4The research of ground source heat exchanger which is U shape bellows on ground source heat pump system's heat exchanging in soil17-20
7An analysis on economic efficiency of adding a new pneumatic water pump for the heat-power plant of baogang group27-28
9Application of parallel active power filter to eliminate harmonic produced by converter used in air compressor38-40
10The application of new pattern frequency conversion and constant pressure to water supply equipment41-42