Calculating method for measuring thermal performance of filler of lower cooling tower based on two-point boundary value

Abstract

The invention discloses a calculating method for measuring thermal performance of a filler of a lower cooling tower based on a two-point boundary value. The method comprises the following steps of describing heat and mass transfer in the filler through four ordinary differential equations; collecting field operation parameters and environment parameters of the cooling tower, confirming air temperature Ta and humidity ratio X of the bottom part (z is equal to 0) of the filler, and water temperature Tw and mass flow rate mw boundary values of the top part (z is equal to H) of the filler; assuming and iteration adjusting unknown boundary conditions of the bottom part (z is equal to 0) of the filler, so that the top part (z is equal to H) of the filler meets known boundary conditions; building a cooling tower filler thermal performance calculation model based on a filler thermal performance linear model; substituting into the above for calculation to obtain the conditions of the top part (z is equal to H) of the filler, and calculating the cooling tower thermal performance. According to the method, model building is carried out based on real-time measurement values, so that real-time on-line evaluation of the cooling tower thermal performance can be realized favorably, the calculation model is simplified under the measurement based on the two-point boundary value, and compared with the existing calculation method, under the premise of ensuring the calculation accuracy, the calculation time is greatly shortened.

Description

technical field [0001] The invention relates to a calculation method for the thermal performance of a cooling tower, in particular to a calculation method for the thermal performance of a cooling tower filler based on two-point boundary value measurement. Background technique [0002] With the rapid development of industry, industrial systems have increasing requirements for cooling systems. As the main terminal cooling device, the cooling tower is widely used to remove a large amount of waste heat generated by power plants, HVAC systems, and steel plants, and is an important part of the circulating cooling system. Wet cooling towers have become the mainstream of cooling towers due to their high efficiency. Through the heat and mass transfer process of air and high-temperature circulating cooling water, high-temperature and high-humidity air is discharged out of the tower, taking away heat, and realizing recycling of cooling water. Therefore, the thermal performance of cooli...

AI Technical Summary

Problems solved by technology

The Merkel model is established based on assumptions, the model is simple, the calculation error is large, and it needs to be solved by numerical integration or iterative method, the e-NTU model introduces the number of heat transfer units, avoids numerical integration or iterative calculation, but has the same level of calculation error as the Merkel model , the calculation result of the Poppe model is accurate, but the model is complex, the solution process involves multiple iterations, and the calculation time is long. The classic cooling tower thermal performance calculation model cannot meet the requirements of high precision and small calculation amount at the same time

With the development of computer technology, artificial intelligence algorithms are introduced into the thermal performance evaluation of cooling towers to avoid the modeling process of cooling tower mechanisms, but a large number of training samples are required and the evaluation time is long

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