Pressure regulating device and method for incoming natural gas in LNG factory

Abstract

The invention discloses a pressure regulating device for entering natural gas in an LNG factory, which comprises a first regulating valve arranged on a gas transmission pipeline, and a second regulating valve is arranged in parallel at both ends of the first regulating valve, and the maximum flow capacity of the second regulating valve is greater than The minimum flow capacity of the first regulating valve, the gas transmission end is provided with a pressure detection device and a controller for collecting the pressure signal of the pressure detection device and outputting an electrical signal, the controller includes a PID module, and the controller is connected with the first regulating valve and the first regulating valve respectively. The positioner of the second regulating valve is connected. In the present invention, two regulating valves are arranged in parallel in the gas transmission pipeline, and only one of the regulating valves needs to be opened to work at a large opening during the gas-limited period, which avoids the working of the regulating valve at a small opening and prolongs the service life. The invention also discloses a method for adjusting the pressure of the natural gas entering the LNG factory, which can set the split points of the two valves according to the actual needs and the flow characteristics of the valves to realize the smooth adjustment of the overall flow.

Description

technical field [0001] The invention relates to the technical field of natural gas, in particular to a pressure regulating device and method for inbound natural gas in an LNG plant. Background technique [0002] In the prior art, the natural gas introduced from the distribution station to the factory by the LNG (liquefied natural gas) factory needs to be pressure regulated, and the pressure is stabilized before being transported to the next process flow. Now the factory basically uses self-operated regulating valves and single regulating valves to regulate and stabilize the pressure. As a single regulating valve, in order to meet its process flow, it is inevitable to choose a valve with a large diameter. However, there is a shortage of natural gas in the country at present, and the country (especially in the north) has a gas restriction time of about half a year, so this valve will work at a small opening for half a year, and the characteristics of the valve are prone to di...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the present invention provides a pressure regulating device for entering natural gas in an LNG plant, which is used to solve the problem of short service life of the entering natural gas pressure regulating valve

Images