scholarly journals Heating of natural gas before expander - generator unit

2021 ◽  
Vol 2094 (5) ◽  
pp. 052049
Author(s):  
A A Mukolyants ◽  
I V Sotnikova ◽  
D K Ergasheva ◽  
F T Shadibekova ◽  
A A Taubaldiev

Abstract The article discusses the replacement of throttling at the stations of technological lowering of the pressure of main natural gas by an expander-generator technology that allows the production of a cheap one with high environmental indicators. The disadvantage of this method of generating electricity is a significant cooling of the gas at the outlet of the expander, which necessitates its heating. The efficiency of the expander-generator set is largely determined by the adopted gas heating scheme. Achieving such heating temperatures is possible only by using high-potential energy resources, which are present in the technological equipment of gas distribution stations in the form of gas heaters with an intermediate heat carrier, designed to heat gas before expansion. Calculations of the amount of fuel gas required for heating the main natural gas in front of the expander-generator unit at the gas distribution stations under consideration have been carried out. The results of the study of the influence of the temperature of gas heating in front of the expander on the consumption of fuel gas supplied for heating and the numbers of heaters are presented. An analytical dependence of the electric power of the heat pump installation on the difference between the total power consumption of the compressor and the power of the air turbine is obtained.

2016 ◽  
Author(s):  
S. Tesch ◽  
T. Morosuk ◽  
G. Tsatsaronis

The increasing demand for primary energy leads to a growing market of natural gas and the associated market for liquefied natural gas (LNG) increases, too. The liquefaction of natural gas is an energy- and cost-intensive process. After exploration, natural gas, is pretreated and cooled to the liquefaction temperature of around −160°C. In this paper, a novel concept for the integration of the liquefaction of natural gas into an air separation process is introduced. The system is evaluated from the energetic and exergetic points of view. Additionally, an advanced exergy analysis is conducted. The analysis of the concepts shows the effect of important parameters regarding the maximum amount of liquefiable of natural gas and the total power consumption. Comparing the different cases, the amount of LNG production could be increased by two thirds, while the power consumption is doubled. The results of the exergy analysis show, that the introduction of the liquefaction of natural gas has a positive effect on the exergetic efficiency of a convetional air separation unit, which increases from 38% to 49%.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xiao Wu ◽  
Zhaoting Wang ◽  
Xiaodong Dai ◽  
Quan Ge ◽  
Fei Liu

Small-scale natural gas liquefaction processes have several clear advantages, particularly in the exploitation of ‘unconventional’ natural gas (NG) from sources such as difficult-to-access and offshore gas fields. Moreover, conventional liquefaction processes have a number of disadvantages such as high energy consumption, large cooling loads required in the refrigeration cycle, and non-uniform matching of cold and hot flows in liquified natural gas (LNG) heat exchanger (HE). The main objective of this study was to optimize the most commonly used mixed refrigerant process. The liquefaction performance of the optimized process was analyzed and the influence of gas parameters on the power consumption, exergy loss, freezing mixture circulation, and cooling water load were investigated. The results show that compressor power consumption can be reduced by 29.8%, the cooling water load can be reduced by 21.3%, and the system exergy efficiency can be increased by 41% with the optimized process. Furthermore, throttling and compression of the freezing mixture were increased during the refrigeration stage. It can be concluded that reducing the feed gas temperature and increasing the feed gas pressure can reduce the total power consumption, exergy loss, freezing mixture circulation, and cooling water load, which can significantly improve liquefaction performance.


2008 ◽  
Vol 6 (1) ◽  
pp. 139-153 ◽  
Author(s):  
Dejan Brkic

Natural gas can be directly used for heating of flats by gas distribution system. Indirectly, heating power plant can disburse natural gas and deliver hot water or steam for heating of flats. Decision of optimal way for gas heating usage is done based on spatial disposal of building, number and size of buildings in settlement, etc. Optimal solution, between gas distribution and district heating system (local or district heating by natural gas), can be done according to methodology (model approach) shown in this paper. According to variety of Serbian settlements (in density, size and layout of buildings) model which has ability to represent their different characteristics is formed. This model could be simple and useful tool for initial decision about energy supply system.


2021 ◽  
Vol 289 ◽  
pp. 07034
Author(s):  
A. A. Mukolyants ◽  
I V Sotnikova ◽  
D K Ergasheva ◽  
A. A. Taubaldiev

The article deals with the problem of using secondary energy resources in the system of transportation and distribution of natural gas, and the possibility of generating electricity without burning fuel by reducing high-pressure natural gas at gas distribution stations. The analysis of the influence of the gas temperature at the entrance to the expander - generator unit, as well as the dependence of the power of the expander - generator unit on the gas temperature and the temperature of the low-potential source is presented. Optimal temperatures are obtained at which the power of the expander-generator unit is maximal for the given gas parameters.


2017 ◽  
Author(s):  
Dejan Brkić

Natural gas can be directly used for heating of flats by gas distribution system. Indirectly, heating power plant can disburse natural gas and deliver hot water or steam for heating of flats. Decision of optimal way for gas heating usage is done based on spatial disposal of building, number and size of buildings in settlement, etc. Optimal solution, between gas distribution and district heating system (local or district heating by natural gas), can be done according to methodology (model approach) shown in this paper. According to variety of Serbian settlements (in density, size and layout of buildings) model which has ability to represent their different characteristics is formed. This model could be simple and useful tool for initial decision about energy supply system.


Author(s):  
S. Daniele ◽  
P. Jansohn ◽  
K. Boulouchos

The experimental work presented in this paper focuses on the characterization of four syngas mixtures, primarily in terms of NOx emissions and Lean Blow Out (LBO) limits; these mixtures were selected to simulate various syngas types derived from coal, refinery residues, biomass and co-firing of syngas with natural gas. These fuel mixtures are all of interest for applications in gasturbine processes for power generation. The experiments were carried out in a High Pressure Test Rig. Preheating of the fuel/air mixture to a temperature of 673 K, inlet bulk velocities between 40 and 80 m/s and operating pressures between 5 and 15 bars have been applied. The results show the expected strong difference between the CH4 containing mixture and all the other “pure” syngas mixtures concerning the “operational window”. As the focus of this paper is on lean extinction limits and NOx emissions, flashback phenomena are not discussed in further detail. Lean Blow Out limits were found to have weak pressure dependence for the methane containing mixture whereas for the other mixtures this dependence is slightly stronger: “Lean Blow Out” limits move to less lean condition with increasing pressure. No significant dependence on the Inlet velocity was found. Lean blow out occurs at much leaner conditions, ΦLBO≈0.25, for the pure syngas mixtures than for the methane containing fuel mixture (simulating co-firing of syngas with natural gas) which shows flame extinction already at ΦLBO≈0.38. NOx emissions show also a significant difference between the CH4 containing mixture and all other “pure” syngas mixtures with higher NOx emissions for the latter fuel gas mixtures. The difference can be attributed to the different O2 concentration in the hot exhaust gas after the flame front (for a given flame temperature) and to the difference in the flame length which leads to longer residence times in the post flame zone (for the much more compact syngas flames).


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