Gao, Kaimi (2015-08). Experimental Evaluation of Silicon Expansion Valve Techonology. Master's Thesis.
Residential and commercial buildings consume 40% of the energy used in the United States. Heating and cooling uses more energy than any other system in a building. Typically, 43% of a building utility bill goes to HVAC equipment. By combining proper equipment maintenance and upgrades with appropriate insulation, air sealing, and thermostat settings, energy usage can be cut from 20% to 50%. In this research, advanced valves and control algorithms are studied to improve the efficiency and reduce the energy consumption of vapor compression air conditioning and refrigeration systems. The characteristics of the new generation of MEMS based flow control devices have been tested on single and multi-evaporator systems. This research conducted a comprehensive set of experimental tests that identify the most effective elements of an advanced valve control strategy under a variety of operating conditions. The performance of the new MEMS actuators with different control strategies is compared with the standard mechanical valves and a commercially available superheat controller. Preliminary research results reveal efficiency gains with a cascaded control algorithm over both the thermal expansion valves and the commercial superheat controller.