scholarly journals Design Optimization of a Natural Gas Substation with Intensification of the Energy Cycle

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Arcangelo Pellegrino ◽  
Francesco Villecco
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
High Pressures ◽  
Electrical Energy ◽  
Heating System ◽  
Pressure Reduction ◽  
Gas Network ◽  
Energy Cycle ◽  
Input Variables ◽  
Gas Expansion

Natural gas is currently the natural substitute of petroleum as an energy source, since the foreseen ending up of this latter in the next decades. As a matter of fact, natural gas is easier to handle, less dangerous to be transported, somehow environmentally more friendly. The gas ducts operate with large flow rates over very long distances at high pressures, which are usually lowered in proximity of the final substations by lamination valves which, in fact, dissipate energy. However, a careful management of the pressure reduction may allow an energy recovery while using the gas expansion to operate a turbine. In this case, gas must be preheated to compensate for the energy required by the expansion. A proper control of all the parameters involved becomes crucial to an intelligent use of these resources. In this paper, the possibility of using a pre-heating system has been examined as a way to intensify the energy cycle in an expansion substation of the city gas network. Fuzzy logic has been used to optimize the natural gas expansion in a turbine to produce electrical energy. A fuzzy system has been designed and realized to control the whole process of gas expansion, from the gas pre-heating to the pressure reduction. The system operates over the whole year, accounting for the pressure, temperature, and gas flow rate variations experienced in the gas line. The exit values of the latter and the inlet value of the gas pressure are selected as input variables, being the output variable the temperature of the pre-heating water at the heat exchanger inlet.

scholarly journals Effects of implementation of co-generation in the district heating system of the Faculty of Mechanical Engineering in Nis

2010 ◽  
Vol 14 (suppl.) ◽  
pp. 41-51 ◽  
Author(s):  
Mladen Stojiljkovic ◽  
Mirko Stojiljkovic ◽  
Bratislav Blagojevic ◽  
Goran Vuckovic ◽  
Marko Ignjatovic
Keyword(s):  
Natural Gas ◽  
Energy Savings ◽  
Boiler House ◽  
District Heating ◽  
Electrical Energy ◽  
Heating System ◽  
Primary Energy ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems

Implementation of co-generation of thermal and electrical energy in district heating systems often results with higher overall energy efficiency of the systems, primary energy savings and environmental benefits. Financial results depend on number of parameters, some of which are very difficult to predict. After introduction of feed-in tariffs for generation of electrical energy in Serbia, better conditions for implementation of co-generation are created, although in district heating systems barriers are still present. In this paper, possibilities and effects of implementation of natural gas fired cogeneration engines are examined and presented for the boiler house that is a part of the district heating system owned and operated by the Faculty of Mechanical Engineering in Nis. At the moment, in this boiler house only thermal energy is produced. The boilers are natural gas fired and often operate in low part load regimes. The plant is working only during the heating season. For estimation of effects of implementation of co-generation, referent values are taken from literature or are based on the results of measurements performed on site. Results are presented in the form of primary energy savings and greenhouse gasses emission reduction potentials. Financial aspects are also considered and triangle of costs is shown.

scholarly journals Techno-Economic Assessment of Turboexpander Application at Natural Gas Regulation Stations

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 755 ◽  
Author(s):  
Szymon Kuczyński ◽  
Mariusz Łaciak ◽  
Andrzej Olijnyk ◽  
Adam Szurlej ◽  
Tomasz Włodek
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Electric Energy ◽  
Economic Assessment ◽  
Gas Pressure ◽  
Operational Parameters ◽  
Pressure Regulator ◽  
Correct Operation ◽  
Process Gas ◽  
Gas Expansion

During the natural gas pipeline transportation process, gas stream pressure is reduced at natural gas regulation stations (GRS). Natural gas pressure reduction is accompanied by energy dissipation which results in irreversible exergy losses in the gas stream. Energy loss depends on the thermodynamic parameters of the natural gas stream on inlet and outlet gas pressure regulation and metering stations. Recovered energy can be used for electricity generation when the pressure regulator is replaced with an expander to drive electric energy generation. To ensure the correct operation of the system, the natural gas stream should be heated, on inlet to expander. This temperature should be higher than the gas stream during choking in the pressure regulator. The purpose of this research was to investigate GRS operational parameters which influence the efficiency of the gas expansion process and to determine selection criteria for a cost-effective application of turboexpanders at selected GRS, instead of pressure regulators. The main novelty presented in this paper shows investigation on discounted payback period (DPP) equation which depends on the annual average natural gas flow rate through the analyzed GRS, average annual level of gas expansion, average annual natural gas purchase price, average annual produced electrical energy sale price and CAPEX.

scholarly journals Thermodynamic analysis of medium pressure reciprocating natural gas expansion engines

2015 ◽  
Vol 17 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Mahmood Farzaneh-Gord ◽  
Soheil Izadi ◽  
Seyed Iman Pishbin ◽  
Hamideh Sheikhani ◽  
Mahdi Deymi-Dashtebayaz
Keyword(s):  
Natural Gas ◽  
Ideal Gas ◽  
Pressure Reduction ◽  
Expansion Engine ◽  
Medium Pressure ◽  
Port Area ◽  
Waste Energy ◽  
Gas Expansion ◽  
Reciprocating Expansion ◽  
Pressure Reduction Station

Abstract Natural gas pressure has to be reduced from medium pressure of 1.724 MPa (250 psia) to lower pressure of 0.414 MPa (60 psia) at Town Border pressure reduction Station (TBS). Currently, the pressure reduction is carried out by throttling valves while considerable amount of pressure energy is wasted. One of the equipment which could be used to recover this waste energy is the reciprocating expansion engine. The purpose of this research is to simulate one-sided reciprocating expansion engine thermodynamically for TBS pressure range. The simulation is based on first law of thermodynamics, conversation of mass and ideal gas assumptions. The model could predict in-cylinder pressure and in-cylinder temperature at various crank angles. In addition, the effects of the engine geometrical characteristics, such as intake and exhaust port area and ports timing on the Indicated work per cycle output are investigated.

Analiza wpływu dodatku wodoru do gazu ziemnego na szczelność połączeń mechanicznych wybranych elementów sieci i instalacji gazowych

2020 ◽  
Author(s):  
Piotr Szewczyk ◽  
Jacek Jaworski
Keyword(s):  
Natural Gas ◽  
Oil And Gas ◽  
Renewable Energy Sources ◽  
Carbon Dioxide Emission ◽  
Electrical Energy ◽  
Gas Network ◽  
Steel Pipes ◽  
Gas Networks ◽  
Threaded Connections ◽  
Sealing Material

One of the ways to use electrical energy obtained from renewable energy sources is hydrogen production, which produces only energy and water vapour when burned. Adding hydrogen to natural gas and burning it will lower carbon dioxide emission, making this fuel more eco-friendly. Hydrogen added to natural gas can be transported using gas transmission pipelines and can then be provided to industrial and individual consumers via a distribution pipeline network. Due to the much lower density of hydrogen compared to natural gas, it is especially important to maintain the tightness of mechanical connections of network elements and gas installations. This publication presents the results of research carried out at the Oil and Gas Institute-National Research Institute on the influence that adding hydrogen to natural gas has on the tightness of connections of selected elements of gas installations and networks. According to the developed methodology, tests were performed on selected elements of gas networks and gas installations, in which joints were made using differing methods and using various sealing materials. In the case of steel pipes used in gas installations in buildings, joined by means of threaded connections with tightness obtained on the thread, the test samples were prepared with the use of linen hemp with sealing paste, Teflon tapes and threads, and anaerobic adhesives. Samples made of copper pipes were joined with press fittings. Other installation elements - such as flexible hoses, both extensible and non-extensible, and metal hose assemblies - were attached by means of threaded connections with tightness obtained beyond the thread; the sealing material was NBR rubber gaskets and klingerite. The gas network elements were connected by means of threaded connections with hemp and sealing paste, flare fittings, and steel and polyethylene flanges (sealing with a flat gasket made of NBR and klingerite). PE/Steel connectors where also tested. The tests included tightness tests of the prepared samples with the use of methane, and then a mix of 85% methane and 15% hydrogen. The tests on samples with simulated leaks were also performed. Based on the tests and the analysis of the results, it was found that adding the hydrogen to the methane did not cause leaks in the joined elements. In addition, it was found that in the case of leaks appearing in elements of installations or gas networks, the methane-hydrogen mixture flows out faster than methane alone, and in closed rooms this may result in the lower explosion limit being reached in a shorter time.

scholarly journals Managing the Pressure to Increase the H2 Capacity Through a Natural Gas Transmission Network

2020 ◽  
Author(s):  
Francis Bainier ◽  
Rainer Kurz ◽  
Philippe Bass
Keyword(s):  
Natural Gas ◽  
Partial Pressure ◽  
Gas Flow ◽  
Network Capacity ◽  
Hydrogen Gas ◽  
Gas Pipeline ◽  
Pipeline Network ◽  
Gas Network ◽  
Natural Gas Pipeline ◽  
Partial Pressures

Abstract Gas Transmission System Operators (TSO1) are considering injecting hydrogen gas into their networks. Blending hydrogen into the existing natural gas pipeline network appears to be a strategy for storing and delivering renewable energy to markets [1], [2], [3]. In the paper GT2019-90348 [4], the authors have explored the efficiency of H2-blending in a natural gas pipeline network. The conclusion of the paper is: the energy transmission capacity and the efficiency decrease with the introduction of H2, nevertheless, the authors conclude that it is not an obstacle, but the way of using transmission natural gas networks should be closely studied to find an economic optimum, based both on capital and operating expenses. To establish the comparison, the paper did not take into account the limits of the equipment; all equipment was considered as compatible with any load of hydrogen blending. In the current paper, the idea is to consider the hypothesis that the only factor which has impact on the infrastructure is the partial pressure of H2. The idea is not new, in 1802, Dalton published a law called Dalton’s Law of Partial Pressures [5]. Dalton established empirically that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual component gases. The partial pressure is the pressure that each gas would exert when it alone occupied the volume of the mixture at the same temperature. Independent of the limits of the equipment, the authors explore the relationships between a network capacity and its associated pressures in regards to the H2 partial pressure. Within the partial pressure constraint, the goal is to find the maximum H2 flowrate. This flowrate is then compared with a flowrate which is a function of % H2. Nevertheless, steel is subjected to hydrogen invasion while being exposed to hydrogen containing environments during mechanical loading: resulting in hydrogen embrittlement (HE). HE also depends on the textured microstructure. In the final results [6] [7], the measured fatigue data reveals that the fatigue life of steel pipeline is degraded by the added hydrogen. The H2 has an effect on the steel fatigue which is not simply due to the partial pressure. The idea of the authors through the results of their 2 papers is to give the key points to help to find the optimum points for introducing H2 into a natural gas network, because, for them, the idea is that partial pressure is a factor in the equilibrium between H2 capacity and the remaining lifetime of the equipment. This paper shows the interest of the pressure management. With this management, it is possible to reach a constant H2 injection flow independently of the natural gas flow in the pipeline. In conclusion, to optimize the H2 capacity in their current network, a proposal to the TSOs is to adjust their dispatching methodology and their Pipeline Integrity Management (PIM) [8] [9].

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

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