Development and Application of Methane Leakage Monitoring System for Gas Transmission Pipeline

Oil and gas pipeline transportation, as a relatively safe way of oil and gas transportation, undertakes most of the transportation tasks of crude oil and natural gas. Oil and gas pipeline accidents affect a wide range of consequences. Therefore, the oil and gas pipeline leakage detection is paid more and more attention. In this paper, ultra-low power methane gas sensor is selected to collect methane gas concentration in the air, and wireless network technology is used to build a wireless network sensor system with 4G function. Through the sensor distribution along the pipeline, it can intuitively and accurately judge whether there is a micro-leakage in the pipeline, and understand the diffusion situation after the leakage. The sensor system has high reliability and stability, and has high value of popularization and application.

Liquefied natural gas (LNG) and DC electric power transfer system by cryogenic pipe of superconducting DC power transmission (SCDC)

We propose a hybrid energy transmission pipeline that combines the liquefied natural gas (LNG) cryogenic pipelines and superconducting direct current (DC) electrical power transmission cable system (SCDC). The system design is based on experimental data from the SCDC Ishikari project in Japan and related laboratory experiments. The particular structure of the hybrid cryogenic pipe connects the thermal radiation shield of the pipe that contains the DC high temperature superconducting (HTS) electrical cable to the LNG pipe and significantly reduces the heat leak into the SCDC pipe. Because the specific heat of LNG is higher than that of liquid nitrogen and the LNG transfer rate is quite high, the thermal loss of the SCDC cable becomes only 1/100 that of present-day conventional copper cables, far below the factor 1/10 reduction achievable by a stand-alone SCDC transmission lines. The LNG temperature rises by less than 2 K over a 100 km transport distance, which is negligible in actual use. LNG also saves significantly on pumping power compared to a natural gas pipeline. To liquefy the LNG at cryogenic temperature from natural gas at ambient temperature requires a large refrigerator that consumes enormous power. The gas pipeline, however, needs a compressor to produce high-pressure gas, which also consumes a massive amount of power. Due to these considerations, the proposed hybrid system is a viable design for the long-distance joint transportation of LNG and electricity.

Efficiency Enhancement of Gas Turbine Systems with Air Injection Driven by Natural Gas Turboexpanders

The fuel source of many simple and combined-cycle power plants usually comes from a nearby natural gas transmission pipeline at a pressure from 50 to over 70 bar. The use of a turboexpander instead of throttling equipment offers a promising alternative to regulate the pressure of natural gas introduced to the power plant. Specifically, it helps recover part of the available energy of the compressed gas in the transmission pipeline, increase the power output and efficiency of the gas turbine system, and decrease the fuel use and harmful emissions. In this paper, the addition of such a turboexpander in a gas pressure-reduction station is studied. The recovered power is then used to drive the compression of extra air added to the combustion chamber of a heavy-duty gas turbine. The performance of this configuration is analyzed for a wide range of ambient temperatures using energy and exergy analyses. Fuel energy recovered in this way increases the output power and the efficiency of the gas turbine system by a minimum of 2.5 MW and 0.25%, respectively. The exergy efficiency of the gas turbine system increases by approximately 0.36% and the annual CO2 emissions decrease by 1.3% per MW.

Analisis Ketersediaan Air Waduk Gadjah Mungkur dengan Adanya Pembangunan Intake dan Jaringan Pipa Trasmisi Wosusokas

Gadjah Mungkur Reservoir is one of the multipurpose reservoirs built by damming the flow of the Bengawan Solo River. The Gadjah Mungkur Reservoir has existed for a long time with the main purpose of controlling flooding, but over time, this reservoir is also useful as a hydropower plant, irrigation, and also to meet the raw water needs of Wonogiri City. The potential of the Gadjah Mungkur Reservoir itself in meeting the needs of drinking water is an essential function in the people’s life around the reservoir. Therefore, the expansion of the scope of providing drinking water can be used to develop the potential of the Gadjah Mungkur Reservoir. This coverage expansion was realized through the construction of the Wosusokas intake and transmission pipeline network to drinking water receiving areas, namely Wonogiri, Sukoharjo, Solo, and Karanganyar, with service coverage of drinking water access resepectively ±78,38, ±70,97%, ±81,85%, and ±70,97%. This study aims to analyze the water availability of the Gadjah Mungkur Reservoir with additional coverage for drinking water services. The method used is a simple reservoir routing calculation by processing secondary data obtained in the form of inflow, outflow, and reservoir storage characteristics. The results of the analysis show that elevation variations with the construction of the Wosusokas intake and transmission pipeline have an annual average of +132,56 m in 2017, with a reservoir storage volume reaching 216,27 MCM and +134,29 m in 2018, with a reservoir storage volume reaching 284,92 MCM. However, there are some elevation values that exceed +138,0 m, namely at February to March 2018. However, overall, the results of the analysis show that the Wosusokas construction can increase the potential utilization of the Gadjah Mungkur Reservoir without endangering the reservoir with water level fluctuations that can still be controlled and in accordance with the regulation of reservoir water level.

Failures of Pipelines

This article discusses the failure analysis of several steel transmission pipeline failures, describes the causes and characteristics of specific pipeline failure modes, and introduces pipeline failure prevention and integrity management practices and methodologies. In addition, it covers the use of transmission pipeline in North America, discusses the procedures in pipeline failure analysis investigation, and provides a brief background on the most commonly observed pipeline flaws and degradation mechanisms. A case study related to hydrogen cracking and a hard spot is also presented.

Evaluation of the Structural Integrity of Bell-Spigot Joints in Steel Gas Pipelines

The most common joining method in steel gas pipelines is welding; however, this method involves time-consuming, expensive manufacturing and assembly processes to ensure quality in operation. Bell-Spigot joints, which work by mechanical interference, have started to be used as an alternative joining method in steel pipes. Its use has increased due to its reduced assembly time and less post-assembly inspection requirements. In this paper, the structural performance of Bell-Spigot joints in 16-inch steel pipe API 5L X70 with Fusion Bonded Epoxy (FBE) coating for Natural Gas transmission pipeline are evaluated experimentally and by modeling. Test pieces were taken from the gas pipeline after 3 years of operation. Then, tensile pull-out and bending with hydrostatic pressure tests were performed to replicate operating conditions. Deformations, displacements, and the potential presence of leaks were monitored. Experimental results were compared with a Finite Element Method model. Finally, an analytical model for the calculation of stresses and strains in the joint system's components was developed. It was determined that the tightness of the joint depends mainly on the radial interference and the interference length. A higher safety factor can be obtained at the bell-spigot joint than the base pipeline by optimizing selection of joint design variables and the service loading conditions. If the interference pressure is lower than half of the operation pressure, the joint's mechanical strength will be higher or equal that the base pipe.