A multifunctional valve for liquefied natural gas cylinders and a method for controlling liquid filling and liquid discharge

Abstract

The invention discloses a multifunctional valve of a liquefied natural gas cylinder and a method for controlling liquid charging and discharging. The multifunctional valve comprises a valve body. A liquid charging inner inlet, a gas using inlet, a liquid using inlet, a liquid meter connector, an economical gas throttle connector, a liquid using stop valve connector, a return gas stop valve connector, a safety valve connector, an overflow valve connector, a liquid charging outer inlet and a return gas connector are formed in the valve body. The gas using inlet, the economical gas throttle connector, the liquid using stop valve connector and the overflow valve connector are communicated to form a gas using channel. The liquid using inlet, the liquid using stop valve connector and the overflow valve connector are communicated to form a liquid using channel. The gas using inlet, the return gas stop valve connector and the gas return connector are communicated to form a return gas channel. The liquid charging outer inlet and the liquid charging inner inlet are communicated to form a liquid charging channel. The gas using inlet and the safety valve connector are communicated to form a pressure measuring channel. A plurality of valves share one valve body, so that cost is low, and the leakage defect caused by multiple welding points is overcome.

Description

technical field [0001] The invention relates to a multifunctional valve of a liquefied natural gas cylinder and a method for controlling liquid filling and liquid discharge, which is especially suitable for an automobile liquefied natural gas cylinder with a conversion joint, and belongs to the technical field of liquefied natural gas application. Background technique [0002] Liquefied natural gas cylinder is a cryogenic liquid insulated gas cylinder. The filling and liquid supply of liquefied natural gas cylinder must be realized through various control valves. [0003] At present, LNG cylinder manufacturers at home and abroad use the connection method of "distribution head-stainless steel steel pipe-control valve-stainless steel steel pipe-connecting head-external pipeline" in the installation of their control valves, that is, in the multi-distribution head A plurality of stainless steel pipes are welded at each interface, and then the stainless steel pipes are welded to ...

AI Technical Summary

Problems solved by technology

The main defect of this connection method in actual use is that there are many leakage points, and it is difficult to manufacture and maintain.

Once the valve is damaged, the stainless steel pipe must be cut and welded to repair or replace the valve. At the same time, the excessively long stainless steel pipe connected to the distribution head will increase the heat transfer, which is not conducive to the heat insulation of the cryogenic gas cylinder, and increases the weld. leak point

[0004] Chinese patent ZL201210170391.2 discloses an integrated valve on a vehicle-mounted gas cylinder. Although the valve structurally omits the connecting pipe from the distribution head to the valve, each valve is installed as an independent valve. In the short cylindrical porous cavity, it has its own valve body, which requires an increase in the size of the distribution head; and an expensive spring energy-storage sealing ring is required as the seal before insertion, so that the sealing performance can be guaranteed

Invisibly increase the cost of each valve body and seals, and the practicability is not strong

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