When designing equipment like boilers and pressure vessels, several common errors can arise. These mistakes can not only impact performance but also pose serious safety risks, lead to equipment failure, or cause economic loss. Below is a detailed analysis of some of the most common technical design errors that engineers may encounter:
1. Accurate determination of Operating Pressure and Temperature
Pressure and temperature are the two most crucial factors affecting the durability of boilers and pressure equipment. To ensure safe operation, the equipment must withstand the maximum pressure and temperature that can occur during operation.
There should be contingency calculations to account for sudden pressure spikes due to system errors or external incidents. The equipment must undergo overpressure testing to evaluate its resilience and safety under unusual conditions.
2. Selecting appropriate Materials for the working conditions
Different materials have unique properties regarding heat resistance, corrosion resistance, and stability under pressure. Boilers and pressure equipment operating in high-temperature and high-pressure environments require materials with high heat and strength tolerance.
High-alloy steel, stainless steel, or special alloys should be used to resist corrosion and oxidation when exposed to corrosive substances. For environments with high sulfur content, corrosion-resistant coatings should be considered to extend the equipment’s lifespan.
3. Designing structures for Durability and Thermal Expansion
High temperatures cause metals to expand, which can lead to stress within the structure, especially at welds and areas with abrupt changes in cross-section.
Thermal stress analysis using simulations helps accurately predict areas that may weaken due to high temperatures. Areas with stress concentration risk (such as sharp corners, joints) should be reinforced with measures like expansion linings or specialized welding techniques to reduce stress.
4. Adhering to Safety Codes and Standards
Standards like ASME, TCVN, or international guidelines provide technical criteria to ensure safe design and operation. These standards outline inspection methods, material requirements, and pressure limits that the equipment must comply with.
Compliance with regulations helps avoid legal risks and builds credibility for the product. Equipment components should be tested per standards, including pressure tests, ultrasonic inspections, weld durability tests, and other examinations.
5. Proper placement of Safety Devices
Safety devices like safety valves, pressure gauges, and temperature sensors are crucial for monitoring and preventing incidents. If these safety devices fail to operate correctly, the risk of explosion and damage increases significantly.
These devices should be placed at points subject to high pressure or pressure fluctuation. The structure must ensure easy access for maintenance and replacement. Additionally, regular calibration is essential for maintaining accuracy.
6. Ease of Maintenance and Routine Inspection
Maintenance and routine inspections help detect potential faults before they become serious issues. The design should consider easy disassembly of parts to minimize maintenance downtime.
Common inspection points include safety valves, weld areas, and components directly exposed to high pressure or temperature. Inspection ports and areas for assembling replacement parts should be designed without disrupting the entire system.
7. Optimizing Efficiency and Energy Savings
Optimizing efficiency helps reduce fuel consumption, thereby saving operational costs and protecting the environment.
One way to optimize efficiency is by designing heat exchange systems and piping that maximize heat recovery. For example, waste heat recovery systems can use heat-resistant piping to improve heat exchange efficiency without being affected by high temperatures.
8. Ensuring Proper Size and Positioning of Piping
The size and layout of piping affect the flow rate and pressure of fluids. Inadequate design can lead to pressure losses or sudden pressure increases, causing incidents.
Piping design should include precise calculations for pressure resistance and pressure loss along each segment. Pipes should be arranged to maintain consistent pressure and allow easy maintenance. Corrosion-resistant materials should be used for steam or compressed air pipes to ensure long-term durability.
9. Effective Water Supply and Sludge Discharge System Design
Water and sludge directly affect boiler efficiency and lifespan. Minerals in water can form deposits when heated, leading to blockages and reduced efficiency.
The water supply system should filter out minerals and sludge before entering the boiler. Sludge discharge valves should be placed at the lowest points of the equipment for easy discharge. For larger systems, filters and settling tanks should be integrated to maintain system efficiency.
10. Integrating Automatic and Backup Control Systems
Automatic control systems enhance stability and safety for boilers and pressure equipment. In case of an incident, the system will automatically stop operation or adjust parameters to safe levels.
Control systems with alert and backup functions should be integrated to respond quickly to incidents. For example, if pressure or temperature exceeds thresholds, the system will automatically alert or adjust settings. Essential components should have backups to ensure the system operates stably even if some parts fail.
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