Online monitoring system and method of heat transfer coefficient and fouling resistance of steady heat exchange process

Abstract

The invention provides an online monitoring system and method of a heat transfer coefficient and fouling resistance of a steady heat exchange process and belongs to the field of heat exchange. The online monitoring system comprises a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a flow meter, a central processing unit and a display device; the online monitoring method adopting the system comprises the following steps: 1, at an operation initial state of a heat exchange system or after the heat exchange system is washed, determining a standard heat transfer coefficient K[0] under the condition that no dirt is deposited at a cold side of a heat exchanger; 2, according to production requirements, calculating a detected heat transfer coefficient K[time] in real time after the heat exchanger is operated; 3, calculating the fouling resistance. According to the system and the method, provided by the invention, the measured heat transfer coefficient and fouling resistance can effectively reflect a real heat exchange condition of a reaction system; a lot of data is accumulated to establish a data set of the heat exchanger; a data foundation is laid for long-time stabilization of the heat exchanger; the construction cost of system equipment is low and an application range is wide.

Description

technical field [0001] The invention relates to the field of heat exchange, more specifically to a system and method for on-line monitoring of heat transfer coefficient and fouling thermal resistance value in a steady-state heat exchange process and its specific implementation technical scheme. Background technique [0002] Heat exchange is one of the most important unit operations in industrial production processes. Various high-temperature fluids in industrial production, such as high-temperature oil and cracked gas in the oil refining process, and low-pressure steam after power generation in power plants, must be cooled by cooling water. However, these fluids cannot be in direct contact with the cooling water. Various types of heat exchangers must be used to separate the hot fluid from the cooling water, and the heat of the hot fluid will be transferred to the cooling water through the wall of the heat exchanger, so that the heat flow between the hot fluid and the cooling...

AI Technical Summary

Problems solved by technology

[0007] First, whether it is dynamic simulation or constant temperature simulation test method, it simulates a certain state of the heat transfer process of the system, and cannot completely reflect the heat transfer state of the actual heat transfer system. Therefore, the measured heat transfer coefficient and The thermal resistance value of fouling is not necessarily representative, and it may not be able to effectively reflect the real heat transfer status of the system

[0008] Second, whether it is a dynamic simulation or a constant temperature state simulation test method, the electrothermal method is used to simulate the constant temperature state of the hot fluid, and it does not consider the changes in the flow, velocity and temperature of the cold fluid side caused by changes in the heat load on the hot fluid side during the actual heat exchange process , so it can only simulate and test the system heat transfer coefficient and fouling thermal resistance in a certain state, but cannot monitor it online in real time

[0009] Third, due to the above reasons, the data measured by either dynamic simulation or constant temperature simulation test method can only be used as a reference value for system operation, but not as a data basis for actual heat exchange operation decisions

[0010] Fourth, the simulation test methods all require proprietary test equipment, high equipment investment, and special personnel are required to maintain it, which increases the burden on the enterprise and is difficult to meet the needs of enterprises, especially small and medium-sized enterprises and small and medium-sized heat exchange systems, and cannot be widely used

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