Method and controller for determining carbon dioxide emissions from a recirculating air heater
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Accused Products
Abstract
A method of determining the amount of air flowing through an outside air damper of a recirculating air heater includes the steps of sensing an amount of airflow flowing through the damper, recording the amount of airflow and a damper position value at a plurality of damper positions, and interpolating a curve relating the amount of airflow to the damper position for all damper positions between a minimum damper position and a maximum damper position. Once the amount of air flowing through the outside air damper is determined from a position on the curve, the concentration of carbon dioxide (CO2) within a building space can be calculated and/or determined to be within acceptable limits.
22 Citations
14 Claims
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1. (canceled)
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2. (Canceled)
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3. (canceled)
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5. A method of determining a concentration C of carbon dioxide (CO2) in air discharged from a recirculating air heater having a burner, an outside air damper, and a recirculating air damper inversely interlocked with the outside air damper, said method comprising the steps of:
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adjusting the outside air damper to a plurality of outside air damper positions;
sensing an amount of airflow flowing through the outside air damper at each of the plurality of outside air damper positions;
recording the amount of airflow and an outside air damper position value at each of the plurality of outside air damper positions;
interpolating a curve relating the amount of airflow to the outside air damper position for all possible outside air damper positions between a minimum damper position and a maximum damper position;
determining an amount of airflow through the outside air damper of the heater based on a current outside air damper position and utilizing the curve relating the amount of airflow to the outside air damper position;
calculating a proportion P of outside air brought through the burner based on the current outside air damper position;
determining a temperature difference Δ
T between a supply air temperature TS of air before the burner and discharge air temperature TD of air after the burner;
receiving a factor K based on a type of fuel used in the heater; and
determining the concentration C of CO2 with an equation utilizing the temperature difference Δ
T, the factor K, and the proportion P of outside air brought through the burner. - View Dependent Claims (6, 7, 8, 9)
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12. A controller for controlling and maintaining a concentration C of carbon dioxide (CO2) in air discharged from a recirculating air heater having a burner, an outside air damper, and a recirculating air damper inversely interlocked with the outside air damper, said controller comprising:
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an airflow measuring sensor for determining an amount of outside air flowing through the outside air damper;
a position sensor operatively connected to the outside air damper for sensing an outside air damper position of the outside air damper;
an outside air temperature sensor for sensing an outside air temperature To of air flowing through the outside air damper;
a return air temperature sensor for sensing a return air temperature TR of air flowing through the recirculating air damper;
a discharge air temperature sensor for sensing a discharge air temperature TD of air flowing through the discharge air damper; and
a processor electrically connected to said sensors for recording the amount of airflow through the outside air damper and the outside air damper position value at a plurality of outside air damper positions, interpolating a curve relating the amount of airflow to the outside air damper position for all possible outside air damper positions between a minimum damper position and a maximum damper position, determining an amount of airflow through the outside air damper based on a current outside air damper position and utilizing the curve, calculating a proportion P of outside air brought through the burner based on the current outside air damper position, calculating a supply air temperature TS utilizing the outside air temperature TO, the return air temperature TR, and the proportion P of outside air, determining a temperature difference Δ
T between the supply air temperature TS and discharge air temperature TD, receiving a factor K based on a type of fuel used in the heater, and determining the concentration C of CO2 with an equation utilizing the temperature difference Δ
T, the factor K, and the proportion P of outside air brought through the burner. - View Dependent Claims (13, 14)
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Specification