In petroleum and petrochemical industries, there are a large number of heat pipelines for steam transport, raw materials, products and so on. The heat preservation of heat pipeline can not only improve the heat economy of heat network, reduce heat loss and save energy, but also achieve the purpose of extending the life of heat network pipeline and maintaining a good working environment. But in actual use process, due to the thermal insulation structure strength is not enough, people trample, the destruction of the factors such as wind, rain, combined with the heat preservation of pipelines and accessories importance is not enough, the heat pipe can appear all kinds of insulation degradation, thermal loss will cause the waste of energy, also in imperceptible in brings to the enterprise loss. In terms of the current pipeline insulation problems in petrochemical plants, we have found the following problems:

1. Deformation and damage of the outer protective layer of the insulation structure are relatively common;

2. Some pipes are intact in appearance, but the internal insulation structure has been damaged, forming thermal defects;

3. Valve, bracket, flange and other pipe accessories are exposed;

4. Some pipes have sinking and plugging problems of insulation materials;

5. The thermal insulation materials of high-pressure steam pipelines are seriously powdering, and the thermal insulation effect is seriously reduced;

6. The annular gap is formed between the outer protective layer and the insulation layer because the outer protective layer is not tightly wrapped.

As a result of the above problems, the enterprise energy consumption increases significantly, especially after the rain, a medium-sized refinery will use about 10 tons of high-pressure steam, which will cause energy waste and property loss. Most of the damage or wear of insulation material is not visible to the naked eye, but the change in temperature caused by the wear is sufficient for the thermal imager to detect. Through the infrared thermal imager, the temperature distribution on the pipe surface can be easily viewed. The small temperature difference that cannot be intuitively perceived can be visually presented to our eyes through the thermal image and temperature distribution, and the defects, wear, heat loss and other faults will be clear at a glance.

It is embodied in the following aspects:

1. If the inner wall of the pipeline is damaged or corroded, the pipeline will become thinner, and its temperature will be higher than that of the normal part, so the fault can be detected;

2. There are materials sinking and plugging in the pipeline, and the difference in heat capacity between the plugging part and other parts leads to temperature difference. These temperature differences are transferred to the shell of the pipeline, and the fault can be photographed outside the pipeline with a thermal imager;

3. The thermal imager can also detect the pipe temperature, which serves as the judgment basis for whether the insulation has reached the specified effect;

4. Identify the problematic condenser valve by heat check, in general, if the thermal image shows higher inlet temperature and lower outlet temperature (<100. C), indicating that the condenser valve works normally. If the inlet temperature is significantly lower than the system temperature, the steam does not reach the condenser valve. Look for upstream problems: closed valves, clogged pipes, etc. If the inlet and outlet temperatures are the same, the condenser valve may not open and is "blowing steam" into the condensing line. In this case, the system can still operate, but with a significant loss of energy. If inlet and outlet temperatures are low, the condenser valve cannot be closed and the condensate water is filling the condenser valve and inlet line. The detection of the pipeline and its accessories by the infrared thermal imager provides an analysis basis for the subsequent pipeline renovation. The reduced heat dissipation loss after the renovation can be converted into standard oil and converted into oil price, and the investment in pipeline renovation can usually be recovered within one to two years. So keeping your pipes insulated and reducing heat loss means reducing the loss of capital and energy.