This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Cabin Air Humidity Model and its Application
Technical Paper
2015-01-0369
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
In addition to the thermal comfort of the vehicle occupants, their safety by ensuring adequate visibility is an objective of the automotive climate control system. An integrated dew point and glass temperature sensor is widely used among several other technologies to detect risk of fog formation on the cabin side (or inner) surface of the windshield. The erroneous information from a sensor such as the measurement lag can cause imperfect visibility due to the delayed response of the climate control system. Also the high value, low cost vehicles may not have this sensor due to its high cost. A differential equation based model of the cabin air humidity is proposed to calculate in real-time specific humidity of the passenger compartment air. The specific humidity is used along with the windshield surface temperature to determine relative humidity of air and therefore, the risk of fog formation on the interior surface of a windshield. The generally uniform spatial distribution of cabin air humidity is used to advantage. However, the accuracy of a cabin air humidity model is evaluated for the non-uniform distribution of the windshield surface temperature and the uncertainty of the parameters of a differential equation model. The sensitivity analysis is performed to determine acceptable range of each parameter for an accurate prediction of fog or frost formation on the windshield surface. Application of a cabin air humidity model to predict risk of fog formation is demonstrated with an experimental vehicle installed with three humidity - integrated dew point and glass temperature sensors. The implication of the use of a model for diagnosis of a humidity sensor is also outlined.
Authors
Citation
Kakade, R., "Cabin Air Humidity Model and its Application," SAE Technical Paper 2015-01-0369, 2015, https://doi.org/10.4271/2015-01-0369.Also In
References
- Urbank , T. , Kelly , S. , King , T. , and Archibald , C. Development and Application of an Integrated Dew Point and Glass Temperature Sensor SAE Technical Paper 2001-01-0585 2001 10.4271/2001-01-0585
- Hirai , S. , Kataoka , T. , Kumada , T. , and Goto , T. The Humidity Control System Applied to Reduce Ventilation Heat Loss of HVAC Systems SAE Technical Paper 2011-01-0134 2011 10.4271/2011-01-0134
- Wijaya , H. and Koberstein , M. Engine Start Stop Control Strategy for Optimization of Cabin Comfort and Fuel Economy United States Patent Application Publication, US 2014/0032086 2014
- Cengel , Y. and Boles , M. Thermodynamics: An Engineering Approach Fifth McGraw-Hill 2006 9780072884951
- Olesen , B. Thermal Comfort Technical Review No. 2 Bruel & Kjaer 1982
- Jette , M. , Sidney , K. and Blumchen , G. Metabolic Equivalents (METS) in Exercise Testing, Exercise Prescription and Evaluation of Functional Capacity Clin. Cardiol. 13 555 565 1990 10.1002/clc.4960130809
- Wallaart , J. A Study of the Relationship Between Heart Rate and Minute Breathing Volume at Various Levels of Work Demonstrating the Spread Between Individuals in a Group and the Implications in Industry Intl. Soc. Of Respiratory Protection Conf. Amsterdam 1997