Impact of the pipe row spacing on the capacity of ice bank formed in a volume-limited water bath

Abstract

In this study, a design of an ice bank heat exchanger with pipes arranged in a column inside a volume-limited water bath, was investigated by a numerical simulation. The aim of the research is to determine the design of heat exchanger which would result in the highest quantity of ice formed in a given time period. Prior to the consideration, the accuracy of the numerical model was validated by comparison with experimental measurements. The boundary conditions are chosen to simulate the real process during the regeneration of the ice bank in the draft beverage cooler. The study is carried out for the condition of natural convection in a water bath and constant temperatures of a secondary coolant flowing through the pipes. The base design of the water bath and the heat exchanger used in the experimental measurements was further considered by CFD simulations through the variation of number of pipes in a column i.e. pipe row spacing. The optimal distance between the axes of the adjacent pipes and consequently the optimal distance gap between the pipes (x) are found as a function of the pipe diameter (d) as x/d ∼ 1.5. This finding is further confirmed by CFD simulations which are performed for cases of different pipe diameters, with different water bath height as well as by heat flow analysis for individual pipes in the bundle.