scholarly journals Development of a model of the optimal temperature mode of the main gas pipeline operation

2021 ◽  
Vol 5 (8 (113)) ◽  
pp. 30-37
Author(s):  
Mykhail Kologrivov ◽  
Vitalii Buzovskyi
Keyword(s):  
Heat Exchange ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Gas Pipeline ◽  
Gas Temperature ◽  
Inversion Point ◽  
Pipe Length ◽  
Temperature Mode ◽  
Gas Cooling

The influence of the ambient air temperature on changes in the parameters and thermophysical characteristics of the gas pumped through the underground pipeline was investigated. This was done because there are no scientifically sound recommendations for the optimal gas temperature after coolers at the compressor station. The presence of the site of inversion of heat exchange between gas and soil – a change in the direction of heat exchange along the length of the gas pipeline was revealed. It was proved that the air temperature above the soil surface should be substituted into the formula for calculating the change in gas temperature along the length of the pipeline between compressor stations. This made it possible to determine quantitative changes in the thermophysical and hydraulic characteristics of the gas along the pipe length, in particular, the change in density, viscosity, heat capacity, flow regime. It is shown that the change in air temperature during the year leads to a change in the gas pressure at the end of the gas pipeline section up to 0.15 MPa. A change in air temperature by 10 °С leads to a change in gas temperature by approximately 5 °С. Analytical studies made it possible to develop practical recommendations for the power-saving operation of air coolers at compressor stations. It was determined that the optimum gas temperature at the cooler outlet will be the temperature at which the heat exchange inversion point along the length of the gas pipeline coincides with the location of the subsequent station. It is shown how to control gas cooling in air coolers. In particular, by shutting down one of several operating devices and changing the speed of the fan drive. The developed recommendations will make it possible to quickly regulate the temperature mode of the underground gas pipeline operation at optimal power consumption for the operation of the gas cooling system after gas compression

OPTIMIZATION OF ELECTROTECHNICAL POWER CONSUMPTION OF GAS COOLING SYSTEM COMPLEX

2018 ◽  
Vol 8 (1) ◽  
pp. 124-129
Author(s):  
Alexander I. DANILUSHKIN ◽  
Ivan A. DANILUSHKIN
Keyword(s):  
Process Model ◽  
Cooling System ◽  
Optimization Technique ◽  
Minimum Energy ◽  
Individual Characteristics ◽  
Gas Temperature ◽  
Electric Drives ◽  
Optimal Load ◽  
Cooling Unit ◽  
Gas Cooling

The problem of the optimal load distribution between electric drives of fans in a multi-section gas cooling unit is considered based on the minimum energy expenditure for cooling. The optimization problem is solved on the basis of the obtained analytical model for the gas temperature at the outlet of the cooling unit. The model takes into account the mutual infl uence of the operating modes of all fans of the installation. A technique for solving the problem of optimal load sharing between electric drives of fans for a linearized process model is developed using the procedure of integer programming. The optimization technique takes into account the individual characteristics of the devices.

scholarly journals АНАЛІЗ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ КОГЕНЕРАЦІЙНОГО ГАЗОПОРШНЕВОГО МОДУЛЯ УСТАНОВКИ АВТОНОМНОГО ЕНЕРГОЗАБЕЗПЕЧЕННЯ

2019 ◽  
pp. 76-80
Author(s):  
Андрій Миколайович Радченко ◽  
Анатолій Анатолійович Зубарєв ◽  
Сергій Георгійович Фордуй ◽  
Володимир Володимирович Бойчук ◽  
Віталій Васильович Цуцман
Keyword(s):  
Air Temperature ◽  
Elevated Temperatures ◽  
Cooling System ◽  
Electric Energy ◽  
Ambient Air ◽  
Hot Water ◽  
Lubricating Oil ◽  
Air Cooling ◽  
Air Conditioner ◽  
Engine Room

The analysis of the efficiency of cooling air of cogeneration gas-piston module of installations for combined production of electric energy, heat, and cold is performed. The installation for energy supply includes two JMS 420 GS-N.LC GE Jenbacher cogeneration gas-piston engines manufactured as cogeneration modules with heat exchangers for removing the heat of exhaust gases, scavenge gas-air mixture, cooling water of engine and lubricating oil. The heat of hot water is transformed by the absorption lithium-bromide chiller AR-D500L2 Century into the cold, which is spent on technological needs and for the operation of the central air conditioner for cooling the incoming air of the engine room, wherefrom it is sucked by the turbocharger of the engine. The temperature of the scavenge gas-air mixture at the entrance to the working cylinders of the engine is maintained by the system of recirculating cooling with the removal of its heat into surroundings by the radiator. Because of significant heat influx from working engines and other equipment, as well as through the enclosures of the engine room from the outside to the air-cooled in the central air conditioner in the engine room, from where it is sucked by a turbocharger, the air temperature at the inlet of the turbocharger is quite high: 25...30 °C. At elevated temperatures of the ambient air at the inlet of the radiator for cooling scavenge gas-air mixture and the air at the turbocharger inlet the fuel economy of engine is falling, which indicates the need for efficient cooling of air. The efficiency of cooling the air of the gas-piston module was estimated by a reduction in the consumption of gaseous fuel and the increase in electric power of the engine. For this purpose, the data of monitoring on the fuel efficiency of the gas-piston engine with the combined influence of the ambient air temperature at the inlet of the radiator and the air at the turbocharger inlet were processed to obtain data on their separate effects and to determine the ways to further improve the air cooling system of the gas-piston module.

scholarly journals ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГОЛОВНОГО СУДНОВОГО ДВИГУНА АБСОРБЦІЙНОЮ БРОМИСТОЛІТІЄВОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ В ТРОПІЧНИХ УМОВАХ

2020 ◽  
pp. 18-23
Author(s):  
Роман Миколайович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Максим Андрійович Пирисунько ◽  
Чжан Цян ◽  
Луо Зевей
Keyword(s):  
Air Temperature ◽  
High Efficiency ◽  
Waste Heat ◽  
Cooling System ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Exhaust Gas ◽  
Low Speed ◽  
Speed Engine

The efficiency of air cooling at the inlet of the main low speed engine of a transport vessel during operation in tropical climatic conditions on the Shanghai-Karachi-Shanghai route was analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures, and hence the increased thermal load on the cooling system, which requires efficient transformation of the waste heat into the cold in the case of the use of waste heat recovery refrigeration machines. The cooling of the air at the inlet of the low speed engine by absorption lithium bromide chillers, which are characterized by high efficiency of transformation of waste heat into cold – by high coefficients of performance, is investigated. A schematic-construction solution of the air cooling system at the inlet of the ship's main engine using the heat of exhaust gases by an absorption chiller is proposed and analyzed. With this the cooling potential of the inlet air cooling from the current ambient air temperature to 15 ° C and the corresponding heat consumption for the operation of the adsorption chiller, on the one hand, was compared with the available exhaust gas heat potential, on the other hand. The effect of using the exhaust gas heat to cool the air at the inlet of the engine has been analyzed taking into account the changing climatic conditions during the voyage. Enhancement of fuel efficiency of the ship's engine by reducing the inlet air temperature were evaluated by current values of the reduction in specific and total fuel consumption. It is shown that due to the high efficiency of heat conversion in absorption chillers (high coefficients of performance 0.7…0.8), a significant amount of excessive exhaust gas heat over the heat required to cool the ambient air at the inlet of the engine to 15 ° C, which reaches almost half of the available exhaust gas heat during the Shanghai-Karachi-Shanghai route. This reveals the possibility of additional cooling a scavenge air too with almost double fuel economy due to the cooling of all cycle air of the low speed engine, including the air at the inlet.

An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part II—Thermodynamic Analysis

2012 ◽  
Author(s):  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Ambient Air ◽  
Combined Cycle ◽  
Air Separation ◽  
Air Cooling ◽  
Separation Unit ◽  
Gasification Process

Integrated Gasification Combined Cycles (IGCCs) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, the plant also has an Air Separation Unit (ASU). Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. Since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance when ambient temperature increases. In this paper, an innovative system for power augmentation in IGCC plants is presented. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first chilled and liquefied and then it can be used for inlet air cooling or stored for a postponed use. This system is not characterized by the limits of water evaporative cooling (where the lower temperature is limited by air saturation) and refrigeration cooling (where the effectiveness is limited by pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters (e.g. ambient air temperature, inlet air temperature difference, etc.) is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year.

Economic Evaluation on GTCC Inlet Air Cooling With Absorption Chiller

2005 ◽  
Author(s):  
Cheng Yang ◽  
Zeliang Yang ◽  
Ruixian Cai
Keyword(s):  
Economic Evaluation ◽  
Fuel Consumption ◽  
Output Power ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Air Cooling System ◽  
Temperature Depression

Inlet air temperature increase results in a considerable reduction in GTCC power output. Present design of inlet air cooling system usually applied static method, which considered a constant depression of inlet air temperature, an approximate estimate of runtime, output power increase and fuel consumption variation per temperature depression, etc. However, to a crumb, at least another two problems should be studied. One is GTCC performance variation with inlet air temperature, since the kilowatt increment per centigrade is not a constant; the other is off design performance of inlet air cooling system, since the inlet air temperature depression through the cooling system varies with the actual operation conditions, such as ambient air temperature and cooling water temperature, etc. This paper presents an economic evaluation with numerical integration method on GTCC inlet air cooling with absorption chiller. For a typical GTCC composed of series E gas turbine and combined components, their non-dimensional performance curves are fitted with regression equations. Associating with these equations, the inlet air temperature characteristics of GTCC are simulated; and the fitted analytical expressions for GTCC inlet air temperature characteristics are also presented. The simulation method of off design performance of a typical absorption chiller is described. For a typical GTCC with inlet air cooling in south China area, integrated with the everyday typical weather data, GTCC everyday average output power and fuel consumption, output power increment and GTCC fuel consumption increment are simulated. The simulation results show that, for every 1°C depression in inlet air temperature, the GTCC output power increases 0.5%, while heat rate varies slightly and trends towards a rise at the inlet air temperature of about 15°C. Research on inlet air cooling scheme (Scheme 10°C, cooling the ambient air temperature from ambient temperature 30°C to 10°C) shows that, Scheme 10°C yields annual average 16°C of inlet air temperature depression. Economic evaluation based on numerical integration indicates that, in the case of Scheme 10°C, annual output power increases by 8.27%, fuel consumption rate increases by 1.03%; payback period approximately amounts to 2.0 years when power price is 12 cent/(kW.h) and fuel cost is $265/t.

Enhancing the Performance of the Building’s Vapor Compression Air Cooling System Using Earth-Air Heat Exchanger

2017 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Fadi J. Alsouda
Keyword(s):  
Heat Exchanger ◽  
Soil Temperature ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Coefficient Of Performance ◽  
Maximum Deviation ◽  
Air Cooling ◽  
Vapor Compression ◽  
Air Cooling System

This paper aims to evaluate the thermal performance and feasibility of integrating the Earth-Air Heat Exchanger (EAHE) with the building’s vapor compression air cooling system. In the proposed system, the ambient air is forced by an axial fan through an EAHE buried at a certain depth below the ground surface. EAHE uses the subsoil low temperature and soil thermal properties to reduce the air temperature. The outlet air from the EAHE was used for the purpose of cooling the condenser of the vapor compression cycle (VCC) to enhance its coefficient of performance (COP). The potential enhancement on the COP was investigated for two different refrigerants (i.e. R-22 and R410a) cooling systems. A mathematical model was developed to estimate the underground soil temperature at different depths and the corresponding outlet air temperature of EAHE was calculated. The obtained results showed that the soil temperature in Dubai at 4 meters depth is about 27°C and remains relatively constant across the year. In order to estimate the effect of using EAHE on the performance of the VCC system, a sample villa project was selected as a case study. The obtained results showed that EAHE system contributed efficiently to the COP of the VCC with an overall increase of 47 % and 49 % for R-22 and R410a cycles, respectively. Moreover, the calculated values were validated against Cycle_D simulation model and showed good agreement with a maximum deviation of 5%. The payback period for this project was found to be around two years while the expected life time is about 10 years which makes it an attractive investment.

scholarly journals A Machine Learning Solution for Data Center Thermal Characteristics Analysis

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4378
Author(s):  
Anastasiia Grishina ◽  
Marta Chinnici ◽  
Ah-Lian Kor ◽  
Eric Rondeau ◽  
Jean-Philippe Georges
Keyword(s):  
Machine Learning ◽  
Energy Efficiency ◽  
Air Temperature ◽  
Data Center ◽  
Waste Heat ◽  
Cooling System ◽  
Thermal Characteristics ◽  
Ambient Air ◽  
Characteristics Analysis ◽  
Temperature Ranges

The energy efficiency of Data Center (DC) operations heavily relies on a DC ambient temperature as well as its IT and cooling systems performance. A reliable and efficient cooling system is necessary to produce a persistent flow of cold air to cool servers that are subjected to constantly increasing computational load due to the advent of smart cloud-based applications. Consequently, the increased demand for computing power will inadvertently increase server waste heat creation in data centers. To improve a DC thermal profile which could undeniably influence energy efficiency and reliability of IT equipment, it is imperative to explore the thermal characteristics analysis of an IT room. This work encompasses the employment of an unsupervised machine learning technique for uncovering weaknesses of a DC cooling system based on real DC monitoring thermal data. The findings of the analysis result in the identification of areas for thermal management and cooling improvement that further feeds into DC recommendations. With the aim to identify overheated zones in a DC IT room and corresponding servers, we applied analyzed thermal characteristics of the IT room. Experimental dataset includes measurements of ambient air temperature in the hot aisle of the IT room in ENEA Portici research center hosting the CRESCO6 computing cluster. We use machine learning clustering techniques to identify overheated locations and categorize computing nodes based on surrounding air temperature ranges abstracted from the data. This work employs the principles and approaches replicable for the analysis of thermal characteristics of any DC, thereby fostering transferability. This paper demonstrates how best practices and guidelines could be applied for thermal analysis and profiling of a commercial DC based on real thermal monitoring data.

Studies of Radiative Cooling Systems for Storing Thermal Energy

1989 ◽  
Vol 111 (3) ◽  
pp. 251-256 ◽  
Author(s):  
S. Ito ◽  
N. Miura
Keyword(s):  
Heat Flux ◽  
Energy Storage ◽  
Air Temperature ◽  
Storage Tank ◽  
Cooling System ◽  
Ambient Air ◽  
Radiative Cooling ◽  
Cooling Systems ◽  
Average Temperature ◽  
Radiative Power

The thermal performance of an uncovered radiator and a radiative cooling system was investigated experimentally and theoretically. The net radiative power of a black painted surface at ambient air temperature was measured by heat flux plates at night in order to use the results for predicting temperatures of the radiator surface and the fluid in the cooling system on the same night. The net radiative power obtained by the measurements was 40–60 W/m2 on clear nights in the summer and 60–80 W/m2 in the fall and winter. The average temperature of the energy storage tank on clear nights became 2–5°C below the ambient temperature. The experimental and analytical results agreed well with each other.

scholarly journals Field Experiments to Evaluate Thermal Performance of Energy Slabs with Different Installation Conditions

2018 ◽  
Vol 8 (11) ◽  
pp. 2214 ◽  
Author(s):  
Seokjae Lee ◽  
Sangwoo Park ◽  
Minkyu Kang ◽  
Hangseok Choi
Keyword(s):  
Heat Exchange ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Thermal Performance ◽  
Field Experiments ◽  
Side Wall ◽  
Ambient Air ◽  
Test Bed ◽  
Interior Space ◽  
Ambient Air Temperature

The energy slab is a novel type of horizontal Ground Heat Exchanger (GHEX), where heat exchange pipes are encased in building slab structures. The thermal performance of energy slabs is usually inferior to the conventional closed-loop vertical GHEX because its installation depth is relatively shallow and therefore affected by ambient air temperature. In this paper, heat exchange pipes were made of not only conventional high-density polyethylene (HDPE), but also stainless steel (STS), which is expected to enhance the thermal performance of the energy slabs. In addition to a floor slab, a side wall slab was also used as a component of energy slabs to maximize the use of geothermal energy that can be generated from the underground space. Moreover, a thermal insulation layer in the energy slabs was considered in order to reduce thermal interference induced by ambient air temperature. Consequently, two different field-scale energy slabs (i.e., floor-type and wall-type energy slabs) were constructed in a test bed, and two types of heat exchange pipes (i.e., STS pipe and HDPE pipes) were installed in each energy slab. A series of thermal response tests (TRTs) and thermal performance tests (TPTs) were conducted to evaluate the heat exchange performance of the constructed energy slabs. Use of the STS heat exchange pipe enhanced the thermal performance of energy slabs. Additionally, the wall-type energy slab had a similar thermal performance to the floor-type energy slab, which infers the applicability of the additional use of the wall-type energy slab. Note that if an energy slab is not thermally cut off from the building’s interior space with the aid of thermal insulation layers, heat exchange within the energy slabs should be significantly influenced by fluctuations in ambient temperature.

Predictions and observations on the behaviour of a warm gas pipeline on permafrost

1976 ◽  
Vol 13 (4) ◽  
pp. 452-480 ◽  
Author(s):  
C. T. Hwang
Keyword(s):  
Meteorological Data ◽  
Canadian Arctic ◽  
Ground Surface ◽  
Transient Heat Conduction ◽  
Ambient Air ◽  
Theoretical Background ◽  
Gas Pipeline ◽  
Test Facility ◽  
Gas Temperature ◽  
Freezing And Thawing

This paper deals with predictions and measured observations of the behaviour of a warm gas pipeline on permafrost. In the paper, descriptions of the theoretical background for a mathematical model developed by the Canadian Arctic Gas Study Limited will be made. The model incorporates the following aspects: (a) transient heat conduction mechanism during freezing and thawing in the ground, in which the latent heat is considered as a heat source in the energy balance equation; (b) heat exchange mechanism at the ground surface with respect to meteorological data such as ambient air temperature, solar radiation, greenhouse factor, wind velocity, snow depth, and evapotranspiration; and (c) changes in geometry of the thermal domain due to thaw subsidence.Verification of the model was made using field data obtained from a hot-berm module with a gas temperature of 65 °F (18.3 °C), at the Norman Wells Test Facility of Canadian Arctic Gas Study Limited. Good correlation was found for predicted and measured values of: (a) ground temperature profiles in instrumented locations, (b) ground surface settlement, (c) pipe settlement, and (d) heat flux around the pipe.

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