In industrial production, the safety of heating equipment is always a top priority. Traditional steam boilers heat water to generate steam, but as the temperature rises, the steam pressure rises dramatically. Once it exceeds the pressure limit of the vessel, it can easily cause serious safety accidents such as explosions. To address this problem, hot water oil heating boilers were developed. They use a special thermal oil as the heat transfer medium, fundamentally avoiding the risks associated with high steam pressure, making them an ideal choice for high-temperature, low-pressure, and safe heating.
1. Pressure Hazards of Traditional Steam Boilers
Water boils at 100°C at normal pressure. To generate heat at higher temperatures, its boiling point must be raised by applying pressure. Operating in such a high-pressure environment requires extremely strong and leak-proof pressure-bearing components such as the boiler body, piping, and valves. Any defects or improper operation can cause leaks, burst pipes, or even explosions. Furthermore, high-pressure systems require multiple protective devices such as safety valves, pressure gauges, and water level gauges, making maintenance complex and operationally risky. For industrial applications requiring high temperatures but unsuitable high pressures, traditional steam boilers present obvious safety risks.
2. Thermal Oil: Replacing Vaporization Heat Transfer with "Liquid-Phase Circulation"
The core of a hot water oil heating boiler lies in its use of thermal oil as the heat transfer medium. Thermal oil is a specially treated organic synthetic oil or mineral oil with a high boiling point, low volatility, and excellent thermal stability. During system operation, the thermal oil circulates in a liquid state within a closed pipeline. After being heated by a burner, it transfers heat to the heat-consuming equipment and then returns to the boiler for reheating, forming a "liquid-phase closed loop." Because the entire process does not involve phase change, the internal pressure of the system is generated solely by the circulation pump and is significantly lower than the pressure of a steam system at the same temperature. This fundamentally eliminates the risk of explosion caused by high steam pressure.
3. High Temperature, Low Pressure: The Dual Advantages of Safety and Efficiency
A hot water oil heating boiler can achieve heating temperatures exceeding 300°C at atmospheric or low pressure. For example, when the thermal oil temperature reaches 250°C, the system pressure may be only around 0.3 MPa, while saturated steam at the same temperature has a pressure of over 4.0 MPa. This "high temperature, low pressure" operating characteristic not only significantly reduces the equipment's pressure requirements, simplifying and reducing the cost of boiler, piping, and accessory designs, but also significantly improves the system's safety level. Even if a leak occurs, the thermal oil will not instantly burst out, causing severe burns or impact injuries like high-pressure steam. Instead, it will flow out slowly, making it easier to detect and address promptly.
4. Multiple Safety Mechanisms Ensure System Stability
In addition to the inherent advantages of the medium, modern hot water oil heating boilers are equipped with a series of safety measures. For example, an expansion tank absorbs the volume expansion of the thermal oil after heating, maintaining a stable system pressure; an oil storage tank stores the oil during shutdown to prevent oxidation; a nitrogen seal system isolates the air to prevent oxidation and degradation of the high-temperature thermal oil; and automatic alarms and interlocking shutdowns for overtemperature, overpressure, low liquid level, and flow interruption ensure timely response to abnormal conditions. Furthermore, thermal oil has high flash and ignition points, and when used in conjunction with standardized installation and operation, it effectively prevents fire risks.
By utilizing thermal oil as the heat transfer medium, hot water oil heating boilers achieve the technological breakthrough of "liquid heat transfer and low-pressure operation," completely eliminating the safety dilemma of traditional steam boilers that rely on high-pressure steam for heating. This significantly reduces the risk of explosion during operation while also improving temperature control accuracy and thermal efficiency. It is widely used in industries such as chemicals, textiles, printing and dyeing, plastics, and food, which require high-temperature heating but place high demands on safety.
