What knowledge is necessary to understand boiler modifications?

In terms of boiler efficiency, it’s best to minimize heat losses after Q2.

The last edit to this post was made by yingel on 2010-6-19 at 23:19. Topics related to boiler design are fine; there is a book titled \"A Comprehensive Guide to Boiler Design, Manufacturing, Installation, Operation, Maintenance, and Renovation.\" It’s not of very high quality, but it can still be used as a reference – at least it covers a wide range of topics

Principles for the renovation of industrial boilers (1) The renovated boiler should be capable of using local fuels, with the main goal being to improve thermal efficiency. 　　(II) Old-style boilers that have no value for renovation, feature outdated designs, low efficiency, and cause severe environmental pollution, such as Lancashire and Cornish boilers as well as old cast-iron boilers, must be completely phased out. 　　(III) Boiler modifications must comply with the relevant regulations of safety inspection procedures, and should be carried out based on the actual conditions of the respective unit; it is not advisable to blindly follow the experiences of others. Main measures for the technical renovation of industrial boilers (1) Constructing a furnace arch of appropriate shape to increase the temperature in the preheating section and to organize the airflow within the furnace effectively. 　　(II) Improve combustion equipment. 　　(III) Improve the combustion method. 　　(IV) Variable frequency speed control technology is used for the blower and exhaust fans. 　　(5) Install a economizer. 　　(VI) Install boiler tube bundles. 　　(7) Modify the furnace radiant heating surface. 　　(8) Improve the scouring of the heated surfaces by airflow. 　　(IX) Reduce air leakage through various openings and wall cracks. 　　(10) Improve the insulation of the furnace body. Precautions: 1. When switching from coal to gas, different renovation plans should be devised based on the type of furnace. 2. Key steps in the renovation of coal-fired boilers: (1) Remove the auxiliary equipment of the original coal-fired boiler. (2) By performing heat transfer calculations for the furnace chamber, the geometric dimensions of the furnace chamber and the position of the flame center within it are determined. Refill the furnace chamber. To keep the boiler’s rear arch tube away from the center of the flame, the original rear arch tube was raised on top of its original slope. (3) Install explosion-proof doors. (4) Conduct a hydrostatic test on the boiler body at 1.5 times the operating pressure. Under normal circumstances, efforts should be made to leave the pressure-bearing components of the boiler itself unchanged, and only partial modifications should be made to the furnace arch and furnace walls. 3 Points to Note: (1) Ensure smooth flow of flue gas, with good filling; dead corners and dead zones should be avoided. (2) The burner should be placed at the center of the furnace, with sufficient combustion space and length. The flame should not reach the walls of the heated tubes, to prevent incomplete combustion of the gas and localized overheating and damage to the tube walls. (3) The bottom of the boiler drum exposed inside the furnace should be insulated. In addition, the flue gas temperature at the inlet of the tube sheet in fire-tube boilers should be controlled to prevent cracks in the tube sheet. (4) Add insulation material and protective plates to the furnace wall. Reduce the existing furnace doors, inspection doors, etc. (5) The furnace of coal-fired boilers is larger than that of gas-fired boilers, providing sufficient combustion space; after modification, the amount of gas used can be increased without affecting the combustion conditions. If the user requests a significant increase in the boiler’s output, it is possible to appropriately increase the radiant heating surfaces in the furnace, while simultaneously removing scale and soot from both the inside and outside of the existing heating surfaces. In this way, it is feasible to increase the boiler’s output without having to increase its size. However, it is necessary to conduct thermal calculations for the boiler as well as calculations of smoke and air resistance, in addition to performing strength calculations. 4. Choose the appropriate burner correctly: Take into account various factors such as gas pressure, boiler backpressure, air supply pressure, and pipeline resistance, and make a comprehensive decision to select a suitable burner. 5 Deflagration and Explosion Prevention (1) Reliable safety protection control measures must be in place, such as various interlock protections. (2) For water-tube boilers, explosion-proof doors shall be installed at the flue outlet of the furnace chamber, directly opposite the center of the furnace chamber, and on the flue. (3) Strictly establish and enforce safety operating procedures; in particular, thorough purging must be carried out every time the system is started up, and the purging time must be properly controlled. (4) When several boilers share a flue, each boiler should be equipped with a flue door, and each flue door should be fitted with a limit switch. It must be ensured that the boiler can be put into use only after the flue door is opened before starting the boiler. Prevent accidents caused by poor ventilation due to improper operation resulting from the flue door not being opened.