure 1 is a side view showing the principle of a heat conduction type hydrogen sensor device.

Looking at the above-mentioned phenomenon in more detail, in the case of a heat conduction type hydrogen gas sensor, compensation/correction must be performed by measuring the atmospheric temperature (T)/atmospheric relative humidity (%RH). In the case of relative humidity, a desiccant is generally used, and durability deterioration/VOC deterioration may occur. When the corresponding deterioration occurs, the humidity sensor 15 measures the relative humidity higher than the atmosphere (%RH) (%RH + α), and when the hydrogen concentration of the hydrogen sensor 20 is corrected with this value, the hydrogen concentration is higher than the actual is measured at a low value (%vol - β).

Accordingly, a relative humidity sensor with a built-in heater can be used to recover the deteriorated desiccant, but durable deterioration cannot be recovered with a heater, and only VOC poisoning can be recovered with a heater, so it is not possible to distinguish between durable deterioration and VOC poisoning. If not, it is inefficient and wastes unnecessary heating time. In other words, since the hydrogen concentration cannot be detected while the heater is applied, a situation occurs in which the hydrogen concentration cannot be measured by using the heater unnecessarily in conditions of durability deterioration that cannot be recovered.

Republic of Korea Registration Publication No. 10-1490178

The present invention is a humidity sensor with a heater function that provides a standard for enabling the heater of the humidity sensor by distinguishing between VOC poisoning and durability deterioration as an ENABLE condition for the humidity sensor heater function of a hydrogen gas sensor that is calibrated using a humidity sensor equipped with a heater function. The aim is to provide a method for compensating for deterioration of a hydrogen gas sensor device equipped with a.

A deterioration correction method for a hydrogen gas sensor device equipped with a heater function humidity sensor according to an aspect of the present invention is a deterioration correction method for a hydrogen gas sensor device equipped with a heater function humidity sensor that applies temperature and humidity compensation, comprising: Comparing the first hydrogen gas measurement value and a predetermined reference value after power is applied to the hydrogen gas sensor device; If the first hydrogen gas measurement value is not higher than the reference value, heating the humidity sensor for a predetermined time; And it may include obtaining a hydrogen gas measurement value of the hydrogen sensor module after the predetermined time has elapsed.

Here, after the step of obtaining the hydrogen gas measurement value of the hydrogen sensor module after the elapse of the predetermined time, if the hydrogen gas measurement value after the elapse of the predetermined time is lower than or at the same level as the reference value, the step of weighting the reference value is further performed. It can be included.

Here, the predetermined time may be determined within the range of 1 minute to 60 minutes.

Here, the reference value may be a value selected within the range of -0.05% to -2.0%.

Here, the same level may be defined as one value selected in the range of -0.01 to -0.3% for the negative limit, and one value selected in the range of +0.01 to +0.3% for the positive limit.

A hydrogen gas sensor device according to another aspect of the present invention includes a temperature sensor that measures temperature; Humidity sensor to measure humidity; Hydrogen sensor that measures hydrogen gas concentration through heat conduction; a heater capable of heating the humidity sensor; a correction calculation unit that calculates a ‘hydrogen gas measurement value’ by performing correction on the measurement value of the hydrogen sensor according to the measurement value of the temperature sensor and the measurement value of the humidity sensor; And a heater control unit that compares the first hydrogen gas measurement value with a predetermined reference value after power is applied to the humidity sensor and the hydrogen sensor, and operates the heater if the first measurement value of the hydrogen concentration is not higher than the reference value. can do.

Here, a storage unit for storing the predetermined reference value; And if the hydrogen gas measurement value calculated by the correction calculation unit after the predetermined time has elapsed is lower than or at the same level as the reference value, it may further include a standard updating unit that weights the reference value and stores it in the storage unit.

If the deterioration correction method of the hydrogen gas sensor device with the heater function humidity sensor according to the spirit of the present invention of the above-described configuration is implemented, the humidity sensor heater function ENABLE condition of the hydrogen gas sensor is corrected using a humidity sensor to which the heater function is applied. As such, it has the advantage of providing an effective standard for enabling the heater of the humidity sensor by distinguishing between VOC poisoning and durability deterioration.

The deterioration correction method of a hydrogen gas sensor device equipped with a heater function humidity sensor according to the idea of the present invention distinguishes between durability deterioration and VOC poisoning deterioration, appropriately applies a heater to the desiccant, and restores the VOC poisoned humidity sensor. There are benefits to this.

Figure 1 is a side view showing the principle of a heat conduction type hydrogen sensor device.
Figure 2 is a graph showing the thermal conductivity of hydrogen gas according to relative humidity.
Figure 3 is a block diagram showing the configuration of a hydrogen sensor device including a temperature and humidity sensor that measures temperature and humidity and a hydrogen sensor that measures hydrogen gas concentration by heat conduction.
Figure 4 is a flow chart showing a deterioration correction method of a hydrogen gas sensor device equipped with a heater function humidity sensor according to the spirit of the present invention.
Figure 5a is a graph showing an example of a relative humidity sensor heater enable process.
Figure 5b is a graph showing another example of the relative humidity sensor heater enable process.
Figure 6 is a block diagram showing an embodiment of a hydrogen gas sensor device equipped with a heater function humidity sensor according to the spirit of the present invention.

In describing the present invention, terms such as first and second may be used to describe various components, but the components may not be limited by the terms. Terms are intended only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may be referred to as a first component without departing from the scope of the present invention.

When a component is mentioned as being connected or connected to another component, it can be understood that it may be directly connected to or connected to the other component, but other components may exist in between. .

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions may include plural expressions, unless the context clearly indicates otherwise.

In this specification, terms such as include or have are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, including one or more other features or numbers, It can be understood that the existence or addition possibility of steps, operations, components, parts, or combinations thereof is not excluded in advance.

Additionally, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Before presenting a relative humidity compensation method in a heat conduction type hydrogen gas sensor device according to the spirit of the present invention, we will look at the operating principle of the heat conduction type hydrogen gas sensor, durability deterioration of the humidity sensor, and problems caused therefrom.

Figure 2 is a graph showing the thermal conductivity of hydrogen gas according to relative humidity.

In the case of a heat conduction type hydrogen gas sensor, compensation/correction must be performed by measuring the air temperature/relative humidity. In the case of relative humidity, a desiccant is generally used, and durability deterioration/VOC deterioration may occur.

Durability deterioration of the relative humidity sensor applied to compensate for the relative humidity of the heat conduction type hydrogen gas sensor easily occurs. In general, a relative humidity sensor with a desiccant applied will experience durability deterioration of 0.5%RH per year and generate a relative humidity deviation of 7.5%RH over a period of use of up to 15 years.

Additionally, even when the desiccant is poisoned by VOC (volatile organic compounds), the relative humidity is generally measured to be higher than that of the atmosphere.

As shown in FIG. 2, when the temperature in the air increases, the thermal conductivity of the gas changes depending on the relative humidity, so the thermal conductivity must be corrected by compensating for the actual relative humidity value in the air to accurately measure the gas concentration.

However, if the relative humidity in the actual atmosphere is measured higher, the thermal conductivity is compensated incorrectly in the minus direction, resulting in a problem of measuring the thermal conductivity lower than the actual air. This also occurs in the measurement of hydrogen gas, when the relative humidity in the actual atmosphere is This causes the problem of output being lower than the hydrogen gas concentration in the gas.

Figure 3 is a block diagram showing the configuration of a hydrogen sensor device including a temperature and humidity sensor that measures temperature and humidity and a hydrogen sensor that measures hydrogen gas concentration by heat conduction.

Figure 3 shows the configuration of a hydrogen sensor device including a temperature and humidity sensor 10 that measures temperature and humidity and a hydrogen sensor 20 that measures hydrogen gas concentration by heat conduction. In process ① shown for the MCU 40, the MCU 40 acquires air temperature/air relative humidity information from the temperature and humidity sensor, in process ②, temperature/humidity value compensation is performed, and in process ③, the temperature/humidity value is obtained. Compensated hydrogen concentration can be output. For example, in process ②, the thermal conductivity is corrected using the temperature/atmospheric relative humidity received by the hydrogen sensor 20 and a hydrogen concentration measurement value is output. The hydrogen sensor 20 is a sensor that detects hydrogen leakage and is exposed to an environment with 0% hydrogen under normal use conditions.

However, if poisoning by VOC occurs in the humidity sensor 20, it incorrectly measures higher than the relative humidity in the air (e.g., the relative humidity in the air is 50%RH, but incorrectly measures 55%RH). .

If there is a standard (reference) relative humidity sensor in which VOC poisoning has not occurred, it can be known that the humidity sensor 20 is currently poisoned, but since poisoning occurs regardless of how many humidity sensors there are at the same installation location, its significance as a reference is reduced. do. In other words, realistically, it cannot be used as a standard humidity sensor in a VOC poisoning situation, so an indirect confirmation method is needed to determine that the humidity sensor has been VOC poisoned.

Accordingly, the present invention first defines conditions for enabling the humidity sensor heater function (ENABLE) of a hydrogen gas sensor device that is calibrated using a humidity sensor equipped with a heater function. At this time, the indirect basis for determining VOC poisoning of the humidity sensor is as follows.

In the case of heat conduction, deviation occurs depending on the temperature/relative humidity in the atmosphere, and thus the temperature and relative humidity are measured by the temperature and humidity sensor to compensate for the heat conduction value measured by the hydrogen sensor.

However, in the same hydrogen concentration (%vol) state, the relative humidity is incorrectly measured in a direction that is higher than the actual concentration (cause: durability deterioration or VOC poisoning), and when the hydrogen sensor is corrected for a different value, the hydrogen sensor detects a lower concentration than the actual concentration. It is measured by value.

Therefore, considering that most operating conditions are hydrogen 0% VOL due to the operating characteristics of the hydrogen leak sensor, it is possible to indirectly determine that the humidity sensor has deteriorated when the hydrogen sensor value decreases below a predetermined standard.

When humidity sensor deterioration occurs due to VOC poisoning, the poisoning deterioration can be recovered using the heater function built into the humidity sensor, but durability deterioration cannot be recovered.

Since the hydrogen concentration cannot be measured while the humidity sensor's heater function is in use, periodic use of the heater function may result in a situation in which hydrogen leakage cannot be detected, so simply using it periodically should be avoided. In other words, the present invention seeks to distinguish between VOC poisoning and durability deterioration, and also propose a method of adjusting the standard for enabling the heater of the humidity sensor in the case of durability deterioration.

Figure 4 is a flow chart showing a deterioration correction method of a hydrogen gas sensor device equipped with a heater function humidity sensor according to the spirit of the present invention.

The deterioration correction method shown is a deterioration correction method for a hydrogen gas sensor device that applies temperature and humidity compensation and has a heater function humidity sensor, and obtains (S120) after power is applied to the hydrogen gas sensor device (S110). ) Comparing the first hydrogen gas measurement value and a predetermined reference value (β) (S130); If the first hydrogen gas measurement value is not higher than the reference value (β), heating the humidity sensor for a predetermined time (S150); And it may include obtaining a hydrogen gas measurement value of the hydrogen sensor module after the predetermined time has elapsed (S160).

As a result of the comparison in step S130, if the first hydrogen gas measurement value is between the reference value (β) and 0%, a step (S140) of processing the first measurement value of hydrogen concentration as an offset is further included. Here, the reference value (β) is a negative value, and the offset refers to a measurement error measured as a negative concentration in an atmosphere where the actual hydrogen gas concentration is 0% due to manufacturing deviation, etc. Afterwards, the offset is removed (by adding a negative offset value) to the hydrogen gas measurement value measured in the routine hydrogen gas measurement step (S190), and output as the final measurement value of the hydrogen gas sensor device.

In addition, after the step of acquiring the hydrogen gas measurement value of the hydrogen sensor module after the predetermined time (S160), if the hydrogen gas measurement value after the predetermined time elapses is lower than or at the same level as the reference value (S170), the reference value It further includes a step (S180) of weighting (updating) (β).

In addition to applying the above-described indirect conditions, we will look specifically at an example of adjusting (updating) the reference value (β) as a condition for enabling the relative humidity sensor heater in step S150 in the case of durability deterioration.

Figure 5a is a graph showing an example of a relative humidity sensor heater enable process.

Figure 5b is a graph showing another example of the relative humidity sensor heater enable process.

As shown, if the hydrogen concentration falls below the β value during operation (as a result of performing step S130), it is assumed that durability deterioration or VOC poisoning has occurred and the heater is enabled for a predetermined time (10 minutes) (S150).

As in the case of Figure 5a, if the hydrogen concentration is measured to be higher than β after 10 minutes, the heater operation (enable) standard is fixed again based on the β value in the future.

As in the case of Figure 5b, if the hydrogen concentration is at the same level as β (within ±0.1%) after 10 minutes, it is judged to be simple durability deterioration and the heater operation (Enable) standard is adjusted to, for example, 2β (S180).

In the above example, the heater application time was set to 10 minutes, but in other implementations, the time determined within 1 to 60 minutes can be selected by considering the influence of the installation location on VOC poisoning substances. In addition, β was selected as -0.2%, but in other implementations, it can be selected by considering the hourly slope at which the hydrogen concentration decreases due to poisoning with VOC poisoning substances at the installation location within -0.01% to -2.0%. Additionally, in other implementations, adjusting the heater operation standard can also be performed in units of multiples (e.g., 2β, 3β) or fractions (e.g., β/2, β/3) of the β value, which is the standard when there is no durability deterioration. there is.

For example, if the reference value (β) is -0.2%, in this case, in step S130 shown, it is checked whether the first hydrogen gas measurement value is greater (higher) than -0.2%, and in step S170 shown again, Check whether the measured hydrogen gas value is in the range of -0.3% to -0.1%, and if it is in that range, step S180 is performed.

In another implementation, the same level may be a value selected in the range of -0.01 to -0.3% for the minus limit, and a value selected in the range of +0.01 to +0.3% for the plus limit.

Figure 6 is a block diagram showing an embodiment of a hydrogen gas sensor device equipped with a heater function humidity sensor according to the spirit of the present invention.

The hydrogen gas sensor device 100 equipped with a heater function humidity sensor includes a temperature sensor 110 that measures temperature; Humidity sensor 120 that measures humidity; A hydrogen sensor 130 that measures hydrogen gas concentration by heat conduction; A heater 140 capable of heating the humidity sensor 120; A correction calculation unit 162 that calculates a hydrogen gas measurement value by performing correction according to the measurement value of the temperature sensor 110 and the measurement value of the humidity sensor 120 with respect to the measurement value of the hydrogen sensor 130; And after power is applied to the humidity sensor 120 and the hydrogen sensor 130, the first hydrogen gas measurement value is compared with a predetermined reference value, and if the first measurement value of the hydrogen concentration is not higher than the reference value, the heater ( It may include a heater control unit 164 that operates 140).

The hydrogen gas sensor device 100 equipped with a heater function humidity sensor includes a storage unit 166 that stores the predetermined reference value; And if the hydrogen gas measurement value calculated by the correction calculation unit 162 after the predetermined time has elapsed is lower than or at the same level as the reference value, a standard update unit 168 for weighting and storing the reference value in the storage unit 166. More may be included.

In addition, depending on the implementation, if the first hydrogen gas measurement value is between the reference value and 0%, it may further include an offset application unit that processes the first measurement value of the hydrogen concentration as an offset. Although not separately shown, the offset application unit may be implemented as an internal module of the correction calculation unit 162.

The hydrogen gas measurement value calculated by the correction calculation unit 162 may be output to the outside through the output unit 190 as a final measurement value after an offset is applied by the offset application unit.

In the case of the hydrogen gas sensor device 100 shown, the correction calculation unit 162, the storage unit 166, the heater control unit 164, and the reference update unit 168 are internal calculation modules of a single MCU 160. It was implemented as.

The storage unit 166 may be implemented as a memory inside or outside the single MCU 160, such as an EEPROM (implemented as an MCU-embedded EEPROM in the drawing) to store the frequently updated reference value β. Additionally, the first measured value of the hydrogen concentration may be stored in the storage unit 166 as an offset by the offset application unit.

Those skilled in the art to which the present invention pertains should understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features, and that the embodiments described above are illustrative in all respects and not restrictive. Just do it. The scope of the present invention is indicated by the claims described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. .

100: hydrogen gas sensor device 110: temperature sensor
120: humidity sensor 130: hydrogen sensor
140: Heater 160: MCU
162: Correction calculation unit 164: Heater control unit
166: storage unit 168: standard update unit

Claims (10)

A deterioration correction method for a hydrogen gas sensor device that applies temperature and humidity compensation and has a heater function humidity sensor,
Comparing the first hydrogen gas measurement value and a predetermined reference value after power is applied to the hydrogen gas sensor device;
If the first hydrogen gas measurement value is not higher than the reference value, heating the humidity sensor for a predetermined time; and
Obtaining a hydrogen gas measurement value of the hydrogen sensor module after the predetermined time has elapsed
Deterioration correction method comprising:
According to paragraph 1,
After obtaining the hydrogen gas measurement value of the hydrogen sensor module after the predetermined time has elapsed,
If the hydrogen gas measured value after the predetermined time is lower than or at the same level as the reference value, weighting the reference value
A deterioration correction method further comprising:
According to paragraph 2,
The above same level is,
A deterioration correction method in which the negative limit is defined as one value selected from the range of -0.01 to -0.3%, and the positive limit is defined as one value selected from the range of +0.01 to +0.3%.
According to paragraph 1,
The predetermined time is,
Deterioration correction method, the time being determined within the range of 1 minute to 60 minutes.
According to paragraph 1,
The above reference value is,
Deterioration correction method where the value is selected within the range of -0.01% to -2.0%.
A temperature sensor that measures temperature;
Humidity sensor to measure humidity;
Hydrogen sensor that measures hydrogen gas concentration through heat conduction;
a heater capable of heating the humidity sensor;
a correction calculation unit that calculates a ‘hydrogen gas measurement value’ by performing correction on the measurement value of the hydrogen sensor according to the measurement value of the temperature sensor and the measurement value of the humidity sensor; and
A heater control unit that compares the first hydrogen gas measurement value with a predetermined reference value after power is applied to the humidity sensor and the hydrogen sensor, and operates the heater if the first measurement value of the hydrogen concentration is not higher than the reference value.
A hydrogen gas sensor device comprising a.
According to clause 6,
a storage unit that stores the predetermined reference value; and
If the hydrogen gas measurement value calculated by the correction calculation unit after a predetermined time is lower than or at the same level as the reference value, a standard update unit that weights the reference value and stores it in the storage unit.
A hydrogen gas sensor device further comprising:
In clause 7,
The above same level is,
A hydrogen gas sensor device in which the negative limit is defined as one value selected in the range of -0.01 to -0.3%, and the positive limit is defined as one value selected in the range of +0.01 to +0.3%.
In clause 7,
The predetermined time is,
A hydrogen gas sensor device whose time is determined within the range of 1 minute to 60 minutes.
According to clause 6,
The above reference value is,
Hydrogen gas sensor device with a value selected within the range of -0.01% to -2.0%.