| Ocean fish culture of our country is faced with two serious problems, one is environment pollution and the other is energy waste. It is one of important ways to solve the problems to use absorption system on the ocean fishing. But the change of the performance of the absorber, which is an important component in the absorption machine, under the fluctuant state of the fisher is the key that determines whether the absorption system can be used on ocean fishers. In this paper the flow field of falling film along the inner of vertical tube is simulated and it's the necessary base of the further research that includes characteristics of heat and mass transfer in the absorber under the fluctuant state.In this paper the ocean fisher's movement in the ocean is studied and the physical and the mathematical models of fisher are founded, then the expressions of the force by the movement are obtained. The expressions are combined with partial different equations of falling film under the static state, thus the mathematical model of the falling film under fluctuant state can be gained. After simplifying the equations and supposing the profile of velocity, the integral equation of the falling film is gotten. Then the flow field of the falling film can be simulated through dispersing the integral equation and using numerical methods.An experimental apparatus of falling film absorption in a vacillating is set up to check the reliability of theoretical model and to have a deep understanding of heat and transfer of practical falling film absorption; Falling film absorption with TFE/NMP solution in a static vertical tube and that in a vacillating tube are investigated respectively.The experiment results show that when other initial parameters are kept constant, the heat and mass transfer of falling film absorption under the condition of normal vacillation of fishing vessels is better than that in static status; The amplitude and period of vacillation directly influence the performance of the absorber and an adequate decrease of vacillation period or vacillation amplitude is beneficial to the absorption performance. This conclusion tallies with the numerical results. The TFE/NMP absorption refrigeration system can completely meet the demands of the refrigeration of fishing boats when the sea wind is not strong. |
