JP7216517B2 - gas separation system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas separation system, and more particularly to a function of monitoring an abnormality in a gas separation device.

PSA (pressure swing adsorption) is known as a technique for producing nitrogen gas or oxygen gas. According to the PSA method, nitrogen gas can be obtained by separating nitrogen by adsorbing oxygen from the raw material air with an adsorbent using air as a raw material.

Japanese Patent Application Laid-Open No. 2002-100002 discloses a technique for detecting anomalies and searching for causes of failures in a gas separation apparatus using the PSA method. The operation of abnormality detection and failure cause search in Patent Document 1 is based on the raw air pressure P0, the first adsorption tank pressure P1, the second adsorption tank pressure P2, the product tank pressure P3, and the valve drive signals SV1, SV2, SV3, SV4, It is described that SV5, SV6, SV7, the nitrogen gas flow rate value, and the contained oxygen concentration value are processed by the controller.

JP-A-2002-239330

Patent Document 1 identifies the cause of failure of the PSA separation unit (including product gas pressure) from the valve drive signal and each pressure, but does not detect other abnormalities within the gas separation device. In particular, it is not suggested to detect anomalies when product gas leaks from the downstream piping of the product gas tank toward the nitrogen gas outlet from the product gas tank.

In addition, although Patent Document 1 uses the flow rate and oxygen concentration for abnormality determination, as shown in FIG. or) is judged only by comparison.

SUMMARY OF THE INVENTION It is an object of the present invention to detect anomalies within a gas separation device other than a PSA separation unit.

A preferred example of the present invention is a gas separation system comprising a gas separation device and a monitoring device, wherein the gas separation device comprises a compressor for compressing air and an air tank for storing the compressed air compressed by the compressor. an adsorption tank for adsorbing a part of the compressed air stored in the air tank; a product gas tank for storing product gas not adsorbed by the adsorption tank; and a pipe for discharging the product gas to the outside of the apparatus. and a control unit for controlling the operation of the adsorption vessel, wherein the monitoring device uses correlated detection data about the product gas vessel or the piping to detect when the gas separation device is abnormal. It is a gas separation system that determines whether

According to the invention, it is possible to detect anomalies in the gas separation device different from the PSA separation unit.

FIG. 1 is an overall configuration diagram of a gas separation device. FIG. 2 is a diagram showing the determination logic of abnormality determination 1. As shown in FIG. FIG. 3 is a diagram showing the determination logic of abnormality determination 2. As shown in FIG. FIG. 4 is a diagram showing the determination logic of abnormality determination 3. As shown in FIG. FIG. 5 shows a configuration diagram of a gas separation system that gives a sign of abnormality. FIG. 6 shows a processing block diagram of the monitoring device 100. As shown in FIG. FIG. 7 is a diagram showing a processing flow of abnormality determination of the monitoring device 100. As shown in FIG. FIG. 8 is a diagram showing the determination logic of abnormality determination 4. As shown in FIG. FIG. 9 is a diagram showing the determination logic of abnormality determination 5. As shown in FIG. FIG. 10 is a diagram showing the determination logic of abnormality determination 6. As shown in FIG. FIG. 11 is a diagram showing the determination logic of abnormality determination 7. As shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of a gas separation device. The gas separation device shown in FIG. 1 is a PSA (Pressure Swing Adsorption) type gas separation device. A PSA type gas separation apparatus 1 is composed of an air supply unit 2 for supplying air and a PSA unit 3 for producing a product gas. In this embodiment, the air supply unit 2 and the PSA unit 3 are configured in separate housings, but they may be in the same housing.

In this embodiment, as an example, the air supply unit 2 and the PSA unit 3 are housed in separate housings, but the two units may be housed in the same housing.

1, the air supply unit 2 includes a compressor 4 for compressing air, an electric motor 9 for driving the compressor 4, an inverter circuit 10 for controlling the capacity of the electric motor 9, and the compressed air. , an air dryer 6 for dehumidifying the compressed air, and a drain filter 7 for removing impurities while recovering the precipitated drain water. In this embodiment, the compressor 4, air tank 5, air dryer 6 and drain filter 7 are housed in the same housing.

The PSA unit 3 has adsorption tanks 19A and 19B that generate product gas by separating a predetermined gas from the compressed air supplied from the air supply unit 2, and stores the product gas (nitrogen gas in this embodiment). It has a nitrogen tank (product gas tank) 41 .

Compressed air stored in the air tank 5 is supplied to adsorption tanks 19A and 19B, which will be described later, and a predetermined gas is separated from the compressed air stored in the air tank 5 .

In this embodiment, a case will be described in which nitrogen is separated by adsorbing oxygen in the adsorption tanks 19A and 19B, but oxygen may be separated by adsorbing nitrogen. of gas may be separated.

As the compressor 4, a reciprocating double-acting compressor, a screw compressor, a scroll compressor, or the like, or a booster compressor that recompresses the primary pressure supplied from the outside, or the like is used.

The air tank 5 is provided with a pressure detection output stage 63 , which is communicably connected to the control section 60 of the PSA type gas separation apparatus 1 and outputs detection data to the control section 60 .

Furthermore, the air tank 5 is connected to a pipe 16 through which the compressed air from the air tank 5 flows through the drain filter 7. To this pipe 16, pipes 17A and 17B branched into two systems are connected. . The pipes 17A and 17B are provided with supply valves 18A and 18B for opening and closing the flow paths, respectively, and are connected to adsorption tanks 19A and 19B for adsorbing oxygen molecules and extracting nitrogen gas as a product gas. ing. This adsorption tank has a constant volume.

Pipes 21A and 21B are connected to the pipes 17A and 17B between the supply valves 18A and 18B and the adsorption tanks 19A and 19B, respectively. Exhaust valves 22A and 22B are provided, and an exhaust silencer 23 with a filter for silencing is provided at the end.

This exhaust silencer may be provided for each adsorption tank 19A, 19B. Pipes 25A and 25B are connected to the pipes 17A and 17B so as to connect positions between the pipes 21A and 21B and the adsorption tanks 19A and 19B. Lower pressure equalizing valves 26A and 26B are provided.

The adsorption tanks 19A and 19B are filled with, for example, an adsorbent that is an adsorption means for adsorbing oxygen molecules. Specifically, molecular sieve carbon, zeolite, or the like is used as the adsorbent. Pipes 31A and 31B are connected to the adsorption tanks 19A and 19B, respectively. Pipes 32A and 32B are connected to these pipes 31A and 31B so as to connect the sides of the adsorption tanks 19A and 19B.

Pipes 35A and 35B are connected to the pipes 31A and 31B on the opposite (downstream) side of the adsorption tanks 19A and 19B from the pipes 32A and 32B of each other so as to connect the pipes 32A and 32B. The pipes 35A, 35B are provided with upper equalizing valves 36A, 36B for opening and closing the flow paths.

Further, the pipes 31A and 31B are provided with take-out valves 38A and 38B for opening and closing the flow paths on the opposite (downstream) side of the adsorption tanks 19A and 19B with respect to the respective pipes 35A and 35B. A pipe 40 is connected to the confluence position of the pipes 31A and 31B, and a nitrogen tank 41 is connected to the pipe 40 as a product gas tank for storing nitrogen gas.

A pipe 43 provided with a discharge port 42 and a pressure detecting means 64 are connected to the nitrogen tank 41. In the middle of the pipe 43, dust and the like are removed in order from the nitrogen tank 41 side and gas pressure is detected. , a discharge valve 45 for opening and closing the flow path, a flow control valve 46 for adjusting the flow rate of the product gas, and a flow rate detecting means 61 for sensing the flow rate of the product gas.

Between the filter regulator 44 and the discharge valve 45 of the pipe 43, a pipe 48 and a pipe 49 are connected. A flow control valve 51 for adjusting the flow rate and a silencer 52 are provided.

The pipe 49 is provided with, in order from the pipe 43 side, an on-off valve 54 for opening and closing the flow path, a flow control valve 55 for adjusting the gas flow rate, and an oxygen sensor 56 for detecting the oxygen concentration. The oxygen sensor 56 and the flow rate detection means 61 are communicably connected to the control section 60 and output detection data to the control section 60 . The control unit 60 receives the detection data and controls the generation of nitrogen gas in the adsorption tanks 19A and 19B.

Specifically, the supply valves 18A, 18B, the exhaust valves 22A, 22B, the lower pressure equalizing valves 26A, 26B, the upper pressure equalizing valves 36A, 36B, the take-out valves 38A, 38B, the discharge valve 45, the on-off valves 50 and 54 are controlled by the control unit. 60 and operates according to commands from the control unit 60 .

The nitrogen tank 41 is provided with pressure detection means 64 for detecting pressure. Further, the PSA type gas separation apparatus 1 is provided with a temperature sensor 62 for detecting environmental temperature and environmental humidity. It should be noted that the temperature sensor and the humidity sensor may be connected to two devices.

The temperature sensor 62 and the pressure detection means 64 are communicably connected to the control section 60 and output detection data to the control section 60 . The control unit 60 receives the detection data and controls the generation of nitrogen gas in the adsorption tanks 19A and 19B.

The control unit 60 is capable of outputting detection data from the oxygen sensor 56, the flow rate detection means 61, the temperature sensor 62 and the pressure detection means 64, as well as the operating time to the outside.

So far, the configuration of the PSA type gas separation apparatus 1 has been described. Now, the gas separation method performed in the PSA type gas separation apparatus will be described.

In the PSA type gas separation apparatus 1, a compression step of compressing air with a compressor 4, a storage step of storing the air compressed in the compression step in an air tank 5, a dehumidification step of dehumidifying the compressed air with an air dryer 6, and a dehumidification step A separation step is performed to separate the gases from the air dehumidified by.

In the separation process of the PSA type gas separation apparatus 1, the following processes (a) to (d) are sequentially repeated.

(a) Adsorption/reflux step: The compressed air compressed by the compressor 4 and stored in the air tank 5 is supplied to the adsorption tank 19 filled with the adsorbent by opening the supply valve 18, and the nitrogen tank 41 The nitrogen gas remaining inside is circulated to the adsorption tank 19 by opening the take-out valve 38 to increase the pressure in the adsorption tank 19, and the pressure is used to cause the adsorbent to adsorb oxygen molecules.

(b) Take-out step: Continuing from the adsorption step, the compressed air is continuously supplied from the air tank 5 to the adsorption tank 19, and at the same time the nitrogen gas separated and produced by the adsorbent is taken out from the adsorption tank 19 and stored in the nitrogen tank 41. The process of making

(c) Pressure equalization process: By opening and closing the upper pressure equalization valve 36 and the lower pressure equalization valve 26, the pressure in the pair of adsorption tanks 19 after the extraction process is completed is equalized, and the adsorption efficiency in the next adsorption process is increased, resulting in higher purity. of nitrogen gas.

(d) Regeneration step: After the pressure equalization step, the adsorption tank 19 is filled with the adsorbent by opening the exhaust valves 22A and 22B and desorbing the oxygen molecules adsorbed by the adsorbent through the pipes 21A and 21B. The process of playing

In this regeneration step, the supply valve 18, the lower pressure equalizing valve 26, the upper pressure equalizing valve 36 and the take-out valve 38 related to the adsorption tank 19 other than the exhaust valves 22A and 22B are closed.

While the adsorption step and extraction step (steps (a) and (b)) are being performed in the adsorption tank 19A, the regeneration step (step (d)) is performed in the adsorption tank 19B. Thereafter, (c) the pressure equalization step is performed simultaneously, and the adsorption tanks 19A and 19B are exchanged to perform the adsorption step/removal step (steps (a) and (b)) and the regeneration step (step (d)). The time taken for the adsorption step (a), the take-out step (b), and the pressure equalization step (c) is collectively referred to as the cycle time.

Next, the gas separation system will be explained.

FIG. 5 shows a configuration diagram of a gas separation system that gives a sign of abnormality. In this gas separation system, a PSA type gas separation device 1 as the gas separation device in FIG. 1 and a monitoring device 100 for providing a monitoring service for the PSA type gas separation device 1 are connected. In this embodiment, remote monitoring is realized by using a network 80a (wireless communication or dedicated line) such as a wireless communication network such as a mobile phone using a dedicated line. may be a function of

Also, the monitoring device 100 and the information terminal that receives the service are connected via a network 80b such as the Internet. Also, the monitoring device 100 and an information terminal 82 that receives service are connected via a network 80c such as the Internet.

The information terminal 81 is an information terminal used by the owner of the PSA type gas separation apparatus 1 . The information terminal 82 is a pay-as-you-go biller who supplies the product gas to a person other than the owner of the PSA type gas separation apparatus 1, for example, a business operator at the installation site on a meter-rate basis and charges according to the supply amount, a special agent (Business: business operator who sells, wholesales and maintains gas separation equipment), dealers (business business: business operator who sells and maintains gas separation equipment), or maintenance companies.

The monitoring device 100 of this embodiment is operated by a monitoring service provider. This monitoring service provider may be an application provider for the information terminals 81 and 82, or may also serve as a platform operator that provides application software. The monitoring device 100, the information terminal 81, and the information terminal 82 each have a processor, which is a processing device of a computer, and a storage device, although they are not shown.

FIG. 6 shows a processing block diagram of the monitoring device 100. As shown in FIG. FIG. 7 is a diagram showing a processing flow of abnormality determination of the monitoring device 100. As shown in FIG. A processor of the monitoring device 100 executes each process of the data acquisition unit 101 , the abnormality determination unit 103 , and the transmission unit 104 . Threshold data is stored in the threshold recording unit 102 .

The monitoring device 100 of this embodiment receives detection data from the oxygen sensor 56, the flow rate detection means 61, the temperature sensor 62 and the pressure detection means 64, as well as the operating time from the control unit 60 of the PSA type gas separation apparatus 1. ,Remember.

As shown in FIG. 7, the data acquisition unit 101 in FIG. 6 acquires detection data detected by various sensors from the control unit 60 of the PSA type gas separation apparatus 1 (S1). In this embodiment, the pressure of the nitrogen tank 41, which is the product gas tank, the nitrogen gas flow rate, the temperature and humidity detected by the temperature sensor 62 of the PSA type gas separation apparatus 1, and the detection data of the cumulative operating time detected by the control unit are used. get.

Next, the abnormality determination unit 103 receives from the threshold recording unit 102 the thresholds determined corresponding to the temperature, humidity, and cumulative operating time of the PSA type gas separation apparatus 1 .

Then, the abnormality determination unit 103 compares the received threshold with the detection data acquired in S1, and determines whether it is normal or abnormal (S2). The transmission unit 104 notifies the information terminal 81 and the information terminal 82 of FIG. 5 of the result determined in S2 (S3, S4). It should be noted that there are many cases in which the communication is normal, and constant communication places a heavy load on the line.

The data acquisition unit 101 acquires the following data (YES in S5). In this embodiment, data acquisition is performed at preset time intervals.
Further, the data acquisition unit 101 terminates acquisition of the next data, for example, when performing maintenance on the PSA type gas separation apparatus 1 (No in S5).

In addition, when it is arranged in one housing and used as one function of the PSA type gas separation device, the transmission unit 104 does not directly transmit the determination result to the information terminals 81 and 82, but instead of the monitoring device in FIG. , a center server for distribution to the information terminals 81 and 82 is provided.

Next, abnormality determination performed by the abnormality determination unit 103 will be described.

(Abnormality judgment 1)
FIG. 2 is a diagram showing the determination logic of abnormality determination 1. As shown in FIG.

This abnormality determination is performed based on the correlation between the lower limit pressure of the nitrogen tank 41 corresponding to the temperature of the PSA type gas separation apparatus 1 detected by the temperature sensor 62 and the nitrogen gas flow rate. The vertical axis represents the lower limit pressure (MPa) of the nitrogen tank 41, and the horizontal axis represents the take-out flow rate (L/min) of nitrogen gas, which is the product gas. The lower limit pressure is detected by pressure detection means 64 . The pressure of the nitrogen bath 41 fluctuates periodically. Therefore, the lower limit pressure of the fluctuated pressure is used here.

In FIG. 2, the lines indicated by the highest environmental threshold (low temperature) 20, the standard environmental threshold (standard temperature) 21, and the lowest environmental threshold (high temperature) 22 indicate the relationship between the lower limit pressure corresponding to the environmental temperature in the apparatus and the product gas extraction flow rate. represents the correlation threshold. The correlation between the pressure detected by the pressure detection means 64 provided in the nitrogen tank 41 and the flow rate detected by the flow rate detection means 61 is shown as detection data 25 . The standard temperature is 20°C.

When the correlated detection data 25 becomes lower than the corresponding threshold value, it indicates that the product gas is leaking from the downstream pipe 43 connected to the nitrogen tank 41, or that the pressure detection means 64 and the flow rate detection means 61 have deteriorated over time. Since there is a possibility, it is judged as abnormal.

Although the standard environmental threshold alone may be used for determination, if the environmental temperature changes significantly, the compression performance of the compressor will also change (for example, at high temperatures, the gas expands, reducing the intake air volume of the compressor). , the compression performance deteriorates.) Therefore, even though the operation is normal, it is below the threshold value and is determined as abnormal operation, or even though it is an abnormal operation, it is above the threshold value and is determined as normal operation. may occur.

Therefore, in this embodiment, the pressure threshold value for determining abnormality is changed according to the change in temperature. Specifically, a threshold is set between the highest environmental threshold (low temperature) 20 and the lowest environmental threshold (high temperature) 22 according to the temperature at the time of detection. By doing so, it is possible to suppress the occurrence of temperature-dependent erroneous detection.

In this embodiment, regardless of the product gas flow rate, when the lower limit pressure detection data 25 falls below the threshold value 24, it is determined to be abnormal because it cannot occur in normal operation.

(Abnormality judgment 2)
FIG. 3 is a diagram showing the determination logic of abnormality determination 2. As shown in FIG. The description of the same parts as in FIG. 2 is omitted.
In FIG. 3, the lines indicated by the highest environmental threshold (low humidity) 30, the standard environmental threshold (standard humidity) 31, and the lowest environmental threshold (high humidity) 32 are the correlation between the lower limit pressure corresponding to the humidity and the product gas extraction flow rate. represents the threshold of Detection data 33 shows the correlation between the lower limit pressure of the nitrogen tank 41 and the flow rate detected by the flow rate detection means 61 . The standard humidity is 65%.

When the correlated detection data 33 falls below the corresponding threshold value, it indicates that the product gas is leaking from the downstream pipe 43 connected to the nitrogen tank 41, or that the pressure detection means 64 or the flow rate detection means 61 have deteriorated over time. Since there is a possibility, it is judged as abnormal.

The standard humidity threshold alone may be used for determination, but if the environmental humidity changes significantly, the compression performance of the compressor will also change (for example, if the humidity is high, the amount of air taken into the compressor will decrease, resulting in a decrease in compression performance). ), there are cases where normal operation is determined to be abnormal below the threshold, and abnormal operation is determined to be normal above the threshold.

Therefore, in this embodiment, the pressure threshold for determining abnormality is changed according to the change in humidity. Specifically, a threshold is set between the highest environmental threshold (low humidity) 30 and the lowest environmental threshold (high humidity) 32 according to the humidity at the time of detection. By doing so, it is possible to suppress the occurrence of erroneous detection depending on humidity.

In this embodiment, regardless of the product gas flow rate, when the lower limit pressure detection data 33 is below the threshold value 34, it is determined to be abnormal because it cannot occur in normal operation.

(Abnormality determination 3)
FIG. 4 is a diagram showing the determination logic of abnormality determination 3. As shown in FIG. The description of the same parts as in FIG. 2 is omitted.
In FIG. 4, the lines indicated by the maximum environmental threshold (cumulative operating time: small) 400, the standard environmental threshold (cumulative operating time: medium) 401, and the minimum environmental threshold (cumulative operating time: large) 402 correspond to the cumulative operating time. Represents the threshold of the correlation between the lower limit pressure and the product gas extraction flow rate. Detection data 403 shows the correlation between the pressure detected by the pressure detection means 64 provided in the nitrogen tank 41 and the flow rate detected by the flow rate detection means 61 . The cumulative operating time is managed by the control section 60 .

When the correlated detection data 403 becomes lower than the corresponding threshold value, it indicates that the product gas is leaking from the downstream pipe 43 connected to the nitrogen tank 41, or that the pressure detection means 64 and the flow rate detection means 61 have deteriorated over time. Since there is a possibility, it is judged as abnormal.

It is possible to judge only by the standard environmental threshold (cumulative operating time: medium), but if the cumulative operating time becomes long, the compression performance of the compressor will deteriorate and the adsorption tanks 19A and 19B will deteriorate, so even if it is operating normally, there will be an abnormality. may be judged.

Therefore, in the present embodiment, the pressure threshold for judging abnormality is changed according to the change in the accumulated operating time.

Incidentally, regardless of the product gas flow rate, when the detection data 403 is below the threshold value 404, it is determined to be abnormal.

(Abnormality judgment 4)
FIG. 8 is a diagram showing the determination logic of abnormality determination 4. As shown in FIG. The vertical axis represents the concentration (%) of oxygen, which is the removal gas, and the horizontal axis represents the extraction flow rate (L/min) of the nitrogen gas, which is the product gas. Oxygen concentration is detected by an oxygen sensor 56 . Since the nitrogen gas concentration is approximately equal to the value obtained by subtracting the oxygen concentration from 100, the lower the oxygen concentration, the higher the nitrogen gas concentration.

FIG. 8 shows thresholds in the correlation between the concentration of oxygen, which is the removal gas, and the flow rate of nitrogen gas, which are detected by the temperature sensor 62 and correspond to changes in the temperature of the PSA type gas separation apparatus 1 .

In FIG. 8, the lines indicated by the highest environmental threshold (high temperature) 80, the standard environmental threshold (standard temperature) 81, and the lowest environmental threshold (low temperature) 82 are the correlation between the oxygen concentration corresponding to the temperature and the nitrogen gas extraction flow rate. represents the threshold of A correlation between the oxygen concentration detected by the oxygen sensor 56 and the flow rate detected by the flow rate detection means 61 is shown as detection data 83 . The standard temperature is 20°C.

When the correlated detection data 83 becomes higher than the corresponding threshold value, it indicates that the concentration of nitrogen gas is low. Since there is a possibility that the sensor 56 has deteriorated over time, it is judged to be abnormal.

Since the compression performance of the compressor deteriorates at high temperatures, false detection can be prevented by lowering the threshold for determining abnormality (increasing the oxygen concentration threshold for determining abnormality).

In this embodiment, regardless of the product gas flow rate, when the lower limit pressure detection data 25 exceeds the threshold value 84, this cannot occur in normal operation, so it is determined to be abnormal.

(Abnormality judgment 5)
FIG. 9 is a diagram showing the determination logic of abnormality determination 5. As shown in FIG. The description of the same parts as in FIG. 8 is omitted.
In FIG. 9, the lines indicated by the maximum environmental threshold (high humidity) 90, the standard environmental threshold (standard humidity) 91, and the minimum environmental threshold (low humidity) 92 are the oxygen gas concentration and the product gas, which are removal gases corresponding to humidity. Represents a threshold of correlation with a certain nitrogen gas extraction flow rate. A correlation between the oxygen concentration detected by the oxygen sensor 56 and the flow rate detected by the flow rate detection means 61 is shown as detection data 93 .

When the correlated detection data 93 becomes higher than the corresponding threshold value, it indicates that the concentration of nitrogen gas is low. Since there is a possibility that the sensor 56 has deteriorated over time, it is judged to be abnormal.

Since the compression performance of the compressor deteriorates when the humidity is high, it is possible to prevent erroneous detection by lowering the threshold for determining abnormality (increasing the oxygen concentration threshold for determining abnormality).

In this embodiment, regardless of the product gas flow rate, when the lower limit pressure detection data 93 exceeds the threshold value 94, it is determined to be abnormal because it cannot occur in normal operation.

(Abnormality determination 6)
FIG. 10 is a diagram showing the determination logic of abnormality determination 6. As shown in FIG. The description of the same parts as in FIG. 8 is omitted.
In FIG. 10, the lines indicated by the maximum environmental threshold (cumulative operating time: large) 105, the standard environmental threshold (cumulative operating time: medium) 106, and the minimum environmental threshold (cumulative operating time: small) 107 correspond to the cumulative operating time. Represents the threshold of the correlation between the oxygen gas concentration and the product gas extraction flow rate. A correlation between the oxygen concentration detected by the oxygen sensor 56 and the flow rate detected by the flow rate detection means 61 is shown as detection data 108 .

When the detection data 108 becomes lower than the threshold value, there is a possibility that the product gas is leaking from the pipe 43 on the downstream side connected to the nitrogen tank 41, or that the pressure detection means 64 or the flow rate detection means 61 have deteriorated over time. Judged as abnormal.

When the correlated detection data 108 becomes higher than the corresponding threshold value, it indicates that the concentration of nitrogen gas is low. Since there is a possibility that the sensor 56 has deteriorated over time, it is judged to be abnormal.

Judgment can be made based only on the standard operating time, but as the cumulative operating time increases, the compression performance and nitrogen production capacity of the compressor will decline. .

In this embodiment, regardless of the flow rate of the product gas, if the lower limit pressure detection data 108 exceeds the threshold value 109, it cannot occur in normal operation, so it is determined to be abnormal.

(Abnormality determination 7)
FIG. 11 is a diagram showing the determination logic of abnormality determination 7. As shown in FIG.
FIG. 11 shows the relationship between the lower limit pressure of the nitrogen tank 41 and the time from when the PSA type gas separation apparatus 1 is stopped to when it is started. The vertical axis represents the lower limit pressure (MPa) of the nitrogen tank 41 and the horizontal axis represents the elapsed time (Hour) detected by the control unit 60 .

Normally, the pressure of the nitrogen tank 41 of the PSA type gas separation apparatus 1 decreases from the pressure P0 at the time of stopping to the pressure P2 at the time of starting. If it is longer than the time .DELTA.T, there is a possibility that nitrogen gas is leaking from the pipe downstream of the nitrogen tank 41. FIG.

Therefore, in this abnormality determination, a threshold is set for ΔP/ΔT, and when the correlation between the detected ΔP and ΔT is greater than the predetermined threshold, it is determined that there is an abnormality.

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications. Moreover, it is not necessarily limited to what has all the structures described. Moreover, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

DESCRIPTION OF SYMBOLS 1... PSA-type gas separation apparatus, 2... Air supply unit, 3... PSA unit, 4... Compressor, 5... Air tank, 6... Air dryer, 7... Drain filter, 9... Electric motor, 10... Inverter circuit, 19 Adsorption tank 41 Nitrogen tank 56 Oxygen sensor 60 Control unit 61 Flow rate detection means 62 Temperature sensor 64 Pressure detection means 80a, 80b, 80c Network 81, 82 Information terminal , 100... Monitoring device, 101... Data acquisition unit, 102... Threshold value recording unit, 103... Abnormality determination unit, 104... Transmission unit

Claims (8)

In a gas separation system comprising a gas separation device and a monitoring device,
The gas separation device is
a compressor for compressing air;
an air tank for storing compressed air compressed by the compressor;
an adsorption tank that adsorbs a part of the compressed air stored in the air tank;
a product gas tank for storing product gas not adsorbed in the adsorption tank;
a pipe for discharging the product gas to the outside of the apparatus;
a control unit that controls the operation of the adsorption tank;
a pressure detector for detecting the pressure of the product gas tank;
and a flow rate detection means for detecting the flow rate of the product gas ,
The monitoring device
A gas separation system according to claim 1, wherein a determination is made as to whether the gas separator is abnormal based on the detected pressure in the product gas tank and the detected flow rate of the product gas in the pipe . In claim 1 ,
In the monitoring device, the detected pressure of the product gas tank is lower than a predetermined threshold for determining abnormality , and the detected flow rate of the product gas is lower than a predetermined threshold for determining abnormality. A gas separation system characterized in that when the number is low, it is regarded as abnormal. In claim 1 ,
The gas separation system, wherein the monitoring device changes a predetermined threshold value for judging abnormality according to temperature, humidity, or cumulative operating time . In a gas separation system comprising a gas separation device and a monitoring device,
The gas separation device is
a compressor for compressing air;
an air tank for storing compressed air compressed by the compressor;
an adsorption tank that adsorbs a part of the compressed air stored in the air tank;
a product gas tank for storing product gas not adsorbed in the adsorption tank;
a pipe for discharging the product gas to the outside of the apparatus;
a control unit that controls the operation of the adsorption tank;
an oxygen concentration detector for detecting the oxygen concentration of the gas flowing from the product gas tank;
and a flow rate detection means for detecting the flow rate of the product gas,
The monitoring device
A gas separation system, wherein whether or not the gas separator is abnormal is determined from both the oxygen concentration of the product gas and the detected flow rate of the product gas. In claim 4 ,
When the concentration of the product gas is lower than a predetermined threshold value for judging abnormality and the detected flow rate of the product gas is lower than a predetermined threshold value for judging abnormality , as abnormal. In claim 4 ,
The gas separation system, wherein the monitoring device changes a predetermined threshold value for judging abnormality according to temperature, humidity, or cumulative operating time . In a gas separation system comprising a gas separation device and a monitoring device,
The gas separation device is
a compressor for compressing air;
an air tank for storing compressed air compressed by the compressor;
an adsorption tank that adsorbs a part of the compressed air stored in the air tank;
a product gas tank for storing product gas not adsorbed in the adsorption tank;
a pipe for discharging the product gas to the outside of the apparatus;
a control unit that controls the operation of the adsorption tank,
The control unit detects the time from when the gas separation device is stopped to when it is started,
The gas separation device comprises a pressure detector that detects the pressure of the product gas tank,
The monitoring device
A gas separation system characterized by judging whether the gas separation device is abnormal based on a pressure change in the product gas tank during the time from when the gas separation device is stopped to when it is started. In any one of claims 1 to 7 ,
A gas separation system, wherein the monitoring device is arranged in the gas separation device or configured separately from the gas separation device and connected to the gas separation device via a network.

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