Packing case with deterioration monitoring

Abstract

A method for monitoring degradation of packing case seals includes receiving a signal from a first temperature sensor mounted at a first location within the packing case housing, receiving a signal from a second temperature sensor mounted at a second location within the packing case housing, calculating a temperature difference between the first temperature sensor and the second temperature sensor from the signals at two or more times, and determining a degradation indicator for at least one of the packing case seals at least partially from the two or more temperature differences.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority under 35 U.S.C. Section 119 to U.S. Patent Application Publication No. 63 / 417,931 (Patent Document 1), filed October 20, 2022, and U.S. Patent Application Publication No. 63 / 422,233 (Patent Document 2), filed November 3, 2022, the contents of each of which are incorporated by reference.

[0002] The present invention relates in particular to sealing shafts in high pressure gas processing equipment such as reciprocating compressors with progressive sealing systems. [Background technology]

[0003] Progressive or multi-stage sealing systems are commonly employed when high pressure differentials must be maintained, such as between the atmosphere and a high-pressure cavity into which a moving shaft extends. Effective and reliable sealing often requires a sealing system in which pressure is reduced in stages along the shaft or gradually along a labyrinth. The compression industry strives to increase maximum allowable operating pressures and system speeds to meet demands for increasingly sophisticated customer specifications. However, increasing pressure differentials typically makes it more difficult to contain gas within the system and can also place higher stresses on associated sealing elements, thereby increasing pressure pulsations within the system, lubricant consumption, and undesirable gas emissions to the atmosphere. The pressures encountered during operation result in wear and reduced reliability on seals.

[0004] The reciprocating compressor packing case works with a series of rod rings within an individual housing. The compressor stroke of a reciprocating compressor is a dynamic event that occurs within a very short time frame (e.g., 20 times per second for a 1200 RPM compressor). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 63 / 417,931 [Patent Document 2] U.S. Patent Application Publication No. 63 / 422,233 Summary of the Invention [Problem to be solved by the invention]

[0006] The useful life of sealing components of a progressive sealing system, such as a packing case, varies depending on load conditions, sealing material properties, environmental conditions, and other factors. The risk of seal failure can be partially addressed by routine maintenance to replace seals before they fail. Nevertheless, uncertainty in the actual performance of a given sealing system during operation can result in maintenance being performed too early, or worse, too late for a particular system. [Means for solving the problem]

[0007] The implementations described herein may be particularly useful in connection with packing cases for gas processing systems such as reciprocating compressors.

[0008] In one aspect of the present disclosure, a method for monitoring degradation of packing case seals includes receiving a signal from a first temperature sensor mounted at a first location within a packing case housing, receiving a signal from a second temperature sensor mounted at a second location within the packing case housing, calculating a temperature difference between the first temperature sensor and the second temperature sensor from the signals at two or more times, and determining a degradation indicator for at least one of the packing case seals at least partially from the two or more temperature differences.

[0009] In some implementations, the packing case defines a cylinder side and a driver side, and the first location is on the cylinder side of one of the packing case seals and the second location is on the driver side of one of the packing case seals.

[0010] In some implementations, the first temperature sensor and the second temperature sensor are axially spaced apart from one another along the length of the packing case.

[0011] In some implementations, at least one of the temperature sensors is embedded in a hole in the housing of the packing case.

[0012] In some implementations, the degradation indicator is based at least in part on an increase in differential temperature between the first temperature sensor and the second temperature sensor over time.

[0013] In some implementations, the degradation indicator is based at least in part on one or more changes over time in the differential temperature between the first temperature sensor and the second temperature sensor.

[0014] In some implementations, the degradation indicator is based at least in part on a maximum differential temperature between the first temperature sensor and the second temperature sensor.

[0015] In some implementations, the degradation indicator is based at least in part on an increase in differential temperature at the first temperature sensor over time.

[0016] In some implementations, at least one of the degradation indicators is based, at least in part, on a deduced leak flow rate.

[0017] In some implementations, the method includes sensing a pressure within the packing case and determining a degradation indicator for at least one of the seals of the packing case from the at least one sensed pressure.

[0018] In some implementations, pressure is sensed on at least one cylinder side of the temperature sensor.

[0019] In some implementations, the pressure is sensed on at least one driver side of the temperature sensor.

[0020] In some implementations, pressure is sensed in the lubricant lines of the packing case.

[0021] In some implementations, the pressure is sensed in a vent line of the packing case.

[0022] In some implementations, the method includes providing a notification to a user based on the degradation indicator.

[0023] In another aspect of the present disclosure, a monitoring system for a packing case includes a first temperature sensor, a second temperature sensor, and a computing device. The packing case has two or more seals and defines a cylinder side and a driver side. The first temperature sensor is coupled to a housing of the packing case and configured to sense a temperature at the cylinder side of one of the seals. The second temperature sensor is coupled to the housing and configured to sense a temperature at the driver side of one of the seals. The computing device is communicatively coupled to the first temperature sensor and the second temperature sensor and configured to receive signals from the first temperature sensor and the second temperature sensor, calculate a temperature difference between the first temperature sensor and the second temperature sensor two or more times from the signals, and determine a degradation indicator for at least one of the seals of the packing case at least partially from the two or more temperature differences.

[0024] In some implementations, the two or more seals include a pressure interrupter, a first seal, a second seal, and a third seal. The first seal is axially disposed on a driver side of the pressure interrupter. The second seal is axially disposed on a driver side of the third seal. The third seal is axially disposed on a driver side of the second seal. One of the seals is the third seal. The first temperature sensor is axially disposed between the second seal and the third seal.

[0025] In some implementations, the second temperature sensor is axially disposed between the third seal and the end plate seal.

[0026] In some implementations, the two or more seals include a second seal axially disposed on a cylinder side of one of the seals. The system further includes a third temperature sensor axially disposed on the cylinder side of the second seal. The computing device is communicatively coupled to the third temperature sensor. The computing device is configured to calculate a temperature difference between the third temperature sensor and at least one of the first temperature sensor and the second temperature sensor.

[0027] In some implementations, the monitoring system includes a pressure sensor configured to sense pressure on one cylinder side of the seal.

[0028] In some implementations, the monitoring system includes a pressure sensor coupled to a lubricant line in the packing case.

[0029] In some implementations, the monitoring system includes a pressure sensor configured to sense pressure on one driver side of the seal.

[0030] In some implementations, the monitoring system includes a pressure sensor coupled to a vent line of the packing case.

[0031] In some implementations, the packing case monitoring system is communicatively coupled to the cylinder-side pressure sensor and configured to determine a degradation indicator from information received from the cylinder-side pressure sensor.

[0032] In some implementations, the packing case monitoring system is communicatively coupled to the driver-side pressure sensor and configured to determine a degradation indicator from information received from the driver-side pressure sensor.

[0033] In some implementations, the packing case monitoring system is configured to provide a notification of the degradation indicator to a user.

[0034] In some implementations, the packing case monitoring system is configured to provide a notification to a user regarding the degradation of one or more seals.

[0035] In some implementations, the packing case monitoring system is configured to provide notifications to a user regarding timing of maintenance events related to one or more of the seals of the packing case based at least in part on the degradation indicators.

[0036] In some implementations, the packing case monitoring system is configured to provide a warning to a user regarding a seal failure in the packing case based at least in part on the degradation indicator.

[0037] In some implementations, the packing case monitoring system is configured to provide a user with a predictor regarding one or more of the seals of the packing case based at least in part on the degradation indicators.

[0038] In another aspect of the present disclosure, a packing case assembly includes a plurality of seals, a housing, an end plate, a first temperature sensor, and a second temperature sensor. The housing is configured to hold at least two of the seals. The end plate is coupled to the housing. The first temperature sensor is coupled to the packing case housing and configured to sense a temperature on a cylinder side of one of the seals. The second temperature sensor is coupled to the housing and configured to sense a temperature on a driver side of one of the seals.

[0039] In another aspect of the present disclosure, a reciprocating compressor system includes a compression cylinder, a driver, a rod, a packing case through which the rod passes, and a packing case monitoring system. The compression cylinder defines a compression chamber. The rod is coupled between the driver and the compression cylinder. The driver is operable to reciprocate the rod so that gas is compressed within the compression chamber. The packing case is between the compression cylinder and the driver. The packing case defines a cylinder side and a driver side. The packing case includes a plurality of seals through which the rod passes, a housing configured to retain at least two of the seals, and an end plate coupled to the housing. The packing case monitoring system includes a first temperature sensor, a second temperature sensor, and a computing device. The first temperature sensor is coupled to the housing of the packing case and configured to sense a temperature on the cylinder side of one of the seals. The second temperature sensor is coupled to the housing and configured to sense a temperature on the driver side of one of the seals. The computing device is communicatively coupled to the first temperature sensor and the second temperature sensor. The computing device is configured to receive signals from the first temperature sensor and the second temperature sensor, calculate a temperature difference between the first temperature sensor and the second temperature sensor from the signals two or more times, and determine a degradation indicator for at least one of the seals of the packing case at least in part from the two or more temperature differences.

[0040] In another aspect of the present disclosure, a method for monitoring degradation of packing case seals includes receiving signals from one or more temperature sensors mounted within a packing case housing, receiving signals from one or more temperature sensors coupled to the packing case housing, calculating two or more temperatures and two or more pressures from the signals, and determining one or more degradation indicators for at least one of the packing case seals from at least one of the temperatures and at least one of the pressures.

[0041] In some implementations, at least one of the degradation indicators is determined from two or more temperatures.

[0042] In some implementations, at least one of the degradation indicators is determined from two or more pressures.

[0043] In some implementations, at least one of the degradation indicators is determined from a deduced leakage flow rate.

[0044] In some implementations, at least one of the degradation indicators is an early degradation indicator.

[0045] In some implementations, at least one of the degradation indicators is a medium-term degradation indicator.

[0046] In some implementations, at least one of the degradation indicators is a late degradation indicator.

[0047] In another aspect of the present disclosure, a monitoring system for a packing case includes one or more temperature sensors, one or more pressure sensors, and one or more computing devices. The one or more temperature sensors are coupled to the housing and configured to sense temperature at at least one location within the packing case. The one or more pressure sensors are fluidly connected to one or more spaces within the packing case and configured to sense pressure at at least one location within the packing case. The computing device is communicatively coupled to at least one of the one or more temperature sensors and at least one of the one or more pressure sensors. The computing device is configured to receive signals from the at least one temperature sensor and the at least one pressure sensor and to calculate a degradation indicator for at least one seal of the packing case from the signals obtained from the at least one temperature sensor and the at least one pressure sensor.

[0048] In some implementations, the one or more temperature sensors include two or more temperature sensors, and the computing device is configured to calculate the temperature difference two or more times based on signals obtained from the temperature sensors.

[0049] In some implementations, at least one of the pressure sensors is coupled to a vent line of the packing case.

[0050] In some implementations, at least one of the pressure sensors couples to a lubricant line in the packing case.

[0051] In another aspect of the present disclosure, a packing case assembly includes a plurality of seals, a housing, an end plate, one or more temperature sensors, and one or more pressure sensors. The housing is configured to hold at least two of the seals. The end plate is coupled to the housing. The one or more temperature sensors are mounted within the packing case housing and configured to sense a temperature within the packing case. The one or more pressure sensors are coupled to the housing and configured to sense a pressure in one or more spaces within the packing case.

[0052] In another aspect of the present disclosure, a method for detecting wear of seals in a progressive sealing system includes receiving signals from one or more temperature sensors coupled to a housing of the progressive sealing system, calculating temperatures associated with the temperature sensors from the signals two or more times, and determining a degradation indicator for at least one of the seals of the progressive sealing system at least in part from the two or more calculated temperatures.

[0053] In some implementations, the method includes sensing pressure in one or more spaces within the progressive sealing system and determining a degradation indicator for at least one of the seals of the progressive sealing system at least in part from the pressures of the two or more sensors.

[0054] The details of one or more implementations of the subject matter of this disclosure are set forth in the accompanying drawings and the specification. Other features, aspects, and advantages of the subject matter will become apparent from the specification, drawings, and claims. [Brief explanation of the drawings]

[0055] [Figure 1] 1 is a schematic representation of a single-stage gas treatment system with a multi-stage sealing system. [Figure 2] FIG. 1 is a perspective view of a portion of a reciprocating shaft compressor. [Figure 3] FIG. 2 is an end view of a compressor portion of the gas processing system. [Figure 4] FIG. 10 is a cross-sectional view showing the shaft at one end of its travel. [Figure 5] FIG. 10 is a cross-sectional view showing the shaft at the opposite end of its travel. [Figure 6] FIG. 4 is an exploded view of the compressor portion of FIG. 3. [Figure 7] FIG. 1 is a block diagram of a compressor system having a packing case monitoring system according to some implementations. [Figure 8] 1 is a cross-sectional view of a packing case including a temperature sensor according to some implementations. [Figure 9] 1 illustrates a temperature sensor in a packing case. [Figure 10] 1 illustrates the back side of the end plate of the packing case, including a passage for the temperature sensor wiring. [Figure 11] 1 illustrates a pressure sensor for sensing dynamic pressure, according to some implementations. [Figure 12] 1 illustrates a pressure sensor for sensing dynamic pressure, according to some implementations. [Figure 13] 1 is a graph illustrating temperature monitoring at a compressor packing case using a temperature sensor mounted within the packing case housing. [Figure 14] 1 illustrates a process for monitoring a packing case with temperature measurements, according to some implementations. [Figure 15] 1 illustrates a process for monitoring a packing case with temperature and pressure measurements, according to some implementations. [Figure 16] 1 illustrates a packing case with a temperature sensor between each of the seals of the packing case, according to some implementations. DETAILED DESCRIPTION OF THE INVENTION

[0056] The same reference numbers in different figures indicate similar elements.

[0057] In various implementations, the gas processing system includes a system for monitoring a progressive sealing system of the gas processing system, wherein the monitoring system can use measurements of temperature, pressure, or both to determine an indication of the condition of the seals and to estimate or predict the stage of life of the seals in the progressive sealing system.

[0058] 1-6 illustrate an example compressor that can be equipped with an instrumentation suite as described herein to monitor the condition of seals in a gas processing system.

[0059] For purposes of explanation, when describing the relative positions of components or system features, "driver side" may also be referred to herein as "crank side" or "outside." "Cylinder side" may also be referred to as "head side."

[0060] Referring initially to FIG. 1 , a gas processing system 100 includes a compressor 102 having a vessel 104 and a driver 106. The vessel 104 defines a cavity with a process gas inlet 108 and a process gas outlet 110. The compressor 102 can be, for example, a positive displacement compressor. In some cases, the compressor 102 is a reciprocating compressor, such as a double-acting compressor. The vessel 104, configured to contain the process gas, is operably coupled to a shaft extending into the compressor. A multi-stage sealing system 114, represented in this case by a series of boxes along the shaft, inhibits leakage of the process gas along the shaft. In some embodiments, adjacent seals are adjacent portions of a continuous labyrinth seal. The shaft transfers mechanical energy (e.g., by moving or being moved along the longitudinal axis of the shaft) to the process gas within the vessel 104, which extends through the multi-stage sealing system 114 and into the cavity.

[0061] The driver 106 provides mechanical energy to operate the gas processing system 100. In some embodiments, the driver 106 may be, for example, an internal combustion engine with a crankshaft, or an electric motor driving the shaft of the compressor 102.

[0062] 2, the cylinder of the compressor 102 has a housing 118 and an end plate 120 that is bolted to the housing and from which a shaft 122 extends. In some cases, the housing 118 is made of two parts: a cast iron part forms the main cylinder, and a steel bulkhead bolted to the end of the cylinder contains a sealing system. The compressor 102 may be a linear reciprocating compressor with two inlets 108 and two outlets 110. The shaft 122 may be operably coupled to a driver.

[0063] 3 is an end view of the compressor portion of the gas processing system. Compressor 102 includes an end plate 120, an inlet 108, and an outlet 110. A shaft 122 passes through end plate 120.

[0064] 4 and 5, a piston 124 is provided at the end of a shaft 122. The housing 118 defines a cylinder chamber 126. The end of the shaft 122 opposite the piston 124 can be coupled to a driver. In operation, the piston 124, and a portion of the shaft 122, can be driven to reciprocate within the cylinder chamber 126, for example, between the pistons shown in FIGS. 4 and 5 (the shaft of the compressor 102 that supports the piston 124 may also be referred to as a "rod").

[0065] A multi-stage sealing system 114 is disposed around the shaft 122. In FIGS. 4 and 5, the progressive sealing system 114 is implemented as a packing case 130. In this example, the multi-stage sealing system 114 includes six seals 132 spaced along the shaft and a pressure isolation rod ring 134. The multi-stage sealing system 114 can be provided in the form of a packing case for the compressor 102. Each seal can include multiple sealing elements or rod rings stacked closely together on the shaft to form a series of gap-free sealing interfaces with the shaft. In this example, the pressure isolation rod ring 134 is a single-element seal that forms the first seal of the multi-stage sealing system. The pressure isolation rod ring 134 controls leakage to accommodate backflow into the cylinder during the intake stroke, preventing damage to the ring and separation of the ring from the rod. The pressure isolation rod ring 134 can also reduce gas flow out of the cylinder during the exhaust stroke. In certain implementations, as discussed below, the pressure interrupter rod ring 134 can be modified to provide an optimal effective opening for the expected flow behind the rod ring back to the inlet. The term "seal" does not imply zero shaft surface clearance or complete absence of leakage across the seal. As those working in the field of high-pressure gas machinery understand, some leakage is expected to pass the seal at high pressure differentials and may also be necessary to avoid high friction and premature seal failure. Gas expansion between the seal and shaft surface can beneficially cause cooling of the shaft, resulting in less seal wear.

[0066] As shown in these cross sections, the multi-stage sealing system includes a pressure interrupter rod ring housing 136 and multiple seal housings 138 stacked along the shaft and positioned within the bore of housing 118. The innermost seal housing is sealed against the outer surface of the cylinder housing by a nose gasket 140. Each seal housing 138 contains a corresponding seal 132, with the outermost seal (dual-acting ring) contained within end plate 120. Each seal 132 may be a stack of multiple elements, such as a seal ring sandwiched between two other rings that assist in the sealing function.

[0067] The inlet 108 and outlet 110 of the compressor cylinder of gas processing system 100 each feature a one-way valve that allows flow into (inlet) or out of (outlet) the compressor cylinder while inhibiting flow in the opposite direction. Each valve may have multiple parallel flow openings. The inlets and outlets operate in pairs, with each pair operating in a respective direction of shaft stroke. For example, during a piston stroke from right to left, the right inlet 108 and left outlet 110 open at different times during the stroke. Similarly, during a return stroke from left to right, the left inlet 108 and right outlet 110 open at different times during the stroke, while the right inlet and left outlet remain closed. During this return stroke from left to right, the sealed end of the cylinder experiences a pressure buildup to at least the outlet pressure of the compressor. This high pressure gradually reduces along the shaft through various stages, starting at pressure interruption rod ring 134. During the right-to-left stroke, the instantaneous pressure at the pressure interrupter rod ring can sometimes fall below the inlet or suction pressure of the compressor, causing flow to flow in the opposite direction toward the sealing system. Thus, the sealing system not only must withstand high pressures, but must also accommodate extreme pressure waves or pressure cycles that can rise and fall very quickly.

[0068] 6, end plates 120 and stacks of seal housings 138 connected to end plates 120, aligned and held together by tie rods 142, are inserted into holes in compressor housing 118 and held in place by housing bolts 144. All seal housings are axially connected to end plates 120 by tie rods 142 that thread into the distal seal housing containing the pressure breaker rod ring to hold the stack of seal housings together for shipping and assembly. The tie rods 142 can also provide an alignment function.

[0069] 7 is a block diagram of a compressor system with a packing case monitoring system according to some implementations. System 160 includes compressor 102 and packing case monitoring system 161. Compressor 102 includes packing cases 130. Packing case monitoring system 161 includes computing equipment 162, monitoring application 163, user equipment 164, and sensors 165.

[0070] Computing device 162 includes one or more processors 166, memory 167, and network interface controller 168. Memory 167 provides data storage of an appropriate size and format. Network interface controller 168 can facilitate communication between computing device 162 and other devices (e.g., external monitoring devices and / or sensors) over one or more wired or wireless networks.

[0071] Temperature sensors 170 and 172 and pressure sensors 174 and 176 emit signals including sensor data that describe conditions within or related to packing case 130. The sensor data is communicated from temperature sensors 170 and 172 and pressure sensors 174 and 176 to computing equipment 162. In some implementations, temperature sensors 170, 172, pressure sensors 174, 176, and system sensor 177 digitize signals communicating the sensor data before transmitting the signals to computing equipment.

[0072] Calculations and analysis based on the sensor data may be performed at least in part by computing device 162, such as by processing running on one or more processors 166. In some implementations, calculations and analysis of the sensor data are performed by one or more computing systems coupled to computing device 162, such as remote devices connected to computing device 162 via a network.

[0073] The computing device 162 can provide notifications to the operator regarding the condition and maintenance of the packing case 130. For example, the computing device 162 can provide notifications regarding the deterioration of the seals within the packing case 130.

[0074] In some implementations, computing device 162 provides notifications via monitoring application 163. Monitoring application 163 couples to user device 164. User device 164 may include a display device that allows a user to view temperature and pressure readings, notifications, and other information.

[0075] In some implementations, the packing case monitoring system 161 acquires data regarding packing case seal life. The information acquired by the monitoring system can be used to establish a maintenance schedule for the compressor system.

[0076] 8 is a cross-sectional view of a packing case including a temperature sensor according to some implementations. Packing case 130 includes seals 132a, 132b, 132c, and 132d. Pressure interruption rod ring 134 is held within pressure interruption rod ring housing 136. Each of seals 132a, 132b, 132c, and 132d may include one or more seal elements and one or more backup rings. Each of seal housings 138a, 138b, and 138c may be a cup with a through hole that receives shaft 122 and a larger hole that accommodates the seal housing's corresponding seal rod ring.

[0077] The packing case 130 defines pressure spaces bounded by various seals along the shaft surface. Moving from the high-pressure end to the atmospheric end of the sealed system, high-pressure process gas leaking past the pressure interruption rod ring first reaches the intermediate pressure space between the pressure interruption rod ring 134 and the first seal 132a.

[0078] Additionally, leakage past seal 132a reaches a pressure space that may be, for example, at a pressure of about 500 psig. Thus, during operation, the multi-stage sealing system defines a series of pressure spaces of progressively decreasing pressure along the shaft, with each seal creating a pressure differential between two of the pressure spaces. The amount of leakage flowing past a seal and the pressure differential across the seal are interrelated. Generally, the greater the pressure differential across the seal, the greater the operating friction of the seal and the greater the heat generated by the seal.

[0079] Temperature sensors 170 and 172 are axially spaced apart from one another along packing case 130. Temperature sensor 170 is mounted within housing 138c. Temperature sensor 172 is mounted within plate 178, which is retained by end plate 120. In this example, sensors 170 and 172 are located on either side of seal 132c. Temperature sensor 170 is between the second and third seals relative to the cylinder side of pressure isolation ring 134.

[0080] The temperature sensors 170, 172 can provide signals to a computing device (e.g., computing device 162 described above in connection with FIG. 7). Data from the temperature sensors 170 and 172 can be used in providing indicators related to the condition of one or more of the seals 132a, 132b, 132c, and 132d.

[0081] 8, temperature sensors 170 and 172 are mounted in radial holes in housing 138c and plate 178, respectively. Each of the holes terminates near the inner surface of the housing (e.g., near the annular space between shaft 122 and housing 138c). Each of the holes is adjacent to seal 132c. Temperature sensor 172 is on the cylinder side. In some implementations, temperature sensors 170 and 172 are thermocouples.

[0082] Figure 9 illustrates a temperature sensor within the packing case. The seal housing 138c of the packing case 130 includes a groove 180 on the outer surface of the housing. The groove 180 extends axially along the housing 138c to an adjacent hole 182 in the end plate 120. A temperature sensor wiring assembly 184 resides within the groove 180. Figure 10 illustrates the reverse side of the end plate 120 with the hole 182 for passing the temperature sensor wiring assembly 184.

[0083] 11 illustrates a pressure sensor for sensing dynamic pressure, according to some implementations. System 100 includes a lubricant line 202 and a pressure sensor 204. Lubricant line 202 includes an internal passage 206 and an external passage 207. External passage 207 connects to internal passage 206 via a port 208 in end plate 120. Oil can be supplied to lubricant line 202 through fitting 212. Pressure sensor 204 is fluidly connected to lubricant line 202 via a T-connector 210.

[0084] A pressure sensor 204 can be used to sense the dynamic pressure within the packing case 130. In some implementations, the pressure sensor 204 senses the pressure on the cylinder side of a temperature sensor within the packing case (e.g., temperature sensors 170 and 172 described above with respect to FIG. 8).

[0085] 12 illustrates a pressure sensor for detecting dynamic pressure according to some implementations. The system 100 includes a vent line 220 and a pressure sensor 222. The vent line 220 includes an internal vent passage 224, a first external vent line 226, and a second external vent line 228. The first external vent line 226 and the second external vent line 228 are fluidly connected to the internal vent passage 224. In this example, the first vent line 226 is used to allow the packing case to be vented to the atmosphere. The internal vent passage 224 is connected to the pressure sensor 222 via a port 230 and the second external vent line 228. The pressure sensor 222 can be used to detect static pressure within the packing case 130. In some implementations, the pressure sensor 222 senses pressure on the driver side of the temperature sensors (eg, temperature sensors 170 and 172) within the packing case.

[0086] 13 is a graph 260 illustrating temperature monitoring at a compressor packing case using a temperature sensor mounted within the packing case housing. In this example, curve 262 may correspond to the temperature sensed by temperature sensor 170 (TC1) on the cylinder side of third seal (132c) shown in FIG. 8. Curve 264 may correspond to the temperature sensed by temperature sensor 172 (TC2) on the driver side of third seal (132c) shown in FIG. 8. Curve 266 may represent a trend line calculated from the temperatures sensed from TC1. Curve 268 may represent a trend line calculated from the temperatures sensed from TC2.

[0087] Initially, the compressor is in a normal operating phase. At time 270, the monitoring system may detect the start of a rise in TC1 and / or that TC1 has begun to diverge from TC2. The rise in TC1 is reflected by the temperature rise in curve 266.

[0088] Time 270 may be associated with one or more notifications provided to the user, such as warnings. During stage 274, the operator may be alerted and may take pre-planned measurement interventions. Stage 274 may be associated with an expected approximate remaining life (in this example, 30% remaining life).

[0089] The system may continue to sense temperatures and calculate differential temperatures between the sensors through step 272. Beyond this step, the temperatures may continue to diverge from one another.

[0090] At time 274, the system detects that the maximum temperature difference has been reached, as indicated by the maximum temperature difference 275 between curves 266 and 268.

[0091] Time 274 may be associated with one or more additional notifications provided to the user, such as a maintenance alert. Stage 276 may be associated with the expected approximate life remaining (in this example, 10% remaining life). Stage 276 may correspond to an ideal MRO period for the seal in the packing case.

[0092] The system may continue to sense temperatures and calculate differential temperatures between the sensors through stage 276. Beyond this stage, the temperatures may converge until a crossover point is reached. Also beyond this stage, the temperature fluctuations of each temperature sensor over time may become increasingly variable.

[0093] At time 278, the system may detect a temperature fluctuation that exceeds a predetermined threshold, which is reflected, for example, by a larger amount of change in each of curves 262 and 264 (e.g., as seen at time 277).

[0094] Time 278 may be associated with one or more additional notifications provided to the user, such as a warning to the user that there is a high risk of failure. Stage 280 may be associated with the expected approximate life remaining (in this example, end of life). Stage 280 may correspond to high air leakage and the risk of complete failure. Beyond this stage, the temperatures may converge until a crossover point is reached. The temperature fluctuations of each temperature sensor over time may become more variable. In some cases, the actual / measured temperatures may be highly variable relative to environmental and operating conditions, but the fluctuations of the temperature measurements at any given time may track each other closely.

[0095] 14 illustrates a process 300 for monitoring a packing case with temperature measurements, according to some implementations. A differential temperature between temperature sensors at two or more locations within the packing case is calculated 302. The temperature sensors may be, for example, like those installed within the packing case described above in connection with FIG. 8.

[0096] Based on the calculation, the system determines whether the temperature differential has diverged (304). If the temperature differential has not diverged, the system continues measuring the temperature (306). If the temperature differential has diverged (and / or if TC1 begins to increase in temperature), the system provides a first seal life stage alert (308). In one example, the temperature differential divergence corresponds to time 270 in FIG. 13.

[0097] As the compressor system continues to operate (e.g., step 272 in FIG. 13 ), the system continues to calculate the differential temperature. Based on the calculation, the system determines (310) whether the maximum temperature differential has been reached. If the maximum has not been reached, the system continues measuring the temperature (312). If the maximum temperature differential has been reached, the system provides (314) a second seal life stage alert. In one example, the maximum temperature differential corresponds to time 274 in FIG. 13 . The second stage indicator may trigger an action by maintenance personnel to replace the packing case seal.

[0098] As the compressor system continues to operate (e.g., step 276 of FIG. 13), the system continues to calculate the differential temperature. Based on the calculation, the system determines whether the temperature fluctuation exceeds a predetermined threshold. If the threshold is not reached, the system continues measuring the temperature (318). If the threshold is reached, the system provides a third seal life stage warning (320). In one example, the maximum temperature differential corresponds to time 278 of FIG. 13. The third stage indicator may be associated with the end of seal life.

[0099] 15 illustrates a process 400 for monitoring a packing case with temperature and pressure measurements according to some implementations. The temperature and pressure sensors, in one implementation, may be as installed in the packing case described above in connection with FIGS. 8, 9, and 10.

[0100] The dynamic pressure inside the packing case (e.g., cylinder side, lubricant line) is measured (402) and the pressure is calculated. Based on the calculation, the system determines whether the dynamic pressure exceeds a predetermined threshold (404). If the dynamic pressure does not exceed the threshold, the system continues measuring the dynamic pressure (406). If the dynamic pressure exceeds the threshold, the system provides an early life degradation indicator (408).

[0101] As the compressor system continues to operate, the system calculates the differential temperature between two or more temperature sensors. Based on the calculation, the system determines (410) whether a mid-life trigger point has been reached. If the mid-life trigger point has not been reached, the system continues measuring temperature (412). If the mid-life trigger point has been reached, the system provides (414) a mid-life degradation indicator. The mid-life indicator may trigger an action by maintenance personnel to replace the packing case seal.

[0102] As the compressor system continues to operate, the system measures the static pressure within the packing case. Based on the calculation, the system determines (416) whether the static pressure threshold has been reached. If the static pressure threshold has not been reached, the system continues measuring pressure (418). If the static pressure threshold has been reached, the system provides (420) a late deterioration indicator. The late indicator may be associated with the end of life of the seal. In various implementations, the late indicator is based on a deduced leakage flow rate, a pressure measurement, or a combination of both.

[0103] In some implementations, the early degradation indicators are derived from on-board instrumentation data, such as dynamic pressure measured using a pressure sensor in fluid communication with the lubrication oil line. In some implementations, the later degradation indicators are derived from on-board instrumentation data, such as static pressure measured using a pressure sensor in fluid communication with the vent line. The later degradation indicators can also be determined based on a deduced leak flow rate.

[0104] In some of the processes described above, the system determined the seal condition indicator based on temperature data generated from a temperature sensor coupled to the packing case. In some implementations, the seal condition indicator is determined based on data obtained from a pressure sensor coupled to the packing case. In some implementations, the seal condition indicator is determined based on data obtained from a combination of a temperature sensor and a pressure sensor coupled to the packing case.

[0105] In some of the processes described above, the system determines a seal degradation indicator.

[0106] In the implementation described above in connection with FIG. 8, a pair of temperature sensors are located on the side of the third seal from the packing case pressure interrupter. The temperature sensors are axially spaced apart from one another, each on one side of the seal. In other implementations, the monitoring system includes temperature sensors elsewhere in the enclosure. In certain implementations, the packing case monitoring system includes only one temperature sensor or two or more temperature sensors.

[0107] The temperature sensors are also circumferentially spaced apart from one another. For example, a first temperature sensor can be at the bottom of the packing case between the first and second seals, while a second temperature sensor is at the top of the packing case between the second and third seals.

[0108] 16 illustrates a packing case with a temperature sensor between each of the packing case's seals, according to some implementations. Packing case 500 includes temperature sensors 502a, 502b, 502c, 502d, and 502e. Temperature sensors 502a, 502b, 502c, 502d, and 502e are axially spaced apart from one another along the length of packing case 500, with one temperature sensor between each pair of adjacent seals. Temperature sensor 502f is circumferentially spaced apart from temperature sensor 502d. Temperature sensor 502g is circumferentially spaced apart from temperature sensor 502e.

[0109] The above system has been described in the context of a reciprocating compressor, where the shaft output actually acts on process gas to produce a high-pressure gas flow that can be used to operate elsewhere in the system. A progressive seal monitoring system as described herein can also be implemented in other process systems, such as reciprocating pumps. Additionally, a monitoring system as described herein can be applied to several engines. For example, a progressive seal monitoring system can be included in a linear reciprocating gas engine, which uses a high-pressure flow of gas to drive a shaft back and forth in a reciprocating manner.

[0110] The monitoring systems, instrumentation, and methods (such as the packing case monitoring system 161 described above in connection with FIG. 7) can be implemented in electronic circuitry, computer hardware, firmware, software, or combinations of these elements. The devices can include input / output devices, computer processors, and computer program products embodied in machine-readable storage devices for execution by a programmable processor. The techniques can be performed by a programmable processor executing a program of instructions that perform a desired function by manipulating input data to produce appropriate output. The techniques can be implemented in one or more computer programs that can be executed on a programmable system that includes at least one programmable processor coupled to receive data and instructions from, and transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Suitable processors include, by way of example, both general-purpose and special-purpose microprocessors. Typically, suitable processors receive both instructions and data from read-only memory and / or random-access memory. Storage elements may include all forms of non-volatile memory, including, by way of example, semiconductor memory elements such as EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), and flash memory elements, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, and CD-ROMs (Compact Disc Read-Only Memory). Any of the foregoing may be supplemented by or incorporated in specially designed application-specific integrated circuits (ASICs).

[0111] In another aspect of the present disclosure, a monitoring system for a packing case includes one or more temperature sensors, one or more pressure sensors, and a computing device. The one or more temperature sensors are coupled to the housing and configured to sense temperature at at least one location within the packing case. The one or more pressure sensors are fluidly coupled to one or more spaces within the packing case and configured to sense pressure at at least one location within the packing case. The computing device is communicatively coupled to at least one of the one or more temperature sensors and at least one of the one or more pressure sensors. The computing device is configured to receive signals from the at least one temperature sensor and the at least one pressure sensor and to calculate a degradation indicator for at least one seal of the packing case from the signals obtained from the at least one temperature sensor and the at least one pressure sensor.

[0112] In some implementations, the one or more temperature sensors include two or more temperature sensors, and the computing device is configured to calculate the temperature difference two or more times based on signals obtained from the temperature sensors.

[0113] In some implementations, at least one of the pressure sensors is coupled to a vent line of the packing case.

[0114] In some implementations, at least one of the pressure sensors couples to a lubricant line in the packing case.

[0115] In some implementations, the packing case assembly includes a plurality of seals, a housing configured to hold at least two of the seals, an end plate coupled to the housing, one or more temperature sensors, and one or more pressure sensors. The one or more temperature sensors are coupled to the packing case housing and configured to sense a temperature within the packing case. The one or more pressure sensors are coupled to the housing and configured to sense a pressure in one or more spaces within the packing case.

[0116] In some implementations, a method for detecting wear of seals in a progressive sealing system includes receiving signals from one or more temperature sensors coupled to a housing of the progressive sealing system, calculating temperatures associated with the temperature sensors from the signals two or more times, and determining a degradation indicator for at least one of the seals of the progressive sealing system at least in part from the two or more calculated temperatures.

[0117] In some implementations, the method further includes sensing pressure in one or more spaces within the progressive sealing system and determining a degradation indicator for at least one of the seals of the progressive sealing system at least in part from the pressures of the two or more sensors.

[0118] As used herein in reference to a sealing system, "deterioration" includes any change in one or more seals that reduces the effectiveness of the sealing system or that brings the seals toward the end of their useful life.

[0119] As used herein, an "indicator" includes a value, number, code, symbol, description, or other item of information that indicates or describes a condition, status, or level of a component, system, or equipment. For example, a seal condition indicator may describe the stage of life of a seal system (e.g., normal operation, replacement recommended, end of life reached, impending failure) or the percentage of life remaining in the seal system.

[0120] As used herein, a "predictor" includes an indicator that predicts or estimates an outcome or outcome related to a system, component, or device.

[0121] As used herein, a "chamber" includes an at least partially enclosed space.

[0122] As used herein, "driver" includes a device that provides mechanical energy to operate a system.

[0123] As used herein, an "enclosure" may completely enclose or only partially enclose the component or components it houses.

[0124] As used herein, "gradual" refers to a sealing system having multiple sealing members between high and low pressure points. In many cases, such systems provide a gradual reduction in pressure between the high and low pressure points in steps.

[0125] Specific embodiments of the subject matter have been described. Other embodiments, variations, and permutations of the described embodiments will be apparent to those skilled in the art and are within the scope of the following claims. Although operations are depicted in the figures or in the claims in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or in sequential order, or to perform all of the illustrated operations (some operations may be considered optional) to achieve a desired result.

[0126] Therefore, the exemplary embodiments set forth above do not define or constrain this disclosure, and other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure.

Claims

1. 1. A method for monitoring deterioration of a packing case seal, comprising: receiving a signal from a first temperature sensor mounted at a first location within the packing case enclosure; receiving a signal from a second temperature sensor mounted at a second location within the packing case enclosure; calculating a temperature difference between the first temperature sensor and the second temperature sensor from the signal two or more times; determining a degradation indicator for at least one of the seals of the packing case from at least two or more of the temperature differences; A method for providing

2. the packing case defines a cylinder side and a driver side; the first location is on the cylinder side of one of the seals of the packing case; the second location is on the driver side of the one of the seals of the packing case; The method of claim 1.

3. 3. The method of claim 1, wherein the first temperature sensor and the second temperature sensor are axially spaced apart from one another along the length of the packing case.

4. The method according to any one of claims 1 to 3, wherein at least one of the temperature sensors is embedded in a hole in the housing of the packing case.

5. The method of any one of claims 1 to 4, wherein the degradation indicator is based at least in part on an increase in differential temperature between the first temperature sensor and the second temperature sensor over time.

6. The method of any one of claims 1 to 5, wherein the degradation indicator is based at least in part on one or more changes in the differential temperature between the first temperature sensor and the second temperature sensor over time.

7. The method of any one of claims 1 to 6, wherein the degradation indicator is based at least in part on a maximum differential temperature between the first temperature sensor and the second temperature sensor.

8. The method of any one of claims 1 to 7, wherein the degradation indicator is based at least in part on an increase in differential temperature of the first temperature sensor over time.

9. Detecting the pressure inside the packing case; determining the deterioration indicator for at least one of the seals of the packing case from at least one sensed pressure; The method of any one of claims 1 to 8, further comprising:

10. The method according to any one of claims 1 to 9, wherein the pressure is sensed on the cylinder side of at least one of the temperature sensors.

11. The method according to any one of claims 1 to 10, wherein the pressure is sensed on the driver side of the at least one temperature sensor.

12. The method according to any one of claims 1 to 11, wherein the pressure is sensed in a lubricating oil line of the packing case.

13. The method according to any one of claims 1 to 12, wherein the pressure is sensed in a vent line of the packing case.

14. The method of any one of claims 1 to 13, further comprising the step of providing a notification to a user based on said degradation indicator.

15. 1. A packing case monitoring system having two or more seals defining a cylinder side and a driver side, comprising: a first temperature sensor coupled to the packing case housing and configured to sense a temperature at the cylinder side of one of the seals; a second temperature sensor coupled to the housing and configured to sense a temperature on the driver side of the one of the seals; and a computing device communicatively coupled to the first temperature sensor and the second temperature sensor, receiving signals from the first temperature sensor and the second temperature sensor; calculating a temperature difference between the first temperature sensor and the second temperature sensor from the signal two or more times; determining a degradation indicator for at least one of the seals of the packing case from at least two or more of the temperature differences; and a computing device configured as follows: A monitoring system comprising:

16. The two or more seals are: A pressure circuit breaker; a first seal axially disposed on the driver side of the pressure interrupter; a second seal axially disposed on the driver side of the first seal; a third seal axially disposed on the driver side of the second seal; and Equipped with the one of the seals is the third seal, and the first temperature sensor is axially disposed between the second seal and the third seal.

16. The monitoring system of claim 15.

17. The monitoring system of claim 16 , wherein the second temperature sensor is axially disposed between the third seal and an end plate seal.

18. the two or more seals include a second seal axially disposed on the cylinder side of the one of the seals; the monitoring system further includes a third temperature sensor axially disposed on the second one of the cylinders; the computing device is communicatively coupled to the third temperature sensor; the computing device is configured to calculate a temperature difference between the third temperature sensor and at least one of the first temperature sensor and the second temperature sensor. A monitoring system according to any one of claims 15 to 17.

19. A monitoring system according to any one of claims 15 to 18, further comprising a pressure sensor configured to sense pressure on the cylinder side of said one of said seals.

20. 20. The monitoring system of any one of claims 15 to 19, further comprising a pressure sensor coupled to a lubricating oil line of the packing case.

21. A monitoring system according to any one of claims 15 to 20, further comprising a pressure sensor configured to sense pressure on the driver side of said one of said seals.

22. 22. The monitoring system of claim 15, further comprising a pressure sensor coupled to a ventilation line of the packing case.

23. A monitoring system according to any one of claims 15 to 22, communicatively coupled to a cylinder side pressure sensor and configured to determine the deterioration indicator from information received from the cylinder side pressure sensor.

24. A monitoring system according to any one of claims 15 to 23, communicatively coupled to a driver-side pressure sensor and configured to determine the degradation indicator from information received from the driver-side pressure sensor.

25. A monitoring system according to any one of claims 15 to 24, configured to provide notification of said degradation indicators to a user.

26. A monitoring system according to any one of claims 15 to 25, configured to provide notification to the user regarding degradation of one or more of the seals.

27. 27. The monitoring system of any one of claims 15 to 26, configured to provide notification to the user regarding timing of a maintenance event for one or more of the seals of the packing case based at least in part on the degradation indicator.

28. A monitoring system according to any one of claims 15 to 27, configured to provide a warning to the user regarding a seal failure in the packing case based at least in part on the degradation indicator.

29. A monitoring system according to any one of claims 15 to 28, configured to provide the user with a predictive factor for one or more of the seals of the packing case based at least in part on the degradation indicator.

30. A packing case assembly, A plurality of seals; a housing configured to hold at least two of the seals; an end plate coupled to the housing; a first temperature sensor coupled to the housing of the packing case and configured to sense a temperature at one cylinder side of the seal; a second temperature sensor coupled to the housing and configured to sense a temperature on the one driver side of the seal; and A packing case assembly comprising:

31. 1. A reciprocating compressor system comprising: a compression cylinder defining a compression chamber; A driver; a rod connected between the driver and the compression cylinder, the driver operable to reciprocate the rod to compress gas in the compression chamber; a packing case through which the rod passes between the compression cylinder and the driver, the packing case defining a cylinder side and a driver side; a plurality of seals through which the rod passes; a housing configured to hold at least two of the seals; and an end plate coupled to the housing a packing case comprising: Packing case monitoring system and Equipped with The packing case monitoring system a first temperature sensor coupled to the packing case housing and configured to sense a temperature at the cylinder side of one of the seals; a second temperature sensor coupled to the housing and configured to sense a temperature on the driver side of the one of the seals; and a computing device communicatively coupled to the first temperature sensor and the second temperature sensor, receiving signals from the first temperature sensor and the second temperature sensor; calculating a temperature difference between the first temperature sensor and the second temperature sensor from the signal two or more times; determining a degradation indicator for at least one of the seals of the packing case from at least two or more of the temperature differences; and a computing device configured as follows: A reciprocating compressor system comprising:

32. 1. A method for monitoring deterioration of a packing case seal, comprising: receiving signals from one or more temperature sensors mounted within the packing case enclosure; receiving signals from one or more pressure sensors coupled within the packing case enclosure; calculating temperature two or more times and pressure two or more times from said signal; determining a degradation indicator for at least one of the seals of the packing case from at least one of the temperatures and at least one of the pressures; A method for providing

33. 33. The method of claim 32, wherein at least one of the degradation indicators is determined from two or more of the temperatures.

34. 34. The method of claim 32 or 33, wherein at least one of the degradation indicators is determined from two or more of said pressures.

35. A method according to any one of claims 32 to 34, wherein at least one of the indicators of deterioration is an early indicator of deterioration.

36. The method of any one of claims 32 to 34, wherein at least one of the deterioration indicators is a medium-term deterioration indicator.

37. The method of any one of claims 32 to 34, wherein at least one of the deterioration indicators is a late deterioration indicator.

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