Manually operated metallic gas values for use in above ground piping systems up to 5 psi 5psi及以下的地上管道系统用手动金属气阀
4.
A thoroughly study on characteristics of ground pipe - heat exchanger of gshp has been made in this ph . d . thesis . the research method used in this thesis is very useful for other ground energy storage system . the research results could be very significant for engineering application of gshp technique 本文对地下埋管换热器传热性能的研究较为深入，研究方法对其他地下蓄能系统的研究有借鉴意义，研究成果对地源热泵技术的推广具有工程指导意义。
