Numerical Simulation Of Heat And Mass Transfer Of The Internally Cooled/heated Thermal Mass Tower

The heat & mass cycle energy recovery system is a new kind of adaptable energy recovery, which can be driven directly by low temperature waste heat, the system has the advantages of energy saving, improving IAQ, reducing greenhouse gas and diesel particulate emission, reducing city heat-island effect. The tower for heat and mass transfer the core equipment of the heat & mass cycle energy recovery system, its heat and mass transfer performance directly determines the heat and mass recovery efficiency of the system. The equipment of a thin liquid outside vertical tube has wide application prospects in heat recovery field. This article apply the tower of a thin liquid outside internally cooled/heated vertical tube in the heat & mass cycle energy recovery system, and simulates its performance of mass and heat transfer on solution regeneration in summer conditions. The main contents as follows:1. The heat and mass transfer mathematical model of falling film outside the internally cooled/heated vertical tube is built up, the change rules of the falling film flow and its heat and mass transfer under different conditions. The results show: The falling film move as the air flow, and it is ruptured in the lower part of the tube. The falling film has a wave after leaving the entrance; The inlet temperature of the falling film is not the determining factor of the performance of mass and heat transfer, and the falling film’s performance of mass and heat transfer is heavy influenced by the flow rate of solution and air.2. The heat and mass transfer mathematical model of the tower of a thin liquid outside internally cooled/heated vertical tube is built up, and simulates its performance of mass and heat transfer on solution regeneration in summer conditions, The results show: the flow field distribution in the tower is complicated; the distribution of the films influenced by the air flow is also complicated. In general, the falling film coverage increases along the air flow; The tubes evaporation capacity is different, and it is influenced by the flow rate of solution and air.3. According to the the tower running environment and running characteristic, Optimizations about surface active additives, tubes arrangement, strengthened tube are analyzed. In order to enhance the heat and mass transfer efficiency of the tower, a program that controlled every tube individually is put forward, aud a design plans is proposed to implemented the program.