How to ensure proper heat protection and freeze protection for chemical processing units in Xinjiang region

1. Design phase: – Select materials suitable for high and low temperatures: For pipes, reactors, etc. in chemical plants, materials that can withstand high temperatures as well as freezing conditions should be chosen, such as higher-grade stainless steel or special alloy materials. - Enhance insulation and heat protection measures: Ensure that the temperature inside the device remains within a reasonable range under extreme temperatures in summer and winter. - Selection of air coolers: Given the large temperature fluctuations in Xinjiang, air coolers capable of withstanding large temperature differences should be chosen, and the heat exchange efficiency should be improved by installing fans. 2. Construction phase: - Selection of construction season: Try to avoid carrying out major construction work during periods of extreme heat or cold. - Anti-freezing measures: In areas where water is used during construction, it is necessary to add appropriate antifreeze to prevent damage to equipment and pipes due to freezing. 3. Operation phase: - Enhance monitoring and inspections: Especially during periods of extreme temperatures, strengthen real-time monitoring and inspections of the equipment’s operating status to identify and address issues promptly. - Adjusting operational parameters: Based on seasonal changes and temperature differences, parameters such as operating pressure, flow rate, and temperature are adjusted in a timely manner to ensure the stable operation of the chemical process. - Train operators: Equip them with knowledge of emergency measures and operational techniques in extreme weather conditions, thereby enhancing their ability to cope with such weather situations. - Reserved redundancy design: When designing chemical plants, a certain amount of design redundancy can be included to address the uncertain impacts of extreme weather conditions. Overall, chemical processing facilities in Xinjiang must take extreme climate conditions into account throughout the design, construction, and operation phases. By making appropriate choices regarding materials, applying suitable technologies, and providing proper training for personnel, it is possible to ensure the safe and stable operation of these facilities. .

Guidelines for Heat and Freeze Protection Measures in Chemical Plants in Xinjiang. In the Xinjiang region, due to the severe cold in winter (with extreme temperatures reaching -40°C) and the intense heat in summer (with extreme temperatures exceeding 40°C), along with large temperature differences between day and night, chemical plants need to adopt dual protection strategies to deal with both heat and freeze risks. The following are specific measure suggestions: I. Heat prevention measures (to cope with high temperatures in summer) 1. Optimization of equipment and processes: Use of heat-resistant materials – Materials such as high-temperature alloys and ceramic fibers should be used to manufacture key equipment (such as reactors and pipes), in order to prevent deformation due to high temperatures (for example, carbon steel tends to creep at temperatures above 300°C). Insulation design: The surface of high-temperature equipment is covered with nano-airolgels (thermal conductivity ≤ 0.02 W/m·K) or aluminum silicate fiber blankets (thickness ≥ 50 mm) to reduce the surface temperature to below 50°C. Evaporative cooling system: By installing spray cooling devices (with water mist particle size ≤ 50μm) in the outdoor equipment area, along with axial flow fans (with wind speed ≥ 3 m/s), it is possible to reduce the ambient temperature by 5~8°C. 2. Process control – Temperature monitoring: Invertible thermal cameras (with a precision of ±1°C) and thermocouples are installed at key locations such as reactors and storage tanks to monitor temperature fluctuations in real time. Process adjustment: Reduce the rate of exothermic reactions in summer (for example, lower the temperature of the nitration reaction from 40°C to 35°C); if necessary, activate the backup cooling tower (increasing the water circulation volume by 20%). 3. Personnel protection and management during high-temperature periods: Implement a system of starting work early and taking breaks in the heat (suspending outdoor work from 12:00 to 16:00), and provide wearable physiological monitoring devices (for real-time monitoring of heart rate and body temperature). Emergency protection: Equipe the control room with first-aid supplies such as medical ice blankets (with a cooling rate of ≥0.5°C/min) and Huoxiang Zhengqi liquid. II. Anti-freezing measures (to cope with severe winter conditions) 1. Heat tracing and insulation systems: Electric heat tracing – MI mineral-insulated cables (with a temperature resistance of 600°C) are used for the pipes, with a power rating of ≥30 W/m; these cables are paired with PID temperature controllers (offering a temperature control accuracy of ±2°C). Steam tracing: Steam jackets are installed in areas sensitive to low temperatures (such as instrument air pipelines) to maintain the tube wall temperature above 5°C. Insulation layer: Pipeline insulation uses polyurethane foam (thickness ≥ 80 mm) + aluminum foil reflective layer to ensure heat loss ≤ 20 W/m². 2. Emptying and Anticoagulation: Emptying design: During shutdown, water pipes and fire protection pipelines are purged with compressed air (pressure ≥ 0.6 MPa) to remove any residual liquid. Antifreeze injection: Ethylene glycol antifreeze (concentration 40%, freezing point -30°C) is added to the instrument air system. 3. Intelligent monitoring and low-temperature warning: Wireless temperature sensors (with LoRa transmission and a measurement range of -50~80°C) are installed; the data is fed into the DCS system, which triggers a low-temperature alarm (with a threshold set at -10°C). Automatic interlock: An interlock is set between the valve and the heat tracing system, which automatically activates the electric heat tracing when the pipeline temperature is detected to be ≤0°C. III. Management during seasonal transitions: Spring and autumn maintenance: Clean the fill material in the cooling tower (to increase heat exchange efficiency by 10%~15% in summer), and test the impedance of the electric heating circuit (with a deviation of ≤5%). Replace the aged insulation layer (pay special attention to elbows and flanges), and use an infrared camera to detect insulation defects. Emergency plan: In summer, a diesel generator (with a backup capacity of ≥500kW) is installed to prevent disruptions to the cooling system ； Stock up on methanol de-icing agents for winter (suitable for -45°C), and install mobile gas heaters (with a heat capacity of ≥50kW) to cope with extreme cold waves. IV. Recommendations for economic optimization: Energy recovery: Utilize the high temperatures in summer to preheat raw materials (for example, by recovering waste heat from reactions through heat exchangers, which can result in an energy savings rate of up to 15%). Intelligent control: Digital twin systems are deployed to simulate the operation of equipment under extreme temperatures, thereby optimizing energy consumption for heating/cooling (with an expected 20% reduction in annual operational costs). Through the above technical measures and refined management, it is possible to ensure the safe and stable operation of chemical plants in Xinjiang under extreme conditions ranging from -40°C to 40°C, while also taking into account energy efficiency and economic viability. Special attention should be paid to the effect of Xinjiang’s dry climate on the aging of equipment sealing materials such as rubber gaskets; it is recommended to conduct comprehensive leak tests twice a year (using a HALO laser detector with a sensitivity of 0.1 ppm).