Abstract: Valves are a very important installation device in thermal power plants. The installation of valves in thermal power plants also has certain standards. In the design process, the sealing of valves should be ensured, and the characteristics of valves should be familiar. This paper mainly deals with valves of thermal power plants. The application is analyzed, and it is hoped that it can provide reference for future valve design and improve the design effect of the valve in the thermal power plant.
Key words: thermal power plant; valve; application 1 Introduction Thermal power plant can not lack the use of this part of the valve in the operation process. Regarding the design and application of the valve, it is necessary to first define the theoretical standard of the valve and understand the specificity of the valve of the thermal power plant. Structure, in the formal design and use can identify the shortcomings and can be improved, through the analysis of the structural characteristics of the valve, combined with the overall structure of the thermal power plant machinery, the final formation of thermal power valve design standards.
2 Valve design standards There are two types of valves for thermal power plants. One is full-sealing and the other is auxiliary sealing. When performing certain machining, it is necessary to level the sealing surface and process some details. Only in this way can we use it effectively. In the process of actual processing, some traces will appear on the plane, which requires the improvement of the processing technique, and timely processing when scratches occur. In addition, when the sealing surface is in contact, it is necessary to reinforce the contact surface, and also pay attention to whether the sealing surface outside the plane is restricted, and the sealing surface of the contact is appropriately adjusted to reduce the size of the groove, however, It is still necessary to treat the trench, because if the trench is too small, the molecule will be difficult to pass through the trench, and the trench can be treated by means of a medium, so that the molecule does not have to be hindered when passing through the trench, and finally forms a higher degree. seal.
3 Valve installation and application 3.1 Check valve installation There are two types of check valves, including lift type and swing type. The application conditions of these two types of check valves are also different. The lift type is suitable for DN less than 50mm. The swing check valve is suitable for the case where the DN is greater than or equal to 50 mm. The lift check valve is installed on a horizontal pipe. When installing, ensure that the valve flap is in a vertical state because the lifting process is flexible. Conveniently, the lift check valve has a greater resistance than the swing check valve, and the swing check valve can be installed on a horizontal or vertical pipe, so its installation The range is wider than the lift type, and the swing check valve rotates when it is used, so it must be ensured that it is level with the pin during installation so as to facilitate the use of the swing. Generally speaking, if the diameter of the pipe is relatively large or the pump is used, a slow-closed check valve is required, and in order to prevent problems from being repaired in time, a gate valve may be provided, and if a backflow preventer is installed in one pipe, It is not necessary to install a check valve.
3.2 Installation of the pressure reducing valve The installation of the pressure reducing valve is conditional. Generally, the pressure reducing valve is also required to increase the bypass passage. However, if the pressure reducing valve is added to the partition of one system, the bypass passage cannot be increased. In order to achieve the effect of decompression, two sets of pressure reducing valves of the same configuration can be designed. One group can be put into use, and the other group can be reserved. The installation of the pressure reducing valve must be careful not to tilt and maintain the upright state. Will affect the later use.
3.3 The selection and principle of the valve is firstly the stop valve. Generally, if it is an air-conditioning pipe, try not to install a shut-off valve. It is often used in the water supply pipe, and it can be applied only when the DN is less than or equal to 50mm. In addition, it is a gate valve. The gate valve has its own irreplaceable function, but it cannot adjust the flow rate or pressure compared with other valves, and it is not suitable for the pipeline for mud transportation, and the gate valve cannot be opened or closed frequently during use. It is determined by its characteristics, and its state is generally in the process of full open or full currency. The gate valve should pay great attention during the process of opening or closing. If it is in the case of small opening, in order to avoid the occurrence of water hammer, it should be slowed down to close as much as possible. There is also a butterfly valve, which is used to control the flow rate, but care should be taken not to generate vibration and cavitation when using the butterfly valve. The functions of the valves are different. For example, the ball valve and the plunger valve are the valves that control the tightness of the closing. The cocking gate and the ball valve are controlled in the direction. The two valves also have suspended particulate fluid. The ball valve and the gate valve are in the It is most convenient in full opening and full closing. In addition, if the installation space is relatively small, butterfly valve and ball valve can be used. At the same time, the butterfly valve is also suitable for the inlet and outlet of the water pump. In the heating engineering, the valve used in the variable flow system is a balancing valve.
3.4 Installation of the valve The installation of the valve is very critical, it will affect the quality of the later use, and the engineering of different nature also has different requirements for the installation of the valve. If it is not installed according to the standard, the efficiency of the later use will be reduced. The inner wall coating of the valve installed in the project must be safe and harmless. If it is sewage engineering, the valve should be corrosion resistant and can not be blocked. To install the valve, you can refer to the following steps. First, first understand the characteristics of the valve. Read the instructions of the valve carefully to avoid mistakes during installation. Second, when lifting the valve, the rope should not be placed on the handwheel or the valve stem, and should be connected to the valve cover and the valve body. Third, when the valve and the pipe are connected to each other, the connection cannot be made tough, and the connection is made slowly and fixed at the end. Fourth, there should not be too many bends when installing the valve, so as not to affect the quality of the installation. Fifth, the stability of the hemp must be ensured when installing the valve, thus improving the safety performance of the valve. Sixth, if it is to install the steam pipe, be sure to fix the bracket of the fixed valve, and determine the best position of the bracket to prevent the valve from bursting.
4 Conclusion In summary, the application of thermal power valve machinery has certain standards, the analysis of valve products, at the same time, it should be noted that different valves have different characteristics, to understand these characteristics, and then correctly install the valve, so In order to maximize the role of the valve, and will not affect the later use.
references:
[1] Liu Wanjie. Common problems and treatment processes in maintenance and repair of power plant valves [J]. Science and Technology Promotion Development (Application Edition), 2011 (04): 30-32.
[2]Chen Changjun, Wang Wei, Wang Haitao, Car Welfare. Research on common faults and maintenance of valves[J].Electromechanical Information,2012(11):33-35.
Key words: thermal power plant; valve; application 1 Introduction Thermal power plant can not lack the use of this part of the valve in the operation process. Regarding the design and application of the valve, it is necessary to first define the theoretical standard of the valve and understand the specificity of the valve of the thermal power plant. Structure, in the formal design and use can identify the shortcomings and can be improved, through the analysis of the structural characteristics of the valve, combined with the overall structure of the thermal power plant machinery, the final formation of thermal power valve design standards.
2 Valve design standards There are two types of valves for thermal power plants. One is full-sealing and the other is auxiliary sealing. When performing certain machining, it is necessary to level the sealing surface and process some details. Only in this way can we use it effectively. In the process of actual processing, some traces will appear on the plane, which requires the improvement of the processing technique, and timely processing when scratches occur. In addition, when the sealing surface is in contact, it is necessary to reinforce the contact surface, and also pay attention to whether the sealing surface outside the plane is restricted, and the sealing surface of the contact is appropriately adjusted to reduce the size of the groove, however, It is still necessary to treat the trench, because if the trench is too small, the molecule will be difficult to pass through the trench, and the trench can be treated by means of a medium, so that the molecule does not have to be hindered when passing through the trench, and finally forms a higher degree. seal.
3 Valve installation and application 3.1 Check valve installation There are two types of check valves, including lift type and swing type. The application conditions of these two types of check valves are also different. The lift type is suitable for DN less than 50mm. The swing check valve is suitable for the case where the DN is greater than or equal to 50 mm. The lift check valve is installed on a horizontal pipe. When installing, ensure that the valve flap is in a vertical state because the lifting process is flexible. Conveniently, the lift check valve has a greater resistance than the swing check valve, and the swing check valve can be installed on a horizontal or vertical pipe, so its installation The range is wider than the lift type, and the swing check valve rotates when it is used, so it must be ensured that it is level with the pin during installation so as to facilitate the use of the swing. Generally speaking, if the diameter of the pipe is relatively large or the pump is used, a slow-closed check valve is required, and in order to prevent problems from being repaired in time, a gate valve may be provided, and if a backflow preventer is installed in one pipe, It is not necessary to install a check valve.
3.2 Installation of the pressure reducing valve The installation of the pressure reducing valve is conditional. Generally, the pressure reducing valve is also required to increase the bypass passage. However, if the pressure reducing valve is added to the partition of one system, the bypass passage cannot be increased. In order to achieve the effect of decompression, two sets of pressure reducing valves of the same configuration can be designed. One group can be put into use, and the other group can be reserved. The installation of the pressure reducing valve must be careful not to tilt and maintain the upright state. Will affect the later use.
3.3 The selection and principle of the valve is firstly the stop valve. Generally, if it is an air-conditioning pipe, try not to install a shut-off valve. It is often used in the water supply pipe, and it can be applied only when the DN is less than or equal to 50mm. In addition, it is a gate valve. The gate valve has its own irreplaceable function, but it cannot adjust the flow rate or pressure compared with other valves, and it is not suitable for the pipeline for mud transportation, and the gate valve cannot be opened or closed frequently during use. It is determined by its characteristics, and its state is generally in the process of full open or full currency. The gate valve should pay great attention during the process of opening or closing. If it is in the case of small opening, in order to avoid the occurrence of water hammer, it should be slowed down to close as much as possible. There is also a butterfly valve, which is used to control the flow rate, but care should be taken not to generate vibration and cavitation when using the butterfly valve. The functions of the valves are different. For example, the ball valve and the plunger valve are the valves that control the tightness of the closing. The cocking gate and the ball valve are controlled in the direction. The two valves also have suspended particulate fluid. The ball valve and the gate valve are in the It is most convenient in full opening and full closing. In addition, if the installation space is relatively small, butterfly valve and ball valve can be used. At the same time, the butterfly valve is also suitable for the inlet and outlet of the water pump. In the heating engineering, the valve used in the variable flow system is a balancing valve.
3.4 Installation of the valve The installation of the valve is very critical, it will affect the quality of the later use, and the engineering of different nature also has different requirements for the installation of the valve. If it is not installed according to the standard, the efficiency of the later use will be reduced. The inner wall coating of the valve installed in the project must be safe and harmless. If it is sewage engineering, the valve should be corrosion resistant and can not be blocked. To install the valve, you can refer to the following steps. First, first understand the characteristics of the valve. Read the instructions of the valve carefully to avoid mistakes during installation. Second, when lifting the valve, the rope should not be placed on the handwheel or the valve stem, and should be connected to the valve cover and the valve body. Third, when the valve and the pipe are connected to each other, the connection cannot be made tough, and the connection is made slowly and fixed at the end. Fourth, there should not be too many bends when installing the valve, so as not to affect the quality of the installation. Fifth, the stability of the hemp must be ensured when installing the valve, thus improving the safety performance of the valve. Sixth, if it is to install the steam pipe, be sure to fix the bracket of the fixed valve, and determine the best position of the bracket to prevent the valve from bursting.
4 Conclusion In summary, the application of thermal power valve machinery has certain standards, the analysis of valve products, at the same time, it should be noted that different valves have different characteristics, to understand these characteristics, and then correctly install the valve, so In order to maximize the role of the valve, and will not affect the later use.
references:
[1] Liu Wanjie. Common problems and treatment processes in maintenance and repair of power plant valves [J]. Science and Technology Promotion Development (Application Edition), 2011 (04): 30-32.
[2]Chen Changjun, Wang Wei, Wang Haitao, Car Welfare. Research on common faults and maintenance of valves[J].Electromechanical Information,2012(11):33-35.
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