Session: FSI-02-01 Tube Arrays - 1

Paper Number: 106282

106282 - Study on the Circumferential Pressure Distribution of the Tube Bundle in the Center of the Heat Exchanger 

The fluidic vibration problem of heat exchanger tube bundle is an important factor causing its wear, failure and even destruction. In order to study the vibration behavior of the tube bundle under the action of fluid, this paper uses a combination of experimental and numerical simulation to study the pressure distribution and inter-tube flow field of the tube bundle in the center of the heat exchanger to provide data support and theoretical support for the vibration analysis of the tube bundle.

A two-phase water cavern experimental device was designed and built with customized heat exchanger tubes. The device can perform air-water two-phase heat transfer tube rheological vibration experiments for 0~240m³/h water flow rate, 0~360m³/h air flow rate, and 0~90% air content. The fluid excitation force around the heat exchanger tube bundle was measured by an electronic pressure scanning valve. The vibration characteristics of a positive triangular arrangement of the tube array with a 1.41 pitch ratio were investigated using water tunnel experiments.

Based on the computational fluid dynamics method, ANSYS Fluent software was used to verify the experimental data. Numerical simulations were carried out for four types of arrangements: square triangle, square, corner triangle and corner square with different incoming flow velocities and pitch ratios. The calculation results show that the stationary point of the central tube varies in position and number with the change of flow velocity at low flow velocity, and gradually stabilizes after the flow velocity increases. It is also observed that the stationary point of the central tube gradually moves backward with the increase of the incoming flow velocity. The angular size of the boundary layer separation point: the angle of the corner triangle arrangement is the largest, the angle of the square triangle arrangement and the square arrangement is the second largest, and the angle of the corner square arrangement is the smallest; there is no significant change in the pressure of the center tube in the incoming flow direction under different pitch ratios, and the position of the stationary point remains basically the same, but the pressure in the wake direction decreases slightly with the increase of the pitch ratio.

Presenting Author: Sijiu Qi Tianjin University

Presenting Author Biography: Master's degree in chemical process machinery, studied in Tianjin University

Authors:

Sijiu Qi Tianjin University
Wei Tan Tianjin University
Guihong Zhu Tianjin University
Guorui Zhu Tianjin University