6138 results about "Liquid nitrogen" patented technology

The invention relates to a plunger pump used for pumping ultralow-temperature liquid nitrogen, which comprises a power end and a cold end, wherein the cold end comprises a cold end shell; one end of the cold end shell is provided with a plunger; the other end of the cold end shell is provided with a suction inlet and an exhaust port; the positions of the suction inlet and an exhaust port of the cold end shell are provided with a valve seat; one end of the plunger is connected with a power end; the other end of the plunger is mutually matched with the cold end shell and the valve seat to form an inner cavity; the valve seat is provided with a first channel and a second channel, wherein the first channel is used for communicating the inner cavity with the suction inlet; the second channel is used for communicating the inner cavity with the exhaust port; a lower-pressure valve used for controlling the liquid nitrogen to be sucked into the inner cavity is arranged between the first channel and the inner cavity; a high-pressure valve used for controlling the liquid nitrogen to be discharged out of the inner cavity is arranged in the second channel; the plunger is driven by the power end to carry out linear reciprocating motion in the inner cavity so as to drive the lower-pressure valve or the high-pressure valve to be opened and closed; when the low-pressure valve is opened, the liquid nitrogen enters the inner cavity from the suction inlet; when the high-pressure valve is opened, the liquid nitrogen is discharged out of the inner cavity from the exhaust port; and the cold end shell is provided with an overflow port communicated with the inner cavity.

The invention relates to a hole bottom freezing cord coring drill and a coring method thereof. In the invention, liquid nitrogen is taken as a refrigerant; the liquid nitrogen absorbs heat in the gasification process so as to freeze a core at a hole bottom and inhibit a natural gas hydrate from being decomposed. The drill comprises an outer tube assembly and an inner tube assembly; and in the process of acquiring the core, a sand hitch is utilized to drag the inner tube assembly out from the outer tube assembly, an end cover and a clamp spring are dismounted, a semi-closed tube and a core sample are pumped out together from a core tube, the two ends of the semi-closed tube are sealed by rubber plugs, and the core sample and the semi-closed tube are stored in a liquid nitrogen hold-up vessel or a high-pressure container together. The invention has the advantages that rapid freezing can be realized, and the freezing effect is good; since cord coring and hole bottom freezing are combined, rapid coring without lifting the drill is achieved; in the drilling process, the inner tube assembly does not rotate, thus damages on a hydras core caused by mechanical force generated by rotation of the drill is avoided to a greater degree, the percentage of coring, the core integrity degree and the representativeness are more effectively improved; and semi-closed tube type rapid ground surfacesampling is adopted, thus the core can be rapidly obtained from the ground surface.