Design of CO₂ Heat Pump Water Temperature Control System Based on C8051F500 SCM and Electronic Expansion Valve

Abstract:

The paper has designed the controlling circuit of CO2 heat pump water based on C8051F500 SCM and electronic expansion valve. The controlling circuit is composed of a temperature detection circuit and a electronic expansion valve drive As the temperature detection circuit uses a constant current source design, it would not be influenced by ambient temperature and can work in different temperature environment. This detection circuit’s temperature range is -50 °C - +135 °C. Electronic expansion valve drive circuit has added a photoelectric coupling isolation circuit to enhance its anti-interference capability. The system can adjust the size of the opening of electronic expansion valve according to water temperature. The opening adjustment can reach 480 steps; and the adjust speed is 2 steps per second.

• Periodical: Advanced Materials Research (Volumes 490-495)
• Pages: 3197-3201
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.490-495.3197
• Online since: March 2012
• Authors: Ji You Fei, Kai Gao, Ran Deng, Xue Fei Yang
• Keywords: Constant Circuit, Current Source, Electronic Expansion Valve, NTC Sensor

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