Modeling of the fired preheater of crude oil considering the effect of geometrical parameters on fuel consumption

Heat Transfer ◽  
2021 ◽  
Author(s):  
Seyed Alireza Mostafavi ◽  
Ali Rezaei
Author(s):  
A. Yu. Brycheva ◽  
V. D. Molyakov

The article considers capabilities of the gas turbine engine to be used as a drive of the crude oil pump. It is noted that the gas turbine drive proves to be more advantageous than the electric motor when there is no external power supply or building periods of power transmission lines are significantly long, as well as quantities of oil products pumped are often changed.The main objective of this work is to select the optimum engine cycle parameters for a particular pump model, which oil pumping stations use. As an object of research, a crude oil pump of the НМ 10000 / 1.25-210 brand was chosen. The paper presents technical characteristics of the HM 10000 / 1.25-210 centrifugal pump and experimental values of head, power, and efficiency of the pump for a number of feeds. To obtain the pressure and power characteristics of a centrifugal pump for different rotational speeds of the rotor the similarity formulas are used.As the centrifugal pump drive, the paper considers a two-shaft plant with the free power turbine. This scheme was chosen in accordance with the features of the gas turbine pump unit at the oil pumping station. It is noted that the free power turbine scheme allows us to bring into accordance the characteristics of a gas turbine engine and an oil pump in abnormal modes, since there is no mechanical connection between high and low pressure turbines.The paper presents the calculated parameters of the gas turbine engine cycle with power Ne = 8 MW. The graphs show dependence of the airflow rate GB, the specific fuel consumption Ce and the efficiency ηe on the degree of pressure increase πk in the compressor. In accordance with the graphs, the optimum value of the degree of pressure increase πk = 15 in the compressor  is adopted. With πk = 15, the specific fuel consumption in the gas turbine engine with power Ne = 8 MW is equal to Ce = 0,22 kg/kW*h and the airflow rate is GB = 20,5kg/s. The efficiency of the engine with the selected parameters is ηe = 38,4%.It is noted that in order to ensure the most economical gas turbine engine operation, it is necessary to select the optimal control program, which is determined taking into account the load characteristics, in this case the characteristics of the pump.


2015 ◽  
Author(s):  
S. Bari ◽  
Idris Saad

Diesel engine can be run with renewable biodiesel which has the potential to supplement the receding supply of crude oil. Use of biodiesel in diesel engines can also reduce harmful emissions of CO, unburned HC and particulates. As biodiesel possess similar physiochemical properties to diesel, most diesel engines can be run with biodiesel with minimum modifications. However, the viscosity and calorific values of biodiesel are higher and lower, respectively than diesel which will affect the performance of diesel engine run with biodiesel. Use of 100% biodiesel in diesel engines shows inferior performance of having lower power and torque. Guide vanes into the intake runner to improve the in-cylinder airflow characteristic to break down higher viscous biodiesel is the aim of this research. This is expected to improve the air-fuel mixing resulting better combustion. The experimental results of biodiesel run in a diesel-gen set showed that break specific fuel consumption reduced in between 0.90 and 1.77% with vane numbers of 3 to 5. In regards to emissions, CO reduced in the range 0.05 and 8.78%, CO2 reduced in the range of 0.82 and 1.75%, and HC in the range of 1.19 and 7.49% with vane numbers of 3 to 5. Interestingly, most improvements were found with the vane numbers of 4.


2019 ◽  
Vol 9 (1) ◽  
pp. 2-11
Author(s):  
Marina Efthymiou ◽  
Frank Fichert ◽  
Olaf Lantzsch

Abstract. The paper examines the workload perceived by air traffic control officers (ATCOs) and pilots during continuous descent operations (CDOs), applying closed- and open-path procedures. CDOs reduce fuel consumption and noise emissions. Therefore, they are supported by airports as well as airlines. However, their use often depends on pilots asking for CDOs and controllers giving approval and directions. An adapted NASA Total Load Index (TLX) was used to measure the workload perception of ATCOs and pilots when applying CDOs at selected European airports. The main finding is that ATCOs’ workload increased when giving both closed- and open-path CDOs, which may have a negative impact on their willingness to apply CDOs. The main problem reported by pilots was insufficient distance-to-go information provided by ATCOs. The workload change is important when considering the use of CDOs.


2020 ◽  
pp. 34-42
Author(s):  
Thibault Chastel ◽  
Kevin Botten ◽  
Nathalie Durand ◽  
Nicole Goutal

Seagrass meadows are essential for protection of coastal erosion by damping wave and stabilizing the seabed. Seagrass are considered as a source of water resistance which modifies strongly the wave dynamics. As a part of EDF R & D seagrass restoration project in the Berre lagoon, we quantify the wave attenuation due to artificial vegetation distributed in a flume. Experiments have been conducted at Saint-Venant Hydraulics Laboratory wave flume (Chatou, France). We measure the wave damping with 13 resistive waves gauges along a distance L = 22.5 m for the “low” density and L = 12.15 m for the “high” density of vegetation mimics. A JONSWAP spectrum is used for the generation of irregular waves with significant wave height Hs ranging from 0.10 to 0.23 m and peak period Tp ranging from 1 to 3 s. Artificial vegetation is a model of Posidonia oceanica seagrass species represented by slightly flexible polypropylene shoots with 8 artificial leaves of 0.28 and 0.16 m height. Different hydrodynamics conditions (Hs, Tp, water depth hw) and geometrical parameters (submergence ratio α, shoot density N) have been tested to see their influence on wave attenuation. For a high submergence ratio (typically 0.7), the wave attenuation can reach 67% of the incident wave height whereas for a low submergence ratio (< 0.2) the wave attenuation is negligible. From each experiment, a bulk drag coefficient has been extracted following the energy dissipation model for irregular non-breaking waves developed by Mendez and Losada (2004). This model, based on the assumption that the energy loss over the species meadow is essentially due to the drag force, takes into account both wave and vegetation parameter. Finally, we found an empirical relationship for Cd depending on 2 dimensionless parameters: the Reynolds and Keulegan-Carpenter numbers. These relationships are compared with other similar studies.


Author(s):  
I. G. Shubin ◽  
A. A. Kurkin

During manufacturing nuts of increased height, a problem of obtaining correct cylindrical form of the hole for thread and overall geometrical parameters arises. To solve the problem it is necessary to know regularity of the blank forming process. Results of the study of a technological process of high hexahedral nuts forming presented. The nuts were M18 of 22 mm height, M16 of 19 mm height and M12 of normal height 10 mm according to GOST 5915–70, accuracy class B, steel grade 10 according to GOST 10702–78. The volumetric stamping was accomplished at the five-position automatic presses of АА1822 type. It was determined, that unevenness of the metal flow in the process of plastic deformation of blanks of increased height nuts was caused by different stress conditions by their sections. To simulate the mode of deformation, the program complex QForm-3D was chosen. The complex ensured to forecast with necessary accuracy the metal flow in a blank, as well as to define the deformation force and arising stress in the working instrument. The simulation showed the presence of regularity between preliminary formed buffle and deviation of dimensions and form of a blank wall after its finishing piercing, which can be expressed by a nonlinear dependence. The limit values of the relative height of the buffle С/D = 0.56–0.588 defined, exceeding which will result in rejection of the finished product. Accounting the limit values of the relative height of the buffle will enable to correct a mode of technological operations and technological instruments at stamping of high hexahedral nuts.


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