Extraction and application of the best comprehensi

2022-08-08
  • Detail

Extraction and application of the best comprehensive management parameters of Equipment Abstract: the best comprehensive management parameters of equipment are obtained by comprehensive inference and calculation based on the parameter values of various key parameters extracted under the best operation state of equipment and the three principles of extraction of the best comprehensive management parameters of equipment. Comparing it with the comprehensive management parameters of equipment in the form of analog quantity can provide important guidance for production management. It has built a good technical platform for daily production management and making the equipment always in the best running state

key words: best comprehensive management parameters; Negative pressure of drying cylinder; Induced draft fan current

there are advantages and disadvantages in the operation state of any type of equipment. In the normal operation state of an equipment, various key parameters related to the operation of the equipment can be synthesized and calculated with scientific theory, and a parameter that can comprehensively reflect the operation status of the equipment at any time can be obtained. Since this parameter is the real-time comprehensive reflection of the equipment operation state, if it is expressed in the form of analog quantity, it can be directly compared with the comprehensive parameters of the equipment in the best operation state (derived from the inference and operation of various key parameters of the comprehensive equipment in the best operation state), and the manager can judge and adjust the equipment's deviation from the best operation state at any time, which has a guiding role in production

1 three principles of extracting the best comprehensive management parameters

the extraction of the best comprehensive management parameters should grasp the following three principles:

1.1 extracting the best comprehensive management parameters. The selected parameters should be the key parameters related to production and operation, or the basic parameters that have an important impact on the key parameters

1.2 there are relationships or connections between various key parameters that affect each other or facilitate inference

1.3 the comprehensive parameters obtained from the inference of various key parameters should be easily and immediately expressed in the form of analog quantities (current, temperature, etc.) to provide reference for production and form comprehensive management parameters

2 extraction of the best comprehensive management parameters

2.1 combined with LQC240 asphalt concrete mixing plant, this paper makes a specific analysis of the three principles of extracting the best comprehensive management parameters

in recent years, we have better used the comprehensive management parameters in the production management of LQC240 asphalt concrete mixing plant, and achieved good production benefits. In the extraction of comprehensive management parameters of LQC240 asphalt concrete mixing plant, we carefully measured and checked various basic data, and cooperated with various manufacturers to make a detailed study and Analysis on it according to the above three principles. The introduction is as follows:

① according to the above principle 1.1, according to the production characteristics of the asphalt mixture mixer, the production capacity of the mixer is most closely related to the temperature raising capacity of the drying drum system for the aggregate. Because the proportion of hot aggregate accounts for more than 94% of the total quality of asphalt mixture, the output of hot aggregate almost determines the output of asphalt mixture of a mixer. Therefore, the parameters of each part of the drying drum system are the key preferred parameters. It includes: 1. Various parameters of the dryer's self-contained blower. (such as the working air volume and other basic parameters provided by the blower) 2. Various characteristic parameters and working parameters of the drying cylinder itself. (such as basic parameters such as cross-sectional size, cross-sectional area of openings at the front and rear ends of the drying drum and working negative pressure)

② according to the above principle 1.2, the parameters of each part of the induced draft and dust removal system working with the drying drum system are the second type of parameters to be emphatically considered. Because the working negative pressure required by the drying drum is provided by the induced draft and dust removal system, the parameters of the two systems have mutual influence and are easy to infer. If there is no working negative pressure, there will be many papers published and more than 20 invention and utility model patents. The fuel combustion of the drying drum burner is insufficient, the fire is weak, and the fire is extinguished, which will seriously affect the temperature raising ability of the drying drum system to the aggregate, and then affect the output of hot aggregate and asphalt mixture. Such parameters include: 1. Dimensional parameters of each part of the induced draft flue. 2. Pore passing rate parameter of dust removal bag. 3. Various parameters of induced draft fan. 4. Parameters of induced draft motor. 5. Parameters of working medium of induced draft fan

③ according to the above principle 1.3, there is a direct ratio between the air volume parameter of the induced draft fan of the induced draft and dust removal system and the current of the induced draft motor (the increase of the induced draft increases the actual working power of the induced draft motor, resulting in the increase of the working current of the induced draft motor), and the current of the induced draft fan is an analog quantity, which can be conveniently expressed in real time with the induced draft ammeter to provide reference services for production, and then can be formed into a comprehensive management parameter

2.2 determine the main inferential relationship between the parameters

based on the above analysis and our long-term observation of the best operating state of LQC240 asphalt concrete mixing plant (the output of LQC240 asphalt concrete mixing plant under the best operating state is 150 tons/hour), in order to determine its best comprehensive management parameters, The main inferential relationships among its parameters are determined as follows:

① for LQC240 asphalt concrete mixing plant, when the burner of the drying drum system works normally, its ability to raise the temperature of aggregate depends on the working negative pressure of the drying drum. (the working negative pressure of the drying drum is provided by the induced draft fan of the induced draft and dust removal system). Under normal circumstances, there are the following relationships among the main parameters: if the section parameter s of the air inlet of the induced draft fan (the size is determined by the opening of the damper) is increased, the induced air volume parameter q is increased, and the working negative pressure parameter p of the drying cylinder is increased accordingly. When the negative pressure of the drying drum increases to the appropriate no-load height value of several handwheels and nut screw adjustable experimental machines, the working medium of the burner of the drying drum system - fuel oil, in addition to the air provided by the burner blower, will also obtain enough air from the outside to fully burn and generate the maximum heat. The temperature raising capacity of the system is the highest, the output of hot aggregate is the largest, and the output of asphalt mixture of the mixer is driven to the peak

② the working negative pressure P1 of the drying drum system is affected not only by the total pressure P6 generated by the induced draft fan, but also by the positive pressure P2 of the high-temperature and high-pressure gas generated by the combustion of the burner; Pressure P3 of gas resistance loss along the pipeline; Pressure P4 of gas loss caused by bag resistance of dust collector; The impact of negative pressure loss P5 caused by lax sealing of individual pipelines is shown in the following figure:

the relationship is: P6 =p1-p2+p3+p4+p5

2.3 for LQC240 asphalt concrete mixing plant, the specific extraction of the best comprehensive management parameters

2.3.1 extraction conditions

generally, due to the complexity of the induced air flow path, except that the working negative pressure P1 of the drying drum can be directly measured by the negative pressure sensor at the front of the drying drum, Other forms of pressure loss are not easy to be measured or obtained by theoretical calculation. Therefore, a negative pressure sensor can be installed at the inlet of the induced draft fan. When the asphalt mixing plant is in the best operating state, the negative pressure parameter P6 at the inlet port of the induced draft fan can be directly measured to simplify the research process

Measurement conditions of

p6:

① according to the design conditions of LQC240 asphalt mixture mixer, P1 should be 6-7mm water column, that is, P1 ≈ 60.3n/m2. At this time, the fuel oil of the burner is fully burned and P2 is normal

② the sand and gravel entering the drying drum has reached the qualified conditions, and the water content is controlled below 5%

③ the induced draft flue is unblocked, the dust removal bag eyelet is not blocked, and the pressure P3 of gas loss by resistance along the way and the pressure P4 of bag loss are at the low limit

④ the pipeline is tightly sealed, and the negative pressure loss P5 is basically eliminated

⑤ the induced draft fan and induced draft motor work normally

note: the above conditions are necessary for the mixer to enter the best working state

2.3.2 extraction process

measured p6= 2864pa; The temperature at the inlet of induced draft fan is 40 ℃, and the density of flue gas =11.339 n/m3; Cross sectional area at the inlet of induced draft fan s=0.37m2 (determined by the opening of damper) u: flue gas flow rate at the inlet of induced draft fan

q: flue gas flow at the inlet of induced draft fan

q= u*s=49.75*0.37=18.40 m3/s

pe= p6*q/1000=2864*18.40/1000 =52.72kwpe: actual power of induced draft fan

p axis =pe/η= 56.72/0.585=90.13kw P-axis: shaft power of induced draft fan; η: Fan efficiency

pg = ks*p axis/η Tw=1.05*90.13/0.95=99.62 kw

pg: induced draft motor power KS: motor safety factor η Tw: mechanical transmission has a higher profit margin level, efficiency

IP: induced draft fan current up: line voltage

ip=171.99 is the best comprehensive management parameter obtained

2.3.3 analysis of extraction results

from the above extraction process of IP, it can be found that the acquisition of the best comprehensive management parameter ip=171.99 (only refers to LQC240 asphalt concrete mixing plant) involves almost all the key parameters of the drying drum and induced draft dust removal system of LQC240 asphalt concrete mixing plant. Such as negative pressure of drying drum, flue gas density, induced draft fan efficiency, section size and a series of important parameters. These parameters are also affected by many basic parameters, such as the influence of the positive gas pressure P2 produced by the combustion of the burner on the negative pressure P1 of the drying cylinder, the influence of the water content of sand and gravel on the density of flue gas, and so on. Although these parameters are not directly involved in the operation, they have an important impact on the operation parameters in actual production. The changes of the above parameters will have different forms of influence on the best comprehensive management parameter induced draft current ip=171.99a due to their different properties. According to the reflection of IP ammeter on these different forms of influence, it is convenient to analyze those parameters that have changed, so as to find and find out the problems in the operation of asphalt mixing plant, deal with and correct those changed parameters in advance, and make the equipment always operate in the best state. This is the important role of IP in actual production management. IP is no longer a simple technical parameter, Become comprehensive management data that can provide direct reference for production management

2.3.4 specific application

the best comprehensive management parameters are mainly used in the following two aspects in production management:

1. Analysis and judgment of the hidden trouble of the equipment itself. For LQC240 asphalt concrete mixing plant:

A. analysis and judgment of dust removal flue blockage

when there is blockage in the dust removal flue, it is equivalent to that the flue section becomes smaller. Therefore, only by increasing the normal opening of the air valve can we ensure sufficient induced air volume and make the negative pressure P1 of the drying cylinder normal. Before the normal damper is not enlarged, IP is usually less than the best comprehensive management parameter ip=171.99a, and the more serious the flue blockage is, the smaller it is. According to this phenomenon, we can judge whether the flue is blocked and the degree of blocking

b. analysis and judgment on the blockage of dust removal bag eyelets

the blockage of the dust removal cloth bag eyelet is mostly caused by the insufficient combustion of the burner and the oil smoke sticking to the cloth bag eyelet. At this time, even if the air valve of the induced draft fan is opened to the maximum, IP will not change much. The value of IP cannot reach the value required by the best management parameters

c. judgment on the cause of induced draft fan itself

when the induced draft fan works for a long time, the blades of the induced draft fan will sometimes be stained with soil, causing uneven load. The induced draft current IP has abnormal irregular swing. The fuselage will also vibrate. According to this phenomenon, we can judge whether the induced draft fan itself has a problem

2. Judge the arbitrary behavior of the operator

before the best comprehensive management parameters of a device are obtained, all operators go

Copyright © 2011 JIN SHI