I. Criteria for Evaluating Retrofit Results Generally, the qualification of a boiler retrofit is determined by assessing steam pressure or steam flow. 1. Steam Pressure: The retrofit is evaluated by monitoring the time taken for the boiler to reach the required steam pressure from a cold start, both before and after the retrofit. 2. Steam Flow: Professional institutions use specialized testing equipment to measure the steam flow of the boiler under rated or operational conditions. The retrofit is deemed successful if the steam flow measured after the retrofit meets or exceeds the pre-retrofit steam flow under the same conditions. The semi-coke boiler is a horizontal quick-assembly steam boiler with natural circulation of the working medium. The heat exchange system of this steam boiler consists of a drum, left and right headers, and water-cooled walls. The main heating surfaces include the furnace water-cooled walls, part of the drum, and the convection tube bundles inside the drum. This series of steam boilers is delivered in five major parts: the boiler body, flue gas ducts, dust collectors, and piping systems. The first four parts are manufactured in the factory and transported to the installation site for assembly, significantly shortening the installation cycle and ensuring product installation quality. Currently, the retrofit plan for coal-fired boilers above 20 tons has been announced, recommending the use of clean energy semi-coke as a replacement for coal. What is semi-coke? It is already well-known in the industrial sector. Semi-coke, also known as semi-coke, is produced by carbonizing high-quality Jurassic coal blocks from the Shenfu Coalfield. As a new carbon material, it is characterized by high fixed carbon, high specific resistance, high chemical activity, low ash content, low aluminum, low sulfur, and low phosphorus. It has gradually become one of the important alternatives to coal. However, as an excellent substitute for coal, ordinary coal-fired boilers cannot effectively burn semi-coke. Thus, semi-coke boilers have emerged as a dark horse in this year's coal-fired boiler retrofitting efforts. Specifically designed for the combustion characteristics of semi-coke, these boilers not only successfully address the challenges of ignition and complete combustion but also offer advantages such as high thermal efficiency and low emissions of SO?, NOx, and smoke dust.