CN116242607A

CN116242607A - Mechanical seal state analysis system for shaft end

Info

Publication number: CN116242607A
Application number: CN202310242885.5A
Authority: CN
Inventors: 任宝杰; 郭崇斌; 王曰升; 郝木明; 赵英杰; 任喜子
Original assignee: DONGYING HISCIEN SEALING TECHNOLOGY CO LTD
Current assignee: DONGYING HISCIEN SEALING TECHNOLOGY CO LTD
Priority date: 2023-03-14
Filing date: 2023-03-14
Publication date: 2023-06-09

Abstract

The invention discloses a mechanical seal state analysis system for shaft ends, which comprises: a mechanical seal portion provided at the shaft end; a temperature analysis unit that receives the acquired plurality of temperatures and acquires the temperature of the seal end surface based on an established temperature relationship model; a friction coefficient analysis unit that receives the detected torque and obtains a friction coefficient of the seal end surface based on the established torque and friction coefficient model; and a sealing state analysis unit that analyzes and acquires the sealing state of the sealing end surface based on the temperature and the friction coefficient of the sealing end surface. The invention can effectively monitor the sealing state of the sealing end face in real time.

Description

Mechanical seal state analysis system for shaft end

Technical Field

The invention relates to the technical field of mechanical sealing of shaft ends, in particular to a mechanical sealing state analysis system for shaft ends.

Background

The mechanical seal is widely applied to the fields of metallurgy, electric power, petroleum, chemical industry, rubber and the like and is used for shaft end sealing of fluid medium conveying equipment. The mechanical seal can generally stably operate under the design parameters of corresponding working conditions, but under some variable working conditions or severe working conditions, the load of the sealing end face can fluctuate, so that the liquid film of the sealing end face of the mechanical seal is extremely easy to damage, the sealing end face is in a semi-dry or dry friction state, the sealing face is quickly worn, failure is generated, and the sealing life is reduced. In critical equipment in the fields of petrochemical industry, nuclear power and the like, the loss caused by mechanical seal failure is immeasurable, so that the monitoring of the sealing state of a shaft end is extremely important.

At present, the sealing operation state is generally monitored indirectly by monitoring parameters such as pressure, temperature, liquid level and the like of a mechanical sealing auxiliary system, but the mode only gives an alarm after the sealing has failed, and has time delay and uncertainty, so that a sealing monitoring technology capable of timely and effectively monitoring the friction state of the end face of the mechanical sealing in real time is needed.

Disclosure of Invention

In order to solve the technical problems, the invention provides a mechanical seal state analysis system for shaft ends, which can effectively monitor the seal state of a seal end surface in real time.

In order to achieve the aim of the invention, the invention is realized by adopting the following technical scheme:

the application provides a mechanical seal state analysis system for shaft ends, which comprises the following components:

a mechanical seal disposed at the shaft end, the mechanical seal comprising:

the sealing moving assembly rotates along with a main shaft where the shaft end is located, and comprises a shaft sleeve, a rotating ring part and an elastic supporting part, wherein the shaft sleeve is sealed and sleeved on the main shaft; the rotary ring part is sleeved on part of the shaft sleeve, and the elastic supporting part provides elastic supporting force along the length direction of the main shaft;

the sealing static assembly is arranged on the periphery of the sealing dynamic assembly and is static relative to the sealing dynamic assembly, the sealing static assembly comprises a static ring part, at least one torque sensor and a plurality of temperature sensors, the static ring part is in contact with the end face of the rotating ring part to form a sealing end face, each torque sensor is used for detecting the torque transmitted to the static ring part by the sealing end face, and the plurality of temperature sensors are in scattered contact with the static ring part and are used for acquiring a plurality of temperatures at a plurality of points on the static ring part;

a temperature analysis unit that receives the acquired plurality of temperatures and acquires the temperature of the seal end surface based on an established temperature relationship model;

a friction coefficient analysis unit that receives the detected torque and obtains a friction coefficient of the seal end surface based on the established torque and friction coefficient model;

and a sealing state analysis unit that analyzes and acquires the sealing state of the sealing end surface based on the temperature and the friction coefficient of the sealing end surface.

In the application, a plurality of arc-shaped grooves and at least one detection groove are formed on the side surface of the static ring part, which is far away from the sealing end surface;

the sensing heads of the temperature sensors extend into the arc-shaped grooves and are in contact with the groove walls of the arc-shaped grooves;

the sensing heads of the torque sensors extend into the detection grooves.

In this application, the seal stationary assembly further comprises:

the base is fixed, an embedded groove is formed in one side, facing the sealing end face, of the base, and the static ring part is embedded into the embedded groove;

a plurality of first mounting grooves are formed in the base corresponding to the plurality of arc-shaped grooves, and the temperature sensor is arranged in the first mounting grooves and enables a probe of the temperature sensor to be in contact with the groove walls of the corresponding arc-shaped grooves;

at least one second mounting groove is formed in the base corresponding to each detection groove, and each torque sensor is mounted in each second mounting groove.

In the application, the embedded groove is concavely provided with a sealing ring mounting groove, and a sealing ring is embedded in the sealing ring mounting groove and is used for sealing a gap between the circumferential outer side wall of the static ring part and the circumferential inner side wall of the embedded groove;

a coating for reducing rotational friction between the circumferential inner side wall of the embedded groove and the circumferential outer side wall of the stationary ring part is provided between the circumferential inner side wall and the circumferential outer side wall of the stationary ring part.

In the application, the temperature of the sealing end face comprises a first temperature and a second temperature corresponding to the inner diameter and the outer diameter of the sealing end face and the highest temperature in the sealing end face area.

In the present application, the sealing state analysis unit includes:

a maximum temperature determination unit that determines a temperature coefficient Q2, Q2 e [0,1] corresponding to the maximum temperature based on the fluid medium temperature, a set temperature related to a sealing material, and the maximum temperature;

an inside and outside diameter temperature difference judging unit for judging deformation coefficients Q3, Q3E [0,1] corresponding to the inside and outside diameter temperature differences based on the absolute value of the difference between the first temperature and the second temperature, the first preset inside and outside diameter temperature difference, and the second preset inside and outside diameter temperature difference;

a friction coefficient judgment unit which judges a friction state coefficient Q1 corresponding to the friction coefficient, Q1 epsilon [0,1] based on the friction coefficient, a first preset coefficient and a second preset coefficient;

the comprehensive analysis unit is used for analyzing and acquiring a sealing coefficient Q for representing the sealing state of the sealing end face based on the temperature coefficient Q2, the deformation coefficient Q3 and the friction state coefficient Q1;

wherein the set temperature is greater than the fluid medium temperature; the first preset inner and outer diameter temperature difference is larger than the second preset inner and outer diameter temperature difference; the first preset coefficient is greater than the second preset coefficient.

In the present application, the comprehensive analysis unit obtains the sealing coefficient Q representing the sealing state of the sealing end surface based on the temperature coefficient Q2, the deformation coefficient Q3 and the friction state coefficient Q1, specifically:

respectively assigning weights s and 1-s to the temperature coefficient Q2 and the deformation coefficient Q3, wherein s is a preset coefficient;

obtaining a temperature coefficient q2' =q2×s+q3×1-s;

respectively assigning weights v and 1-v to the temperature coefficient Q2' and the friction state coefficient Q1, wherein v is a preset coefficient;

a sealing coefficient q=q2' ×v+q1×1-v is obtained.

In the present application, the mechanical seal state analysis system for shaft ends further includes:

and the alarm unit is used for sending an alarm prompt when the sealing coefficient does not meet the sealing condition.

In the present application, the sealing state is classified into a plurality of classes based on the sealing coefficient Q.

In the present application, the mechanical seal state analysis system for shaft ends includes:

and the display screen can display a temperature curve of the temperature change along with time and a coefficient curve of the friction coefficient along with time on the display screen based on the temperature of the sealing end face and the friction coefficient.

Compared with the prior art, the mechanical seal state analysis system for the shaft end has the following advantages and beneficial effects:

(1) By designing the sealing dynamic component and the sealing static component, the leakage of the fluid medium to the external atmosphere is avoided on hardware;

(2) The sealing state of the sealing end face is obtained by monitoring the temperature and the torque of the sealing end face in real time, and the real-time sealing state of the sealing end face can be reflected in time due to the adoption of real-time data, so that the timeliness is high;

(3) A plurality of temperature sensors are arranged in a scattered manner, the temperatures are obtained from a plurality of different positions of the static ring part, the temperature of the static ring part is accurately measured, a plurality of temperatures and torques are adopted, the sealing state of the sealing end face is measured in two dimensions of force and temperature, and the accuracy of the result of judging the sealing state is ensured.

Other features and advantages of the present invention will become apparent upon review of the detailed description of the invention in conjunction with the drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an embodiment of a mechanical seal state analysis system for shaft ends according to the present invention;

FIG. 2 is a schematic diagram of a structure in which torque sensors and three temperature sensors are disposed at an end face of a stationary ring portion in an embodiment of a mechanical seal state analysis system for shaft ends according to the present invention;

FIG. 3 is a schematic view of a seal face between a rotating ring portion and a stationary ring portion in an embodiment of a mechanical seal condition analysis system for shaft ends according to the present invention;

FIG. 4 is a schematic flow chart of a maximum temperature judging unit in an embodiment of the mechanical seal state analysis system for shaft ends according to the present invention;

FIG. 5 is a schematic flow chart of an inner and outer diameter temperature difference judging unit in an embodiment of a mechanical seal state analysis system for shaft ends, which is provided by the invention;

FIG. 6 is a schematic flow chart of a friction coefficient judging unit in an embodiment of the mechanical seal state analyzing system for shaft ends according to the present invention;

fig. 7 is a schematic flow chart of an integrated analysis unit in an embodiment of the mechanical seal state analysis system for shaft ends according to the present invention.

Reference numerals:

a 1-O-shaped sealing ring; 2-shaft sleeve; 3-a set screw; 4-push ring; a 5-O-shaped sealing ring; 6-rotating the ring portion; 7-a stationary ring portion; 8-O-shaped sealing rings; 9-a set screw; 10-a torque sensor; 11-O type sealing ring; 12-a base; 13.1-a first temperature sensor; 13.2-a second temperature sensor; 13.3-a third temperature sensor; 14-a spring; 15-spring seats;

20-a temperature analysis unit; 30-a friction coefficient analysis unit; 40-a sealing state analysis unit; 41-a maximum temperature judgment unit; 42-a friction coefficient judgment unit; 43-comprehensive analysis unit;

a-main shaft.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.

All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that the terms "mounted," "connected," and "coupled" are to be construed broadly, as well as, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically indicated and defined. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art. In the description of the above embodiments, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In order to timely and real-time monitor the sealing state of the shaft end, the application relates to a mechanical sealing device for the shaft end, see fig. 1, including: a mechanical seal section, a temperature analysis section 20, a friction coefficient analysis section 30, and a sealing state analysis section 40.

The mechanical seal forms part of the mechanical structure of the shaft end for sealing, preventing the fluid medium from flowing out of the medium side through the shaft end and out of the outside atmosphere side.

The mechanical seal part comprises a seal moving assembly and a seal static assembly.

The sealing moving assembly is sealed and sleeved on a main shaft A where the shaft end is located and rotates along with the main shaft A.

Specifically, the sealing dynamic assembly comprises a shaft sleeve 2, a rotary ring part 6 and an elastic supporting part, wherein the shaft sleeve 2 is arranged on the main shaft A in a sealing way, a first embedded groove (not marked) can be formed in the inner side wall of the shaft sleeve 2, which is in contact with the main shaft A, and an O-shaped sealing ring 1 is embedded in the first embedded groove so as to seal a gap between the shaft sleeve 2 and the circumferential outer side wall of the main shaft A.

The rotary ring portion 6 is fitted over a part of the sleeve 2 and is rotatable together with the sleeve 2, a second fitting groove (not shown) is provided in an inner wall of the rotary ring portion 6 in contact with a circumferential outer wall of the sleeve 2, and an O-ring 5 is fitted into the second fitting groove to seal a gap between the rotary ring portion 6 and the circumferential outer wall of the sleeve 2.

In the present application, the elastic support portion is used to achieve soft cushioning performance of the mechanical seal portion, the elastic support portion is capable of being deformed in the length direction of the spindle a, and is capable of providing the rotating ring portion 6 with an elastic support force in the length direction of the spindle a.

In the present application, the elastic support portion may be provided as the spring 14, or may be another element capable of being deformed.

In order to seal and mount the spring 14, the sealing moving assembly as described above further comprises a spring seat 15, which spring seat 15 may be detachably (e.g. with a set screw 3) fixedly mounted to the sleeve 2, a part of the sleeve 2 to which the spring seat 15 is fixed being closer to the medium side than a part of the sleeve 2 in which the rotating ring portion 6 is sleeved.

The spring seat 15 is provided with a blind hole for placing the spring 14 and extending into a space limited by the spring seat 15 and the rotary ring portion 6 to provide elastic supporting force for the rotary ring portion 6.

In this application, still be provided with push ring 4 between spring holder 15 and rotatory ring portion 6, it also overlaps and establishes on axle sleeve 2 and support rotatory ring portion 6, and spring 14 is in the blind hole of seting up on spring holder 15 and stretches out the end and support push ring 4, through effect elastic support power to push ring 4, and then on the transmission rotatory ring portion 6.

The spring seat 15, the push ring 4 and the rotary ring portion 6 are arranged along the sleeve 2 from the medium side to the atmosphere side.

The above-mentioned members are rotatable together with the spindle a when the spindle a rotates.

Referring again to fig. 1, the seal stationary assembly is disposed about the periphery of the seal moving assembly and is stationary and stationary relative to the seal moving assembly.

The seal stationary assembly comprises a stationary ring part 7, at least one torque sensor and a plurality of temperature sensors.

The stationary ring portion 7 is fitted over the sleeve 2 and located outside the end of the rotary ring portion 6 close to the atmosphere, and the end face of the stationary ring portion 7 contacting the rotary ring portion 6 forms a seal end face.

To achieve the arrangement of the stationary ring part 7, the sealing stationary assembly further comprises a base 12, which base 12 is fixed, e.g. detachably fixed (e.g. with set screws 9) to a fixed platform, which may be a fixed table of a device for transporting a fluid medium, which stationary ring part 7 may be embedded in the base 12 and limited by the base 12 and the resilient support.

In this application, a third insertion groove (not labeled) is provided in the side of the base 12 facing the sealing end face, into which the stationary ring portion 7 is inserted.

For sealing, a first sealing installation groove (not marked) is formed on the base 12, and is used for installing an O-ring 11 for sealing a gap between the base 12 and the fixed platform end face when the base 12 contacts the fixed platform end face.

Further, the base 12 is provided with a second seal mounting groove (not labeled) for mounting the O-ring 8 for sealing a gap between the base 12 and the stationary ring portion 7 when the base 12 contacts the end face thereof, that is, a gap between the circumferential outer side wall of the stationary ring portion 7 and the circumferential inner side wall of the third fitting groove.

When the seal moving assembly rotates along with the main shaft A, the rotary ring part 6 and the static ring part 7 generate rotary friction motion at the sealing end face, and the working state of the sealing end face between the rotary ring part 6 and the static ring part 7 determines the service performance of the whole mechanical seal structure.

The sealing state of the mechanical seal portion is monitored by monitoring the state of the sealing end face.

In the present application, the state of the seal end face is measured in terms of the temperature of the seal end face, the distribution of the temperature, and the friction state of the seal end face.

For this purpose, at least one torque sensor is provided for detecting the torque transmitted by the sealing end face to the stationary ring part 7 in the operating state, for assisting in measuring the coefficient of friction of the sealing end face; a plurality of temperature sensors are arranged for detecting a plurality of temperatures at the multipoint of the fixed ring part 7 in the working state and measuring the temperature and the distribution of the sealing end face.

In the present application, referring to fig. 1, a torque sensor 10 is provided in consideration of the installation position; if the mounting position is satisfied, a plurality of torque sensors may be provided, and the average value of the torques detected by the plurality of torque sensors may be obtained as the torque transmitted from the seal end surface to the stationary ring portion 7.

Regardless of the number of torque sensors provided, a torque value indicative of the transmission to the stationary ring part 7 is eventually obtained.

Since the rotating ring portion 6 generates a force to the sealing end face and is transferred to the stationary ring portion 7 when rotating in an operating state due to the presence of the elastic support portion when generating a rotating friction at the sealing end face, the torque sensor 10 should be abutted against a side of the stationary ring portion 7 remote from the sealing end face and located above the sleeve 2, see fig. 1 and 2.

Specifically, a detection groove (not labeled) corresponding to the installation of the torque sensor 10 is formed in one side of the stationary ring part 7 away from the sealing end surface and above the shaft sleeve 2, and the sensing head of the torque sensor 10 extends into the detection groove.

In order to improve the temperature detection accuracy of the stationary ring portion 7, a plurality of temperature sensors are provided, and specifically in this application, three temperature sensors are provided in a dispersed manner.

Referring to fig. 1 to 3, three temperature sensors detect a plurality of different positions of the stationary ring portion 7, respectively, wherein a first position point a is disposed on a side of the stationary ring portion 7 away from the seal end face and below the sleeve 2, and a second position point B and a third position point C are disposed on a circumferential outer side wall of the stationary ring portion 7 below the sleeve 2 at angles.

Arc grooves are formed in the positions corresponding to the first position A point, the second position B point and the third position C point, the sensing head of the first temperature sensor 13.3 stretches into the arc groove in the first position A point (see figure 3) and is in fit contact with the groove wall, the sensing head of the second temperature sensor 13.2 stretches into the arc groove in the second position B point (see figure 3) and is in fit contact with the groove wall, and the sensing head of the third temperature sensor 13.1 stretches into the arc groove in the third position C point (see figure 3) and is in fit contact with the groove wall, so that the close contact of the temperature sensor and the static ring part 7 can be realized, and the accurate detection temperature is realized.

In order to mount the torque sensor 10, the first temperature sensor 13.3 detecting the temperature at the first position a, the second temperature sensor 13.2 detecting the temperature at the second position B and the third position C, and the third temperature sensor 13.1, mounting grooves (not marked, see fig. 1) are opened in the base 12 corresponding to the mounting positions.

A plurality of first mounting grooves (not shown) are formed in a portion of the base 12 located below the sleeve 2 and on a side away from the seal end surface, and each temperature sensor is mounted in each first mounting groove.

A second mounting groove (see fig. 1) is formed in a portion of the base 12 above the sleeve 2 and on a side away from the seal end surface, and the torque sensor 10 is mounted in the second mounting groove.

The number of temperature sensors described above is shown by way of example only, and the specific number may be freely selected as desired without limitation.

The increase of the number of the temperature measuring points is more beneficial to fully measuring the temperature and the distribution of the sealing end face and is beneficial to the accuracy of the analysis result of the sealing state.

In order to reduce friction between the stationary ring part 7 and the base 12 when the rotary ring part 6 and the stationary ring part 7 perform a rotary friction operation, a coating layer for reducing the rotary friction between the circumferential inner side wall of the third fitting groove of the base 12 and the circumferential outer side wall of the stationary ring part 7 is provided between them so as to avoid affecting torque transmitted to the stationary ring part 7.

The coating may be provided on the circumferential inner side wall of the third insert groove or on the circumferential outer side wall of the stationary ring part 7, for example molybdenum disulphide.

The description in terms of the mechanical structure of the mechanical seal portion is completed as above, and as follows, analysis of the sealing state of the seal end face using the detected temperature and torque will be described.

The temperature analysis unit 20 receives the acquired plurality of temperatures, and acquires the temperature of the seal end face based on the established temperature relationship model.

In the present application, the temperature conditions of the end face are sealed from two angles of the temperature magnitude and the temperature distribution of the end face.

Accordingly, the temperature of the seal face as described above includes a first temperature (also referred to as an inner diameter temperature) and a second temperature (also referred to as an outer diameter temperature) corresponding to the inner and outer diameters of the seal face, and the highest temperature in the seal face region.

The inner and outer diameters of the sealing end face refer to a first radius and a second radius when the static ring part 7 is concentric with the cross section of the main shaft A, wherein the first radius is smaller than the second radius.

The first temperature corresponding to the inner diameter of the seal end surface refers to the temperature at the first radius position on the end surface of the stationary ring portion 7 facing the rotary ring portion 6.

The second temperature corresponding to the outer diameter of the seal end face refers to the temperature at the position of the second radius on the end face of the stationary ring portion 7 facing the rotary ring portion 6.

Since in the present application, the plurality of temperature sensors are all disposed on the portion of the stationary ring portion 7 located below the sleeve 2, referring to fig. 3, the first temperature here refers correspondingly to the temperature Td at the point D at the first radius on the end face of the portion of the stationary ring portion 7 located below the sleeve 2 facing the rotary ring portion 6, and the second temperature here refers correspondingly to the temperature Te at the point E at the second radius on the end face of the portion of the stationary ring portion 7 located below the sleeve 2 facing the rotary ring portion 6.

The established temperature relation model is established in advance, describing the detected temperature of the stationary ring part 7 as input, and the inside diameter temperature Td, the outside diameter temperature Te, and the highest temperature Tmax in the seal end face area of the stationary ring part 7 as output.

And constructing a temperature calculation model of the stationary ring part by using a thermal transfer mathematical model based on the elastic body and a general convective heat transfer coefficient empirical formula.

The temperature calculation model is corrected by utilizing a large amount of experimental test data of a preliminary laboratory to obtain a temperature relation model of each point of the stationary ring part 7, wherein the accuracy meets the engineering use requirement, and in actual use, the actual size, the sealing structure parameters such as material performance parameters, the operation parameters such as rotation speed, temperature, pressure and the like are taken into consideration, and the corrected temperature relation model of each point of the stationary ring part 7, namely the temperature relation model of the stationary ring part 7 established as described above, is obtained by means of the temperature relation model of each point of the stationary ring part 7.

In this way, the inside and outside diameter temperatures Td, te and the maximum temperature Tmax of the stationary ring portion 7 can be obtained.

The friction coefficient analysis unit 30 receives the acquired torque and acquires the friction coefficient of the seal end face based on the established torque and friction coefficient model.

The established torque and friction coefficient model is established in advance, describing the torque as input and the friction coefficient as output.

And obtaining a corresponding relation between the torque and the friction coefficient by utilizing a common torque-friction coefficient empirical formula and combining a large amount of experimental test data, and obtaining a corrected corresponding relation between the torque and the friction coefficient by taking into consideration actual sealing structure parameters such as size and material performance parameters, and operating parameters such as rotating speed and pressure during actual use, namely, the established torque and friction coefficient model as described above.

In this way, the friction coefficient f can be obtained.

In order to establish the relationship between the inner diameter temperature Td, the outer diameter temperature Te, the highest temperature Tmax and the friction coefficient f and the sealing state, the sealing state analysis part 40 is adopted to analyze and acquire the sealing state of the sealing end surface so as to monitor the sealing state of the mechanical sealing part in real time in the working process, discover problems in time, and avoid the problem expansion to cause immeasurable loss.

Referring to fig. 1, the sealing state analysis section 40 includes a maximum temperature determination unit 41, an inside and outside diameter temperature difference determination unit 42, and a friction coefficient determination unit 43.

The maximum temperature determination unit 41 determines a temperature coefficient Q2, Q2 e [0,1] corresponding to the maximum temperature Tmax based on the fluid medium temperature T2, the set temperature T1 related to the sealing material, and the maximum temperature Tmax.

The set temperature T1 associated with the sealing material belongs to the upper sealing material temperature limit, which temperature represents a serious risk of overtemperature.

Referring to 4, when Tmax is larger than or equal to T1, the current temperature is too high, and the overtemperature risk exists, and the temperature coefficient Q2=0 is judged; when tmax=t2, the current temperature is represented as an ideal state, and the temperature coefficient q2=1 is determined; when T2 < Tmax < T1, the current temperature is represented as normal, and linear relation interpolation assignment is adopted, and Q2=1- (Tmax-T2)/(T1-T2).

The inside-outside diameter temperature difference judging unit 42 judges the deformation coefficient Q3, Q3 e [0,1] corresponding to the inside-outside diameter temperature difference based on the absolute value between the temperatures Td and Te, the first preset inside-outside diameter temperature difference, and the second preset inside-outside diameter temperature difference.

Wherein the first preset inner and outer temperature difference is greater than the second preset inner and outer temperature difference.

The first preset internal and external temperature difference is a temperature difference point which is set by adopting an expert experience method and indicates that the deformation value of the sealing end face is overlarge, and the temperature difference point is marked as T3.

The second preset internal-external temperature difference is the minimum allowable Wen Chadian selected from the previous design data, and is marked as T4, wherein the deformation value of the sealing end face corresponding to the minimum temperature difference point is the design value, and is preset.

Referring to fig. 5, when Δt= |td-te|Σt3 is larger than or equal to the seal face deformation value, it is determined that the deformation coefficient q3=0; when the absolute value Td-Te is less than or equal to T4, representing the current deformation value as a design value, and judging the deformation coefficient Q3=1 at the moment; when T4 < |Td-Te| < T3, the current deformation value is represented as a normal state, and at the moment, linear relation interpolation assignment is adopted, and Q3=1- (|Td-Te| -T4)/(T3-T4).

The friction coefficient judgment unit 43 acquires the friction state coefficient Q1, Q1 e [0,1] from the friction coefficient f, the first preset coefficient f1, and the second preset coefficient f 2.

The first preset coefficient f1 and the second preset coefficient f2 are preset parameters, and may be designed according to a specific structure of the mechanical seal portion, for example, the first preset coefficient f1 may be set to 0.12, and the second preset coefficient f2 may be set to 0.05.

Referring to fig. 6, when f is equal to or greater than f1, it is indicated that the present dry friction state is present, and the friction state coefficient q1=0 is determined at this time; when f is less than or equal to f2, the fluid friction state is currently shown, and the deformation coefficient Q1=0.6 is judged at the moment; when f2 < f1, it indicates that the friction state is currently in a mixed friction state, q1=1 in a standard mixed friction state occurring when the friction coefficient f is 0.07, and a linear relation interpolation value is adopted during the period, q1=1- (f-0.07)/0.05.

In this way, the friction state coefficient Q1, the temperature coefficient Q2, and the deformation coefficient Q3 can be obtained.

The values of the coefficients Q1, Q2, and Q3 described above may be calculated in other ways as long as the sealing state of the seal end face can be obtained based on the temperature of the stationary ring portion 7 and the friction coefficient f.

The sealing state analysis section 40 further includes an integrated analysis unit 43 that analyzes the acquired sealing coefficient Q based on the friction state coefficient Q1, the temperature coefficient Q2, and the deformation coefficient Q3, and measures the sealing state with the sealing coefficient Q.

Since the temperature coefficient Q2 and the deformation coefficient Q3 are both temperature-dependent, the temperature coefficient Q2' may be obtained by assigning weights in consideration of the influence of temperature on the sealing state.

And then, the sealing state is integrally measured from the two angles of temperature and friction by using the Q2' and the friction state coefficient Q1, and the sealing coefficient Q representing the sealing state is obtained.

Referring to fig. 7, considering the influence of the temperature coefficient Q2 and the deformation coefficient Q3, weights s and 1-s are assigned to the temperature coefficient Q2 and the deformation coefficient Q3, respectively, where s is a preset coefficient.

Thus, Q2' =q2×s+q3×1-s.

Wherein, the value range of s is generally 0.3-0.5.

Weights v and 1-v are assigned to the temperature coefficient Q2' and the friction state coefficient Q1, respectively, where v is a preset coefficient.

Thus, a sealing coefficient q=q2' ×v+q1×1 (1-v), q∈ [0,1] is obtained.

Wherein, the value range of v is generally 0.5-0.7.

From the above-described manner of acquiring Q1, Q2' and Q3, it is known that the greater the Q value is, the better the sealing state is, and the smaller the Q value is, the worse the sealing state is.

Therefore, in order to conveniently reflect the sealing state, different sealing levels are defined according to the magnitude of the sealing coefficient Q, respectively.

In this application, seal levels are defined as four levels.

With continued reference to FIG. 7, when Q.gtoreq.0.9, a seal rating is defined as A, which represents a "good condition," i.e., a condition that meets expectations.

At 0.9 > Q.gtoreq.gtoreq.0.75, a seal rating is defined as class B, which represents an "acceptable state," i.e., a state in which sealing continues for operation without additional measures.

When Q is more than 0.75 and is more than or equal to 0.6, the sealing grade is defined as C grade, and the grade represents a 'state needing to be treated in time', namely, a state which can continue to operate for a short period but should be stopped and overhauled in time.

At Q < 0.6, a seal level is defined as level D, which represents an "unacceptable state", i.e., a state in which use must be immediately stopped.

Alternatively, other numbers of classification of seal classes may be used, as just an example and not limiting herein.

The sealing conditions (for example, the sealing coefficient Q is required to meet a certain range) of the mechanical sealing part required by the user are also different according to different sealing requirements, so in order to avoid the accident that the sealing state does not meet the requirements and the loss occurs, an alarm unit (not shown) should be adopted to alarm the situation that the sealing state does not meet the sealing conditions in time.

For example, if the sealing condition is set to Q.gtoreq.0.75, therefore, when the sealing grade is at C level, an alarm prompt message needs to be output through the alarm unit to remind the user to stop and overhaul immediately.

If the sealing condition is set to Q is more than or equal to 0.6, therefore, when the sealing grade is in the D grade, the alarm unit is required to output alarm prompt information so as to remind a user of immediately stopping the machine for maintenance.

After the seal analysis part obtains the seal grade, in order to timely display the current seal state to a user, the output characters can be displayed in green when in the grade A, and the output characters can be displayed in green when in the grade B and flash; the C level outputs words in yellow and flash quickly to prompt alarming words; when the D level is displayed, the output text is red and flashes rapidly, and if an external alarm unit is connected, a signal is sent to alarm.

The alarm unit can be an audible and visual alarm, a buzzer, an LED flashing lamp and the like.

When the temperature (for example, the inner diameter temperature Td, the outer diameter temperature Te, the highest temperature Tmax) and the friction coefficient f of the sealing end face are obtained in real time, a temperature curve of the temperature change with time and a coefficient curve of the friction coefficient change with time can be established, and the curve graph can be checked at any time so as to predict the running state development trend of the sealing end face according to the curve change.

The mechanical seal state analysis system for the shaft end can monitor the running state and the development trend of the mechanical seal state analysis system when the sealing end face normally runs, and can also give an alarm to prompt when abnormal states occur or possibly occur, and give data references to whether equipment needs to be shut down, overhauled and replaced, so that huge losses caused by sealing sudden failure cannot be remedied are effectively avoided.

The above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be apparent to one skilled in the art that modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for some of the technical features thereof; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. A mechanical seal condition analysis system for a shaft end, comprising:

a mechanical seal disposed at the shaft end, the mechanical seal comprising:

2. The mechanical seal state analysis system for shaft ends according to claim 1, wherein,

a plurality of arc-shaped grooves and at least one detection groove are formed in the side surface, far away from the sealing end surface, of the static ring part;

the sensing heads of the torque sensors extend into the detection grooves.

3. The mechanical seal condition analysis system for shaft ends according to claim 2, wherein the seal stationary assembly further comprises:

4. A mechanical seal condition analysis system for shaft ends according to claim 3, wherein,

the embedded groove is concavely provided with a sealing ring mounting groove, and a sealing ring is embedded in the sealing ring mounting groove and is used for sealing a gap between the circumferential outer side wall of the static ring part and the circumferential inner side wall of the embedded groove;

5. The mechanical seal condition analysis system for a shaft end according to claim 1, wherein the temperature of the seal face includes a first temperature and a second temperature corresponding to an inner diameter and an outer diameter of the seal face, and a highest temperature in a region of the seal face.

6. The mechanical seal state analysis system for a shaft end according to claim 5, wherein the seal state analysis section includes:

7. The mechanical seal state analysis system for shaft ends according to claim 6, wherein the comprehensive analysis unit obtains a seal coefficient Q representing a seal state of the seal end face based on a temperature coefficient Q2, a deformation coefficient Q3, and a friction state coefficient Q1, specifically:

obtaining a temperature coefficient q2' =q2×s+q3×1-s;

a sealing coefficient q=q2' ×v+q1×1-v is obtained.

8. The mechanical seal state analysis system for shaft ends according to claim 6 or 7, characterized in that the mechanical seal state analysis system for shaft ends further comprises:

9. The mechanical seal state analysis system for shaft ends according to claim 6 or 7, wherein,

and classifying the sealing state in multiple grades based on the sealing coefficient Q.

10. The mechanical seal state analysis system for shaft ends according to claim 1, wherein the mechanical seal state analysis system for shaft ends comprises: