Design and optimization of steam tracing systems for chemical process pipelines

Design and optimization of steam tracing systems for chemical process pipelines

Chemical process pipeline in the actual transportation process will be affected by a variety of factors, need to actively take measures to ensure the safety and stability of chemical process pipeline transportation. In the actual production process, some workers do not pay attention to the design and research of the heat tracing system of chemical process pipeline, which leads to more problems. In this regard, the article briefly introduces the steam tracing system used in the chemical process pipeline, and composes the design points of the chemical process pipeline tracing system from the aspects of safety design, classification transportation and economic design; analyzes the design content of the steam tracing system of the chemical process pipeline, including clarifying the flow chart of the steam tracing pipe, setting the steam distribution station and hydrophobic station, designing the condensate station and heat preservation design; studies the design of the chemical process pipeline steam tracing system The functional design of steam tracing heat system of chemical process pipeline, including medium temperature control, pipeline temperature regulation, etc., was studied; the specific design method of electric tracing heat of related industries was explored, so as to improve the steam tracing heat design system and help the orderly development of chemical pipeline engineering. 

In the process of production and operation of chemical enterprises, it is necessary to use chemical process pipelines to transport different kinds of media, and it is also necessary to use advanced heat preservation and anti-freezing processes according to the material characteristics of different media to guarantee the safety and stability of media transport and avoid the phenomenon of freezing in the process of transport. Therefore, it is necessary to study the steam tracing system of chemical process pipeline, and put forward optimization suggestions.

Chemical process pipeline steam heating system overview

The chemical process pipeline is in the low temperature environment for a long time, easy to lead to heat loss and solidification phenomenon in the process of medium transportation, once the above problems occur, it will make the chemical process pipeline appear damage, affect the normal use of related machinery and equipment and pipelines, leading to the chemical process pipeline can not give full play to its original performance, slowing down the work progress of chemical enterprises. Steam tracing system can improve the chemical process pipeline internal low temperature environment, so as to transport different media escort, guarantee the safety and stability of media transmission. Therefore, it is necessary to design the steam tracing system reasonably, so that it can play its proper role.

Chemical process pipeline steam with heat system design points

• (1) Safety design. Relevant staff in the design of steam tracing system, to ensure that the steam tracing system has a high degree of safety, so as to improve the safety and stability of the chemical process pipeline transmission medium. At the same time, the designer must adhere to the principle of economy, so as to reduce the medium in the transmission process of economic losses and energy consumption. Usually, steam tracing tube design needs to use saturated media, the use of saturated media can meet the design needs of steam tracing tube heat source media. In this process, need to clarify the critical point and high temperature point of different media, according to different kinds of transport media, choose the correct pipeline temperature, strict control of the accompanying heat temperature, so that it is higher than the actual medium temperature, targeted control of steam temperature, give full play to the advantages of steam accompanying heat system.
• (2) Classification transport. If the transported medium has strong corrosiveness or acidity, to design the external pipeline outside the steam with heat system, to achieve the classification of transport with corrosive medium and no corrosive material. In no corrosive material internal set up with heat pipe, so as to protect the safe and stable operation of the chemical process pipeline, to prevent the media caused by pollution, improve the scientific and rational nature of the transport of media.
• (3) Economic design. Distribution station installation generally take vertical, horizontal and other installation mode, distribution station connected pipeline not more than 6, steam accompanying pipe spacing to take 1 m. Reasonable completion of pipeline optimization design, effective control of pipeline length, reduce pipeline costs.

Specific design of steam accompanying heat system for chemical process pipeline

Clarify the flow chart of steam accompanying pipe

Staff in the design of steam with heat system, must be clear steam with the flow of the pipe, to make the chemical process pipeline of the relevant pipeline, instrumentation and pipeline equipment and steam with the flow of the pipe consistent, to avoid the emergence of pipeline or pipeline disorderly connection, resulting in transport work can not be carried out smoothly, hinder the site management work smoothly, for the later transport work to bring adverse effects. Staff also according to the actual design needs and work situation to analyze the flow chart. For example, when the length of the accompanying heat pipeline is long, the designer should take the way of segmentation accompanying heat design steam accompanying heat system, so that the steam accompanying pipe can be close to the actual work needs.

Set steam distribution station and hydrophobic station

First of all, the relevant designers must connect the steam pipe to the steam from the bottom or the side, and keep the horizontal and vertical forms of the installation direction with a high degree of consistency. It is necessary to install the supply pipe in the horizontal direction and lead the conduit from the top or side to the condensate water, so as to play the role of steam distribution station. Second, the relevant designers must clarify the size of the diameter of the pipeline, to control the diameter within a reasonable range, and if there are more than three steam distribution stations, the corresponding steam distribution stations and hydrophobic stations should be set up, so as to ensure that steam resources can be reasonably allocated.

Condensate Station Design

The relevant staff should connect the main piping of the condensate station with the main piping of condensate, and pay attention to absorbing the top heat of the condensate station. During the heating process, the condensate pipe is drawn out and the valve is opened, and the trap door is designed at the outlet of the pipeline, and then the steam is transferred to the condensate and the condensate is discharged. The above operations ensure the safe and stable operation of chemical process piping and prevent media transport from affecting other piping and machinery and equipment.
When carrying out condensate collection work, according to the actual situation, steam tracing distribution station should be established, and vertical installation can be used. This way is conducive to the smooth completion of condensate collection work, and can avoid the risk of pipeline corrosion. Another key point of steam tracing design is to design steam tracing piping, adding a shut-off valve at the output position of the condensate main, and adding a set of traps when the condensate is transferred back to the tracing piping, so as to recycle the condensate. In the design of steam tracing piping, separate traps should be used to ensure that the trapping of steam tracing is carried out independently and that the condensate and other impurities inside the piping are discharged in a timely manner to improve the safety of the steam tracing system.

Thermal insulation design

The steam tracing pipe contains two kinds of materials, hard and soft, which form two kinds of heat preservation system accordingly, and the hard material is designed as round heat preservation and the soft material is designed as shaped heat preservation. If you choose hard material, it will increase the heat preservation space and effectively control the heat loss problem, when designing, you need to bundle the heat preservation layer and pay attention to the smoothness of the heat preservation structure to prevent the problem of reducing the heat transfer speed; soft heat preservation layer will reduce the heat preservation space and increase the heat loss amount, when designing, you need to use wire mesh to adjust the heating space.
Steam tracing system will use tracing heat chemical process pipeline to convey the medium concerned, can reduce the heat loss of the medium in the process of conveying, prevent the medium from solution in the process of conveying, and even corrosive gas which corrodes the pipeline. If heat loss occurs in the transported medium, it may lead to a sudden drop in the temperature of the medium and make the viscosity of the medium increase, thus affecting the effective transportation of the chemical process pipeline, causing the medium to be connected to the pipeline, affecting the characteristics of the medium, not conducive to the chemical process pipeline to keep clean and tidy, thus shortening the service life of the chemical process pipeline. Therefore, it is necessary to effectively regulate and control the temperature of the medium through the form of steam tracing heat.
Steam tracing system mainly uses steam distribution station and steam piping, etc. to control the internal temperature of the pipeline. The design of heat tracing for chemical process piping is usually carried out at the steam tracing distribution station. The steam tracing distribution station is an important link in the design of steam tracing system, which needs to attract the high attention of the staff. The steam tracing distribution station is mainly composed of instruments, valves, pipes, brackets and other components. The designer should clarify the size of the platform, valve, pipe and the specific installation position according to the specific operation demand, and also equip a fixed bracket and a sliding bracket for the steam tracing distribution station; at the same time, it should be equipped with shut-off valve, shut-off valve and trap, and according to the actual operation condition, reasonably plan the specific position of the half pipe and the total pipe, and the specific size of the pipe, so as to ensure the steam tracing system The subsequent work can be carried out in an orderly manner, and improve the efficiency of the steam tracing system. Designers should clarify the specific design requirements of the steam tracing station, install the steam tracing station on the wall or wall column, and clarify the installation operation process of the steam tracing distribution station, to ensure that the steam distribution station can dissipate the steam in the pipeline quickly, to avoid excessive steam inside the chemical process pipeline, the formation of condensate, corrosion process pipeline. In the installation of steam tracing distribution station, it is necessary to reserve 1 to 2 preparatory ports, so that in case of emergency, it is possible to guarantee the effective distribution of steam.

Installation of steam tracing system equipment for chemical process piping

In the installation of steam tracing system related machinery and equipment, the staff should clarify the specific installation process according to the installation drawings, pay close attention to the change of steam temperature inside the steam tracing pipe, and actively take measures to reasonably control the steam temperature.
When installing the steam tracing system, the trap set position should not be designed bypass valve. If a bypass valve is provided, once a bypass leakage problem occurs, it will cause steam to be mixed in the condensate line, indirectly increasing the back pressure, weakening the trap function, causing condensate to converge, and reducing the operating capacity of the condensing program. When installing a collection station, it is necessary to add a shut-off valve and a drain valve, and to add a shut-off valve in front of the trap as a means of performing operations such as pressure testing and purging, and to prevent damage to the trap by blocking both the companion pipe and the drainage process. The design of a drain valve effectively prevents rust from flowing into the trap and improves the damage to the trap. The tracing pipe connection is made at the location of the gas transmission and water return of the tracing line, and the equivalence of the connection potential is ensured. If the vertical arrangement is adopted and the accompanying pipe is not less than 2, it is necessary to lay the accompanying pipe evenly with the accompanied pipe as the main body; if the horizontal arrangement form is adopted, it should be reasonably laid on both sides of the accompanied pipeline in conjunction with the number of accompanied pipe requirements.
The installation position of the gas transmission line of the steam station should be located at the top of the steam pipe, and the shut-off valve should be added in the adjacent position of the branch pipeline to ensure the standardization of the installation position of the equipment at each place. The specification of the condensing location hydrophobic pipeline is high, the specification of the pipeline is at least DN50, and the heat tracing pipeline should be installed in the form of 45° downstream, keeping this angle into the condensing bus location. The heat tracing line is installed at the condensing program and connected to the filtration and hydrophobic programs simultaneously. The installation position of the hydrophobic station should be chosen at the lowest point of the system. The backup piping for each program needs to be reasonably designed on the side of the station for easy access. Standardize the installation of each program to improve the system operation capacity, simplify the system operation process, and comply with the requirements of long-term operation of the equipment. After the installation of each system is completed, it is necessary to check the installation of the system with reference to the standard design scheme, and timely exclude the installation irregularities.

Chemical process pipeline steam with heat system design problems and solution measures

The design of steam tracing system should achieve the double goal of clean production and cost control, so as to improve the quality of chemical process piping design. The theoretical calculation of steam tracing heat system is mainly through the total heat loss of all the pipelines and equipment in the system, to determine the total area of the required tracing heat, and finally determine the total length of steam tracing heat pipe required to meet the tracing heat temperature and the total amount of steam required.
In practice, the steam accompanying heat system design has the following problems.

• (1) The system planning is not complete, there is a design standardization is not comprehensive problem, will increase the difficulty of workers operation.
• (2) The calculation results of the accompanying heat effect is not accurate, most use the empirical formula, there is a large error, will produce a certain amount of heat loss, increase the system operating costs.
• (3) The innovative design scheme needs to be enhanced.

Steam heat tracing system design follow-up improvement measures.

• (1) Strengthen the industry personnel specification awareness, comply with the design standards, create supervision system.
• (2) To fine design ideas as the starting point, comprehensive simulation calculation of various operating conditions, accurate steam consumption, improve the optimization of the design of the accompanying pipe, effective control of heat loss problems.
• (3) Integrating integrated design technology, carrying out design work from a global perspective, using 3D platform simulation to run the steam tracing program, visually viewing the design scheme, detecting possible collision problems, and improving the usability of the design scheme.

Design optimization of steam tracing system for chemical process piping

Steam tracing heat and electric tracing heat are the common methods in the design of chemical process pipeline tracing heat, and they have different advantages. Therefore, when designing steam tracing heat systems for chemical process pipelines, the working principle of electric tracing heat design can be borrowed. Electric tracing heat is usually used to heat the device with electricity, and is an effective way to heat and keep warm to serve the chemical process pipeline. The use of electric heat tracing method can reduce the work burden of the staff, simplify the work process, has the characteristics of operability, simple and convenient work. And, the electric tracing heat work way work cycle is shorter, the later maintenance and management work is more convenient, the daily maintenance work demand is less, can reduce the work difficulty for the chemical enterprise, reduce the actual input cost of the chemical enterprise. The use of thermal switch and electric tracing heat system to the temperature of accurate control, can avoid the medium in the transmission process of leakage problems, but also can effectively prevent pollution phenomenon, electric tracing heat operation method in the design process of chemical process pipeline has been widely used.
Can take “steam + electric” joint with heat design method, in order to obtain both the advantages of two kinds of accompanying heat design, so as to continuously improve the steam accompanying heat system running ability, actively solve the steam accompanying heat system in the actual work of the problem and shortage, so as to enhance the steam accompanying heat system in the actual work of running efficiency, minimize energy consumption In order to achieve the goal of chemical industry enterprises.

Conclusion

In the new situation, the staff must use advanced science and technology to constantly optimize and upgrade the steam tracing system, to understand the design principles and application status of the steam tracing system, to clarify the design points of the chemical process pipeline, to enhance the operation capacity of the chemical pipeline with the optimal design scheme, and to drive the orderly development of the chemical device related industries. For this reason, the article elaborates the design points of chemical process pipeline tracing heat system, specifically discusses the design content of chemical process pipeline steam tracing heat system, then introduces the function design of chemical process pipeline steam tracing heat system, and finally analyzes the specific design method of electric tracing heat of related industries, combines the design advantages of electric tracing heat system, makes up for the defects and shortcomings of steam tracing heat system, so as to continuously optimize the steam tracing heat system The system is optimized and the practical value of steam tracing heat system is better played.

Source: China Chemical Process Pipelines Manufacturer – Yaang Pipe Industry Co., Limited (www.ugsteelmill.com)