Fundamental Study on Hydrogen Low-NOx Combustion Using Exhaust Gas Self-Recirculation

Hydrogen is expected to be a next-generation energy source that does not emit carbon dioxide, but when used as a fuel, the issue is the increase in the amount of NOx that is caused by the increase in flame temperature. In this study, we experimentally investigated NOx emissions rate when hydrogen was burned in a hydrocarbon gas burner, which is used in a wide temperature range. As a result of the experiments, the amount of NOx when burning hydrogen in a nozzle mixed burner was twice as high as when burning city gas. However, by increasing the flow velocity of the combustion air, the amount of NOx could be reduced. In addition, by reducing the number of combustion air nozzles rather than decreasing the diameter of the air nozzles, a larger recirculation flow could be formed into the furnace, and the amount of NOx could be reduced by up to 51%. Furthermore, the amount of exhaust gas recirculation was estimated from the reduction rate of NOx, and the validity was confirmed by the relationship between adiabatic flame temperature and NOx calculated from the equilibrium calculation by chemical kinetics simulator software.

Energy analysis of vacuum tube collector system to supply the required heat gas pressure reduction station

In city gas pressure reducing stations, in order not to hydrate natural gas after a sudden drop in pressure, the gas temperature is raised by a heater. The increase in temperature is such that after the pressure drop, the gas inside the pipes does not freeze. These heaters are gas burning and very high consumption, and because they use fossil fuels, produce environmental pollution. Accordingly, in this research, solar energy will be used to preheat the gas, which will be used for the most accurate analysis of TRNSYS software. In this regard, the amount of utilization of the sun and the amount of energy required for preheating will be obtained. After the implementation of the TRNSYS program, the highest amount of energy supply by the sun is related to spring, which on this day provides 55% of the thermal energy required by the load by solar energy.

HVDC Interference on MGL Pipelines

Mahanagar Gas is a City Gas Distribution Company engaged in the distribution of Natural Gas in and around Mumbai City. MGL has around 415 km of commissioned steel pipeline network which is being protected by ICCP. These pipelines are coated with three layer polyethylene coatings. Rectifying the external interferences on pipeline network is a major challenge for pipeline operating personnel in order to maintain safety and integrity of their pipeline. This technical paper is based on study of one of such external interference which posed a threat to MGL’s steel pipeline network. High Voltage Direct Current (HVDC) is a system for transmission of electricity over long distances. This system uses Direct Current (DC) for bulk transmission of electricity in contrast with the more common Alternating Current (AC) systems. HVDC is considered to be more effective to increase power grid delivery capabilities. A part of MGL’s pipeline network is currently facing interference due to a HVDC power substation on the outskirts of Mumbai. This substation is being operated by State Government and is affecting around 145 kms of MGL’s steel pipeline network during its monopolar operation for transmission of electricity. This interference is creating multiple anodic and cathodic areas on pipeline network with the help of a high magnitude current entering and exiting from pipeline at multiple locations which are difficult to predict and rectify. This technical paper will elaborate the concept of HVDC interference on steel pipelines. It will give a brief overview on the methodology adopted for identifying, monitoring and analyzing this interference phenomenon and will comment on the results of this analysis. It will throw light on a variety of technical challenges faced in dealing with this interference while operating a city gas distribution network in particular. And finally, it will discuss about possible remedial measures available and their effectiveness to curb this interference.

Monitoring and Maintenance of CP System in MGL

Mahanagar Gas Limited is a City Gas distribution (CGD) company based out of the city of Mumbai and around. MGL currently has around 480 Kms of Steel gas pipelines for transportation of natural gas. The diameters of these pipelines are ranging from 2” to 18” and almost all are coated with 3 layer Poly Ethylene coating (3LPE). We are installing Permanent Cathodic Protection (PCP) for all commissioned pipelines and Temporary Cathodic Protection (TCP) having a design life of 5 years for un-commissioned pipelines during the projects stage itself. This paper shall basically outline the CP system in MGL along with various practices being followed in MGL to ascertain the effectiveness of CP. MGL has installed various CP assets like CP stations, Diode stations, external ER probes, corrosion coupons to ascertain the CP effectiveness. This paper shall outline the detailed monitoring procedure along with monitoring frequency of all the assets. MGL is also carrying out health adequacy surveys like DCVG, CIPL etc over the steel pipeline network. Few case studies arising out of these monitoring results shall be presented in this paper. (1) Casing carrier short at Taloja Railway crossing. The detailed procedure of monitoring and rectification shall be presented. (2) Case study on CP under-protection at Andheri which was resolved using a flange isolation kit.

Design of Natural Gas Pipeline

India today has an in depth network of underground pipelines used for the transportation and distribution of gas. Large factories, fertilizer factories and other industrial enterprises are the most consumers in PNG and today, however, with the rise in its popularity, it's currently utilized in the domestic sector similarly as a fuel within the automotive sector in large metropolitan cities. To bring gas to those end users within the boundaries of a significant city, it's necessary to create city gas distribution pipeline networks. India today has an intensive network of underground pipelines used for the transportation and distribution of fossil fuel. Large factories, fertilizer factories and other industrial enterprises are the most consumers in PNG and today, however, with the rise in its popularity, it's currently employed in the domestic sector additionally as a fuel within the automotive sector in large metropolitan cities. To bring gas to those end users within the boundaries of a significant city, it's necessary to create city gas distribution pipeline networks, these networks have already been founded within the cities of Delhi, Mumbai, Vadodara, Firozabad, Kanpur and plenty of more such networks are planned within the near future. Given the infrastructure and layout available in typical Indian cities, it becomes difficult to make such gas distribution networks without separate corridors for competing utilities. Reckoning on pressures, flow rates and economic criteria, these networks may be constructed with steel pipes, polyethylene (PE) pipes or a hybrid PE-steel pipe system. In contrast to borehole pipelines, which stretch for miles directly through open fields, the CGD network is more complex. These are located in densely populated areas, and an oversized number of network branches meet the wants of users in several locations in an exceedingly city. Although they're much smaller long and size than background pipelines, a city's network is far more dispersed and diverse. The rise within the number of branches means over the amount of sleeves, bends, reducers, fittings, etc. within the network, with the exception of the quantity of delivery points for the availability of fossil fuel. Due to the assorted activities of third parties other city agencies, the chance of injury and accidents is even on top of the substantial pipelines. of these factors require better security systems integrated into the network and therefore the need for special preparation to manage any emergency situation.

Analysis and Treatment of Defects on the Buried Civil Gas Pipeline

In recent years, with the development of society, people pay more attention to environmental problems year by year. Because gas has the characteristics of low pollution and high calorific value, the proportion of gas in energy structure is increasing year by year. With the continuous development of civil gas business, the safety of gas pipeline has become a widely concerned focus. How to ensure the safe operation of gas pipeline has become the first problem to be considered by each pipeline gas operators. Civil gas pipeline accidents have the characteristics of sociality, suddenness and complexity. The civil gas pipeline system is distributed in the area where the population and public facilities are concentrated. Once the accident occurs, it not only causes serious casualties and property losses, but also causes social insecurity, environmental pollution and other problems. Therefore, the Chinese regulations, Periodical Inspection Regulation for City Gas Pressure Pipeline and Thermal Pressure Pipeline (TSG D7004-2010), require regular inspection of civil gas pipelines. During the regular inspection of a gas pipeline, the damaged point of the pipeline anticorrosive coating is found by the PCM (Pipeline Current Mapper) system. We decided to dig the point and make a direct inspection. Two dents and a gouge were found on the pipe. We evaluated these defects according to the technical standard. Because the pipeline delivery can’t be stopped for the time being, we used carbon fiber reinforcement method to repair the defects temporarily. This paper describes in detail the process of defect evaluation and repair, which has certain reference significance for the repair and use management of civil gas pipeline defects.