Method and system for monitoring the condition of a sample handling system of a gas analyzer

Abstract

The present invention discloses a method and system for monitoring the condition of a sample handling system connected to a gas analyzer. The sample handling system includes a sample handling device and a sample circuit for supplying a gas sample to the gas analyzer. The system for monitoring the condition receives measurements from temperature and pressure sensors connected to the sample circuit and obtains operating characteristics of the sample handling device based on a model of the sample handling system and the measurements; and determines the condition of the sample handling system based on a comparison of the operating characteristics of the sample handling device and a plurality of reference values ​​associated with the sample handling device.

Description

Technical Field

[0001] The present invention relates generally to gas analyzers and, more particularly, to condition monitoring of a sample handling system of a gas analyzer. Background Art

[0002] For gas analysis, a gas sample is collected from a process line and supplied to a gas analyzer such as a gas chromatograph. This is performed by a sample handling subsystem (also referred to as a sampling system) of the gas analyzer. The sampling system equipment continuously purifies a sample of gas (or gas sample) to remove solid and fluid contaminants in the gas sample. The purified gas sample is delivered to the gas analyzer by the sampling system. If the solid and fluid contaminants are not efficiently reduced and are allowed to pass through the gas analyzer, the remaining service life of the gas analyzer may be shortened. Such solid and fluid contaminants (such as dust, condensate, and corrosive substances) further interfere with gas analysis and cause inaccurate gas analysis measurements.

[0003] The sampling system can typically be considered to consist of two parts: a) a main sampling system; and b) an auxiliary sampling system. A gas sample from a process line first enters the main sampling system. The main sampling system uses a high-pressure filter to filter the gas. The filtered gas passes through a gas cooler, which separates any moisture or other condensable gases present in the gas sample. The separated moisture or condensate will be collected in a condensate container. The auxiliary sampling system is typically provided with a fast loop / bypass system to shorten the response time of the overall system. The conditioned sample gas from the main sampling system enters the auxiliary sampling system. The condensate monitor further removes any residual moisture in the gas sample. After the condensate monitoring, the gas sample goes to the gas analyzer through a flow meter. The flow rate should be set for a value within the acceptable range for the gas analyzer, and is typically about 60 (+ / -10) liters per hour (LPH). The gas analyzer then performs measurements and analysis on the gas sample. Following the measurements and analyses performed on the gas sample, the gas sample is safely discharged to the atmosphere or to a gas discharge area provided for this purpose or returned to the process line.

[0004] Failure of any component in the primary or secondary handling system will result in an erroneous indication of the measured value or the analyzer sensor will be damaged and stop functioning. Currently, most sample handling systems have been designed in such a way that if the sample does not meet the requirements of flow rate, temperature, humidity, etc., an interlock controlled by a controller (such as a programmable logic controller) will not allow the sample to enter the analyzer to prevent failure of the analyzer. Abnormal conditions are generally only known when they occur. In order to avoid such accidents, daily routine maintenance is currently implemented in every shift. This is not efficient and therefore not ideal. Summary of the invention

[0005] The above-mentioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading and understanding the following specification.

[0006] In one aspect, the present invention provides a method for monitoring the condition of a sample handling system connected to a gas analyzer. The sample handling system includes a sample line for supplying a gas sample to the gas analyzer and at least one sample handling device on the sample line for operating on the gas sample, the method comprising: receiving measured operating parameters associated with the sample handling system obtained using a plurality of sensors provided in the sample line; determining estimated operating parameters associated with the sample handling system based on the measured operating parameters and data related to at least one of the physical dimensions of the sample line and the operating characteristics of at least one sample handling device; comparing the measured operating parameters and the estimated operating parameters with reference values ​​of the operating parameters associated with at least one sample handling device; determining at least one operating condition of the sample handling system based on the comparison result and based on the rate of change of at least one of the measured operating parameters; and generating an alarm based on the determined at least one operating condition, wherein the alarm includes at least one event related to a fault, a warning about a failure, an estimate of the life of at least one sample handling device, an estimate of the condition of at least one sample handling device, and a schedule for maintenance of at least one sample handling device.

[0007] In an embodiment, the sampling and handling device includes one or more temperature regulators for regulating the temperature of the gas sample, a pump for pumping the gas sample to the gas analyzer, a purge device for purging the sample line to clear blockages in the supply line, and one or more valves for regulating the flow of the gas sample in the sample line.

[0008] In an embodiment, the measured operating parameters associated with the sample handling system include at least one of heat tracer tube temperature, gas cooler temperature, gas sample flow rate, pressure data from pressure sensors across various points in the sample handling system.

[0009] In an embodiment, the data related to physical dimensions is the inner diameter of a conduit of the sample line.

[0010] In an embodiment, the reference value is obtained from historical data of measured operating parameters and estimated operating parameters associated with the sample pump.

[0011] In an embodiment, the sample handling system is monitored by at least one of a distributed control system (DCS) connected to a programmable logic controller (PLC), a sample handling monitoring device, or a combination thereof.

[0012] In an embodiment, the DCS is hosted by a digital platform or one or more servers in a cloud system.

[0013] In another aspect of the present invention, a condition monitoring system for monitoring the condition of a sample handling system connected to a gas analyzer is provided, wherein the sample handling system includes a sample line for supplying a gas sample to the gas analyzer and at least one sample handling device on the sample line for operating on the gas sample, the at least one sample handling device including one or more temperature regulators for regulating the temperature of the gas sample, a pump for pumping the gas sample to the gas analyzer, a purge device for purging the sample line to clear blockages in the supply line, and one or more valves for regulating the flow of the gas sample in the sample line, the condition monitoring system including: a network interface for controlling the flow of gas samples from a plurality of temperature and pressure sensors connected at a plurality of locations in the sample line A force sensor receives one or more sets of measurements; (a) one or more processors, wherein the one or more processors are used to: (i) obtain operating characteristics of at least one sample handling device based on a model of the sample handling system and the one or more sets of measurements; (ii) determine a condition of the sample handling system based on a comparison of the operating characteristics of the at least one sample handling device and a plurality of reference values ​​associated with the at least one sample handling device; and (iii) generate an alarm based on the determined condition of the sample handling system, wherein the alarm includes at least one event related to a malfunction, a warning about a failure, an estimate of the life of the at least one sample handling device, an estimate of the condition of the at least one sample handling device, and a scheduling of maintenance for the at least one sample handling device.

[0014] In another embodiment, the one or more processors are further configured to one of predict and identify one or more faults in the sample handling system and recommend one or more corrective actions based on the one or more faults.

[0015] In another embodiment, the model of the sample handling system is obtained from at least one of a characteristic curve provided by a manufacturer of an apparatus of the sample handling system and historical data associated with operating characteristics of the sample handling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The subject matter of the invention will be explained in more detail in the text below with reference to preferred exemplary embodiments illustrated in the accompanying drawings, in which:

[0017] Figure 1 illustrates a section 100 of an industrial plant including a gas analyzer; and

[0018] Figure 1a A detailed view of the sample handling system is shown;

[0019] Figure 2 Illustration of the operating characteristics of the sample handling system pump.

[0020] Figure 3 A representative sample handling system and gas analyzer unit with a sample handling status monitoring device and a cloud computing interface is shown; and

[0021] Figure 4 A block diagram is illustrated for a method of monitoring a sample handling system according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] In the detailed description below, reference is made to the accompanying drawings which form a part hereof and in which are shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it will be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the embodiments. Therefore, the detailed description below is not to be understood in a limiting sense.

[0023] Figure 1 A section 100 of an industrial plant is shown with a gas analyzer 120. The gas analyzer 120 is connected to a sample handling system 110. The sample handling system 110 is used to provide a gas sample from an industrial process pipeline to the gas analyzer for gas analysis. The sample handling system 110 includes a main sample line through which the gas sample is provided to the gas analyzer 120. A plurality of sample handling devices are connected to the main sample line to adjust various physical properties of the gas sample before supplying to the gas analyzer 120. Such adjustment (control) in this exemplary embodiment is implemented by a programmable logic controller (PLC) 125. The PLC 125 is shown as part of a distributed control system (DCS) 140. A sample handling condition monitoring device 130 is shown that receives a plurality of measured values ​​from sensors installed in the sample handling system. The sensors, sample handling condition monitoring devices, PLCs, and DCS are communicatively connected via a network system well known in the art in relation to process control and automation systems.

[0024] The DCS 140 can support further analysis of the measured data from the sensors to diagnose the condition of the sample circuits and sample handling devices. The DCS 140 can have operational models of various sample handling devices and can compare the measured and estimated values ​​with reference data (thresholds) to assess the condition of one or more sample handling devices. The DCS 140 also records the measured and estimated values ​​(operational data) to create historical data and utilizes these data to obtain trends and perform analysis for diagnostic and predictive maintenance. Alarms and notifications related to operational status / events, condition (health) of the sample handling devices, and maintenance can be generated by the sample handling condition monitoring device and the DCS.

[0025] The present invention discloses a method for monitoring the condition of a sample handling system connected to a gas analyzer by first receiving measured operating parameters associated with the sample handling system, such as pressure, temperature, flow, etc., obtained from sensors provided in various points in the sample circuit.

[0026] Secondly, operating parameters are being estimated, or the step of determining the estimated operating parameters associated with the sample handling system is performed based on measured operating parameters and data related to the physical dimensions of the sample (such as the inner diameter of the catheter of the sample circuit) and the operating characteristics (such as physical characteristics) associated with the sample handling device. Then, the measured operating parameters and the estimated operating parameters are compared with reference values ​​of operating parameters associated with at least one sample handling device. And, based on the comparison results and based on the rate of change of at least one of the measured operating parameters, the operating condition of the sampling handling system is determined. And, finally, an alarm is generated based on at least one determined operating condition, wherein the alarm includes at least one event related to a fault, a warning about a failure, an estimate of the life of at least one sample handling device, an estimate of the condition of at least one sample handling device, and a scheduling of maintenance for at least one sample handling device.

[0027] In an exemplary embodiment, a plurality of sample handling devices include one or more temperature regulating devices for regulating the temperature of the gas sample in the main sample circuit. For example, a gas cooler 104 is provided on the main sample circuit to cool the gas sample and reduce its temperature. Similarly, the sample handling system includes a sample pump 106 for pumping the gas sample to the gas analyzer, a purge device for clearing blockages in the supply line, and one or more valves for regulating the flow of the gas sample in the sample circuit. The sample flow from the process pipeline is extracted by the sample pump 106, and then the desired flow is sent to the gas analyzer 120. Balance is entered through a bypass line. The gas sample after passing through the gas analyzer 120 is finally discharged to a safe place.

[0028] A plurality of temperature and pressure sensors are provided on the sample line. Measurements from the temperature and pressure sensors are provided to the sample handling condition monitoring device 130. The sample handling condition monitoring device 130 is provided with a network interface capability that enables the condition monitoring device to communicate with devices and / or sensors in the sample handling system to receive measurements and states that assist in determining the condition / health. These devices and / or sensors can include one or more valves or any control modules for valves, temperature sensors, pressure sensors, flow rate sensors (flow analyzers), gas coolers, sample pumps, and the like. The network interface capability further facilitates the use of a variety of communication protocols (Modbus, Profibus, Modbus / TCP, etc.) that can be supported by different devices and / or sensors to communicate with the mentioned devices and / or sensors.

[0029] The condition monitoring device 130 utilizes different process measurements of the sample flow, such as pressure measurement, temperature measurement, flow measurement, etc. The flow from the pump discharge port to the analyzer is measured by a flow sensor. The pressure sensor is installed before the sample cooler and after the sample cooler and also after the sample pump to measure the pressure at every moment. With the help of these measurements (i.e., pressure measurement and flow measurement), the condition monitoring device can derive the condition of the sample handling system and can also identify the following problems: blockage in the sample flow tube, failure or poor performance (deterioration) of the sample pump, failure or poor performance of the sample cooler.

[0030] The value of the bypass flow is calculated by subtracting the main flow from the flow through the analyzer. Using continuous measurement of flow and pressure at various levels as described above, there may be a reduction in flow at any level, which is caused by the following reasons: the pump is not working properly, the bypass line is leaking or blocked somewhere, and the main sample line is blocked. The possibility of the main sample being blocked can be further verified by measuring the differential pressure across the gas cooler outlet and the filter inlet / probe outlet. This is derived with the help of a pressure transmitter installed across the sample cooler and by certain calculations in the condition monitoring device / unit to determine the state or condition of the sample line and the associated sample handling device. In the case where the main sample line is blocked, the differential pressure will be followed by a reduction in the sample flow to the analyzer. Similarly, the cooler temperature is also continuously monitored, and in the case of any temperature increase, the cooler temperature indicates a malfunction of the cooler. For example: if the sensor temperature is on a high trend, it will mean that the analyzer is not kept in an air-conditioned (A / C) room or the A / C is not operating. Thus, an alarm notification can be generated by the user or by a PLC (controller) for the required corrections to appropriately adjust the relevant process parameters. Specific alarm notifications can also be made to schedule maintenance.

[0031] Condition monitoring, diagnostics and prognostics of sample handling device and also analyzer health are based on flow and temperature measurements at various levels (locations) based on the type of sample handling system installed. The type of sample handling system is based on the process requirements of the process plant.

[0032] The sample handling condition monitoring device 130 is a means of monitoring the sample handling system. In another exemplary embodiment, the sensor for obtaining the operating parameters is directly implemented using the DCS, and the function of condition monitoring of the sample handling system is performed by the DCS. In another embodiment, the PLC can also perform condition monitoring of the sample handling system, and can coordinate with the DCS for diagnosis and prediction related to the sample handling device and the sample circuit. In other exemplary embodiments, the condition monitoring device, the computing unit of the DCS for condition monitoring including the PLC, and the condition monitoring function or tool implemented in the server of the DCS or in a general-purpose computer for condition monitoring can act as a hardware / software unit for condition monitoring of the sample handling system, and in the exemplary embodiments mentioned, such units can be individually referred to as condition monitoring units, and collectively referred to as condition monitoring systems. Such a condition monitoring system includes sensors, actuators (valves, regulators), a communication module including a network interface, a processor (included in the PLC, DCS or cloud server), and a memory (storage space) for condition monitoring functions.

[0033] In the above Figure 1 The associated description illustrates a section of an industrial plant including a gas analyzer. Figure 1a Further details are provided regarding the sample handling system 110 and operating parameters such as flow rate, pressure, temperature, etc. that are measured or estimated based on well-known techniques for utilizing the sample handling condition monitoring device 130 to perform further analysis related to the diagnosis and prognosis of conditions. In addition, several examples of measurements and techniques for evaluating conditions in the sample handling system that will use these measured parameters to provide operation of the sample handling condition monitoring device 130 to evaluate the health and performance of various components of the sample handling system will be discussed. The techniques provided are referred to as examples and are implemented in a condition monitoring unit / system using an electronic circuit system or using software / firmware provided in the memory of a computer operating in a programmable computer processor system. This evaluation of the health and performance of the various components of the sample handling system facilitates fault isolation and subsequent fault correction through automated mechanisms (controls) or through recommended fault correction procedures implemented by maintenance personnel.

[0034] Figure 1aA detailed diagram of a sample handling system 110 and a gas analyzer 120 according to an embodiment of the present invention is shown. A sample pump 106 provided to the sample handling system 110 creates negative pressure between the sample pump 106 and a sample probe 102 adapted with a process line 200 to extract a sample of the process gas and deliver it to the gas analyzer 120.

[0035] The extracted sample gas is typically at a higher pressure and elevated temperature than that suitable for the gas analyzer 120. In addition, the extracted gas is also composed of various solid and fluid contaminants (such as dirt, moisture, corrosive substances, other condensable gases, etc.) that may cause inaccuracies and failures in the performance of the gas analyzer 120. Contaminants and gas sample flow conditions (temperature, pressure, flow rate, etc.) that are not suitable for the operation of the gas analyzer may cause the gas analyzer 120 to read unstable, report drift and inaccurate measurements, have inconsistent response times, etc. The parameters measured or estimated with respect to the sample gas are related to the quality of the sample gas and can be used to determine and predict the conditions of the sample circuit, sample handling device, and gas analyzer. Therefore, before the gas sample arrives at the gas analyzer 120, it is conditioned to adjust the temperature, pressure, and flow rate of the gas sample and also remove various contaminants (such as the contaminants mentioned above). This ensures that the gas sample delivered at the gas analyzer 120 is a pure gas phase sample that does not have any contaminants and is suitable for accurate measurement and analysis by the gas analyzer.

[0036] It is therefore critical to continually monitor the various components that make up the sample handling system (such as valves, gas coolers, heaters, pumps, sensors for temperature, pressure, flow rate, humidity, etc.) to ensure that they are functioning properly and to preemptively take corrective action on any of the components before a failure disrupts the entire process. Measurements of parameters related to gas quality, operational data / status including data related to maintenance of the various sample handling devices and sample circuits are useful in assessing the condition of the gas analyzer.

[0037] The gas sample extracted by the sample probe 102 flows through a heat tracer tubing or pipe conduit between the sample probe 102 and the gas cooler 104. The heat tracer tubing is configured to operate typically at a temperature that prevents condensation of moisture or any other condensable gases (such as sulfur). For example, the heat tracer tubing can be maintained at approximately 80°C.

[0038] The gas sample is delivered with the help of multiple valves 210a all along the sample handling system. One or more filters (not shown) such as particulate filters and sintered metal filters also facilitate maintenance of the sample handling system 110 by removing various contaminants that may cause clogging due to dirt or other deposits.

[0039] The gas sample is passed to the gas cooler 104. The temperature of the gas cooler 104 is adjusted to promote condensation of moisture and other condensable gases in the gas sample. Condensate 220 is removed externally from the system using a peristaltic pump 225 and removed to a gas / condensate drain 285. Thus, only the gas that needs to be analyzed is allowed to pass along the rest of the sample handling system.

[0040] The filtered, cooled and condensate-removed gas sample flows through the sample pump 106 and into the condensate monitor 240 unit which senses for various condensates and dew formation. Measurements from the condensate monitor can be used to tune the performance of the sample gas cooler 104 through its parameter settings (temperature, flow rate, etc.).

[0041] After passing through the condensate monitor 240, the gas sample flows through a flow analyzer 245 that measures the volume flow rate of the gas sample. The volume flow rate is adjusted to be within an acceptable range for the particular gas analyzer 120 unit. To adjust the gas sample flow rate, the valve in the gas sample bypass line 235a is opened / closed to maintain the gas flow rate for the gas analyzer 120.

[0042] An estimated flow rate using the pressure 235b value is also obtained in the gas sample bypass line 235a to facilitate accurate flow rate adjustments for the gas analyzer 120. The estimated flow rate using the pressure value is obtained from pressure sensor measurements along the gas sample bypass line 235a and also from various points along the gas sample line toward the gas analyzer 120. Additional information that facilitates accurate estimated flow rate using the pressure 235b value includes conduit diameter, flow rate measurements from the flow analyzer 245. One or more well-known principles involving conservation of mass and energy, such as Bernoulli's equations, can be used to estimate the flow rate using the measured flow pressure value and knowledge of the inner diameter of the conduit that is transporting the gas sample.

[0043] In the gas sample bypass line 235 a , the final gas sample is discharged to a specific gas / condensate discharge port 285 area, or the gas is returned to the process pipeline 200 .

[0044] The gas sample passes from the flow analyzer 245 to the filter 250 before ultimately reaching the gas analyzer 120. The filter 250 facilitates the removal of any residual contaminants such as dirt, moisture, and the like.

[0045] The conditioned gas sample thus enters the gas analyzer 120 unit, where the gas sample has acceptable composition (pure gas phase sample) and flow conditions (flow rate, pressure, temperature). The gas analyzer 120 measures and records one or more parameters 260a, such as the concentration of each gas (carbon monoxide, nitrous oxide, sulfur dioxide, etc.) in the gas sample, analyzer pressure, analyzer temperature, analyzer flow rate, etc.

[0046] Once the measurements made by the gas analyzer 120 on the gas sample are completed, the gas sample is discharged to a specific gas / condensate discharge 285 area or returned to the process line 200 through the gas sample discharge line 260b.

[0047] In addition to the above-mentioned components and processes involved in the sample handling system, at least one purge unit is provided. The purge unit can be a source of compressed air 265. The compressed air 265 passes through an air filter 270 to remove any particles or contaminants before being used to back purge the sample probe 102 to remove any dirt, debris, obstructions or blockages of the sample probe 102.

[0048] The gas analyzer 120 and sample handling system 110 are also provided with calibration gas 275 for recalibrating the gas analyzer, which ensures accurate measurements with reduced uncertainty by automatically correcting for any measurement drift.

[0049] As reference Figure 1 As described, there are parameters measured at various points in the sample handling system 110 transferred to the sample handling condition monitoring device 130. Some of the parameters and their measurement locations are described in Figure 1a Highlighted in FIG. 1 are pressure (P1a) 280a upstream of gas cooler 104, pressure (P2b) 280b upstream of sample pump 106 and downstream of gas cooler 104, and pressure 280c upstream of condensate monitor 240 and downstream of sample pump 106. Pressure sensors are used to measure the pressure in each case.

[0050] In addition to the measured pressure values, the sampling handling condition monitoring device 130 also estimates the flow rate at various points along the gas sample path between the sample probe and the gas analyzer.

[0051] The measured data is received by the sample handling condition monitoring device 130, and additional data, such as flow rates at various points on the gas sample line, can be estimated by the condition monitoring device. The measured data is also referred to as measured operating parameters, and the estimated data is also referred to as estimated operating parameters. The measured data, the estimated data, and the data associated with one or more sample handling devices can all be referred to as operating data together. Therefore, the operating data consists of various operating parameters of the sample handling system and the gas analyzer, as well as data about physical dimensions or physical characteristics (operating characteristics) associated with one or more sample handling devices. Examples of such operating parameters can be heat tracer tube temperature, gas cooler temperature, gas sample flow rate, pressure data from pressure sensors at various points across the system, and the like. Some examples of data related to physical dimensions are the inner diameter of the catheter, the length of the sample line, and the measurement position on the length of the sample line, and the like, and an example of data related to the physical characteristics of one or more sample handling devices is sample pump characteristics. Data related to physical dimensions and physical characteristics are used to estimate operating parameters using the measured operating parameters.

[0052] In addition, the operational data also includes data associated with various events, such as faults, warnings regarding failure / degradation, life estimates of one or more sample handling devices (i.e., expected failures occurring after a certain period of time), the condition (health) of one or more sample handling devices, scheduling of maintenance for one or more sample handling devices, and the like. Figure 2 The operating characteristics of the sample pump 106 are shown. The operating characteristics of the sample pump are used to obtain the gas sample bypass line 235a 235b ( Figure 1a ) at 280C, downstream of the condensate monitor 240 and upstream of the sample pump 106. Figure 2 The horizontal axis in represents the position of one or more points (such as Figure 1a Gas pressure measured at P1a280a in the image. Figure 2 The ordinate in represents the flow rate associated with the sample pump 106 for various pressure values. The operating characteristic curve is utilized to determine the flow rate corresponding to the suction and discharge pressure (the estimated operating parameter). It may be well known to those skilled in the art that such a characteristic curve will be different depending on the make of the sample pump. The operating characteristics of the sample pump (sample handling device) for the corresponding make / model are stored in the DCS and used for various calculations related to the operation of the sample handling system including diagnostics and predictive maintenance.

[0053] In this example, for the manufacture of the sample pump, the operating characteristics of the sample pump are therefore used to calculate the flow rate and the pressure and flow data are also used to check whether the two sides of the pump are balanced by comparing the values ​​of the operating parameters (pressure and flow) obtained at the suction side and the discharge side. Here, the values ​​of pressure and flow at one side (e.g., the suction side) are used as reference values ​​for comparison with the corresponding values ​​at the other side (in this example, the discharge side). Reference values ​​for either or both sides can also be obtained from historical data of measured operating parameters and estimated operating parameters associated with the sample pump. These operating parameters can also be generated as reference characteristic values. In the case of imbalance, the sample handling condition monitoring device / DCS can determine the build-up condition of the back pressure on the pump through analysis and generate an alarm related to the sample pump accordingly. Estimates related to the back pressure obtained over a period of time can be used to predict the life of the sample pump including the diaphragm.

[0054] Using such Figure 2 The operational characteristics provided in the condition monitoring unit can be observed and inferred as follows:

[0055] P1 - pressure after the sampler cooler,

[0056] P2 - pressure after the sample pump,

[0057] P0 - pressure before the sample cooler,

[0058] F1 - Flow through the sample pump to the analyzer (excluding bypass flow),

[0059] For conditions where P1 and P2 are the same, but F1 decreases, the condition monitoring device is able to determine and provide an alarm notification that the pump requires maintenance. Similarly, in the event that P1 increases, P2 remains the same, P0 remains the same, and therefore F1 decreases, the condition monitoring device determines that there is a blockage in the sample line located before the sample pump. Likewise, if P2 increases, P1 remains the same, P0 remains the same, and therefore F1 decreases, the condition monitoring device is able to determine that there is a blockage in the line after the sampler cooler and before the pump outlet. And likewise, if P1 increases, P2 remains the same, P0 also increases proportionally, and therefore F1 decreases, there is a blockage before the sampler cooler.

[0060] When the pressure and flow rate reach a specific value as represented by (P1, F1) 210, the sample pump 106 is started by the PLC. The value of the pressure and flow rate below (P1, F1) 210 is represented by area 205. The sample pump 106 thus transfers a gas sample at a pressure and flow rate set above (P1, F1) 210. The flow rate of the gas sample reaches a peak flow rate 215 value at a pressure value represented by 0. In addition, the pressure value is positive. However, as the gas sample pressure increases, the gas sample flow rate begins to decrease. As the gas sample pressure increases and approaches the ambient pressure value, the gas sample flow rate becomes zero. At a positive pressure shown as P2, the gas sample flow rate value reaches F2, and at this point of (P2, F2) 220, the sample pump is closed by the PLC. The sample pump 106 is therefore configured to obtain a gas sample flow rate higher than F1 (such as 40 liters per hour) at a pressure P1 and lower than F2 (such as 60 liters per hour) at a pressure P2.

[0061] Each data as described above is date and time stamped. Event data may relate to user calibration events, sample pump start and sample pump stop times, firmware version and update history, history of restoration to factory settings, service or maintenance logs, etc. Faults and alerts may be associated with measured temperatures above or below upper and / or lower limits, offset drifts exceeding allowable ranges, flow failures such as flow failures, unstable measured value readings, etc. The history of such data collected under various operating conditions of the sampling and handling system and the gas analyzer assists in the monitoring and diagnosis of the system. Various operating conditions may relate to the system's healthy or normal operating stage, degraded operating conditions, and failure conditions.

[0062] When determining the operating condition of the sampling disposal system, an alarm is generated if the condition requires attention or correction. An example of an alarm related to the detection of a fault in the sample disposal device is when a condensate fault is detected as a result of moisture detected in the sample line and may cause the tripping of the sample pump. An alarm is generated, and an alarm notification is provided to check the condensate monitor and replace the condensate filter element so that the system can be restored. Similarly, an example related to diagnosis is when a blockage is inferred at the tapping level based on the determined operating condition according to the values ​​of the pressure and temperature at the probe filter and the probe filter is likely to be completely blocked in the next few hours, an alarm notification is generated. The alarm can notify the probe filter that will be serviced immediately. Another example is an alarm notification based on prediction, in which a prediction of the developing state / condition of the sample disposal device is made. In such an analysis, the current and past operating data of the associated sample disposal device is used to determine the rate of change of the measured / estimated operating parameters, and life and condition assessment can be performed by extrapolation of the rate of change and comparison with preset thresholds representing the condition of failure or failure. Such information can also be used to perform predictive maintenance. For example, blockage inside the gas cooler is inferred from the values ​​of the operating parameters of pressure and temperature, and based on the rate of change of these operating parameters, it is possible to estimate a condition in which the gas cooler may become completely blocked to cause a trip condition at some time in the future. And likewise, such detection of blockage inside the gas cooler is used to provide a prescription-based alarm notification that the cooler path needs to be checked and cleaning is to be performed (alarm for notification of a condition requiring maintenance in the near future).

[0063] Another example of an alarm is reporting degradation of a sample pump. Degradation conditions can be estimated by monitoring the rate of change of the discharge flow rate, and if the discharge flow rate is on a trend of decreasing from a normal flow rate, degradation of the sample pump can be inferred. The rate of change of the discharge flow value can be extrapolated by the PLC and compared to a reference value for an interlock (out of service) to predict the status of a condition (degradation of the sample pump) and a developing condition for a failure due to sample pump degradation. An alarm can notify of the impending need for service of the sample pump and ensure correction for a good sample flow to the analyzer.

[0064] In another embodiment of the invention, data regarding parameters associated with the sample handling system and the gas analyzer are output to a cloud computing system, which acts as a condition monitoring unit / system for further analysis of the acquired operational data. Figure 3 A representative sample handling system and a gas analyzer having a sample handling condition monitoring device provided with a cloud computing system according to various embodiments of the present invention are illustrated.

[0065] Operational data from multiple gas analyzers 300a, 300n and their corresponding sample handling systems 310a, 310n are first collected by their corresponding sample handling monitoring devices 320a, 320n. Operational data from each system such as 300a and 310a is date and time stamped and is additionally tagged with the instrument ID (such as a serial number) and firmware version by which the data was generated.

[0066] All of the data obtained above are output to a cloud computing system 330 configured with storage and processing capabilities. Various data analyses can be performed on the data stored in the cloud computing system 330. The analyses performed can be descriptive, predictive, and prescriptive, and corresponding alarm notifications can be generated and issued to the condition monitoring device or in the human-machine interface of the condition monitoring unit (including handheld devices such as mobile phones). Such analysis facilitates anomaly detection and enables corrective measures to be taken through automated setting of operating parameters or through other maintenance activities to restore the possibility of full operation of the sample handling system and gas analyzer.

[0067] Analysis of time series of such monitored operational data can reveal complex correlations based on analyzing fluctuations of different time scales and noise. Real-time and historical views of operational data and time series analysis thereof facilitate identification of long-term trends that are likely to provide an indication of degradation of the condition monitored operational data. Trends of various operational parameters can be compared to reference values ​​(e.g., minimum and maximum limits) of the corresponding operational parameters.

[0068] If one or more operating data parameters are outside the minimum and maximum limit limits (reference values), the gas analyzer and sample handling system may be unhealthy, and an alert about the detected anomaly is sent to the customer / operator. Utilizing the operating data collected from multiple gas analyzers and sampling handling systems, visualization tools in the cloud computing system can generate distributions of various operating parameters corresponding to various operating states of the gas analyzer and sample handling system. Different operating states can correspond to healthy or normal states, degraded or non-optimal states, failure states, and the like. Analysis of such operating data for various parameters can assist in the accurate estimation of any component in the system that may be approaching failure or non-optimal performance characteristics. This information can then be used to automatically take corrective measures through the setting of various operating parameters or through recommendations for corrective measures sent to the customer / operator.

[0069] This continuous monitoring of multiple operating data parameters enables accurate predictability of failures in various components of the gas analyzer and sample handling system. An estimate of the condition of the sample handling device including an estimate of the life of the sample handling device is obtained using measured operating parameters and estimated rates of change of operating parameters obtained over time (including extrapolation) and by comparison with reference values ​​(threshold values). This facilitates improved maintenance planning and efficiency to reduce overall maintenance costs and improve system availability and maximize the remaining useful life of system components.

[0070] Representative use case examples of the present invention are described along with an overview of a sample handling system and a method for condition monitoring of a gas analyzer. Figure 4 A diagram of a block diagram of a method for monitoring a sample handling system according to an exemplary embodiment of the present disclosure is shown. Only relevant details necessary for the situation illustrated by the diagram are shown.

[0071] refer to Figure 4 In step 400, a sample pump in a sample handling system creates a negative pressure between a sample probe and the sample pump. This causes a sample probe adapted in a process gas line to extract a gas sample from the process gas line and divert the gas sample toward a sample pump in a sample handling unit. Step 405 represents a method in which the sample probe extracts a representative gas sample from a process gas line. In step 410, the extracted gas sample diverted toward the sample pump is transported to a gas cooler upstream of the sample pump. This facilitates purifying the gas sample to remove contaminants, such as moisture or other condensable gases. In step 445, pressure is measured across the gas cooler (before and after it). This enables estimation of the pressure differential across the gas cooler. In addition to pressure monitoring, the sample handling condition monitoring system also monitors and records the temperature at the gas cooler. As indicated in step 465, all measured operating data are transmitted to the sample handling condition monitoring device, where the data is continuously recorded and analysis is performed.

[0072] If a trend is observed that indicates reduced cooling performance, the sample handling condition monitoring device / unit can send an alarm or warning to the customer / operator, for example, performance maintenance on the condenser fins of the gas cooler unit. When the gas cooler temperature is continuously monitored, any temperature increase can indicate a malfunction of the gas cooler. For example: if the temperature is on a high trend, it may mean that the ambient temperature of the gas analyzer system is high and the air conditioning equipment may be cut off. The sample handling condition monitoring device can then send a warning signal to the customer / operator.

[0073] If the estimated differential pressure exceeds acceptable limits, it can indicate a blockage or occlusion in the sample gas flow. This can manifest as a pressure drop imparted to a low vacuum (negative pressure) in the system and a higher vacuum (negative pressure) in the pump. The sample handling condition monitoring device can automatically remove various contaminants in the sample gas line by purging the sample probe through a compressed air jet using high pressure (5-10 Kg / cm2). Therefore, using current and historical operating data, the sample handling condition monitoring device can deduce the condition of the sample handling system and can identify any faults, such as blockages (deterioration) or occlusions in the sample flow line or tube. The sample handling condition monitoring device can then take automated corrective actions, such as adjustment of the purge air pressure and purge timing for cleaning of the sample probe, retraction of the sample probe, and cleaning of the probe using a pneumatically activated cleaning system depending on probe feedback.

[0074] Based on historical trends in the measured pressure values, if a gradual loss of vacuum (negative pressure) is observed over a period of time, this can indicate a worn pump and the sample handling monitoring system can automatically adjust to reduce the load on the pump while maintaining an acceptable flow rate within the range of the gas analyzer. At the same time, the sample handling monitoring system can alert the customer / operator of maintenance requirements for the sample pump.

[0075] Therefore, as described above, using these measurements of three pressure values ​​(upstream of the gas cooler, midstream between the gas cooler and the sample pump, and downstream of the sample pump) and a flow rate measurement midstream between the condensate monitor and the gas analyzer, the sample handling condition monitoring device is able to infer the condition of the sample handling system and is also able to identify the following problems: blockage in the sample flow tube, failure or poor performance of the sample pump, failure or poor performance of the sample cooler.

[0076] Continue to refer Figure 4 In step 415, the cooled gas sample is transported from the gas cooler to a flow analyzer upstream of the sample pump. In step 450, the flow analyzer measures the volume flow rate in the gas sample circuit. In step 465, the measured volume flow rate is transmitted to the sample handling condition monitoring device. Data is continuously recorded and analysis is performed.

[0077] The gas analyzer has an acceptable range for volumetric gas flow rate, and therefore the gas flow rate must be adjusted to be within this acceptable range. In step 420, the valve in the gas sample bypass loop is adjusted to adjust the volumetric flow rate of the gas sample flowing through the gas analyzer. In step 455, the pressure of the gas sample is measured both downstream of the sample pump and in the gas sample bypass loop. In step 465, the measured pressure value is transmitted to the sample handling condition monitoring device. Data is continuously recorded and analysis is performed.

[0078] In step 460, the measured values ​​for the pressures in the bypass loop and the sample analysis circuit are used together with the measured volumetric gas flow rate in the sample analysis circuit to obtain an estimate of the volumetric gas flow rate in the sample bypass circuit. In step 465, the data value is transmitted to the sample handling condition monitoring device.

[0079] In step 425, the gas sample at the regulated flow rate is transported to a gas analyzer for analysis of the pure gas phase of the sample with respect to the flow rate, pressure, and temperature regulated to be acceptable to the gas analyzer.

[0080] In step 430, the analysis of the gas sample by the gas analyzer is completed, and the results of the gas analyzer parameters are transmitted to the sample handling condition monitoring device in step 465. The parameters from the gas analyzer can consist of various gas concentrations, temperatures, pressures, and flow rates in the gas analyzer, etc. All of these parameters are continuously recorded to the sample handling condition monitoring device.

[0081] In step 435, once the gas analysis of the gas sample is completed, all gas samples are discharged to a designated waste disposal area or returned to the process gas pipeline. If the gas analyzer measurement value shows a specific trend of drift of the measured value, the sample disposal monitoring device can automatically trigger the recalibration of the gas analyzer using the calibration gas provided with the system. However, if the sample disposal monitoring device observes an increasing trend of the gas analyzer pressure, the sample disposal monitoring device can prioritize the high-pressure purge of the gas sample exhaust port line to solve the problem of measurement drift and possible blockage or clogging in the gas sample exhaust port line. Therefore, the recalibration of the gas analyzer and the purging of various gas sample lines (such as, sample probes, gas sample exhaust port lines, etc.) can be adapted to the current status of the sample disposal system.

[0082] In step 460, the sample handling monitoring device collects operating parameters such as those described above and performs the same steps as described in reference. Figure 2 and Figure 3 Step 465 highlights the actionable results of such analysis. Various operating parameter changes or / and corrective actions are recommended as necessary to maintain the system of gas analyzers and sample handling systems in a healthy operating state and to maximize the remaining useful life of various components in the system through proactive implementation of corrective actions.

[0083] In an embodiment, the condition monitoring device utilizes historical data. Using the historical data, the condition monitoring device is able to develop a model of the sample handling system and take automated corrective actions, such as adjustment of purge air pressure and purge timing for cleaning of the sample probe, retraction of the sample probe and cleaning of the probe using a pneumatically activated cleaning system depending on probe feedback, recalibration of the analyzer based on measured values ​​and collected periodic data, adjustment of the needle valve to maintain optimal flow rate at the analyzer.

[0084] The method of monitoring the condition of the sample handling system can be performed by the sample handling condition monitoring device or the DCS or in a combination of the sample handling condition monitoring device and the DCS. The DCS can be hosted by one or more servers or digital platforms in a cloud system.

[0085] Although only certain features of the present invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A method for monitoring a condition of a sample handling system (110) connected to a gas analyzer (120), the sample handling system (110) comprising a sample circuit for supplying a gas sample to the gas analyzer (120) and at least one sample handling device on the sample circuit for operating on the gas sample, the method comprising: receiving measured operating parameters associated with the sample handling system (110) obtained using a plurality of sensors provided in the sample circuit; determining an estimated operating parameter associated with the sample handling system (110) based on measured operating parameters and data related to at least one of a physical dimension of the sample circuit and an operating characteristic of the at least one sample handling device; comparing the measured operating parameter and the estimated operating parameter to reference values ​​of operating parameters associated with the at least one sample handling device; determining at least one operating condition of the sample handling system (110) based on the comparison result and based on a rate of change of at least one of the measured operating parameters, wherein determining the at least one operating condition of the sample handling system based on the rate of change comprises an extrapolation of the rate of change and a comparison with the reference value; as well as An alarm is generated based on at least one determined operating condition, wherein the alarm includes at least one event related to a fault, a warning about a failure, an estimate of the life of at least one sample handling device, an estimate of the condition of the at least one sample handling device, and a schedule for maintenance of the at least one sample handling device.

2. The method according to claim 1, wherein: The sample handling device includes one or more temperature regulators for regulating the temperature of the gas sample, a pump for pumping the gas sample to the gas analyzer, a purge device for purging the sample line to clear blockages in the sample line, and one or more valves for regulating the flow of the gas sample in the sample line.

3. The method according to claim 1, wherein: Measured operating parameters associated with the sample handling system include at least one of heat tracer tube temperature, gas cooler temperature, gas sample flow rate, pressure data from pressure sensors across various points in the sample handling system.

4. The method according to claim 1, wherein: The data related to the physical dimensions is the inner diameter of the conduit of the sample line.

5. The method according to claim 1, wherein: The reference value is obtained from historical data of measured operating parameters and estimated operating parameters associated with the sample pump.

6. The method according to claim 1, wherein: The sample handling system is monitored by a sample handling condition monitoring unit included in at least one of a distributed control system (DCS) connected to a programmable logic controller (PLC), a sample handling monitoring device, and combinations thereof.

7. The method according to claim 6, wherein: The distributed control system (DCS) is hosted by a digital platform or one or more servers in a cloud system.

8. A condition monitoring system for monitoring the condition of a sample handling system (110) connected to the gas analyzer (120), wherein the sample handling system (110) comprises a sample line for supplying a gas sample to the gas analyzer (120) and at least one sample handling device on the sample line for operating on the gas sample, the at least one sample handling device comprising one or more temperature regulators for regulating the temperature of the gas sample, a pump for pumping the gas sample to the gas analyzer, a purge device for purging the sample line to clear a blockage in the sample line, and one or more valves for regulating the flow of the gas sample in the sample line, the condition monitoring system comprising: a. a network interface for receiving one or more sets of measurements from a plurality of temperature and pressure sensors connected at a plurality of locations in the sample line; b. One or more processors configured to: i. obtaining an operating characteristic of the at least one sample handling device based on the model of the sample handling system and the one or more sets of measurements; ii. determining the condition of the sample handling system based on a comparison of the operating characteristic of the at least one sample handling device and a plurality of reference values ​​associated with the at least one sample handling device, wherein determining the condition of the sample handling system further comprises extrapolation of a rate of change and comparison with the reference values; as well as iii. generating an alarm based on the determined condition of the sample handling system, wherein the alarm includes at least one event related to a fault, a warning about a failure, an estimate of the life of at least one sample handling device, an estimate of the condition of the at least one sample handling device, and a schedule for maintenance of at least one sample handling device.

9. The condition monitoring system according to claim 8, wherein: The one or more processors are further configured to predict and identify one or more faults in the sample handling system and recommend one or more corrective actions based on the one or more faults.

10. The condition monitoring system according to claim 8, wherein: The model of the sample handling system is obtained from at least one of a characteristic curve provided by a manufacturer of equipment of the sample handling system and historical data associated with operating characteristics of the sample handling system.

Images