Efficient, safe and reliable heating systems have become essential in modern industry. When we discuss such systems, thermal oil boilers indispensably enter the picture. This particular type of boiler, unlike traditional steam boilers, offers unparalleled advantages to a wide range of industries.

From delicate chemical processes to extensive food production, thermal oil boiler systems ensure continuity and efficiency in production. To better understand the impact of this technology and how it has become the preferred choice for several industrial applications, we will take an in-depth look at the principles of thermal oil boiler system and how it performs in a variety of real-world applications.

Thermal oil boiler because the medium used is organic heat carrier, different from water, so the design and operation of the system have certain requirements.

Ensure thermal oil boiler system is unobstructed

Large-capacity thermal oil boiler system is fully closed, small-capacity open system expansion tank can be in contact with the air, the oil flow in the system should be smooth, no flow of dead space, such as pipeline is too long, the flow resistance is too large, to add a secondary circulation oil pump.

Thermal oil boiler (liquid phase) for forced circulation, the flow of oil by the circulating pump to promote, in the system design must be designed to design a backup circulating pump and emergency pumps for power outages to ensure that the oil in the thermal boiler does not stop the flow of oil to prevent the oil from being overcooked, deterioration and carbonization; the entire system within the high temperature oil can not be leaked, and even more so, not to be in contact with the oxygen in the air.

Optimize Thermal Oil Boiler System Flow Rate

In the whole system, thermal oil boiler is heated high-temperature zone, to ensure that the flow rate of thermal oil in the boiler tube, generally in the high-temperature radiation zone tube flow rate should be greater than 2 m / s, convection zone tube flow rate should be greater than 1.5 m / s, such as too low on the possibility of the formation of over-burning carbon, burnt heat exchanger tubes, but should not be greater than the maximum of 3.5 m / s, otherwise the flow resistance in the tube is too large.

In the design of the boiler tube flow rate, such as thermal power is smaller single or two-pipe thermal oil boiler, can be selected according to above requirements of the flow rate; but when the thermal power of the larger parallel tube more, each tube flow rate is not the same, then take the flow rate multiplied by the flow rate coefficient of unevenness.

Expansion Tanks and Oil Reservoirs

Expansion tank as the name suggests its role is to expand the expansion, when the oil temperature rises, the volume of oil in the system expands, the expansion is about 30%, so the expansion tank design should consider the capacity of the entire system. According to the "Boiler Safety Technical Supervision Regulations," the number of one-time injection of organic heat carriers greater than 10 m3 of the system should be designed as a closed system.

 For the closed system expansion tank to be used inert gas to protect and set the pressure, when the maximum pressure in the expansion tank is not greater than 0.01 MPa, it is best to use liquid seal to set the pressure, the liquid seal medium is preferably thermal oil, and with the lower part of the oil storage tank connected.

The function of the oil storage tank is to store oil, if the oil in the expansion tank is too much, it can flow to the oil storage tank through the liquid flow pipe. When you just start to cook the furnace, the excess oil from the expansion tank flows into the oil storage tank, or when the system is being repaired, the oil in the system is put back into the oil storage tank; the temperature of the oil in the oil storage tank should not be too high, and it should be controlled to be below 50 ℃ or else it should be isolated from the air.

Circulating oil pumps

Circulating oil pump is the heart of the whole system, once the circulating oil pump has a problem, to immediately start the backup circulating pump, such as a sudden power outage, to immediately start the blackout backup pump, to ensure the safe flow of oil in the boiler tube.

1. Circulating oil pump head

thermal oil boiler flow resistance is generally 0.15 ~ 0.3 MPa, plus the resistance of the system outside the boiler in the 0.3 MPa or so, therefore, the head of the circulating oil pump is generally taken to 60 ~ 80 m water column high; such as pipeline is too long, or the resistance of the heat equipment is too large, it is necessary to use the secondary circulation of oil pumps to overcome the resistance of the system.

2. Estimation of thermal power of thermal oil boiler on site

From the control cabinet temperature table read out the import and export temperature of thermal oil, from the control cabinet flow meter read out the flow of thermal oil, can be estimated by the thermal power of thermal oil boiler.

Thermal Oil Boiler Application 

The most important feature of the thermal oil boiler is high temperature, low pressure, it can be less than 1.0 MPa pressure to provide a temperature of up to 350 ℃ thermal oil, used to meet the requirements of the production process, such as hot water as a medium, heated to 350 ℃ of the saturation pressure to reach 16.5 MPa, such a high pressure, production process equipment is difficult to achieve.

Application areas of thermal oil boilers

Chemical industry - polymerization, condensation, distillation, rectification, concentration, evaporation, melting;

Oils and fats industry - decomposition, debromination, fatty acid distillation, hydrogenation reactions, lipidation;

Petrochemical industry - synthesis, distillation, rectification, heating, holding;

Air conditioning industry - radiant heating;

Fiber industry - polymerization reactions, melt spinning, heat-setting, molding, stretching, drying;

Coating industry - coating and baking drying, heating and molding, concentration, evaporation, melting;

Dye industry - dyes, intermediates;

Food industry - food drying, drying;

Construction industry - asphalt melting insulation, waterproofing materials, linoleum, plasterboard;

Paper and printing industry - corrugated processing, paper drying, insulation;

Plastic and rubber industry - hot pressing, calendering, extrusion, vulcanization molding, artificial leather processing, etc;

Textile printing and dyeing industry - heat setting, drying, baking, dyeing;

Wood industry - veneer, particle and fiber drying, hot pressing of plywood, medium/high density fiberboard, laminate wood flooring, etc., drying of solid wood, etc;

Other applications - Various applications of thermal energy up to 350 °C.

The above is the application of thermal oil boilers in various industries, the user in the selection of thermal oil boilers as heat-carrying heating equipment, should be from the energy-saving, environmental protection to consider two aspects.

Consider the application of thermal oil boiler from energy saving and environmental protection aspects

Thermal oil boiler is characterized by high temperature, low pressure, high temperature thermal oil in the whole system is forced by the circulating oil pump forced circulation, circulating oil pump power with the flow rate increases; In addition, once the thermal oil boiler is running, the circulating oil pump can not be stopped, only when the system oil temperature drops to below 50 ℃, the pump can be stopped, or else the oil in the boiler tubes will be overcooked carbonization.

Thermal oil boiler circulating oil pump power, and thermal oil boiler thermal power is directly proportional to the selection of boilers, from energy saving and environmental protection aspects of the overall consideration, not only to meet the heat requirements, but also to save energy and protect the environment.

Focus on the following points when selecting a thermal oil boiler:

(1) If the heat equipment can be realized with steam or hot water, try not to use thermal oil boilers.

(2) try not to use thermal oil secondary conversion into steam for production use, such as the amount of steam is particularly small, you can consider using a small steam generator to produce steam, if the steam heat than thermal oil heat, you can consider using direct steam production boiler to produce.

(3) The pipeline of the whole system should be as short as possible, the closer the heat equipment is to the boiler room, the better, as far as possible, do not use the secondary circulation oil pump to overcome the flow resistance.

(4) try to choose a reasonable furnace type, thermal oil boiler for forced circulation, in order to consider the transportation problem, the furnace space is often designed smaller, in the combustion of biomass fuels will be due to the small space, combustion time is not enough, resulting in incomplete combustion losses increased, not only a waste of fuel, but also the exhaust gas is more harmful components, not environmentally friendly.

(5) such as process demand for thermal oil thermal power is relatively large, try to use a single high-power thermal oil boiler, do not use more than one small power thermal oil boiler, high-power thermal oil boiler with high thermal efficiency.

(6) such as the user at the same time to use thermal oil, saturated steam, hot flue gas 3 kinds of heat media, can be designed according to the proportion of heat used in the form of heat center, 3 kinds of heat media share a combustion device and combustion chamber, through the flue gas shunt to produce demand for 3 kinds of heat media.

(7) To consider the total system energy cost of thermal oil boiler or heat center, maintenance costs, and ultimately to achieve high efficiency, low energy consumption, low maintenance costs, low pollution, less emissions.

(8) If the flue gas in the tail is not used as a drying heat medium, it is necessary to add an energy saver at the outlet of the convection zone to reduce the temperature of the exhaust flue gas to 170 ℃ or less, so as to achieve the requirements of energy saving. The energy saver can be designed as low-pressure waste heat steam boiler, low-pressure or normal-pressure waste heat hot water boiler or heat exchanger, air heater, etc. according to the user's requirements.

Conclusion

As technology advances, the need for more efficient and reliable energy systems in industry grows. The thermal oil boiler not only meets these needs, but also offers unrivaled advantages for a variety of industrial applications. It proves that through continuous research and innovation, we can find more environmentally friendly and economical solutions to today's and tomorrow's industrial challenges.

As decision makers and practitioners in the industry, we should be more cognizant of the value of this technology and consider its potential impact in future developments. For it is only through the constant pursuit of excellence and innovation that we can ensure the sustainable progress and prosperity of industry.