CN-121994541-A - Flow mode control system and method for natural gas accumulation sampling system

CN121994541ACN 121994541 ACN121994541 ACN 121994541ACN-121994541-A

Abstract

The invention discloses a flow mode control system and method of a natural gas accumulation sampling system, and relates to the technical field of natural gas analysis; the method comprises the steps of reading instantaneous flow data of a station control system, selecting a flow mode control signal type of a natural gas accumulation sampling system, reading the instantaneous flow data to accumulate when the flow mode control signal is a pulse voltage signal, outputting the pulse voltage signal when the accumulated flow value reaches a preset flow value, controlling a sampling pump of the accumulation sampling system to conduct primary sampling, reading the instantaneous flow data to convert the instantaneous flow data into an analog current signal when the flow mode control signal is an analog current signal, calculating the instantaneous flow by the accumulation sampling system control module to accumulate, conducting primary sampling by the sampling pump when the preset flow value is reached, and accumulating again until the sampling times reach a preset value after primary sampling is completed.

Inventors

WANG WEIJIE
ZENG WENPING
ZHANG PU
CHEN YONG
ZHOU LI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241107

Claims (7)

1. The flow mode control method of the natural gas accumulation sampling system is characterized by comprising the following steps of: the controller reads instantaneous flow data of a station control system of the gas transmission station, and selects a flow mode control signal type of the natural gas accumulation sampling system; When the flow mode control signal is a pulse voltage signal, the controller performs accumulation calculation according to the read instantaneous flow data, when the accumulated flow value reaches a preset flow value, the pulse voltage signal is output, the pulse voltage signal is transmitted to a control module of an accumulated sampling system to trigger a sampling pump to perform sampling once, the value of the sampling times is added with 1, the accumulated flow value is reset to zero, the flow data is read again for accumulation calculation, and the sampling is stopped until the sampling times reach the preset value; when the flow mode control signal is an analog current signal, the controller converts the read instantaneous flow data into an analog current signal, the analog current signal is transmitted to a control module of an accumulation sampling system to calculate the instantaneous flow and accumulate, when the current value reaches a preset flow value, a sampling pump is triggered to perform sampling once, the value of the sampling times is increased by 1, the accumulated flow value is reset, the flow data is read again to perform accumulation calculation, and the sampling is stopped until the sampling times reach the preset value.
2. The method according to claim 1, wherein when the type of the flow pattern control signal of the natural gas cumulative sampling system is a pulse voltage, a pulse voltage signal of 5-24 v is outputted when the cumulative flow value reaches a preset flow value.
3. The method for controlling a flow pattern of a natural gas cumulative sampling system according to claim 1, wherein when the type of the flow pattern control signal of the natural gas cumulative sampling system is an analog current, the read instantaneous flow data is converted into 4-20 ma analog current signals.
4. A natural gas cumulative sampling system flow mode control system, comprising: The cumulative sampling system is arranged on the gas transmission field pipeline; The gas transmission station control system is connected with the accumulation sampling system; The controller is used for reading the instantaneous flow data of the station control system of the gas transmission station and simultaneously selecting the type of the flow mode control signal of the cumulative sampling system; The pulse voltage output module is used for transmitting the pulse voltage signal output by the controller to the accumulated sampling system control module; The analog current output module is used for transmitting the analog current signal output by the controller to the cumulative sampling system control module; When the flow mode control signal of the cumulative sampling system is a pulse voltage signal, the controller performs cumulative calculation according to the read instantaneous flow data, and when the cumulative flow value reaches a preset flow value, the pulse voltage output module outputs a pulse voltage signal to the cumulative sampling system control module to trigger the sampling pump to sample; when the flow mode control signal of the accumulation sampling system is an analog current signal, the controller converts the read instantaneous flow data into the analog current signal, the analog current signal is transmitted to the control module of the accumulation sampling system through the analog current output module, the accumulation sampling system calculates the instantaneous flow and accumulates the instantaneous flow, and when the instantaneous flow reaches a preset flow value, the sampling pump is triggered to sample.
5. The system of claim 4, wherein the gas station control system is connected to a network switch, and the controller is connected to the network switch of the gas station control system via a network cable.
6. The system of claim 4, further comprising a relay coupled between the pulsed voltage output module and the cumulative sampling system control module.
7. The system of claim 4, further comprising a surge protector connected between the analog current output module and the cumulative sampling system control module.

Description

Flow mode control system and method for natural gas accumulation sampling system Technical Field The invention relates to the technical field of natural gas analysis, in particular to a flow mode control system and method of a natural gas accumulation sampling system. Background The cumulative sampling system is taken as an important means for measuring the heating value in the natural gas energy metering process, and plays an important role in ensuring fairness and fairness of natural gas trade handover. The natural gas cumulative sampling system is operated in two sampling modes, one is in a time mode proportional to time and the other is in a flow mode proportional to flow, and both sampling modes have advantages. The accumulated sampling system samples according to the set time interval in the time mode, is simple and convenient to operate and easy to realize, and is suitable for working conditions with stable gas composition and flow. The accumulated sampling system in the flow mode samples according to a preset flow value, is not only suitable for the condition that the gas composition and the flow are relatively stable, but also suitable for the working condition that the gas composition and the flow fluctuation are relatively large, but the mode needs to be connected with a flow computer, converts a flow signal into a pulse voltage or an analog current signal and transmits the pulse voltage or the analog current signal to the accumulated sampling system control module, so that the accumulated sampling system is controlled to sample according to the flow ratio. The implementation mode of the flow mode of the accumulation sampling system on the natural gas transmission station at present comprises the steps of ① preparing relevant hardware modules according to the trigger signal of the accumulation sampling system, ② writing software programs such as flow reading, accumulation calculation, trigger signal sending and the like according to the station control system type of the station, ③ temporarily stopping the gas station, embedding the software programs into the station control system to read flow data, performing software debugging, and testing the control function of the output flow control signal on the accumulation sampling system. The existing mode has the following three aspects that firstly, the normal production of the station is easy to influence, and the implementation difficulty is high. When a flow mode control program is embedded in a station control system, a station is required to stop gas temporarily, the implementation difficulty is high, the data transmission of other online equipment is easy to influence, and the application range of a software program is limited and the system has no universality. Because the reading and transmission of the flow data of different station control systems are different, when the accumulated sampling system is used for replacing stations, software control programs are required to be rewritten and debugged, the workload of operators is increased, the popularization is not easy, and the output of flow control signals is single. The current mode can only generate a specific trigger signal to control the cumulative sampler, and when the type of the cumulative sampler is changed at the site, hardware and software are required to be designed again, so that all the cumulative sampling systems cannot be compatible. Therefore, it is necessary to design a flow mode control system and method which is convenient to operate, can be suitable for different flow trigger signals, and can meet the requirements of different station control systems of each gas transmission station. Disclosure of Invention The invention aims to solve the technical problems that a control program can be embedded only when a station stops gas in the current implementation process of a flow mode of a natural gas accumulation sampling system, the implementation difficulty is high, the universality is low, and the system and the method cannot be suitable for different trigger signals and different types of station control systems. The invention is realized by the following technical scheme: A first object of the present invention is to provide a method for controlling a flow pattern of a natural gas cumulative sampling system, comprising the steps of: the controller reads instantaneous flow data of a station control system of the gas transmission station, and selects a flow mode control signal type of the natural gas accumulation sampling system; When the flow mode control signal is a pulse voltage signal, the controller performs accumulation calculation according to the read instantaneous flow data, when the accumulated flow value reaches a preset flow value, the pulse voltage signal is output, the pulse voltage signal is transmitted to a control module of an accumulated sampling system to trigger a sampling pump to perform sampling once, the value of the sampling times is added with 1, the