Förstudie av motströms koaxialvärmeväxlare till Huddinge sjukhus

Within the next ten years, all central ventilation systems are in need of replacement in Huddinge Hospital. Energy consumption is expected to reduce greatly by installing new, efficient systems for heat recycling and cooling. Numerous technical suggestions are considered and needs to be analyzed.This report presents an evaluation of a simple double pipe heat exchanger and an evaporative cooling system. The systems have been investigated separately and evaluated through numerical simulations in EES, Excel and MATLAB, where the calculations for the heat exchanger have been made according to the NTU method.To satisfy the efficiency demanded, the size of the heat exchanger appears to be intolerably large and the pressure drop in the heat exchanger also results in unacceptable operation costs. The heat exchanger solution is therefore not a sufficient alternative, which is why a Life-Cycle Cost analysis is not included in the report.On the other hand, the evaporative cooling system appears to be more interesting and could be combined with another type of heat exchanger to lower the temperature during hot summer days. However, a more profound investigation of the evaporative cooling system is needed to ensure the system’s suitability and sustainability.