Patent ID: 6631621
Filing Date: 2003-10-14
Classification: B60H,F17C,F25D,G05D

Abstract:
A method of temperature control in a cryogenic temperature control apparatus comprising:providing a heat exchanger in thermal communication with an air-conditioned space, the heat exchanger including an air inlet and an evaporator coil having an outlet; providing a first temperature sensor operatively coupled to a controller, the first temperature sensor measuring the temperature in the outlet and sending the temperature in the outlet to the controller; providing a second temperature sensor operatively coupled to the controller, the second temperature sensor measuring the temperature in the air inlet, and sending the temperature in the air inlet to the controller; providing a first plurality of temperature control values and a second plurality of temperature control values; altering the flow of cryogen from a storage tank to the evaporator coil each time the temperature in the outlet passes one of the first plurality of temperature control values; and altering the flow of cryogen from the storage tank to the evaporator coil each time the temperature in the air inlet passes one of the second plurality of temperature control values; wherein the controller uses ladder logic.