Natural Gas Supply System Research Articles

PROBLEMS ISSUES OF REGULATORY PROVISION OF PRODUCTION ACTIVITY OF NATURAL GAS MARKETS

The formation of the modern Ukrainian natural gas market is accompanied by profound transformations of the national gas infrastructure: the creation and operation of new market operators, the redistribution of infrastructure facilities, the development and implementation of new requirements for the effective functioning of the entire system. At the same time, this requires from all parties a verified and balances strategy for the optimal implementation of all the obligations that Ukraine has undertaken to fully implement the requirements of the EU Third Energy Package, which aims to create an effective natural gas market based on the principles of free competition, proper consumer protection and security of supply. Despite the fact that the capacity of the Ukrainian gas transmission system and gas storages is one of the largest in Europe, the unbanding process has caused a number of threats in the area of regulatory support for production activities, requiring the consolidation of specialists' efforts to form optimal solutions to the problems that have arisen. In addition, the lengthy process of reforming and reorganizing the Ukrainian gas distribution system has led to a situation where the work of a natural gas distribution operator is facing a risk of imbalance in terms of inefficient standardization of the main areas of operation to meet the EU legislation requirements implemented in Ukraine. Therefore, to develop basic directions for the future work of gas infrastructure operators, it is necessary to take into account the acting capabilities of existing system for transportation, underground storage and gas distribution (taking into account the significant number of standardized indicators defined by the existing normative documents of the former USSR) and in accordance with the trends in the development of the European gas infrastructure introduce economically and technically feasible measures to standardize performance activities. Such works have to be incorporated into integrated research programs, during which regional and international trends are to be taken into account and adapted, the results of which will be the basis for future roadmaps and programs for the development of natural gas supply and distribution systems.

Research on Flow Characteristics of Electronically Controlled Injection Device Developed for High-Power Natural Gas Engines

Accurate fuel supply is a key factor that influences the performance of high-power natural gas engines. The premixed and single-point natural gas supply system is the most commonly used method to ensure a large fuel supply but one of its shortcomings is the inaccuracy of the fuel supply. A new type of natural gas injection device with fungiform configuration and electronically controlled actuator was developed to achieve high efficiency and stable operation in high-power natural gas engines. Firstly, a computational fluid dynamics (CFD) model of the injection device was created. Based on this model, the key structure parameters that have a significant influence on the outlet flow were confirmed. A particle swarm optimization (PSO) model was developed to identify the optimal outflow structure. Then, a flow function for precise flow supply control was constructed based on a response surface model, according to the flow rates of the device under different control parameters. Finally, a flow-characteristic test bench and a high-power engine prototype were developed to verify the simulation and optimization results. The results indicate that the optimized outflow structure shows low pressure loss and a large flow rate, improving injection efficiency by 10.37% and mass flow by 11.78% under 0.4 Mpa pressure difference. More importantly, the cycle fuel supply could be controlled accurately for each cylinder owing to the developed flow function. Consequently, compared with the original engine using a single-point natural gas supply system, the cylinder performance imbalance was improved by 37.47%.

Dynamic analysis of SNG and PNG supply: The stability and robustness view #

The methods of robust analysis and stability analysis of natural gas supply system are proposed. Using this method, the integration of bifurcation theory and Lyapunov's stability theory was performed, accounting for uncertainty and complexity. China's natural gas supply system is composed synthetic natural (SNG) and pipeline natural gas (PNG), both of which change unsteadily and interact in a nonlinear manner, making the supply process of the natural gas supply system dynamic. In light of this, and based on the Two Species Competition Model, a natural gas supply dynamics model composed of SNG and PNG is established to express the dynamics of China's natural gas supply system. Fixed points stability analysis theorems are proposed with reference to Lyapunov's stability theory, and the stability of the natural gas supply process was analyzed using these theorems, whose rationality was verified by numerical simulation. The robustness of the natural gas supply system is described in detail in terms of the external disturbance degree and the inherent invulnerability of the system, by means of bifurcation theory and the maximum Lyapunov exponent.

Modelling and optimization of a natural gas supply system at a transient stage: a case study of China

The global energy structure is on a low-carbon transition path featuring more natural gas consumption, and global natural gas demand has been increasing fast. Planning and operation of a natural gas supply system at a transient stage with multiple supply sources, end-consumers, and large infrastructure with multiple sub-systems are challenging tasks. Spatial and seasonal mismatch of natural gas supply and demand makes the natural gas distribution and infrastructure construction planning problem even more complex. Without proper planning, insufficient construction could lead to a shortage of natural gas supply, whilst excessive construction could lead to a higher cost. Quantitative analysis technologies are needed to facilitate decision-making during the transient stage of a natural gas system. In this work, we propose a monthly-scale multi-period and multi-regional modelling and optimization framework for planning and operation of a natural gas supply system at a transient stage, with a case study of the natural gas supply system in China. The optimal planning and operation strategy of the natural gas supply system in China by 2050 is obtained by minimizing the lifespan overall cost. Gaps between actual planning and the optimal planning are pointed out. Finally, policy suggestions are summarized, including establishing market-oriented pricing mechanisms, managing infrastructure centrally, promoting coordination amongst provinces when formulating projections, accelerating current infrastructure construction, and predicting natural gas demand and prices reasonably.

A Co-optimization Model of Natural Gas Supply and Electric Power Systems

A Co-optimization Model of Natural Gas Supply and Electric Power Systems

A systematic data-driven Demand Side Management method for smart natural gas supply systems

Advanced sensor and communication technologies can make natural gas supply systems smarter than ever before, in both system management and operation. This paper presents the development of a novel data-driven Demand Side Management, whose framework includes demand forecasting, customer response analysis, prediction of dynamic condition of the gas network, quick supply reliability evaluation, multi-objective optimization and decision-making. The aims of this DSM method are to smooth load profiles, improve company profit and enhance system reliability, by means of a dynamic pricing strategy. To verify the effectiveness of the developed framework, a case study is considered, concerning the management of a relatively complex gas supply system, wherein four different pricing periods are introduced for comprehensively testing. The results in the case study show that the DSM framework is able to effectively achieve the targets of peak shaving and valley filling. Besides, it can significantly and stably improve the system efficiency and reliability, for different pricing periods. Finally, pricing period determination is discussed in relation to the features of performance.

Development of the instrumentation system for gas-and-diesel fuelled BelAZ dump truck

The prospects for the use of natural gas as a motor fuel are considered. The state-run program for the development of natural-gas-fuelled vehicles will entail an increase in the share of transport operating on natural gas. The data on the thermal performance of natural gas from various fields, the volumetric heat values of the stoichiometric mixture of which is almost the same, are given. The analysis of the operation of gas-diesel-fuelled BelAZ dump truck, which burns liquefied natural gas, is conducted. The schematic diagram for engine power supply with liquefied natural gas is given. The calculation of the liquefied natural gas supply system with the replacement of diesel fuel by 33% was made. As a result of the calculation, the diameter of a fuel manifold after injectors, which provides the recommended gas velocity through a manifold, was determined. The instrumentation system for controlling the amount of supplied natural gas is proposed. The complex allows obtaining data on the instantaneous gas flow rate and the total flow rate over a period of time. A pulsation damper used as part of the system allowed reducing gas pulsation in fuel manifolds after injectors, to create conditions for the use of orifice plate flow meters, and ensured the uniform supply of natural gas to both banks of cylinders, which favourably affected the engine.

Grid Collapse Security, Stability and Vulnerability Issues: Impactful Issues Affecting Nuclear Power Plants, Chemical Plants and Natural Gas Supply Systems

Abstract Vulnerability to extended power outages stemming from grid collapse triggered by terrorism, technological accident, cyber attack or geomagnetic storms is understood to mean the widest possible spectrum of immediate and downstream consequences for our nations critical infrastructure. Regrettably few realistic plans are in place for dealing with this risk especially as it pertains to three primary energy systems of strategic significance to the United States – nuclear power, chemical manufacturing and natural gas supplies. The author argues that greater sustained attention is needed to upgrade the resilience of these systems, foster greater sharing of remedies among them to offset the worst effects of grid collapse which exceeds 15 consecutive calendar days and build collective avenues of enhanced risk mitigation against such scenarios.

Urban Natural Gas Supply Security Evaluation: A Systematic Perspective

As the main power source, the stable supply of energy is important for urban sustainable development. It is necessary to systematically evaluate the security level of urban energy supply, based on which the key influencing factors can be investigated and then the energy supply security can be improved. Ecological network analysis, a helpful systematic analysis tool, was introduced to evaluate the level of urban energy supply security, with the merit of connecting different components within a holistic network system. Such indicators as system sustainability and weights of different components were calculated to analyze the characteristics of energy supply system based on information and structure analysis. The established model and indicators based on ecological network analysis were applied by choosing the natural gas supply system in Chongqing city as the case. The results show that the level of natural gas supply security in Chongqing generally increased during 1997–2012. And the natural gas production sector, consumption sector, and domestic suppliers outside the city caused greater impact on the natural gas supply system than other components during the study period. Based on a few scenario analysis, certian suggestions were put forward to improve the security level of natual gas supply in Chongqing.

A System Dynamics Model for Analyzing Future Natural Gas Supply and Demand

This paper models a natural gas supply and demand system using a system dynamics approach to determine whether current policies for a given country will sustain its long-term natural gas demand. Th...

An ecological network analysis of the structure, development and sustainability of China’s natural gas supply system security

Mitigating the impacts of climate change and ensuring energy supply security has compelled China’s policy makers to maximise the use of alternative and low carbon fuels. Use and production of natural gas (an energy source with low carbon emissions) has experienced remarkable growth in China during the last decade, making China the third largest consumer and importer in the world. This study applied a powerful system-oriented ecological network analysis (ENA) technique to study China’s natural gas policies as they pertain to guarantee supply security. Several indicators based on the ENA were measured to analyse the degree of connectivity, the contributions of different compartments, resource utilisation (aggradation), development (ascendancy) and sustainability of China’s natural gas supply system. It was found that China’s source and route diversification policy have caused the natural gas supply system to exhibit considerable network complexity, demonstrating the high level of development, flexibility and diversity of China’s natural gas supply system. However, the policy also has caused a decrease in the aggradation and sustainability from the perspective of an ecological system network. The most important compartments in terms of their contribution to China’s natural gas supply system were found to be domestic natural gas production and transit compartments.

Evaluating China's natural gas supply security based on ecological network analysis

Growing role of natural gas as an effective policy choice has kindled the discussions surrounding the security of its supplies in the policy circles of the Chinese government. This study tries to evaluate China's natural gas supply security and employs a system-oriented modelling approach namely, Ecological Network Analysis (ENA) to integrate all the critical compartments of China's natural gas supply system. Several ENA indicators are constructed, which disclose that domestic natural gas production contributes significantly to China's natural gas supply system in comparison with all the external natural gas suppliers. In addition, the variations in a system stability indicator suggest that diversification of external natural gas suppliers has a positive influence on China's natural gas supply security. Furthermore, the results revealed that China's natural gas supply security policy is orchestrated on following features 1) to increase the investment in the upstream natural gas production sector to boost its domestic production in order to reduce its import requirements and 2) to diversify the external natural gas supplies by sources and routes to reduce the level of the economic and supply disruption related risks.

A systematic method of evaluation of the Chinese natural gas supply security

As a relatively clean energy, natural gas will be increasingly in demand to meet short-term low-carbon targets. The gap between the demand and supply of natural gas will be increasingly scrutinized, which highlights the significance of natural gas supply security. Considering the extensive connections among various aspects related to natural gas supply and the complex interactions behind these connections, ecological network analysis was applied to simulate the natural gas supply system in China and systematically measure its overall security level. Network Information Analysis, Structural Analysis, and Utility Analysis were conducted. It is found that the Chinese natural gas supply security increased during 2000–2011. In terms of the influence of different compartments on the whole natural gas supply system, in order from the largest to smallest influence they are: supply sources, consumption sector, refining, and reserve sectors. And the relationships among compartments became stronger in the later stage than that in the earlier stage of the study period. Suggestions on improving China’s natural gas supply security were proposed based on the results and further scenario analysis. The network model developed herein is a new perspective for natural gas supply security assessment, which can be used as guidance for policy making.

An Assessment of the Security of China’s Natural Gas Supply System Using Two Network Models

In the context of climate change, natural gas is becoming increasingly important for low-carbon development in China. The gap between the demand and supply of natural gas, domestically, and China’s high dependence on foreign sources, highlights the importance of ensuring a secure system for supplying natural gas in the country. This study applied ecological network analysis, a powerful systems-oriented method, to simulate interactions between different nodes of the natural gas supply system and to evaluate the system’s security level. Two network models were constructed at the regional and national layers, respectively, by dividing external natural gas suppliers into multiple regions and countries. These models were used to evaluate the overall security level and related characteristics of China’s natural gas supply system from 2000 to 2012. The results showed stable improvement in the system’s security during this period. With the exceptions of some specific indicators (e.g., the mutualism index (MI)), analyses of network information and structure yielded the mostly similar results for the two models. In conclusion, a regional layer (RL) network model is considered more economical than a national layer (NL) model for evaluating the overall security of China’s natural gas supply system, especially when available data are limited.

Life-cycle GHG assessment of carbon capture, use and geological storage (CCUS) for linked primary energy and electricity production

Carbon capture, use and geological storage (CCUS) could be feasible when fossil fuel-power plants are close to oil and gas reservoirs where CO2-enhanced oil recovery (EOR) technologies are applicable. In this research, we used a novel “well-to-well” approach that included the operations from natural gas production at oil field to CO2 injection for EOR operations at depleted oil fields. This paper includes estimates for greenhouse gas (GHG) emissions arising from a hypothetical CCUS case with a natural gas combined cycle power plant (NGCC) and Global Warming Potential (GWP) impact, by using Life-Cycle Assessment (LCA) methodology. Our research comprises a comparison with other electricity-generation technologies, including super critical pulverized carbon (SCPC), NGCC without CO2 capture, geothermal, mini-hydro, wind and nuclear. The LCA stages that were undertaken in this study were natural gas supply system, electricity generation, CO2capture, CO2transport, EOR operations and environmental monitoring. Three different functional units were used in this study: MJ, kWh and produced oil barrel (bbl). Results indicate that the energy produced by the described CCUS system had an environmental impact on climate change (global warming potential) of 0.044kg CO2e/MJ. The NGCC power plant with carbon capture unit would produce 0.177kg CO2e/kWh, representing about 21% and 36% of the estimated values for the SCPC and NGCC (without CCS) cases respectively, and about 24% less greenhouse gas emissions than the geothermal scenario. The oil produced in the EOR stage had a greenhouse gas emission rate of 38kg CO2e per oil barrel and 251kg CO2e per oil barrel in the whole CCUS system.

Dynamic Modeling and Interaction of Hybrid Natural Gas and Electricity Supply System in Microgrid

Natural gas (NG) network and electric network are becoming tightly integrated by microturbines in the microgrid. Interactions between these two networks are not well captured by the traditional microturbine (MT) models. To address this issue, two improved models for single-shaft MT and split-shaft MT are proposed in this paper. In addition, dynamic models of the hybrid natural gas and electricity system (HGES) are developed for the analysis of their interactions. Dynamic behaviors of natural gas in pipes are described by partial differential equations (PDEs), while the electric network is described by differential algebraic equations (DAEs). So the overall network is a typical two-time scale dynamic system. Numerical studies indicate that the two-time scale algorithm is faster and can capture the interactions between the two networks. The results also show the HGES with a single-shaft MT is a weakly coupled system in which disturbances in the two networks mainly influence the dc link voltage of the MT, while the split-shaft MT is a strongly coupled system where the impact of an event will affect both networks.

Understanding Institutional Change: The Development of Institutions for the Regulation of the Natural Gas Supply Systems in the United States and the European Union

This article compares the development of the institutions that regulate the natural gas supply systems in the United States and the European Union. Given the technical and functional similarities of these systems, the question arises as to why regulatory institutions in the US and the EU gas markets have developed in such different ways. In this study we have adopted a historical and dynamic approach, in which institutional outcomes are explored not only by focusing on ‘historic breaks’ in structural technological and economic conditions in the US and Europe, but also by looking at the ‘politics of regulation’. We illustrate the analytical value of applying a framework of incremental change over time within regulatory institutions, identifying different modes including displacement and layering, and introducing a new mode: ‘compartmentalization.’ We show that both pre-existing and newly created actors play important strategic roles in the process of institutional change and the creation of regulation, influencing the coordination between public and private parties as well as the interaction of federal and state levels in the US and supranational and national ‘orders’ in the EU. Our exploration is based on a systematic analysis of the literature on US and EU regulation of the natural gas supply systems since their early beginnings.

Ensuring security of local gas supply using pipeline gas storage

Abstract This paper presents a natural gas supply system of a locality. Since power consumption is nonstationary, for supplying the consumption peaks it is used a gas deposit kept in a pipeline built near the locality. The viability of this solution was demonstrated by simulation with the numerical simulator SIMONE.

A New Method to Prevent Stealing Gas in a Natural Gas Supply System

The problem of stealing gas through natural gas supply system is getting increasingly serious in China and other countries. The authors introduce a new technique to prevent and reduce behavior of stealing gas. The new technique is to establish a monitoring network through which data of consumed gas volume and gas flow rate of home gas meters can be monitored dynamically. Through analysis of these data, the monitoring center can automatically discriminate the potential users with stealing gas behavior and then report list of the users to the monitoring center. This method prevents the occurrence of stealing gas effectively.

Evaluation of energy recovery and potential of hydrogen production in Iranian natural gas transmission network

In the natural gas transmission network, from supply points to demand nods there are various technological options that include processing, transportation, conversion and gas distribution. Comprehensive analysis of natural gas network requires evaluation of different chains of gas flow through various levels based on economical and environmental criteria subject to technical and operational constraints such as feasibility, operability and reliability of different alternatives. To aid decision-making process in the sector of natural gas, a generic optimization-based model has been developed for assessing long term energy issues related to planning and design of natural gas supply systems. The model is capable of identifying optimal investment strategies and build up of new capacities of an integrated gas supply system. Evaluation of the potential of energy conservation and hydrogen production in transmission network are also investigated by three energy recovery technologies: turbo expander, ORC and electrolyzer. The model has then been applied in studying the development of Iranian natural gas network. The results indicate the utilization of produced hydrogen by electrolyzer has considerable impact on minimizing the total cost. The total produced hydrogen of the case study is 1337 million kg, in the period 2011–30.