This paper presents a concept adapted to magnetocaloric refrigeration in order to better suit an application of a continuous fluid flow such as an industrial process. The concept, called the by-pass flow, consists in a derivation in the fluid flow from the Active Magnetic Regenerator (AMR) in order to take a part of the heat transfer fluid from the cold side of the regenerator after passing it through a counter-current heat exchanger to reinject it into the hot side. The value of the by-pass fluid flow rate has been studied by using two theoretical methods (qualitative and quantitative approaches) then validated by numerical simulations and experimental measurements. Numerical simulation shows an increase of 27% in the value of cooling power when the by-pass method is implemented. In the case of experimental measurements, the cooling power with the by-pass solution shows values between 8% and 22% more than the classic solution, depending on the frequency values. The main operations are described and the results are presented, analyzed and discussed.

Adapting an active magnetic regenerator to a continuous fluid flow application

Improvement of the AMR's performance: multi-segment regenerator and by-pass flow.

An explicit procedure for the design of a system containing a regenerator with bypass has been developed. Bypass of the regenerator during the energy retrieval process is controlled so that the temperature of the recombined fluid stream is held at a selected value. The procedure involves two sets of curves. The design curves relate the specific characteristics of the storage matrix and the mass rate of flow of the fluid through the regenerator. The performance curves relate the nondimensional length and period to the thermal ratio, maximum pressure drop, duration of hot period, and temperature of the combined fluid stream during the retrieval process. The mass of the storage material and dimensions of the regenerator are determined for the specified operating conditions.

B. T. Kulakowski

Papers

Design of Packed Bed Regenerator with By-pass