Model-based thermobalance with feedback
AssigneeJohnson Service Company
InventorKirk H. Drees
Life of this patent
Estimating the term…
Abstract
A temperature control system and method for maintaining the temperature of air within an air pressure controlled enclosure at a desired temperature. The system uses an energy flow model to determine the temperature to which the air supplied to the enclosure must be heated to attain the desired temperature within the enclosure. The energy flow model determines the desired supply air temperature based on the temperature and flow rate of the supply air, the current temperature of the air in the enclosure, the heat transfer rate within the enclosure, and the temperature and flow rate of make-up air entering the enclosure.
Claims14
A system for maintaining, at a room temperature setpoint, the temperature of air within an enclosure comprising a supply duct and an exhaust duct, said system comprising:
- heating means for heating the air in said supply duct responsive to a control signal;
- a first temperature sensor for generating a room temperature signal indicative of the temperature of the air in said enclosure;
- a second temperature sensor for generating a supply air temperature signal indicative of the temperature of the air heated by said heater means;
- a first air flow sensor for generating a supply air flow signal indicative of the air flow in said supply duct;
- a second air flow sensor for generating an exhaust air flow signal indicative of the air flow in said exhaust duct;
- and
- a temperature controller coupled to said first temperature sensor, said second temperature sensor, said first air flow sensor, and said second air flow sensor, said temperature controller being further coupled to said heating means for providing said heating means with said control signal in response to said room temperature signal, said supply air temperature signal, said supply air flow signal, said exhaust air flow signal, and said room temperature setpoint.
A method of maintaining the temperature of air in an enclosure at a desired temperature, wherein supply air enters said enclosure through one or more supply ducts, exhaust air leaves said enclosure through one or more exhaust ducts, and make-up air enters said enclosure from an exterior environment, said method including the steps of:
- providing a temperature controller;
- applying a signal indicative of the temperature of the air in said enclosure to said temperature controller;
- determining a heat transfer rate based on the temperature of the air in said enclosure and said desired temperature;
- applying a signal indicative of the flow of said supply air to said temperature controller;
- applying a signal indicative of the flow of said exhaust air to said temperature controller;
- determining the flow of said make-up air based on the flows of said supply air and said exhaust air;
- determining a desired supply air temperature based on the flow of said supply air, the flow of said make-up air, the temperature of the air in said enclosure, said desired temperature, and said heat transfer rate;
- and
- heating said supply air to said desired supply air temperature.
Dependencies are inferred from the claim text.