Чисельне моделювання теплообмінного апарата для різних систем вентиляції

Abstract

The purpose of the research is to develop and numerical modeling of the shell-tube heat exchanger of a new design as an element of the microclimate maintenance system for various types of ventilation systems in the summer season. Materials and methods of research. As mentioned above, two types of ventilation systems are considered - tunnel and lateral. For these ventilation systems TA is projected. The poultry house is a traditional type. At the side walls there are openings with jackets in the total number of 80 pieces. with dimensions 0,3×0,85 m. And also on the front end walls are located evacuation cooling tapes with dimensions of 5,1×1,1 m. In place of the cassettes and louver we fit the HE. Consider the shell and tube heat exchanger with a shell of a rectangular cross section in the transverse flow of pipe beams. The geometry of the pipes with diameters d = 10 mm is peculiar, which differs from the traditional chess, corridor and compact beams. Neighboring pipes in such close beams are displaced one relative to the other at a distance of 1 mm. Moreover, we consider two types of beam construction, in which there is a displacement of pipes in a transverse direction along the entire length of the tube beam by 15 mm. All calculations are performed at a volume flow of air 1036 thousand m3/h. As a coolant air is selected with a temperature of +40 o С at the inlet, which flows in the channels for cooling the external heated air in the poultry house in the summer period of the year, where as the cooler is used water underground wells. In the soybean, cold water moving inside the pipes, which has an inlet temperature of +10 o C. The layout of the heat carrier movement is cross-linked. Research results and their discussion. The temperature change for different ventilation systems. For tunnel ventilation, the temperature in the TA decreases from +40 to +22.5 o C (Fig. 2), and for the side - from +40 to +19,7 o С. Conclusions and perspectives. 1. A new design of a shell-tube heat exchanger with a compact arrangement of pipes in tubular beams is proposed and developed. 2. Computer-aided mathematical modeling of heat and mass transfer processes in bundles of pipes of different geometries with compact placement of pipes using the software ANSYS Fluent. The fields of velocities, temperatures, and pressure in the studied channels are obtained. The conditions of the hydrodynamic flow in the channels were analyzed and estimates of the heat transfer intensity between the hot and cold coolant through the wall separating them. 3. It was determined that the tunnel ventilation system would be most effective and TA was designed for it.