COMPACT HELICAL HEAT EXCHANGER WITH STRETCH TO MAINTAIN AIRFLOW

摘要

A heat exchanger (102) for exchanging heat between gasses such as air and a liquid or gaseous coolant has narrow spacing (108) between exchanger surfaces for high efficiency. To avoid undue obstruction of gas flow due to ice buildup on the exchanger surfaces,- the heat exchanger (102) is equipped with sensors (110, 112) to monitor the gas flow and an actuator (116, 118) that widens the spacing (108) between exchanger surfaces such that gas flow remains unimpeded. Embodiments provide for defrosting of the exchanger surfaces when an limit on spacing (108) of exchanger surfaces is reached, and for relaxing the spacing (108) to the original narrow spacing (108) when defrosting is completed.