Numerical investigation of heat transfer and pressure drop characteristics of tube-fin heat exchangers in ice slurry HVAC system

摘要

This paper analyzes the heat transfer and pressure drop characteristics of a tube-fin heat exchanger in ice slurry HVAC system. Ice slurry is a suspension of crystallized water based - ice solution with a freezing point depressant like ethylene glycol. The ice- slurry is pumpable, hence it is also called pumpable ice. The composition of ice slurry considered for analysis is 14% ice fraction, 16% ethylene glycol, and 70% water by volume. It is deduced that the ice slurry HVAC system results in 7.4% increase in temperature drop over the conventional chilled water system The latent heat absorbed by ice slurry on melting makes it an attractive choice for achieving high degree of cooling. The numerical analysis was conducted by simulating the ice slurry tube flow region and air flow region of tube-fin heat exchanger in the air-handling unit of HVAC system. For the simulation six different louver patterns with 10 to 55 louver angle were considered. The design of the tube-fin heat exchanger for optimal heat transfer and pressure drop characteristics was also determined with the optimization parameter like louver angle, fin pitch, and ice slurry flow velocity.