Plunger pump for pumping ultralow-temperature liquid nitrogen

Abstract

The invention relates to the field of plunger pumps, in particular to a plunger pump for pumping ultralow-temperature liquid nitrogen, and mainly solves the problem of influence on the fracturing operation by reduction of pressure after emission of liquid nitrogen due to emission of the liquid nitrogen by an overflow port after gasification through heat absorption. The plunger pump comprises a box; a plunger is slidingly arranged on the box, and one end penetrates out of the box; the box is provided with a pumping device at the outer end of a plunger; the pumping device comprises a shell fixedly arranged on the box; a cavity is formed in the shell; a push rod is slidingly arranged in the cavity; a through hole is formed in the axis of the push rod; a connecting rod is inserted in the through hole, and can slide relative to the push rod; a groove is formed in the inner surface of the push rod; the push rod is provided with a convex block in the groove; a spring is arranged in the groove; one end of the connecting rod penetrates out of the shell, and is connected with an outer end of the plunger; and a feeding device is arranged between a pressure measuring port and a feeding port atthe external of the shell.

Description

technical field [0001] The invention relates to the field of plunger pumps, in particular to a plunger pump for pumping ultra-low temperature liquid nitrogen. Background technique [0002] In recent years, with the continuous maturity of fracturing technology in oilfield applications, more and more high-pressure nitrogen is used, and how to generate high-pressure nitrogen has become a difficult problem. The compressed nitrogen directly produced by ordinary air separation nitrogen production equipment can only produce a maximum discharge pressure of 35 MPa, which is difficult to meet the requirements of oil field fracturing. The liquid nitrogen plunger pump pressurizes low-pressure liquid nitrogen into high-pressure liquid nitrogen, and then uses heat exchange to convert high-pressure liquid nitrogen into high-pressure nitrogen to discharge. This method can successfully obtain nitrogen discharge pressure above 100MPa, which fully meets the requirements of fracturing operation...

AI Technical Summary

Problems solved by technology

[0004] Therefore, in view of the above-mentioned problems, the present invention provides a plunger pump for pumping ultra-low temperature liquid nitrogen, which mainly solves the problem that in the prior art, the liquid nitrogen absorbs heat and gasifies and then is discharged through the overflow port, resulting in the pressure of the liquid nitrogen after it is discharged. Reduced problems that affect fracturing operations

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