Gas pressure regulation system
A gas pressure regulation system ( GDRA ) is a system for single or multi-stage gas pressure reduction. In the case of a gas pressure control and measuring system ( GDRMA ), the gas quantity measurement is also carried out.
General
In order to make long-distance transport from the production to the customer economical, natural gas is compressed to up to 100 bar ( offshore also to over 80 bar). On the way from the customer to the end customer , the pressure is then reduced again to a few millibars overpressure . This pressure reduction requires a so-called gas pressure control or a combined gas pressure control and measuring system.
construction
The main components are: shut-off devices, filters, preheaters, safety devices ( SAV and SBV ), controllers and measuring devices (GDRM). Supplementary facilities are u. a. electrical and odorization devices .
The picture shows the basic arrangement of the main components and the various design variants depending on the required security of supply. In addition, the state variables pressure, temperature, enthalpy and entropy are plotted at the points that are characteristic of the system.
The term OP stands for operating pressure in German operating pressure . The index u for upstream to German upstream, on the input side and the index d for downstream to German downstream, on the output side.
tasks
The system primarily serves to reduce the pressure; in addition, the tasks of filtering, preheating natural gas (due to the Joule-Thomson effect ), protecting the following system parts from impermissibly high (special case: too low) gas pressure, measuring and recording are the most important Parameters as well as the odorization (making it smellable) of the gas realized.
In urban gas networks, transmission at high pressure and on-site relaxation not only reduced the cross-sections of the gas lines, but also saved gas storage tanks ( gasometers ) - the amount of gas stored in the high-pressure lines is sufficient as a buffer.
literature
- Günter Cerbe: Basics of gas technology Carl Hanser Verlag, Munich Vienna 2004, ISBN 3-446-22803-9 .
