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The project for utilizing the excess pressure of medium-pressure saturated steam in the water and steam plant of Shaanxi Shanjiao Chemical Industry was successfully commissioned after passing the acceptance process. Author/Source: Shaanxi Shanjiao Chemical Industry; Date: August 5, 2020; Clicks: 15. At 9 a.m. on July 28, 2020, the site of the production facility where the technical renovation of the circulating water system in the alcohol-ammonia section was carried out was very busy. Organized by the Mechanical and Energy Department, along with representatives from the Asset and Finance Department, the Compliance and Audit Department, the Comprehensive Management Department, and the staff of the water and steam plant, a thorough inspection was conducted to assess the proper operation of the newly installed equipment, the procedures for ensuring the system’s normal functioning, and the energy-saving effects achieved after the system was put into use. The results showed that the upgraded units had been operating stably for over 50 days, achieving the expected goals in terms of reducing electricity consumption; thus, the project for utilizing excess pressure of medium-pressure saturated steam was successfully commissioned. “The \"Medium-pressure Saturated Steam Waste Pressure Utilization Project\" is an initiative taken by the company to make full use of the medium-pressure steam generated during the operation of the methanol conversion and synthesis units. In the circulation water pump room of the alcohol-ammonia section in the water treatment plant, the 3# circulation water pump was modified: the motor at the drive end of the pump was replaced with a multi-stage turbine, while an electric motor was installed at the non-drive end. The turbine drives the 3# circulation water pump, and the newly added electric motor helps in energy utilization, thereby achieving power savings and energy-saving effects through asynchronous power generation. For the specific implementation of the project, Xi’an Shida Energy Co., Ltd. is responsible for the design, supply, modification, installation, and commissioning of all equipment and facilities. Shaanxi Coking Company, on the other hand, is responsible for providing the site where the equipment will be installed and operated, as well as high-quality medium-pressure steam required for the proper operation of the units. Once the units are operating properly, Shaanxi Coking Company will, in accordance with the terms of the contract for energy management, pay Xi’an Shida Energy Co., Ltd. for its investments and reasonable profits, thereby enabling both parties to reap benefits. The renovation work began in March 2020. To meet the requirements of the construction, the water treatment plant brought pumps No. 1, 2, 4, and 5 of the circulating water system online in advance to ensure the safe and reliable operation of this system, while pump No. 3 was shut down and isolated from the system. Xi’an Shida Energy Co., Ltd. carried out the modifications in accordance with the planned scheme: first, the 500KW motor installed in the water pump was removed, and in its place a 1600KW multi-stage steam turbine along with a reducer were installed to drive the water pump; subsequently, a 1600KW asynchronous motor was added to the non-driving end of the water pump. When the driving power exceeded that of the water pump, the asynchronous motor generated electricity which was fed into the grid and integrated into the 10KV production power supply system, with the amount of electricity supplied to the grid being measured using a two-way electric meter ； The two steam pipelines generated by the synthesis and conversion units were modified and combined into one pipeline, which serves as the feed pipe for the newly installed turbine; the backpressure steam is integrated into the plant’s low-pressure steam network, while the cooling water is connected to the inlet of the circulating water pipes within the plant, thereby completing the modification of the steam and water systems for these units ； A central control room is established in the southwest corner of the plant, and a new PLC control system is installed to monitor and control the operation of this unit, thereby ensuring its proper daily operation. Following continuous construction work, the renovation project was fully completed on May 25th. Technical personnel immediately began system debugging, and trial operation started officially on June 3rd. After more than a month of continuous testing, and taking into account the actual amount of steam generated by the methanol conversion and synthesis units, it became possible to ensure the proper operation of the No. 3 circulating water pump, enabling the generation of over 300 kWh of electricity per hour for grid supply. Statistics show that this approach allows for a savings of around 800 kWh of electricity per hour; with the No. 3 circulating water pump operating continuously, approximately 576,000 kWh of electricity can be saved each month. According to the terms of the project contract, the company is entitled to 40%-60% of the profits generated, and at a price of 0.5 yuan per kWh, this results in savings of over 144,000 yuan per month. Over an annual period of 10 months of operation, the total electricity savings can reach over 1.44 million yuan. This energy-saving renovation is overseen by the company’s Mechanical Energy Department, with full cooperation from the Water Vehicles Workshop, the Alcohol-Ammonia Workshop, and the Mechanical, Electrical, and Instrumentation Maintenance Center. By employing new equipment technologies, new operating processes, and new collaboration models, and by innovating in equipment and process technologies based on the current state of production processes, efforts are made to improve efficiency and maximize productivity. As part of the company’s campaign to combat the heat and ensure stable and high production levels over 100 days, the successful trial operation and acceptance of the upgraded units represent an effective measure that helps the company reduce costs and increase efficiency, thereby contributing to its success in this critical struggle for survival.