Determination device, determination program, determination method, and determination system

Abstract

The continuous operating status of the condensate drain is determined without using pressure information that requires modifications to the plant piping. [Solution] The determination device has a determination unit that determines whether the condensate discharge device is in a stagnant state, in which steam is stagnating, based on an inlet side temperature Tin, which is the temperature on the inlet side of the condensate discharge device, which has an inlet through which steam is injected and an outlet through which condensate is discharged, and determines whether the condensate discharge device is in a leaking state, in which condensate is leaking, based on an outlet side temperature Tout, which is the temperature on the outlet side of the condensate discharge device.

Description

[Technical Field]

[0001] The present disclosure relates to a determination device, a determination program, a determination method, and a determination system for determining the operating state of an orifice-type condensate drain device, and a collection device included in the determination system. [Background technology]

[0002] There is an orifice-type condensate drain device in which steam is injected and condensate is drained (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6408734 [Patent Document 2] Patent No. 7641054 Summary of the Invention [Problem to be solved by the invention]

[0004] Orifice-type condensate discharge devices are less likely to break down because they have no moving parts, but it cannot be said that there will be no condensate buildup or steam leakage due to clogging of the orifice hole caused by rust or foreign matter in the upstream piping, or an increase or decrease in condensate due to changes in operating conditions. Maintenance inspections require preparation and are time-consuming, and they only assess the condition at the time of the maintenance inspection, making it difficult to determine continuous conditions or trends.

[0005] Therefore, Patent Document 2 discloses a determination device that determines the state (non-operating state, stagnant state, normal operating state, leak state) of an orifice-type condensate discharge device based on the inlet pressure value, inlet temperature, outlet pressure value, and outlet temperature of the device. Patent Document 2 discloses that an existing pressure sensor can be used (paragraphs 0011 and 0017), but in the case of piping that does not have a pressure sensor, plant modifications are required to install a pressure sensor. Even when pressure cannot be measured, it is desirable to determine the continuous operating state of the condensate discharge device.

[0006] In view of the above, it is an object of the present disclosure to determine the continuous operating status of a condensate drainer without using pressure information. [Means for solving the problem]

[0007] A determination device according to one embodiment of the present disclosure includes a determination unit that determines whether the condensate discharge device is in a stagnant state, in which steam is stagnating, based on an inlet temperature Tin, which is the temperature on the inlet side of the condensate discharge device having an inlet through which steam is injected and an outlet through which condensate is discharged, and determines whether the condensate discharge device is in a leaking state, in which condensate is leaking, based on an outlet temperature Tout, which is the temperature on the outlet side of the condensate discharge device. [Effects of the Invention]

[0008] According to the present disclosure, the continuous operating status of the condensate drain can be determined based on the inlet and outlet temperatures without using pressure information. [Brief explanation of the drawings]

[0009] [Figure 1] The relationship between steam temperature and enthalpy is shown using steam pressure as a parameter. [Figure 2] FIG. 10 is a diagram for explaining an inlet-side reference temperature and an outlet-side reference temperature. [Figure 3] The measurement data of the inlet temperature and outlet temperature are shown. [Figure 4]FIG. 10 is a diagram for explaining a method for determining an inlet-side reference temperature and an outlet-side reference temperature. [Figure 5] 1 illustrates a determination system according to an embodiment of the present disclosure. [Figure 6] 10 is a flowchart showing the operation of the determination system. [Figure 7] 10 is a flowchart illustrating a method for determining the operating state of the condensate discharge device, which is executed by a determining unit. [Figure 8] 10 is an example of a GUI that the result display unit displays on the display device. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1. Overview of this embodiment

[0011] In Patent Document 2, when determining the condition, a reliable determination is made using pressure data on the inlet and outlet sides and a method that uses saturation temperature as a reference. On the other hand, in the case of piping that does not have a pressure sensor, installing a pressure sensor requires plant modification, so it is not expected to become widespread in terms of cost-effectiveness. Therefore, in order to eliminate or minimize the need for plant modification, a method and algorithm for making a determination using only temperature data is being considered.

[0012] Condensate discharge devices are installed in steam systems to properly discharge condensate generated, and are divided into "main pipe" and "heat exchange" types. Main pipe devices discharge condensate generated in the supply piping from the boiler that generates steam to the equipment that uses the steam through a branch pipe. Main pipe devices are installed at the end of the branch pipe. Generally, boiler pressure is controlled during operation, so the pressure is stable, but pressure fluctuations due to changes in steam flow rate and operating conditions can occur depending on steam demand. Heat exchange devices, on the other hand, discharge condensate generated in equipment that uses steam as a heat or power source. Heat exchange devices are installed at the condensate outlet of the equipment. In the case of equipment that operates continuously and steadily, there is little fluctuation in the amount of condensate generated, but in the case of batch processing plants, the amount of condensate generated can fluctuate greatly.

[0013] The behavior of the inlet side of the condensate drainer, under normal and leaking conditions, is a two-phase flow of saturated water and saturated steam corresponding to the inlet pressure. In a stagnant state, heat dissipation from the piping causes the condensate to fall below the saturation temperature, and the temperature gradually decreases. The inlet pressure follows the boiler's operating pressure, but fluctuations in steam demand can cause fluctuations due to pressure losses in the piping and equipment, and condensate stagnation in the piping.

[0014] Under normal conditions, the outlet side of the condensate discharge device behaves as a two-phase state consisting of saturated water corresponding to the outlet pressure and flash steam at the saturation temperature generated by a pressure drop. When the amount of condensate is small and steam leakage occurs, the outlet temperature rises as saturated water, flash steam, and high-temperature leaked steam mix together. When stagnation occurs on the inlet side, only condensate flows in, resulting in a two-phase flow of condensate at the outlet saturation temperature and flash steam. When the inlet temperature falls below the outlet saturation temperature, condensate at approximately the same temperature is discharged.

[0015] Figure 1 shows the relationship between steam temperature and enthalpy, with steam pressure as a parameter.

[0016] (1) Since the inlet fluid is at saturation temperature, it can be considered to be a mixture of saturated water and saturated steam.

[0017] (2) The pressure of the saturated water that flows in decreases at the outlet, but heat radiation to the outside can be ignored. The decrease in enthalpy of the saturated water generates flash steam, and the total enthalpy does not change. In other words, the flowing saturated water (1) changes into flash steam (X) and saturated water (1-X) at the outlet.

[0018] h'in=h"out*X+h'out*(1-X)

[0019] The inlet temperature is Tin, the enthalpy of saturated water at the inlet is h'in, the outlet temperature is Tout, the enthalpy of saturated water at the outlet is h'out, and the enthalpy of saturated steam at the outlet is h"out.

[0020] (3) When the inlet pressure is 0.5 MPa (A) and 1.1 MPa (A), the ratio of flash steam generated by a drop in the outlet pressure (pressure 0.1 MPa (A)) is 9.5% when the inlet pressure is 0.5 MPa (A) (point A in the figure). When the inlet pressure is 1.1 MPa (A), it is 16.1% (point B in the figure).

[0021] (4) When saturated steam flows in from the inlet side, it becomes heated steam at the outlet side due to a drop in pressure. The energy of the heated steam generates further flash steam from the drain, which becomes saturated steam, but it is thought that the temperature will rise near the outlet. The temperature of the heated steam is 136°C when the pressure on the inlet side is 0.5 MPa (A) (point C on the diagram). When the pressure on the inlet side is 1.1 MPa (A), it is 152°C (point D on the diagram).

[0022] (5) When steam leaks, the outlet fluid becomes a mixture of saturated water, saturated steam, and heated steam depending on the outlet pressure. The two types of steam are first mixed together to produce steam at a temperature that depends on the ratio. If the limit of steam leakage is 1%, and the results of (2) and (3) above are used, the steam temperature at an outlet pressure of 0.1 MPa (A) is as follows:

[0023] When the inlet pressure is 0.5 MPa (A), if there is 9.4% flash steam at 100°C and 1.0% heating steam at 136°C, the temperature of the mixed steam will be (100 x 9.4 + 136 x 1.0) / (9.4 + 1) = 103.5°C.

[0024] When the inlet pressure is 1.1 MPa (A), if there is 15.9% flash steam at 100°C and 1.0% heating steam at 152°C, the temperature of the mixed steam will be (100 x 15.9 + 152 x 1.0) / (15.9 + 1) = 103.1°C.

[0025] FIG. 2 is a diagram for explaining the inlet-side reference temperature and the outlet-side reference temperature.

[0026] The steam generated by the electric boiler was passed through a heat exchanger, and the amount of drainage was changed to test the operation of the condensate drain device 10. In the test facility, a temperature sensor was inserted into the piping to directly measure the fluid temperature.

[0027] In section 1 (when condensate generation is at a minimum), the regular fluctuations in the inlet pressure and inlet temperature are the result of the electric boiler used to generate steam being on-off controlled to control the steam pressure inside the boiler. Because the amount of condensate generated is extremely small, the cycle is relatively long and the fluctuations are large. The temperature fluctuations are due to the saturation temperature fluctuating in accordance with pressure fluctuations. Because the outlet side is open to the atmosphere, the pressure is also nearly 0 MPaG. However, the outlet temperature remains at approximately 103°C.

[0028] In section 2 (medium amount of condensate generated), the amount of condensate generated has increased, so the boiler's ON-OFF cycle has become shorter. The inlet and outlet temperatures are maintained near the saturation temperature, which indicates that condensate is being discharged normally.

[0029] In section 3 (maximum amount of condensate generated), the amount of condensate generated exceeds the discharge capacity of the condensate discharge device 10, causing condensate to accumulate on the inlet side. The drop in the inlet temperature is thought to be due to the effect of heat radiation caused by the condensate accumulation. In other words, it is thought that the accumulation of condensate prevents high-temperature gas from entering the inlet side, causing the inlet temperature to drop. When the inlet temperature approaches the outlet temperature, the inlet and outlet temperatures drop in tandem. When the inlet temperature falls below the saturation temperature of the outlet temperature, a phenomenon is observed in which the inlet temperature drops below the outlet temperature. This phenomenon is thought to occur because the temperature of the inflowing condensate drops quickly, causing the temperature of the condensate discharge device 10 body to drop with a delay, heating the fluid.

[0030] FIG. 3 shows the measurement data of the inlet and outlet temperatures.

[0031] The condensate drain system was installed at the end of the piping separating the condensate from the steam supply line, and the discharged steam was connected to a recovery line several meters above. The condensate drain system was installed and the inlet and outlet temperatures were measured over a two-week period. The system was operated with a reference inlet temperature of approximately 169°C and an outlet temperature of approximately 135°C. Temperature fluctuations were observed, with the inlet temperature dropping to approximately 145°C, but these were concentrated during the nighttime hours between 9:00 PM and 6:00 AM (potentially during non-operating hours). This temperature fluctuation is thought to be due to changes in operating conditions in response to fluctuations in steam demand. While the correlation between the inlet and outlet temperatures appears to be large, a frequency distribution at each 1°C interval reveals that certain temperatures occur in a concentrated fashion. There is a slight difference in the frequency distribution between the first half (week 1) and the second half (week 2). Therefore, to determine the reference temperature, it is necessary to select an appropriate judgment period, taking into account factors such as the installation location and operating conditions, as well as overall trends, cycles, batches, and daily and weekly variations. To extract the inlet reference temperature Tsin (°C) and the outlet reference temperature Tsout (°C) from the temperature data, it is considered best to use, for example, the temperature with the highest frequency (mode). By using the mode, it is possible to eliminate temperature fluctuations, particularly those concentrated in the nighttime hours between 9 PM and 6 AM (which may be a non-operating time), where the inlet temperature drops to approximately 145°C.

[0032] FIG. 4 is a diagram for explaining a method for determining the inlet-side reference temperature and the outlet-side reference temperature.

[0033] In the correlation between the inlet temperature and the outlet temperature, a method for determining the operating state will be considered based on knowledge gained from data analysis.

[0034] Determine the inlet-side reference temperature and the outlet-side reference temperature from the temperature data within the determination period, and determine that the range not reaching the attention range is "normal" (the ellipse in the figure). The inlet-side reference temperature and the outlet-side reference temperature shall be the temperatures indicating the maximum frequency (the most frequent value), respectively. When there are multiple temperatures indicating the maximum frequency (the most frequent value), add the frequencies before and after them and adopt the one with the larger frequency. When it still cannot be determined, adopt the higher temperature side for the inlet-side temperature and the lower temperature side for the outlet-side temperature. The reason is that for the inlet-side temperature, the higher temperature side is closer to the normal zone (the ellipse in the figure), and for the outlet-side temperature, the lower temperature side is closer to the normal zone (the ellipse in the figure).

[0035] When the inlet-side temperature drops beyond the temperature change threshold from the reference temperature, it is determined as "stagnation". Specifically, considering the operating conditions, set Tc1 and Tc2 which are temperature changes (Δ) not regarded as normal. When the temperature drop amount (ΔTin = Tsin - Tin) from the inlet-side reference temperature Tsin exceeds the first outlet-side threshold Tl1 and the second outlet-side threshold Tl2 (Tc1 < Tc2), it is determined and displayed as "stagnation attention" and "stagnation warning".

[0036] When the outlet temperature rises beyond the temperature change threshold from the reference temperature, it is determined as "leakage". Specifically, based on the consideration in (5) above, set Tl1 and Tl2 which are temperature changes (Δ) not regarded as normal. When the temperature rise amount (ΔTout = Tout - Tsout) from the outlet-side reference temperature Tsout exceeds the first inlet-side threshold Tc1 and the second inlet-side threshold Tc2 (Tl1 < Tl2), it is determined and displayed as "leakage attention" and "leakage warning".

[0037] Set the default values (initial values) for the set values used in the determination, and also allow the user to change them considering the operating conditions, etc. For example, the default values may be as follows. Stagnation attention Tc1 = 10°C, Stagnation warning Tc2 = 30°C, Leakage attention Tl1 = 3°C, Leakage warning Tl2 = 10°C.

[0038] 2. Structure of the determination system

[0039] FIG. 5 illustrates a determination system according to an embodiment of the present disclosure.

[0040] The determination system 1 is a system for determining the operating state of a condensate discharge device 10 (steam trap). The condensate discharge device 10 is installed at the discharge end of a heat exchanger or in the middle of a steam supply pipe in a plant or the like that uses steam as a heat source, and automatically discharges condensed water (drain) generated after the steam releases heat from the pipe. The condensate discharge device 10 is not a condensate discharge device with a moving part, such as a float or disk type, but an orifice type condensate discharge device without a moving part, such as a float or disk type (see Patent Document 1). The condensate discharge device 10 has an inlet 11 through which steam is injected and an outlet 12 through which condensate is discharged. The inlet 11 of the condensate discharge device 10 is connected to an inlet-side pipe 13. The outlet 12 of the condensate discharge device 10 is connected to an outlet-side pipe 14.

[0041] The inlet temperature sensor 16 and the outlet temperature sensor 15 are, for example, thermocouples, and are installed in the inlet pipe 13 and the outlet pipe 14, respectively. The inlet temperature sensor 16 and the outlet temperature sensor 15 are installed near the inlet 11 and the outlet 12 of the condensate drainage device 10, respectively. The inlet temperature sensor 16 and the outlet temperature sensor 15 preferably measure the internal temperatures of the inlet pipe 13 and the outlet pipe 14, but it has been confirmed that measuring the pipe surface temperature near the inlet 11 and the outlet 12 (within a few centimeters to a few tens of centimeters) does not significantly affect the judgment results. When the inlet temperature sensor 16 and the outlet temperature sensor 15 are sensors that measure the pipe surface temperature, they may be, for example, flat-plate temperature sensors insulated with thin, heat-resistant resin. In this case, the inlet temperature sensor 16 and the outlet temperature sensor 15 are preferably kept warm to prevent them from being affected by the outside air.

[0042] The determination system 1 includes a collection device 20 and a determination device 30. The collection device 20 includes a receiving unit 21, a conversion unit 23, a recording unit 24, a communication interface 25, a timer 26, and a battery 22. The receiving unit 21 is detachably connected to the inlet-side temperature sensor 16 and the outlet-side temperature sensor 15 via a connector and receives analog signals from each sensor 15-16. The conversion unit 23 periodically collects the analog signals received from each sensor 15-16, converts them into digital signals through A / D conversion, and records the digitally converted temperatures and related information in the recording unit 24. The communication interface 25 is, for example, a USB interface, and records the temperatures recorded in the recording unit 24 on a portable USB memory or transmits them to the determination device 30 via a USB cable. The timer 26 is used to count the timing at which the conversion unit 23 converts the analog signals into digital signals and records them. The battery 22 is typically a battery so that an external power connection is not required (cordless), and powers the collection device 20. When the collection device 20 is installed outdoors, it is preferable to store it in a waterproof case. The collection device 20 is installed on-site only during the measurement period, and then removed and connected to the determination device 30 after the measurement period.

[0043] The determination device 30 is a dedicated device or a general-purpose personal computer, etc. The determination device 30 has a communication interface 31, a control circuit 32, and a display device 33. The communication interface 31 is, for example, a USB interface, and receives the temperature and related information recorded in the collection device 20 via a portable USB memory or a USB cable. In the control circuit 32 (computer), the CPU loads a determination program recorded in the ROM into the RAM and executes it, thereby operating as a reference temperature determination unit 35, a determination unit 34, and a result display unit 36. The determination unit 34 determines the time-dependent (continuous) operating state of the condensate discharge device 10 based on the temperature. The display device 33 displays a GUI showing the time-dependent (continuous) operating state of the condensate discharge device 10. The GUI may be in the form of a graph, etc.

[0044] The determination device 30 may receive the temperature and related information recorded in the collection device 20 via wireless communication. The determination device 30 may download the temperature and related information uploaded to a storage device on the cloud from the collection device 20. The collection device 20 may write the temperature and related information to a portable USB memory, and a PC may read the temperature and related information from the portable USB memory and send it to the determination device 30 by email or the like, and the determination device 30 may receive the temperature and related information sent by the PC.

[0045] 3.Reference temperature determination section

[0046] FIG. 6 is a flowchart showing the operation of the determination system.

[0047] As shown in (A), in the determination system 1 configured as described above, the collection device 20 is installed near the condensate discharge device 10 to be investigated, and the collection device 20 is connected to the inlet-side temperature sensor 16 and the outlet-side temperature sensor 15 (step S11). The collection device 20 periodically collects and records temperature data (at a time interval set in the timer 26, for example, every few seconds to once a day) during a collection period (a predetermined target period during which data collection continues) (step S12). After the determination period ends, the collection device 20 is disconnected from the sensors 15-16, and the collection device 20 is connected to the determination device 30 via a wired connection, and the temperature data recorded in the collection device 20 is output (transmitted) to the determination device 30. Alternatively, the temperature data recorded in the collection device 20 is output (transmitted) to the determination device 30 via a portable recording medium such as a USB memory (step S13). The reference temperature determination unit 35 of the determination device 30 determines the inlet-side reference temperature Tsin and the outlet-side reference temperature Tsout based on the temperature data of the inlet-side temperature sensor 16 and the outlet-side temperature sensor 15 during this determination period (step S14). Note that the reference temperature determination unit 35 may be provided in an information processing device separate from the determination device 30.

[0048] As shown in (B), specifically, the reference temperature determination unit 35 collects inlet-side temperatures Tin during the set determination period and determines the most frequent value of the measured inlet-side temperatures Tin as the inlet-side reference temperature Tsin (step S16). On the other hand, if there are multiple most frequent values ​​of the inlet-side temperatures Tin during the determination period (step S15, Yes), the reference temperature determination unit 35 determines the most frequent value, including values ​​near each mode, as the inlet-side reference temperature Tsin (step S18). On the other hand, if the reference temperature determination unit 35 cannot determine the most frequent value, including values ​​near each mode (step S17, No), it determines the highest temperature value among the most frequent values ​​as the inlet-side reference temperature Tsin (step S19).

[0049] Similarly, the reference temperature determination unit 35 collects outlet-side temperatures Tout during the determination period and determines the most frequent value of the measured outlet-side temperatures Tout as the outlet-side reference temperature Tsout (step S16). On the other hand, if there are multiple most frequent values ​​of the outlet-side temperatures Tout during the determination period (step S15, Yes), the reference temperature determination unit 35 determines the most frequent value, including values ​​near each mode, as the outlet-side reference temperature Tsout (step S18). On the other hand, if the reference temperature determination unit 35 cannot determine the most frequent value, including values ​​near each mode (step S17, No), it determines the lowest temperature value among the most frequent values ​​as the outlet-side reference temperature Tsout (step S19).

[0050] 4. Judgment section

[0051] As shown in FIG. 1C, the collection device 20 is installed near the condensate discharge device 10 under investigation and connected to the inlet-side temperature sensor 16 and the outlet-side temperature sensor 15 (step S21). The collection device 20 periodically collects and records temperature data (at a time interval set in the timer 26, for example, every few seconds to once a day) during a measurement period (the period during which the operating state is to be determined) (step S22). After the measurement period ends, the collection device 20 is disconnected from the sensors 15-16, and the collection device 20 is connected to the determination device 30 via a wired connection to output (transmit) the temperature data recorded in the collection device 20 to the determination device 30. Alternatively, the temperature data recorded in the collection device 20 is output (transmitted) to the determination device 30 via a portable recording medium such as a USB memory (step S23). The determination unit 34 of the determination device 30 uses each temperature data and the reference temperature to determine the continuous operating state of the condensate discharge device 10 over time during this measurement period (step S24). The result display unit 36 ​​of the determination device 30 displays the trend of the measurement period (that is, the time-dependent (continuous) transition of the operating state) and the determination result on the display device 33 (step S25).

[0052] The operations of steps S21 to S23 may be performed simultaneously (commonly) with steps S11 to S13. That is, when it is desired to determine the operating state for a specific period (step S24), a reference temperature limited to the specific period may be determined (step S14) based on the temperature data collected and recorded during the specific period (steps S12, S22), and the operating state may be determined (step S24) based on the temperature data collected and recorded during the specific period (steps S12, S22).

[0053] In step S24, the determination unit 34 determines whether the condensate discharge device 10 is in a stagnation state based on the inlet temperature Ti, which is the temperature on the inlet 11 side of the condensate discharge device 10. The determination unit 34 determines whether the condensate discharge device 10 is in a leakage state based on the outlet temperature Tout, which is the temperature on the outlet 12 side of the condensate discharge device 10. The determination unit 34 determines whether the condensate discharge device 10 is in a normal operating state based on the inlet temperature Tin and the outlet temperature Tout. The stagnation state refers to a state in which condensate accumulates at the inlet 11 and prevents necessary discharge, or a blockage occurs due to clogging of the orifice, or accumulation of condensate exceeding the discharge capacity. In a normal operating state, there is no steam leakage and condensate is discharged. In a leakage state, the amount of condensate generated is extremely small and steam leaks from the orifice. More specifically, the determination unit 34 determines the state of the condensate discharge device 10 as follows. The leakage state includes a leakage warning state and a leakage caution state. The stagnation state includes a stagnation warning state and a stagnation caution state.

[0054] FIG. 7 is a flowchart showing a method for determining the operating state of the condensate discharge device, which is executed by the determining unit.

[0055] The judgment unit 34 calculates the value ΔTout (=Tout-Tsout) by subtracting the outlet side reference temperature Tsout from the outlet side temperature Tout (step S31), and if ΔTout is greater than the first outlet side threshold Tl1 (ΔTout>Tl1) (step S32, YES) and if ΔTout is greater than the second outlet side threshold Tl2 (ΔTout>Tl2) which is greater than the first outlet side threshold Tl1 (step S33, YES), it determines that a leak warning state is present (step S34).

[0056] If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1) (step S32, YES) and ΔTout is less than or equal to the second outlet-side threshold Tl2 (ΔTout≦Tl2) (step S33, NO), the judgment unit 34 determines that a leakage warning state is in place (step S35).

[0057] The judgment unit 34 calculates the value ΔTin (=Tsin-Tin) by subtracting the inlet side temperature Tin from the inlet side reference temperature Tsin (step S36), and if ΔTin is greater than the first inlet side threshold Tc1 (ΔTin>Tc1) (step S37, YES) and if ΔTin is greater than the second inlet side threshold Tc2 (ΔTin>Tc2) which is greater than the first inlet side threshold Tc1 (step S38, YES), it determines that a congestion warning state is present (step S39).

[0058] If ΔTin is greater than the first entrance threshold Tc1 (ΔTin>Tc1) (step S37, YES) and ΔTin is less than or equal to the second entrance threshold Tc2 (ΔTin≦Tc2) (step S38, NO), the judgment unit 34 determines that the state is one in which caution is required to stay (step S40).

[0059] If ΔTin is less than or equal to the first inlet side threshold Tc1 (ΔTin≦Tc1) (step S32, NOa) and ΔTout is less than or equal to the first outlet side threshold Tl1 (ΔTout≦Tl1) (step S37, NOb) (step S41), the judgment unit 34 determines that the condensate discharge device 10 is in a normal operating state (step S42).

[0060] 5.Result display section

[0061] FIG. 8 is an example of a GUI that the result display unit displays on the display device.

[0062] A GUI 40 showing the time-dependent (continuous) operating state of the condensate discharge device 10 is displayed on the display device 33. The result display unit 36 ​​displays the inlet temperature Tin and outlet temperature Tout, as well as information showing the normal state 43, the leakage state (leak warning 47, leakage caution 46), and the accumulation state (accumulation warning 45, accumulation caution 44), in synchronization with time information 42 in the display range 41 of the measurement period.

[0063] In this example, specifically, the period when ΔTin≦Tc2 (step S38, NO) is displayed as a retention warning 44A. The period when ΔTout≦Tl2 (step S33, NO) is displayed as a leakage warning 46A. The period when ΔTin≦Tc1 and ΔTout≦Tl1 (step S41) is displayed as a normal operating state.

[0064] By displaying the determined state (normal state, leak warning, leak caution, congestion warning, congestion caution) in synchronization with the time information, the user (plant manager, operator, etc.) can determine that, for example, if a warning or caution occurs during the nighttime, the temperature fluctuation during non-operating hours is caused by a change in operating conditions in response to fluctuations in steam demand, and is not abnormal operation.

[0065] It is also possible to grasp the status more precisely by changing the judgment period from the display of the judgment result, performing recalculation, and displaying the result. Specifically, as described above, there is a case where the operating status of a specific period (e.g., the period corresponding to the accumulation warning 44A in FIG. 8 ) needs to be judged (step S24). The user (e.g., a plant manager, operator, etc.) enters the start date and time and the end date and time of the period corresponding to the accumulation warning 44A in the measurement period display range 41 and operates the recalculation button 48. The reference temperature determination unit 35 then recalculates the inlet-side reference temperature Tsin and the outlet-side reference temperature Tsout based on the temperature data of the inlet-side temperature sensor 16 and the outlet-side temperature sensor 15 in the measurement period display range 41 (step S14). The judgment unit 34 judges (recalculates) the time-dependent (continuous) operating status of the condensate discharge device 10 for this measurement period using each temperature data and the recalculated reference temperature (step S24). The result display unit 36 ​​displays the trend of the measurement period and the judgment result on the display device 33 (step S25).

[0066] 6. Conclusion

[0067] Conventionally, devices for discharging condensate (drainage) include float-type and disk-type condensate discharge devices (steam traps). For example, to monitor float-type condensate discharge devices, a monitoring module equipped with a temperature sensor and an acoustic sensor is installed upstream of the float-type steam trap, and a technology is known that detects whether the condensate discharge device is functioning properly, clogged, or has a steam leak based on temperature, sound, and vibration (https: / / web-material3.yokogawa.com / BU01W06A14-01JA.pdf) (https: / / web-material3.yokogawa.com / GS01W06G01-01JA.pdf).

[0068] On the other hand, orifice-type condensate discharge devices are less prone to breakdowns because they have no moving parts. However, it cannot be said with certainty that condensate accumulation or steam leakage will not occur due to clogging of the orifice hole caused by rust or foreign matter in the upstream piping, or an increase or decrease in condensate due to changes in operating conditions. Maintenance inspections include periodic inspections, confirmation inspections when operating conditions are changed, and inspections when there are signs of abnormality. However, maintenance inspections require preparation and are time-consuming, and they only determine the status at the time of the maintenance inspection, making it difficult to determine continuous conditions or trends. Furthermore, because orifice-type condensate discharge devices have no moving parts, it is difficult to determine the operating status of the condensate discharge device using an acoustic sensor.

[0069] Patent Document 2 discloses a determination device that determines the state of an orifice-type condensate discharge device (non-operating state, stagnant state, normal operating state, leak state) based on the inlet pressure value, inlet temperature, outlet pressure value, and outlet temperature of the device. Patent Document 2 discloses that an existing pressure sensor can be used (paragraphs 0011 and 0017), but in the case of piping that does not have a pressure sensor, the plant must be modified to install a pressure sensor.

[0070] In contrast, according to this embodiment, the determination device 30 does not use output data from the pressure sensor, acoustic sensor, and vibration sensor. The determination unit 34 estimates the steam state from temperature data upstream and downstream of the orifice-type condensate drainer 10 and can determine the operating state of the condensate drainer 10. According to this embodiment, even if the pressure cannot be measured, the continuous operating state of the condensate drainer can be determined based on the inlet and outlet temperatures.

[0071] Furthermore, steam plants are equipped with thousands of condensate drainage devices, and the investigation of these devices takes a great deal of time. While it would be desirable to rely on continuous information for a certain period of time to determine the status of devices when equipment or operating conditions change, this increases the amount of work involved and makes implementation difficult. Even if the status of condensate drainage devices were to be monitored constantly and transmitted to a monitoring system, the investment required would be large, making this method difficult to implement in many cases.

[0072] On the other hand, because orifice-type condensate drain devices are essentially failure-free, it is possible to determine the continuous state and trends of the condensate drain device from data measured over a period of time (several hours to several months) during maintenance and inspection, without constantly monitoring the state. It is considered effective to determine the state by measuring changes over several days or within an operating cycle at times such as during regular inspections, when installing or replacing equipment, when changing operating conditions, or when there are signs of an abnormality.

[0073] Conventional inspection methods only judged the instantaneous state at the time of inspection, but this embodiment can continuously judge the operating state within a set period, making it possible to clearly see changes in state throughout the day and within an operating cycle, enabling more appropriate inspections, i.e., more advanced maintenance and inspection work. Being able to determine continuous states and trends makes problems clear and enables effective countermeasures.

[0074] According to this embodiment, simpler equipment (collection device 20 and determination device 30) is required than building a monitoring system, resulting in a smaller investment. The installation locations of the collection device 20 and determination device 30 can be changed to suit the inspection work cycle (worker movement) and the plant space. The collection device 20 is highly portable because it uses a battery 22 and is cordless. For example, the collection device 20 is connected via connectors to each sensor 15-16 near the condensate discharge device 10 under investigation, and temperature data is collected and recorded during a measurement period. Then, the same collection device 20 is connected via connectors to each sensor 15-16 near another condensate discharge device 10, and temperature data is collected and recorded during the measurement period. The temperature data recorded in the collection device 20 can be transmitted to the determination device 30 via a portable USB memory or a USB cable, as appropriate. In this way, the collection device 20 and the determination device 30 are portable and can be shared by many condensate discharge devices 10 in the plant, so there is no need to install a collection device 20 and a determination device 30 for each condensate discharge device 10, and the number of devices required can be reduced. The on-site work required by workers is simply the attachment and detachment of the collection device 20 to each sensor 15-16 via a connector, which makes it safe and convenient and facilitates on-site maintenance and inspection work. [Explanation of symbols]

[0075] Determination system 1, condensate drain device 10, collection device 20, determination device 30.

Claims

1. a determination unit that determines whether or not the condensate discharge device is in a stagnation state in which condensed water is stagnating, based on an inlet-side temperature Tin that is a temperature on the inlet side of the condensate discharge device having an inlet for injecting steam and an outlet for discharging condensate, Without using the output data of the pressure sensor, A value ΔTin (=Tsin−Tin) is calculated by subtracting the inlet-side temperature Tin from the inlet-side reference temperature Tsin; If ΔTin is greater than the first inlet side threshold Tc1 (ΔTin>Tc1), it is determined that the stagnation state exists. A determination unit; a reference temperature determination unit that collects the inlet-side temperatures Tin during a determination period and determines the most frequent value of the measured inlet-side temperatures Tin as the inlet-side reference temperature Tsin; A determination device comprising:

2. The determination device according to claim 1, The determination unit determining whether the condensate discharge device is in a leaking state in which steam is leaking based on an outlet-side temperature Tout, which is a temperature on the outlet side of the condensate discharge device; A value ΔTout (=Tout−Tsout) is calculated by subtracting the outlet-side reference temperature Tsout from the outlet-side temperature Tout; If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1), it is determined that there is a leakage state. The reference temperature determination unit collects the outlet-side temperatures Tout during a determination period and determines the most frequent value of the measured outlet-side temperatures Tout as the outlet-side reference temperature Tsout. Judgment device.

3. a determination unit that determines whether or not a leakage state in which steam is leaking exists based on an outlet-side temperature Tout that is a temperature on an outlet side of a condensate discharge device having an inlet through which steam is injected and an outlet through which condensate is discharged, Without using the output data of the pressure sensor, A value ΔTout (=Tout−Tsout) is calculated by subtracting the outlet-side reference temperature Tsout from the outlet-side temperature Tout; If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1), it is determined that the leakage state exists. A determination unit; a reference temperature determination unit that collects the outlet-side temperatures Tout during a determination period and determines the most frequent value of the measured outlet-side temperatures Tout as the outlet-side reference temperature Tsout; A determination device comprising:

4. The determination device according to claim 2, The determination unit determines whether the condensate discharge device is in a normal operating state based on the inlet temperature Tin and the outlet temperature Tout. Judgment device.

5. 3. The determination device according to claim 1 or 2, The stagnation state includes a stagnation warning state and a stagnation caution state, The determination unit If ΔTin is greater than the first inlet threshold Tc1 (ΔTin>Tc1) and is greater than the second inlet threshold Tc2 (ΔTin>Tc2) which is greater than the first inlet threshold Tc1, it is determined that the congestion warning state exists, If ΔTin is greater than the first entrance threshold Tc1 (ΔTin>Tc1) and is equal to or less than the second entrance threshold Tc2 (ΔTin≦Tc2), it is determined that the stagnation caution state exists. Judgment device.

6. The determination device according to claim 2 or 3, the leak state includes a leak warning state and a leak attention state; The determination unit If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1) and is greater than the second outlet-side threshold Tl2 (ΔTout>Tl2), which is greater than the first outlet-side threshold Tl1, it is determined that the leakage warning state exists; If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1) and ΔTout is equal to or less than the second outlet-side threshold Tl2 (ΔTout≦Tl2), it is determined that the leakage caution state exists. Judgment device.

7. The determination device according to claim 2, The determination unit If ΔTin is equal to or less than the first inlet threshold Tc1 (ΔTin≦Tc1) and ΔTout is equal to or less than the first outlet threshold Tl1 (ΔTout≦Tl1), it is determined that the condensate discharge device is in a normal operating state. Judgment device.

8. The determination device according to claim 1, When there are a plurality of most frequent values ​​of the inlet-side temperature Tin during the determination period, the reference temperature determination unit determines the most frequent value, including values ​​near each most frequent value, as the inlet-side reference temperature Tsin. Judgment device.

9. The determination device according to claim 1, When there are a plurality of most frequent values ​​of the inlet-side temperature Tin during the determination period, the reference temperature determination unit determines the highest temperature value among the most frequent values ​​as the inlet-side reference temperature Tsin. Judgment device.

10. The determination device according to claim 2 or 3, When there are a plurality of most frequent values ​​of the outlet-side temperature Tout during the determination period, the reference temperature determination unit determines the most frequent value, including values ​​near each most frequent value, as the outlet-side reference temperature Tsout. Judgment device.

11. The determination device according to claim 2 or 3, When there are a plurality of most frequent values ​​of the outlet-side temperature Tout during the determination period, the reference temperature determination unit determines the lowest temperature value among the most frequent values ​​as the outlet-side reference temperature Tsout. Judgment device.

12. 3. The determination device according to claim 1 or 2, a result display unit that displays the inlet temperature Tin and information indicating the retention state in synchronization with time information during the measurement period; The determination device further comprises:

13. The determination device according to claim 2 or 3, a result display unit that displays the outlet temperature Tout and information indicating the leakage state in synchronization with time information during the measurement period; The determination device further comprises:

14. The determination device according to claim 2, The determination unit acquires the inlet-side temperature Tin and the outlet-side temperature Tout output from a collection device that periodically collects and records the inlet-side temperature Tin based on the output of an inlet-side temperature sensor installed in an inlet-side piping connected to the inlet of the condensate discharge device and the outlet-side temperature Tout based on the output of an outlet-side temperature sensor installed in an outlet-side piping connected to the outlet of the condensate discharge device. Judgment device.

15. The determination device according to any one of claims 1 to 3, The condensate drain device is a float or disk type orifice type with no moving parts. Judgment device.

16. The determination device according to any one of claims 1 to 3, The determination unit does not use output data from the acoustic sensor and the vibration sensor. Judgment device.

17. The computer of the determination device a determination step of determining whether or not the condensate discharge device is in a stagnation state in which condensed water is stagnating, based on an inlet-side temperature Tin, which is a temperature on the inlet side of the condensate discharge device having an inlet for injecting steam and an outlet for discharging condensate, Without using the output data of the pressure sensor, A value ΔTin (=Tsin−Tin) is calculated by subtracting the inlet-side temperature Tin from the inlet-side reference temperature Tsin; If ΔTin is greater than the first inlet side threshold Tc1 (ΔTin>Tc1), it is determined that the stagnation state exists. A judgment step; a reference temperature determination step of collecting the inlet-side temperatures Tin during a determination period and determining the most frequent value of the measured inlet-side temperatures Tin as the inlet-side reference temperature Tsin; Run Judging program.

18. The computer of the determination device, a determination step of determining whether or not there is a leakage state in which steam is leaking based on an outlet-side temperature Tout, which is a temperature on the outlet side of a condensate discharge device having an inlet through which steam is injected and an outlet through which condensate is discharged, Without using the output data of the pressure sensor, A value ΔTout (=Tout−Tsout) is calculated by subtracting the outlet-side reference temperature Tsout from the outlet-side temperature Tout; If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1), it is determined that the leakage state exists. A judgment step; a reference temperature determination step of collecting the outlet-side temperatures Tout during a determination period and determining the most frequent value of the measured outlet-side temperatures Tout as the outlet-side reference temperature Tsout; Run Judging program.

19. The computer of the determination device executes the determination program, a determination step of determining whether or not the condensate discharge device is in a stagnation state in which condensed water is stagnating, based on an inlet-side temperature Tin, which is a temperature on the inlet side of the condensate discharge device having an inlet for injecting steam and an outlet for discharging condensate, Without using the output data of the pressure sensor, A value ΔTin (=Tsin−Tin) is calculated by subtracting the inlet-side temperature Tin from the inlet-side reference temperature Tsin; If ΔTin is greater than the first inlet side threshold Tc1 (ΔTin>Tc1), it is determined that the stagnation state exists. A judgment step; a reference temperature determination step of collecting the inlet-side temperatures Tin during a determination period and determining the most frequent value of the measured inlet-side temperatures Tin as the inlet-side reference temperature Tsin; Run Judgment method.

20. When the computer of the determination device executes the determination program, a determination step of determining whether or not there is a leakage state in which steam is leaking based on an outlet-side temperature Tout, which is a temperature on the outlet side of a condensate discharge device having an inlet through which steam is injected and an outlet through which condensate is discharged, Without using the output data of the pressure sensor, A value ΔTout (=Tout−Tsout) is calculated by subtracting the outlet-side reference temperature Tsout from the outlet-side temperature Tout; If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1), it is determined that the leakage state exists. A judgment step; a reference temperature determination step of collecting the outlet-side temperatures Tout during a determination period and determining the most frequent value of the measured outlet-side temperatures Tout as the outlet-side reference temperature Tsout; Run Judgment method.

21. 20. The determination method according to claim 19, A step of determining whether or not there is a leakage state in which steam is leaking based on an outlet temperature Tout, which is the temperature on the outlet side of the condensate drain device, is performed. Judgment method.

22. 22. The method of claim 21, connecting a collector to an inlet temperature sensor installed in an inlet pipe connected to the inlet of the condensate drainage device and an outlet temperature sensor installed in an outlet pipe connected to the outlet of the condensate drainage device; The collecting device periodically collects and records the inlet-side temperature Tin based on the output of the inlet-side temperature sensor and the outlet-side temperature Tout based on the output of the outlet-side temperature sensor; outputting the inlet-side temperature Tin and the outlet-side temperature Tout recorded in the collection device to the determination device; The determination method further comprises:

23. a determination unit that determines whether the condensate discharge device is in a retention state where condensed water is retained, based on an inlet temperature Tin that is a temperature on the inlet side of the condensate discharge device having an inlet through which steam is injected and an outlet through which condensate is discharged, and that determines whether the condensate discharge device is in a leakage state where steam is leaking, based on an outlet temperature Tout that is a temperature on the outlet side of the condensate discharge device, Without using the output data of the pressure sensor, A value ΔTin (=Tsin−Tin) is calculated by subtracting the inlet-side temperature Tin from the inlet-side reference temperature Tsin; If ΔTin is greater than the first inlet side threshold Tc1 (ΔTin>Tc1), it is determined that the stagnation state exists. A determination unit; a reference temperature determination unit that collects the inlet-side temperatures Tin during a determination period and determines the most frequent value of the measured inlet-side temperatures Tin as the inlet-side reference temperature Tsin; a determination device having a collection device that periodically collects and records the inlet-side temperature Tin, which is based on the output of an inlet-side temperature sensor installed in an inlet-side piping connected to the inlet of the condensate discharge device, and the outlet-side temperature Tout, which is based on the output of an outlet-side temperature sensor installed in an outlet-side piping connected to the outlet of the condensate discharge device, and which is output to the determination device; A determination system comprising:

24. A determination unit which determines whether the condensate discharge device is in a stagnation state where condensed water is stagnating, based on an inlet temperature Tin, which is the temperature of the inlet side of the condensate discharge device having an inlet into which steam is injected and an outlet from which condensate is discharged, and which determines whether the condensate discharge device is in a leakage state where steam is leaking, based on an outlet temperature Tout, which is the temperature of the outlet side of the condensate discharge device, Without using the output data of the pressure sensor, A value ΔTout (=Tout−Tsout) is calculated by subtracting the outlet-side reference temperature Tsout from the outlet-side temperature Tout; If ΔTout is greater than the first outlet-side threshold Tl1 (ΔTout>Tl1), it is determined that the leakage state exists. A determination unit; a reference temperature determination unit that collects the outlet-side temperatures Tout during a determination period and determines the most frequent value of the measured outlet-side temperatures Tout as the outlet-side reference temperature Tsout; a determination device having a collection device that periodically collects and records the inlet-side temperature Tin, which is based on the output of an inlet-side temperature sensor installed in an inlet-side piping connected to the inlet of the condensate discharge device, and the outlet-side temperature Tout, which is based on the output of an outlet-side temperature sensor installed in an outlet-side piping connected to the outlet of the condensate discharge device, and which is output to the determination device; A determination system comprising:

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