Analysis and Treatment of Common Faults of Fuel Injection Twin Screw Air Compressor

Analysis and treatment of common faults of Zhongzhou coal-injected twin-screw air compressor Chen Zhanjun (Guotou Coal Zhengzhou Energy Development Co., Ltd., Dengfeng, Henan 452478), and will reduce the production efficiency of enterprises and bring huge economic losses to enterprises. . In order to deal with the fault of the oil-injected twin-screw air compressor quickly and accurately, starting from its working principle, the common faults are analyzed and the corresponding processing methods are proposed.

As the scale of production of modern enterprises continues to expand, higher requirements are placed on the safety and reliability of the equipment used. The fuel-injected twin-screw air compressor is the main power equipment of the enterprise, and its operating status directly affects the production status of the enterprise. Once the air compressor is not properly maintained, various abnormal phenomena and faults will occur during operation, which will seriously affect the service life of the equipment and the production efficiency of the enterprise.

1Injection-type air compressor oil and gas separation principle The injection-type twin-screw compressor mainly includes: main engine, cooling and lubrication system, oil and gas separation system, gas volume adjustment and electrical control system. The main unit is composed of a pair of female and male rotors and a casing. In the process of compressing air, the nozzle on the wall of the casing continuously injects cooling oil into the compression chamber, and 80% of the heat generated in the compression is carried away by the cooling oil, and the cooling oil is discharged out of the machine together with the compressed air, through separation and cooling. After filtering, it can be recycled. The oil-gas separation of the fuel-injected twin-screw compressor is carried out in two stages, namely a coarse separation stage and a fine separation stage.

(1) The coarse separation is completed in the oil separator. After the oil and gas mixture enters the oil separator through the exhaust pipe, the larger oil droplets fall into the oil tank due to gravity and fall apart; the smaller oil droplets and gas rotate in the separator. The oil droplets are smashed toward the cylinder wall by centrifugation, and flow into the oil tank through the cylinder wall to realize centrifugal separation; after the mechanical collision of the smaller diameter oil droplets in the separator, it accumulates on the cylinder wall and flows into the fuel tank to be separated. After coarse separation, more than 99% of the oil in the oil and gas mixture is separated.

(2) Fine separation means coacervation adsorption. After the crude separation, the mixture containing a small amount of oil is subjected to fine separation in the oil separator core. The oil separator core consists of two layers of concentric fiber cylinders. When the oil-gas mixture passes through the oil separator core, the oil adsorbs and condenses on the fiber cylinder. The outer layer graduated from China University of Mining and Technology and has long been engaged in the management of mechanical and electrical equipment.

The oil droplets fall back into the oil tank, and the oil in the inner layer flows to the bottom of the oil separator core by gravity, and then returns to the compressor inlet through the oil return pipe under the pressure difference. After fine separation, the oil content of the compressed air is greatly reduced.

2 common fault diagnosis and treatment 2.1 main engine exhaust temperature is too high Under normal circumstances, the exhaust temperature of the fuel injection twin-screw air compressor is in the range of 70~95 °C, once the exhaust temperature exceeds the preset protection temperature value The over-temperature alarm self-stop switch on the air compressor will act and cause the shutdown fault. 0. (1) Regular parts inspection. Routine inspections are generally performed in the order of easy and difficult. 1 oil filter. The oil filter of the twin-screw air compressor has high precision, and the filter element is extremely easy to block, resulting in insufficient oil supply to the main engine and excessive exhaust gas temperature. The oil filter can be removed by special tools, and the filter element should be carefully checked for dirt. If the filter element is dirty, it should be replaced in time. 2 cooling fan. The cooling fan is a key component of the air-cooled unit and provides forced cooling of the oil cooler and air aftercooler. As a power source, the fan can circulate the cooling air between the casing and the external space to improve the heat dissipation effect of the machine. Once the fan stops rotating, the exhaust temperature of the air compressor will reach the alarm self-stop level within a certain period of time. In view of the large cooling fan area, slender blades, poor rigidity, and easy deformation, it is necessary to check it frequently and adjust if necessary. 3 coolers. Oil coolers and air aftercoolers are the primary heat sink components and must be cleaned regularly. The dirt on the outer surface of the cooler is mainly the oil formed by the cooling oil and the dust, and the cooler is mostly made of finned tubes. The sludge sandwiched between the fins is difficult to remove, and the low-pressure steam spray cleaning and decontamination effect is better; the inside of the cooler tube The dirt is mainly the coke produced during the oil circulation, and is generally rinsed with a special cleaning agent until the carbon is completely removed.

Zhongzhou Coal (2) pressure switch inspection. The main engine exhaust pressure of the twin-screw air compressor is set by the pressure switch. Once the pressure switch is damaged or the lock is not tightly locked, it is affected by the vibration of the machine, and the set value is easily drifted, causing the exhaust pressure to exceed the limit value. Causes the unit to overheat.

(3) Check the temperature control valve. The temperature control valve is a three-way valve. When the air compressor is cooled and started, the oil can be bypassed by the cooler and directly injected into the main machine to achieve a rapid rise of the oil temperature to prevent the water vapor in the compressed air from condensing in the oil separator. When the oil temperature rises to 65 °C, the temperature control valve will gradually open the main circuit as the oil temperature rises. By adjusting the proportion of the oil flowing through the oil cooler and the bypass, the oil temperature is controlled to ensure the air pressure. The injection temperature of the machine is kept at the optimum point; if the temperature control valve fails, the lubricating oil may be directly injected into the main engine without the oil cooler, and the oil temperature cannot be lowered, resulting in high exhaust gas temperature and shutdown. After shutdown, the temperature of the oil cooler entering the drain pipe should be checked first. If the temperature difference is not large, the temperature control valve should be inspected. Possible failure of the temperature control valve: 1 The thermal spring on the valve core can not move normally with the change of oil temperature; 2 the valve body is worn, the action is not in place, and it can not work normally. It should be repaired or updated in time according to the actual situation.

(4) Check the oil shut-off solenoid valve. If the unit is operated in the automatic start-stop mode for a long time, due to frequent start and stop, the oil-disconnecting solenoid valve is easily damaged, causing the unit to overheat due to insufficient oil supply or oil supply interruption.

2.2 After the main engine air inlet returns to the air compressor, the cooling oil is sprayed from the air inlet of the main engine. This phenomenon is the return of the air inlet. The main causes of this phenomenon are the following aspects: H. (1) Compressed air backflow failure. The compressed air can only be returned to the main engine through the exhaust pipe of the main engine. In order to prevent the reverse flow of the compressed air, a check valve is arranged on the exhaust pipe. However, when the valve is used for a long time, the valve core will wear and the seal will fail, causing the compressed air to flow backward, causing the main rotor to reverse and pumping the oil out of the air inlet. The treatment method is to disintegrate the check valve, check the valve core and seal in detail, and replace it in time if damage occurs.

(2) The oil shut-off solenoid valve is faulty. The oil cut-off solenoid valve is a normally closed solenoid valve, which functions to cut off the oil passage after stopping, preventing oil from entering the main unit from the separator. Once the oil shut-off solenoid valve is not completely closed, the oil will flow into the main engine through the fuel tank when the pressure is not completely unloaded, and the air inlet oil return failure occurs. To this end, it is necessary to check the oil-disconnected solenoid valve frequently, and replace it if it is found to be damaged.

(3) The discharge valve is not vented. During the shutdown process, the discharge valve should be opened to release the pressure in the oil separator and the oil filter. If the discharge valve is damaged, the exhaust valve cannot be depressurized, and the shut-off solenoid valve is not closed tightly, which will result in The phenomenon that the oil is ejected from the air inlet after entering the main engine. Always check the drain valve carefully.

2.3 The main engine exhaust oil content exceeds the standard air compressor exhaust oil content exceeds the standard will not only reduce the cleanliness of the gas, pollute the equipment, but also increase fuel consumption and increase production costs. When the exhaust gas content exceeds the standard, you can start the inspection from the following aspects. 4. (1) Check if the oil level of the fuel tank is too high. If the oil level of the fuel tank is too high, a high flow rate will be generated when the oil and gas mixture is separated into the fuel tank, and the high-speed air flow will entrain the lubricating oil into the compressed air, resulting in the oil content of the air compressor exhaust exceeding the standard. Therefore, it is necessary to strictly control the oil level in the fuel tank.

(2) Check the oil and gas separation filter. The service life of the oil and gas separation filter is closely related to the degree of pollution of the cooling oil and the amount of oil flowing through the oil separation core. During long-term operation, impurities such as dust and metal dust in the cooling oil will block the oil-gas separation filter element, causing the pressure difference on both sides of the filter element to increase, the flow rate to increase, and even the separation filter element to be broken down, completely losing the separation function. Therefore, the oil and gas separation filter should be inspected regularly, and if the filter is clogged or damaged, it should be replaced in time.

(3) Check the minimum pressure valve opening value. The role of the minimum pressure valve: 1 to ensure the minimum pressure required for the oil circulation of the unit; 2 to eliminate the phenomenon of high pressure gas backflow to the oil separator in the pipe network; 3 to ensure that the pressure difference between the oil separator before and after is not too large, the gas speed will not be too high, Achieve the effect of oil and gas separation. If the opening pressure is too low, the pressure difference between the oil and gas separator filter element will increase, the gas flow rate will increase, and the oil accumulated on the wall cylinder will be taken away, resulting in an increase in the oil content of the exhaust gas.

2.4 The main engine exhaust pressure is low. The low exhaust pressure of the main engine is mainly caused by insufficient intake air and exhaust leakage. It needs to be checked from the following aspects.

(1) Air filter. Due to long-term use, the air filter is easily blocked by dust, resulting in insufficient air intake and low exhaust pressure. Regularly check the air filter and update it if it is dirty.

(2) Intake regulator. Once the intake regulator is not normally opened or the opening is insufficient, it will also result in insufficient intake and low exhaust pressure.

The air intake regulator should be inspected frequently and repaired or replaced according to actual conditions.

(3) Exhaust piping. The unloading valve and the discharge valve are components that are often leaking on the exhaust line. Due to the frequent operation of these two solenoid valves, it is easy to cause the valve plate to wear and leak. Always check the unloading valve and the discharge valve, and if there is a leak, it must be replaced in time.

3 Conclusion The fuel-injected twin-screw air compressor is the main power equipment of modern enterprises. Once it fails during operation, it will not only affect the service life of the equipment, but also reduce it (turning to page 81) Ren Shuming, etc.: The application of the two-integration framework of coal chemical enterprises under the cloud service concept The continuous management process of enterprise integration and integration (3) The establishment of a continuous evaluation system for the integration of enterprises.

The establishment of an evaluation system should be carried out in the following aspects: (1) evaluate the progress of the integration of the two technologies, so as to make informed decision-making in a timely manner, and then transfer to the next stage after completion of each stage; The expected goals, in order to adjust the information construction measures and methods in a timely manner; 3 to assess the overall effect of the integration of the two technologies, to see whether the two-integration work has played an important role in the fields of corporate safety, production, finance, supply, sales, engineering construction, etc. Whether to ensure the realization of the company's strategy and system management and effectively reduce various production costs, so that the company's management and control efficiency and efficiency are improved, thereby improving the company's core competitiveness.

(Responsible editor: Guo Haixia) is divided into three parts: the first part is the various transmitters scattered throughout the site; the second part is the cabinet room, the signals sent by all the transmitters in the field are concentrated in the cabinet room. Processing; after processing, it is displayed on the computer sent to the central control room through the switch, which is the third part of the system. The DCS control system not only improves the safety and stability of the operation of the device, but also improves the quality of the product.

(2) Seamlessly connect with ERP through cloud computing virtualization technology. Through the cloud computing virtual technology, the production data of the device in the DCS system is directly extracted into the ERP system. In the ERP system, the real-time summary analysis of the production data is realized, and the real-time production report can be automatically generated, which provides a guarantee for timely adjusting the operating parameters of the device and improves the efficiency of the entire production process.

(3) Pass the inspection data to the ERP system. The DCS system transmits the parameters such as temperature, vibration and displacement of important equipment to the ERP system through the cloud computing virtual technology. The equipment management module in the ERP system can help predict and analyze the possible faults of the equipment, thereby reducing the number and time of maintenance. Extend its operating cycle.

2.3 Data Center Informatization Data center construction consists of three parts: 1 Through the construction of a data exchange center, the company data is exchanged between A, NC and DCS systems to realize data sharing; 2 by combing the extracted valid information data Integrate data into application systems and service platforms to integrate data inside and outside the company; 3 analyze the integrated data to provide a basis for production operations and company decisions.

3 Implementation steps of the two-in-one fusion framework (1) The integration of the two enterprises must be planned in an overall way, step by step, and staged. The integration of coal chemical enterprises should be divided into three steps: 1 enterprise informationization. Through the implementation of OA organization collaborative management and control system, DCS production control system and NC business process management and control system, basic business informationization such as work coordination, document management, production control and scheduling, financial management and control, material management and equipment management are realized. 2 Information technology enterprises. Through the construction of the portal to achieve everyone, everywhere, and always synergy, through user development, to achieve e-commerce, and customers, suppliers, banks and other users share information systems. 3 cloud service companies. Through the information center construction, information platform integration and IT service management to achieve data and service sharing, the internal and external users of the enterprise are highly collaborative, allowing users to enjoy the ubiquitous service.

(2) The establishment of a continuous management system should be established for the integration of enterprises.

The company's two-integration work is a dynamic process. The company is constantly developing, the management level is constantly improving, the management mode is constantly changing, and the information technology is constantly improving. Therefore, the company constantly responds to the information development strategy in the process of information construction. Adjust and improve to adapt to the development of the company (). Establishing a two-industry integration leadership and management team, and continuous dynamic management is a necessary guarantee for the integration of the two.

Enterprise informatization (continued from page 78) of the company's production efficiency will bring huge economic losses. Accurate diagnosis and treatment of the failure of the air compressor during operation can ensure its safe and reliable operation and better serve the enterprise.

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