CN112727747A - Online monitoring system of ultralow-temperature reciprocating compressor and power indicating method thereof - Google Patents
Online monitoring system of ultralow-temperature reciprocating compressor and power indicating method thereof Download PDFInfo
- Publication number
- CN112727747A CN112727747A CN202110045244.1A CN202110045244A CN112727747A CN 112727747 A CN112727747 A CN 112727747A CN 202110045244 A CN202110045244 A CN 202110045244A CN 112727747 A CN112727747 A CN 112727747A
- Authority
- CN
- China
- Prior art keywords
- hole
- valve
- indicator
- compressor
- pressure sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B51/00—Testing machines, pumps, or pumping installations
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
Abstract
The invention discloses an on-line monitoring system of an ultralow temperature reciprocating compressor, which comprises a compressor cylinder, a switching mechanism, a power indicating valve, a dynamic pressure sensor, a high-impedance output cable and a monitoring center, wherein the compressor cylinder is connected with the switching mechanism; the cylinder wall of the compressor cylinder is provided with a power indicating hole, and the power indicating hole is used for conducting gas in the compressor cylinder; the switching mechanism is used for mounting and dismounting the indicator valve; one end of the indicator valve is fixedly connected with the compressor cylinder through a switching mechanism, and the other end of the indicator valve is connected with the dynamic pressure sensor; the dynamic pressure sensor is used for detecting the pressure of the compressor cylinder and outputting pressure data; and the monitoring center monitors the pressure data on line and draws a corresponding indicator diagram. The invention is applied to the acquisition of dynamic pressure signals in the cylinder of the low-temperature BOG compressor of the LNG receiving station, so that an analyst can evaluate the running states of wearing parts such as piston rings, air valves, fillers and the like, and can calculate the dynamic load and the reverse angle of the piston rod.
Description
Technical Field
The invention relates to the technical field of compressor monitoring, in particular to an on-line monitoring system of an ultralow-temperature reciprocating compressor and a power indicating method thereof.
Background
The reciprocating compressor belongs to process fluid machinery, and is equipment for converting mechanical energy into internal gas energy (static pressure energy) to meet the requirements of the process and the process. Meanwhile, the reciprocating compressor has high working load and long operation time, and is one of devices with higher energy consumption in enterprises such as oil-gas fields, chemical engineering and the like. Whether a reciprocating compressor can work stably, reliably, efficiently and more economically for a long time depends to a great extent on whether a gas valve of the compressor has good working performance. Therefore, when measuring the working state of such devices, not only the reliability of the mechanical structure and the moving parts thereof but also the working performance and the productivity thereof need to be concerned. Due to the special movement and structure mode, unique work cycle and intermittent air suction and exhaust characteristics, the application of the traditional vibration monitoring technology to the equipment has great limitation.
With the increasing popularity of the performance monitoring technology of the reciprocating compressor, more and more reciprocating compressors have gradually considered the matching of the unit and the condition monitoring system in the overall design process of the compressor. The cylinder of the ultra-low temperature reciprocating compressor works at the working temperature below the ultra-low temperature which is lower than 1K for a long time, the whole cylinder is covered by a thick ice layer, and in order to ensure the real-time performance of a measurement signal, a sensor needs to be installed close to the cylinder as far as possible. This requires a dynamic pressure sensor and indicator valve that can withstand ultra low temperatures below 1K and that can operate stably for long periods at low temperature conditions. The low-temperature BOG compressor is used as an important key device of the LNG receiving station, the stable operation of the low-temperature BOG compressor is important for the whole LNG receiving station, and the low-temperature BOG compressor is directly related to the national energy supply. Unplanned shutdown of the BOG compressor can result in significant BOG gas flare in-line, resulting in significant economic and energy waste. In view of the above, online performance monitoring of the BOG compressor is particularly necessary.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides an on-line monitoring system of an ultralow temperature reciprocating compressor and a power indicating method thereof, which are applied to the acquisition of dynamic pressure signals in a cylinder of a low temperature BOG compressor of an LNG receiving station, so that an analyst can evaluate the running states of wearing parts such as piston rings, air valves, fillers and the like, and can calculate the dynamic load and the reverse angle of a piston rod.
The invention adopts the technical scheme for solving the technical problems that: an on-line monitoring system of an ultralow temperature reciprocating compressor comprises a compressor cylinder, a switching mechanism, a power indicating valve, a dynamic pressure sensor, a high-impedance output cable and a monitoring center;
the cylinder wall of the compressor cylinder is provided with a power indicating hole, and the power indicating hole is used for conducting gas in the compressor cylinder;
the switching mechanism is arranged on the indicator hole and used for mounting and dismounting the indicator valve;
one end of the indicator valve is fixedly connected with the compressor cylinder through a switching mechanism, and the other end of the indicator valve is connected with the dynamic pressure sensor; the device is used for measuring the compression pressure and the explosion pressure inside the compressor cylinder;
the dynamic pressure sensor is used for detecting the pressure of the compressor cylinder in the air suction and exhaust process in the reciprocating period and outputting pressure data;
two ends of the high-impedance output cable are respectively connected with the dynamic pressure sensor and the monitoring center and are used for transmitting pressure data;
the monitoring center is used for monitoring pressure data on line and drawing a corresponding indicator diagram.
For further improvement, the indicator hole is of a multi-stage counter bore structure, the front end through hole, the first step surface, the matching sealing hole, the second step surface and the screw hole are sequentially formed in the structure from inside to outside, the hole diameters of the front end through hole, the matching sealing hole and the screw hole are sequentially increased, the switching mechanism comprises a joint and a soft metal gasket, the joint is of a stepped shaft structure, a matching shaft section, an external thread shaft section and a wrench clamping section are sequentially formed from inside to outside, the external thread shaft section is in threaded connection with the screw hole, the matching shaft section is in sliding fit with the matching sealing hole, compression type sealing is achieved between the matching shaft section and the first step surface through the soft metal gasket, and the length of the matching sealing hole is smaller than the sum of the thickness of the soft metal gasket and the length of the matching shaft section; the joint is provided with a power indicating passage, the inner end of the power indicating passage is communicated with the front end through hole, and the outer end of the power indicating passage is provided with a threaded taper hole.
Further perfection, the indicator valve comprises a valve body, a side pipe body, a valve cover, a valve core and a hand wheel, wherein a taper pipe is arranged at the left end of the valve body and is in threaded connection with a threaded taper hole, a sensor interface is arranged at the right end of the valve body and is connected with a dynamic pressure sensor, the hand wheel is installed and connected with the top end of the valve core, a front section channel and a rear section channel which are parallel to each other are arranged in the valve body, an inclined connecting channel is arranged between the front section channel and the rear section channel, a recess is arranged in the middle of the connecting channel, a valve core through hole is arranged above the recess, a first internal threaded pipe is arranged at the upper end of the valve core through hole, a second internal threaded pipe is arranged at the upper part of the side pipe body, a first external threaded pipe is arranged at the lower part of the side pipe body, a first hexagon nut is arranged between the first external threaded pipe and the second, the lower portion of the valve cover is provided with a second external thread pipe, the second external thread pipe is in threaded connection with the second internal thread pipe, a check nut is arranged on the second external thread pipe, the valve cover is in threaded connection with the valve core, the lower end of the valve core penetrates through the through hole of the valve core and is provided with a conical head matched with the recessed cavity, the hand wheel comprises a hand wheel disc and a hand wheel shaft, the hand wheel disc is installed and connected on the hand wheel shaft, and the lower end of the hand wheel shaft is connected with the top end of the valve core in a.
Further perfect, be equipped with on the anterior segment passageway and prevent exploding send out the mechanism, prevent exploding send out the mechanism including setting up gliding brake shoe about in the brake hole of anterior segment passageway upside inner wall, the brake hole and be used for brake shoe reset spring, be equipped with movable groove between brake hole and the case through-hole, the linkage rod that can move about is equipped with in the movable groove, the one end and the brake shoe lateral part fixed connection of linkage rod, the annular cooperation sliding connection that the other end and case lateral part set up.
Further perfection, the whole indicator valve is made of austenitic stainless steel.
Further perfecting, the dynamic pressure sensor comprises a shell and a quartz resonance pressure sensor welded in the shell, and a differential bridge type sensor monitoring amplifying circuit with temperature compensation is arranged in the quartz resonance pressure sensor; one end of the shell is an electrical socket connected with the high-impedance output cable, and the other end of the shell is a pressure-leading pin.
Further perfect, casing lateral wall middle part is equipped with outer hexagonal screens, has the portion of cup jointing between outer hexagonal screens and the electric socket, is equipped with external screw thread portion between outer hexagonal screens and the sensor joint, the electric socket outside is equipped with the flame proof end cover, and flame proof end cover hole and the interference of portion of cup jointing cup joint the cooperation, it connects to draw the outside flame proof that is equipped with of pressure pipe foot, and flame proof connects one end and connects the indicator valve, and flame proof connects other end threaded connection external screw thread portion.
A method of indicating a power comprising the steps of: the combined piece of the indicator valve and the dynamic pressure sensor is arranged on the compressor cylinder, the indicator valve is indirectly connected with the cylinder wall of the compressor cylinder through a connecting structure, and then the compressor is started to operate; the monitoring center sends a measurement instruction to the dynamic pressure sensor through the high-impedance output cable; the dynamic pressure sensor measures the compression pressure and the explosion pressure in the compressor cylinder and outputs pressure data, and the pressure data is transmitted to the monitoring center through a high-impedance output cable; and the monitoring center receives the uploaded pressure data and then draws a indicator diagram.
The invention has the beneficial effects that:
1. the indicator hole has the advantages of short size and large aperture, and can effectively eliminate the tube cavity effect in the front-end through hole. Meanwhile, a soft metal gasket is adopted to carry out mechanical surface pressing type sealing at the sealing position with the compression cylinder, so that the leakage of process gas can be effectively prevented.
2. The invention is provided with the switching mechanism which provides mounting threads for the external low-temperature indicator valve, and the indicator valve is not directly mounted on the cylinder wall. The advantage of this design is that damage to the cylinder wall threads, and thus thread failure, can be avoided when the pilot valve is installed or removed. When the indicator valve needs to be disassembled, the mechanism can be directly matched with the plug, and reliable sealing is formed.
3. The low-temperature indicator valve disclosed by the invention is designed by adopting integral austenitic 304 stainless steel, and has good corrosion resistance, heat resistance, low-temperature strength and mechanical properties. The valve body, the side pipe body, the valve cover, the valve core and other parts are in threaded fit or metal surface fit, mechanical hard sealing is achieved, sealing performance is good, the sealing structure is not clamped in a low-temperature environment, and embrittlement and deformation of the organic sealing filler in the low-temperature environment are effectively avoided. The valve is designed by a needle valve, and can achieve no leakage when being opened and closed, and the pressure resistance strength is up to 15000 psi.
4. The indicator valve is provided with the explosion prevention mechanism, the liftable brake block is arranged at the front part of the valve core, so that the explosion pressure of the cylinder can be limited, the valve core resists the scouring of high-pressure and high-speed airflow when being opened, the abrasion of the sealing conical surface of the conical head at the lower end of the valve core is effectively reduced, the structural strength of the valve core is greatly improved, and the service life of the valve core is greatly prolonged.
5. The invention adopts the design of the dynamic pressure sensor which is specially used in the low-temperature environment, has good dynamic property and has performance not influenced by low temperature. In terms of signal processing, the sensor monitoring amplifying circuit adopts a special signal amplifier with a built-in temperature compensation algorithm and is connected with a special high-impedance output cable (the dynamic pressure sensor is prevented from electric quantity leakage). The sensor adopts the quartz resonance principle, has small and exquisite structure and convenient installation, can measure the fluid pressure at ultra-low temperature, and has the characteristics of quick response frequency and 100kHz of natural frequency.
6. The sensor shell is provided with the explosion-proof end cover and the explosion-proof joint, and the intrinsic safety and explosion-proof double-insurance design not only meets the electrical safety requirement, but also can prevent low-temperature condensate or liquid from influencing sensitive elements in a processing circuit.
Drawings
FIG. 1 is a schematic diagram of an on-line monitoring system;
FIG. 2 is an enlarged schematic view of the indicator hole and the adapter mechanism of FIG. 1;
FIG. 3 is a schematic view of the combined status of the indicator valve and the dynamic pressure sensor;
FIG. 4 is a schematic diagram of the construction of the indicator valve;
FIG. 5 is an enlarged view of a portion of the structure of FIG. 4;
FIG. 6 is a schematic diagram of the main structure of the dynamic pressure sensor;
FIG. 7 is a schematic diagram of a housing structure of the dynamic pressure sensor;
FIG. 8 is a schematic indicator diagram of indicator valve performance;
FIG. 9 is a schematic diagram of a sensor voltage drive circuit;
FIG. 10 is a schematic diagram of a sensor amplifier circuit;
FIG. 11 is a graph of dynamic pressure curve (P- θ);
FIG. 12 is an indicator diagram (P-V);
FIG. 13 is a logarithmic graph (log P-log V);
FIG. 14 is a standard pressure-volume indicator diagram (P-V diagram) of a reciprocating compressor;
description of reference numerals: 1. a compressor cylinder, 11, a pilot hole, 111, a front end through hole, 112, a first step surface, 113, a fitting seal hole, 114, a second step surface, 115, a screw hole, 2, an adapting mechanism, 21, a joint, 211, a fitting shaft section, 212, an external threaded shaft section, 213, a wrench clamping section, 214, a pilot through hole, 215, a threaded taper hole, 22, a soft metal washer, 3, a pilot valve, 31, a valve body, 311, a taper pipe, 312, a sensor interface, 313, a front section passage, 314, a rear section passage, 315, a connecting passage, 316, a recess, 317, a spool through hole, 318, a first internal threaded pipe, 32, a side pipe body, 321, a second internal threaded pipe, 322, a first external threaded pipe, 323, a first hexagonal nut, 33, a valve cover, 331, a second hexagonal nut, 332, a second external threaded pipe, 333, a locknut, 34, a spool, 341, a cone head, 342, a ring groove, 35, a hand wheel, 351. the device comprises a hand wheel disc, 352, a hand wheel shaft, 4, a dynamic pressure sensor, 41, a shell, 411, an electrical interface, 412, a pressure guide pin, 413, a vent hole, 414, an outer hexagonal clamp, 415, a socket joint part, 416, an outer thread part, 417, an explosion-proof end cover, 418, an explosion-proof joint, 42, a quartz resonance pressure sensor, 5, a high-impedance output cable, 6, a monitoring center, 7, an explosion-proof mechanism, 71, a gate hole, 72, a gate block, 73, a reset spring, 74, a movable groove, 75 and a linkage rod.
Detailed Description
The invention will be further described with reference to the accompanying drawings in which:
as shown in fig. 1, the on-line monitoring system of the ultralow temperature reciprocating compressor in the embodiment includes a compressor cylinder 1, a switching mechanism 2, a power indicating valve 3, a dynamic pressure sensor 4, a high-impedance output cable 5 and a monitoring center 6; the wall of the compressor cylinder 1 is provided with a power indicating hole 11, and the power indicating hole 11 is used for conducting gas inside the compressor cylinder 1; the switching mechanism 2 is arranged on the indicator hole 11, and the switching mechanism 2 is used for installing and detaching the indicator valve 3; one end of the indicator valve 3 is fixedly connected with the compressor cylinder 1 through the switching mechanism 2, and the other end of the indicator valve is connected with the dynamic pressure sensor 4; for measuring the compression pressure and the explosion pressure inside the compressor cylinder 1; the dynamic pressure sensor 4 is used for detecting the pressure of the compressor cylinder 1 in the process of air suction and exhaust in the reciprocating period and outputting pressure data; two ends of the high-impedance output cable 5 are respectively connected with the dynamic pressure sensor 4 and the monitoring center 6 and are used for transmitting pressure data; the monitoring center 6 is used for monitoring pressure data on line and drawing a corresponding indicator diagram.
As shown in fig. 2, the indicator hole 11 is a multi-stage counter bore structure, and includes a front end through hole 111, a first step surface 112, a fitting seal hole 113, a second step surface 114, and a screw hole 115 in sequence from inside to outside, the aperture of the front end through hole 111, the bore of the fitting seal hole 113, and the aperture of the screw hole 115 are sequentially increased, the adapting mechanism 2 includes a joint 21 and a soft metal gasket 22, the joint 21 is a stepped shaft structure, and includes a fitting shaft section 211, an external screw shaft section 212, and a wrench clamping section 213 in sequence from inside to outside, the external screw shaft section 212 is in threaded connection with the screw hole 115, the fitting shaft section 211 is in sliding fit with the fitting seal hole 113, a soft metal gasket 22 is arranged between the fitting shaft section 211 and the first step surface 112 to realize press-type sealing, and the length of the fitting seal hole 113 is less than the sum of the thickness of the soft metal gasket 22 and the length of; the joint 21 is provided with an indicator passage 214, the inner end of the indicator passage 214 is communicated with the front end through hole 111, and the outer end of the indicator passage 214 is provided with a threaded taper hole 215. The design of the indicator hole and the switching mechanism fully considers the sealing and the repeated use reliability of the compression cylinder in low-temperature application and the influence on the compression cylinder structure in the installation and the disassembly of the indicator valve. The indicator hole has shorter size and larger aperture, and can effectively eliminate the lumen effect in the pressure passage. Meanwhile, at the sealing position with the compression cylinder, a soft metal gasket 22 is adopted between the matching shaft section 211 and the first step surface 112 to realize mechanical surface compression type sealing, so that the leakage of process gas can be effectively prevented. The outer end of the core component joint 21 of the adapter mechanism is provided with a threaded taper hole 215 which directly provides mounting threads for an external low-temperature indicator valve, but the indicator valve 3 is not directly mounted on the cylinder wall. The advantage of this design is that damage to the cylinder wall threads, and thus thread failure, can be avoided when the pilot valve 3 is installed or removed. When the indicator valve 3 needs to be disassembled, the mechanism can be directly matched with the conical sealing plug to form reliable sealing.
As shown in fig. 3 to 4, the indicator valve 3 is made of austenitic 304 stainless steel as a whole, and has good corrosion resistance, heat resistance, low-temperature strength and mechanical properties. The indicator valve 3 comprises a valve body 31, a side pipe body 32, a valve cover 33, a valve core 34 and a hand wheel 35, wherein the left end of the valve body 31 is provided with a taper pipe 311, the taper pipe 311 is in threaded connection with a threaded taper hole 215, the right end of the valve body 31 is provided with a sensor interface 312, the sensor interface 312 is connected with a dynamic pressure sensor 4, the hand wheel 35 is installed and connected at the top end of the valve core 34, a front section channel 313 and a rear section channel 314 which are parallel to each other are arranged in the valve body 31, an inclined connecting channel 315 is arranged between the front section channel 313 and the rear section channel 314, a recess 316 is arranged in the middle of the connecting channel 315, a valve core through hole 317 is arranged above the recess 316, a first internal threaded pipe 318 is arranged at the upper end of the valve core through hole 317, the upper part of the side pipe body 32 is a second internal threaded pipe 321, the lower part of the side pipe body 32 is, the first external thread pipe 322 is in threaded connection with the first internal thread pipe 318, the second hexagon nut 331 is arranged at the upper part of the valve cover 33, the second external thread pipe 332 is arranged at the lower part of the valve cover 33, the second external thread pipe 332 is in threaded connection with the second internal thread pipe 321, the locknut 333 is arranged on the second external thread pipe 332, the valve core 34 is in threaded connection with the valve cover 33, the lower end of the valve core 34 penetrates through the valve core through hole 317 and is provided with a conical head 341 matched with the recessed cavity 316, the hand wheel 35 comprises a hand wheel disc 351 and a hand wheel shaft 352, the hand wheel disc 351 is installed and connected on the hand wheel shaft 352, and the lower end of the hand wheel shaft 352 is connected with the top end. The indicator valve 3 adopts mechanical hard seal, the valve body 31, the side pipe body 32, the valve cover 33, the valve core 34 and the hand wheel 35 are adjacent and are in threaded fit or metal surface fit, the sealing performance is good, the valve body, the side pipe body, the valve cover 33, the valve core 34 and the hand wheel 35 are not clamped in a low-temperature environment, and embrittlement and deformation of organic sealing filler in the low-temperature environment are effectively avoided. The indicator valve 3 adopts a needle valve design, and can achieve no leakage when being opened and closed, and the pressure resistance strength is up to 15000 psi. The performance index of the low-temperature indicator valve 3 is shown in the attached figure 8.
As shown in fig. 5, an explosion-proof mechanism 7 is arranged on the front section channel 313 of the power-indicating valve 3, the explosion-proof mechanism 7 includes a gate hole 71 arranged on the inner wall of the upper side of the front section channel 313, a gate block 72 capable of sliding up and down in the gate hole 71 and a return spring 73 for the gate block, a movable groove 74 is arranged between the gate hole 71 and the valve core through hole 317, a linkage rod 75 capable of moving up and down is arranged in the movable groove 74, one end of the linkage rod 75 is fixedly connected with the side portion of the gate block 72, and the other end of the linkage rod is in sliding connection with a ring groove 342 arranged on. When the valve core 34 is opened, the brake block 72 can rise together with the valve core 34, the brake block 72 is always positioned in front of the lower end conical head 341 of the valve core 34, the flushing of high-pressure high-speed airflow can be resisted, the abrasion of the sealing conical surface of the lower end conical head 341 of the valve core 34 is effectively reduced, and the structural strength and the service life of the valve core 34 are greatly improved.
As shown in fig. 6, the dynamic pressure sensor 4 includes a housing 41 and a quartz resonance pressure sensor 42 welded in the housing 41, the quartz resonance pressure sensor 42 adopts a quartz resonance principle, has a small structure and convenient installation, can measure a fluid pressure at-196 ℃, and is characterized by a fast response frequency and a natural frequency of about 100 kHz. A differential bridge type sensor monitoring amplifying circuit with temperature compensation is arranged in the quartz resonance pressure sensor 42; as shown in fig. 9-10, the differential bridge-type sensor monitoring and amplifying circuit with temperature compensation is a complete low-power consumption signal conditioner suitable for bridge-type sensors, and comprises a temperature compensation channel. The circuit is very suitable for various industrial pressure sensors with the driving voltage between 5V and 15V. The circuit can handle full-scale signals of about 10mV to 1V using a built-in Programmable Gain Amplifier (PGA) of a 24-bit sigma-delta ADC, and thus it is suitable for a wide variety of pressure sensors. The whole circuit uses only three ICs and consumes only 1mA (bridge current is not included). The ratiometric technique ensures that the system and stability are independent of the reference voltage source. One end of the housing 41 is an electrical socket 411 for connecting the high impedance output cable 5, and the other end is a voltage pin 412. The working temperature of the BOG compressor is ultralow at a temperature lower than 1K, and the cylinder body can cover a thick ice layer on the working surface due to low temperature, so that the dynamic pressure sensor is specially designed for low-temperature environment application, has good dynamic property and is not influenced by low temperature in performance. The overall design of the ultralow temperature dynamic pressure sensor special for the compressor indicator adopts low temperature protection and low temperature metal sealing technology. In the aspect of signal processing, the sensor monitoring amplifying circuit adopts a special signal amplifier with a built-in temperature compensation algorithm, so that the measuring accuracy can be improved, and finally, pressure data is output through a special high-impedance output cable (preventing the electric quantity of the dynamic pressure sensor from leaking).
As shown in fig. 7, outer hexagonal screens 414 are arranged in the middle of the side wall of the housing 41, a sleeve joint part 415 is arranged between the outer hexagonal screens 414 and the electrical socket 411, an external thread part 416 is arranged between the outer hexagonal screens 414 and the sensor connector 21, an explosion-proof end cover 417 is arranged outside the electrical socket 411, an inner hole of the explosion-proof end cover 417 is in interference sleeve joint with the sleeve joint part 415, the explosion-proof end cover 417 can wrap the connecting end of the high-impedance output cable 5 and the electrical socket 411 to avoid electric leakage, an explosion-proof connector 418 is arranged outside the pressure-inducing pin 412, one end of the explosion-proof connector 418 is connected with the indicator valve 3, and the other end of the explosion-proof. The explosion-proof connector 418 can avoid the direct connection of the pressure guide pin 412 with the indicator valve 3, reduce the phenomena of thread abrasion and breakage at the pressure guide pin 412, improve the connection reliability, reduce the risks of damage and gas leakage at the pressure guide pin 412 and enhance the explosion-proof performance.
A method of indicating a power comprising the steps of: installing the assembly of the indicator valve 3 and the dynamic pressure sensor 4 on the compressor cylinder 1, indirectly connecting the indicator valve 3 with the cylinder wall of the compressor cylinder 1 through a connecting structure, and then starting up to run; the monitoring center 6 sends a measurement instruction to the dynamic pressure sensor 4 through the high-impedance output cable 5; the dynamic pressure sensor 4 measures the compression pressure and the explosion pressure in the compressor cylinder 1 and outputs pressure data, and the pressure data is transmitted to the monitoring center 6 through the high-impedance output cable 5; and the monitoring center 6 receives the uploaded pressure data and then draws a indicator diagram. The failure modes of the reciprocating compressor can be divided into two categories, mechanical function failure and thermal performance failure. The thermal performance fault can be diagnosed by adopting a thermal parameter method, wherein a dynamic pressure signal in a cylinder can be used as a main diagnostic signal. The practical application proves that the dynamic pressure-volume (P-V) monitoring and analyzing technology of the reciprocating compressor is the most effective compressor performance and power state evaluating technology. By applying the dynamic pressure monitoring and phased data processing technology, special computer software can perform cycle-based refinement processing on the dynamic performance of the compressor. Based on the above, various performance calculations and process simulations are performed, such as: indicated power, valve losses, volumetric efficiency, flow balance in a single cycle, and thermodynamic process models of theoretical and actual cycles, etc. (see fig. 11-13).
In the reciprocating device diagnosis, a pressure-volume indicator diagram (P-V diagram) is the best mode for the internal energy circulation of the reaction device. For simplicity, only one end of the compressor cylinder is shown in FIG. 14 as a reference for the thermodynamic cycle description thereof.
At point a, i.e., Top Dead Center (TDC), both the intake and exhaust valves are in a closed state. During expansion, the volume increased by the end piston movement is occupied by the gas which originally occupies the clearance volume, and the increase of the volume of the gas with equal mass leads to the reduction of the pressure in the cylinder. When the piston reaches point B, the in-cylinder pressure is equal to the intake manifold pressure. A slight additional movement of the piston is sufficient to reduce the in-cylinder pressure below the intake manifold pressure, forcing the intake valve to open. When the piston moves from point B to point C, the intake manifold pressure is greater than the in-cylinder pressure and gas enters the cylinder. The portion of the total cylinder volume occupied by the intake cylinder interior gas is called the intake volume.
At point C, the piston begins to move in the opposite direction, causing the volume of gas in the cylinder to decrease and the pressure to gradually increase, forcing the intake valve to close. When the intake valve closes, the piston moves such that the volume of gas within the original clearance volume and that entering the cylinder during the intake stroke is reduced. Thus, the in-cylinder pressure continues to increase until the exhaust line pressure is reached at point D.
At this point, a slight additional movement of the piston is sufficient to increase the in-cylinder pressure above the exhaust line pressure, forcing the exhaust valve to open. From point D to point a, the cylinder pressure is higher than the exhaust line pressure, the gas is exhausted, and the volume of the exhausted gas is called the exhaust volume.
The shaded areas in fig. 14 represent the additional work done to move gas through the intake and exhaust valves. The area of the shaded area represents the valve loss (the dedicated software can directly find the value of the power lost by the valve or the percentage of work indicated with respect to the cycle by means of an integration algorithm). The theoretical P-V indicator diagram superimposed on the actual graph can provide important compressor diagnostic information.
Due to manufacturing and assembly tolerances, reciprocating compressors present a certain clearance volume. Thus, at the end of the entire exhaust stroke (exhaust volume), a certain amount of gas remains in the clearance volume, which residual gas must expand during the intake stroke. The ratio of intake volume to displacement is called intake volumetric efficiency and is expressed by the equation:
VESeffective suction volume/displacement
In the same way, only a portion of the piston stroke is used to exhaust the gas. The ratio of displacement volume to displacement volume, called displacement volumetric efficiency, is expressed by the equation:
VESeffective displacement volume/displacement volume
In addition to the residual gas mentioned above, most of the gas entering the cylinder is exhausted. The ratio between the mass of gas entering the cylinder and the mass of gas discharged (flow balance) is a function of volumetric efficiency and is normally equal to 1. This ratio is the most representative compressor condition parameter. For example, leakage of the exhaust valve may result in a flow balance value of less than 1; intake valve leakage can result in a flow balance greater than 1. The expression is as follows:
through the compressor dynamic pressure monitoring and indicator graph, the following parameters can be monitored and obtained:
while the invention has been shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.
Claims (8)
1. The utility model provides an ultra-low temperature reciprocating compressor's on-line monitoring system which characterized in that: the device comprises a compressor cylinder (1), a switching mechanism (2), a power indicating valve (3), a dynamic pressure sensor (4), a high-impedance output cable (5) and a monitoring center (6);
the indicating hole (11) is formed in the wall of the compressor cylinder (1), and the indicating hole (11) is used for conducting gas inside the compressor cylinder (1);
the switching mechanism (2) is installed on the indicator hole (11), and the switching mechanism (2) is used for installing and detaching the indicator valve (3);
one end of the indicator valve (3) is fixedly connected with the compressor cylinder (1) through the switching mechanism (2), and the other end of the indicator valve is connected with the dynamic pressure sensor (4); for measuring the compression pressure and the explosion pressure inside the compressor cylinder (1);
the dynamic pressure sensor (4) is used for detecting the pressure of the compressor cylinder (1) in the suction and exhaust process in the reciprocating period and outputting pressure data;
two ends of the high-impedance output cable (5) are respectively connected with the dynamic pressure sensor (4) and the monitoring center (6) and are used for transmitting pressure data;
and the monitoring center (6) is used for monitoring pressure data on line and drawing a corresponding indicator diagram.
2. The on-line monitoring system of an ultra-low temperature reciprocating compressor of claim 1, wherein: the indicator hole (11) is of a multi-stage counter bore structure, the indicator hole is sequentially a front end through hole (111), a first step face (112), a matching sealing hole (113), a second step face (114) and a screw hole (115) from inside to outside, the hole diameters of the front end through hole (111), the matching sealing hole (113) and the screw hole (115) are sequentially increased, the switching mechanism (2) comprises a joint (21) and a soft metal gasket (22), the joint (21) is of a stepped shaft structure, a matching shaft section (211), an external threaded shaft section (212) and a wrench clamping section (213) are sequentially arranged from inside to outside, the external threaded shaft section (212) is in threaded connection with the screw hole (115), the matching shaft section (211) is in sliding fit with the matching sealing hole (113), and compression sealing is realized between the matching shaft section (211) and the first step face (112) through the soft metal gasket (22), the length of the matching sealing hole (113) is smaller than the sum of the thickness of the soft metal gasket (22) and the length of the matching shaft section (211); the joint (21) is provided with an indicator passage (214), the inner end of the indicator passage (214) is communicated with the front end through hole (111), and the outer end of the indicator passage (214) is provided with a threaded taper hole (215).
3. The on-line monitoring system of an ultra-low temperature reciprocating compressor according to claim 2, wherein: the indicator valve (3) comprises a valve body (31), a side pipe body (32), a valve cover (33), a valve core (34) and a hand wheel (35), wherein a taper pipe (311) is arranged at the left end of the valve body (31), the taper pipe (311) is in threaded connection with a threaded taper hole (215), a sensor interface (312) is arranged at the right end of the valve body (31), the sensor interface (312) is connected with a dynamic pressure sensor (4), the hand wheel (35) is installed and connected at the top end of the valve core (34), a front section channel (313) and a rear section channel (314) which are parallel to each other are arranged in the valve body (31), an inclined connecting channel (315) is arranged between the front section channel (313) and the rear section channel (314), a concave cavity (316) is arranged in the middle of the connecting channel (315), a valve core through hole (317) is arranged above the valve core through hole (316), a first internal threaded pipe (318) is arranged at the upper end of the valve, the lower part of the side pipe body (32) is provided with a first external thread pipe (322), a first hexagonal nut (323) is arranged between the first external thread pipe (322) and a second internal thread pipe (321), the first external thread pipe (322) is in threaded connection with a first internal thread pipe (318), the upper part of the valve cover (33) is provided with a second hexagonal nut (331), the lower part of the valve cover (33) is provided with a second external thread pipe (332), the second external thread pipe (332) is in threaded connection with the second internal thread pipe (321), the second external thread pipe (332) is provided with a check nut (333), the valve cover (33) is in threaded connection with the valve core (34), the lower end of the valve core (34) penetrates through a valve core through hole (317) and is provided with a conical head (341) matched with the recessed hole (316), the hand wheel (35) comprises a hand wheel disc (351) and a hand wheel shaft (352), and the hand wheel disc (351) is installed and connected on the hand wheel shaft (, the lower end of the hand wheel shaft (352) is connected with the top end of the valve core (34) in a welding mode.
4. The on-line monitoring system of an ultra-low temperature reciprocating compressor of claim 3, wherein: be equipped with explosion-proof mechanism (7) of sending out on anterior segment passageway (313), explosion-proof mechanism (7) of sending out is including setting up brake shoe (72) that can slide from top to bottom and being used for brake shoe reset spring (73) in brake shoe (71) the brake shoe hole (71) of anterior segment passageway (313) upside inner wall, be equipped with movable groove (74) between brake shoe hole (71) and case through-hole (317), be equipped with gangbar (75) that can move about from top to bottom in movable groove (74), the one end and the brake shoe (72) lateral part fixed connection of gangbar (75), the other end and annular groove (342) cooperation sliding connection that case (34) lateral part set up.
5. The on-line monitoring system of an ultra-low temperature reciprocating compressor of claim 1, wherein: the whole indicator valve (3) is made of austenitic 304 stainless steel.
6. The on-line monitoring system of an ultra-low temperature reciprocating compressor of claim 1, wherein: the dynamic pressure sensor (4) comprises a shell (41) and a quartz resonance pressure sensor (42) welded in the shell (41), wherein a differential bridge type sensor monitoring amplifying circuit with temperature compensation is arranged in the quartz resonance pressure sensor (42); one end of the shell (41) is an electric socket (411) connected with the high-impedance output cable (5), and the other end of the shell is a pressure-leading pin (412).
7. The on-line monitoring system of an ultra-low temperature reciprocating compressor according to claim 6, wherein: casing (41) lateral wall middle part is equipped with outer hexagonal screens (414), has between outer hexagonal screens (414) and electric socket (411) and cup joints portion (415), is equipped with external screw thread portion (416) between outer hexagonal screens (414) and sensor joint (21), electric socket (411) outside is equipped with flame proof end cover (417), flame proof end cover (417) hole and the interference of cup jointing portion (415) cup joint the cooperation, draw pressure pin (412) outside to be equipped with flame proof joint (418), flame proof joint (418) one end connection indicator valve (3), flame proof joint (418) other end threaded connection external screw thread portion (416).
8. A method for indicating power in an on-line monitoring system according to any of claims 1-7, comprising the steps of: the combined piece of the indicator valve (3) and the dynamic pressure sensor (4) is installed on the compressor cylinder (1), the indicator valve (3) is indirectly connected with the cylinder wall of the compressor cylinder (1) through a connecting structure, and then the compressor is started to operate; the monitoring center (6) sends a measurement instruction to the dynamic pressure sensor (4) through the high-impedance output cable (5); the dynamic pressure sensor (4) measures the compression pressure and the explosion pressure in the compressor cylinder (1) and outputs pressure data, and the pressure data is transmitted to the monitoring center (6) through a high-impedance output cable (5); and the monitoring center (6) draws a indicator diagram after receiving the uploaded pressure data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110045244.1A CN112727747B (en) | 2021-01-14 | 2021-01-14 | Online monitoring system of ultralow-temperature reciprocating compressor and power indicating method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110045244.1A CN112727747B (en) | 2021-01-14 | 2021-01-14 | Online monitoring system of ultralow-temperature reciprocating compressor and power indicating method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112727747A true CN112727747A (en) | 2021-04-30 |
| CN112727747B CN112727747B (en) | 2022-11-18 |
Family
ID=75592762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110045244.1A Active CN112727747B (en) | 2021-01-14 | 2021-01-14 | Online monitoring system of ultralow-temperature reciprocating compressor and power indicating method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112727747B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2720201Y (en) * | 2004-06-04 | 2005-08-24 | 赵立明 | Flush-free stop valve |
| CN101059130A (en) * | 2007-03-07 | 2007-10-24 | 江苏工业学院 | On-line remote state monitoring and fault analysis diagnosis system of reciprocating compressor |
| US20100040484A1 (en) * | 2008-08-13 | 2010-02-18 | Shade W Norm | Variable volume clearance pocket for a reciprocating compressor cylinder |
| CN105370429A (en) * | 2015-11-25 | 2016-03-02 | 重庆普什机械有限责任公司 | High-power gas engine air cylinder provided with pressure measuring device |
| CN105403350A (en) * | 2015-11-25 | 2016-03-16 | 重庆普什机械有限责任公司 | Cylinder pressure measurement device |
| CN209959975U (en) * | 2019-03-26 | 2020-01-17 | 中国人民解放军陆军军事交通学院镇江校区 | Electric drive indicator valve of medium-large diesel engine |
| CN210531123U (en) * | 2019-07-30 | 2020-05-15 | 江西资生科技有限公司 | Test platform of reciprocating compressor work indicator diagram |
| CN211262574U (en) * | 2020-03-11 | 2020-08-14 | 淄柴动力有限公司 | Adapter of cylinder pressure sensor |
-
2021
- 2021-01-14 CN CN202110045244.1A patent/CN112727747B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2720201Y (en) * | 2004-06-04 | 2005-08-24 | 赵立明 | Flush-free stop valve |
| CN101059130A (en) * | 2007-03-07 | 2007-10-24 | 江苏工业学院 | On-line remote state monitoring and fault analysis diagnosis system of reciprocating compressor |
| US20100040484A1 (en) * | 2008-08-13 | 2010-02-18 | Shade W Norm | Variable volume clearance pocket for a reciprocating compressor cylinder |
| CN105370429A (en) * | 2015-11-25 | 2016-03-02 | 重庆普什机械有限责任公司 | High-power gas engine air cylinder provided with pressure measuring device |
| CN105403350A (en) * | 2015-11-25 | 2016-03-16 | 重庆普什机械有限责任公司 | Cylinder pressure measurement device |
| CN209959975U (en) * | 2019-03-26 | 2020-01-17 | 中国人民解放军陆军军事交通学院镇江校区 | Electric drive indicator valve of medium-large diesel engine |
| CN210531123U (en) * | 2019-07-30 | 2020-05-15 | 江西资生科技有限公司 | Test platform of reciprocating compressor work indicator diagram |
| CN211262574U (en) * | 2020-03-11 | 2020-08-14 | 淄柴动力有限公司 | Adapter of cylinder pressure sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112727747B (en) | 2022-11-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203214990U (en) | Pressure reducing valve for nuclear power water system | |
| CN112727747B (en) | Online monitoring system of ultralow-temperature reciprocating compressor and power indicating method thereof | |
| CN102980718B (en) | On-line pressure detecting method and device thereof | |
| CN203422203U (en) | Air tightness detection apparatus for sealed bearing | |
| CN210774535U (en) | High-pressure sealing ring testing device | |
| CN201034796Y (en) | Device detecting automobile air conditioner system | |
| CN202974549U (en) | Online pressure detection device | |
| CN200958389Y (en) | Manograph of throttle pipe | |
| CN108468632B (en) | Device for leading out pressure in cylinder of compressor | |
| CN204085808U (en) | A kind of air-tightness detection device | |
| CN220649880U (en) | In-cylinder dynamic pressure detection device | |
| CN218271196U (en) | Detection joint for compression pressure and explosion pressure of HXN5 type locomotive diesel engine | |
| US5567121A (en) | Indicator-ported discharge valves for reciprocating compressors | |
| CN210487197U (en) | Pipeline valve pressure test device | |
| CN202648865U (en) | Device for guiding out pressure in a compressor cylinder | |
| CN217059219U (en) | Camshaft mesopore gas tightness testing fixture | |
| CN215985195U (en) | Device for measuring pressure and temperature of aircraft engine | |
| CN215214695U (en) | LNG valve link low temperature test sealing device is taken over in area extension | |
| CN219796237U (en) | Pressure reducing joint for measuring ultrahigh pressure | |
| CN217901083U (en) | Pressure sensor | |
| CN219263352U (en) | Fluorine-adding double-meter valve with good leak-proof performance | |
| CN216116505U (en) | Hydraulic pressure type pressure gauge protector | |
| CN115752947A (en) | High-pressure dynamic seal testing device and testing method thereof | |
| CN103195295A (en) | Method for testing sealing performance of screwed nipple of oil well pipe | |
| CN219795529U (en) | Embedded plunger pump test fixture |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |