Analysis of conjugate heat transfer characteristics of nozzle in middle-high speed marine diesel engine

2022 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Dong Li ◽  
Yong Wang ◽  
Yuan Guo ◽  
Kang Chen ◽  
Yazhou Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
High Speed ◽  
Conjugate Heat Transfer ◽  
Marine Diesel Engine ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Marine Diesel

scholarly journals Numerical determination of the velocity fields of the working medium in the combustion chamber of a marine high-speed diesel engine

2020 ◽  
pp. 92-97
Author(s):  
Б.И. Руднев ◽  
О.В. Повалихина
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Combustion Chamber ◽  
Convective Heat ◽  
Diesel Engines ◽  
High Speed ◽  
Velocity Fields ◽  
Marine Diesel Engine ◽  
Working Medium ◽  
Marine Diesel

Современные тенденции развития судовых дизелей связаны, прежде всего с улучшением их энергетических и экологических характеристик. Это обуславливает появление ряда проблем, важнейшая из которых – возрастание теплонапряженности деталей, образующих камеру сгорания. Высокие локальные тепловые потоки на поверхностях крышки цилиндра, поршня и втулки являются одной из главных причин, снижающих эксплуатационную надежность форсированных судовых дизелей. Достоверность расчетной оценки теплового и напряженно-деформированного состояния деталей, образующих камеру сгорания, определяется главным образом правильностью задания локальных граничных условий со стороны рабочего тела. Учитывая, что доля конвективного теплового потока в суммарном теплообмене достигает в среднем за рабочий цикл 60 – 70%, становится очевидной актуальность разработки надежных расчетно-теоретических методов определения полей скоростей рабочего тела в камере сгорания судовых дизелей. Целью данной статьи является дальнейшее совершенствование математической модели локального конвективного теплообмена в камере сгорания высокооборотного судового дизеля. Показано, что внешнее течение рабочего тела в камере сгорания может быть описано уравнениями Эйлера. Представлены поля скоростей рабочего тела в функции угла поворота коленчатого вала, полученные численным методом. Приведены изотермы и изобары рабочего тела, позволяющие более глубоко проанализировать физику процесса конвективного теплообмена в камере сгорания судового высокооборотного дизельного двигателя. Modern trends in the development of marine diesel engines are associated primarily with the improvement of their energy and environmental characteristics. This gives rise to a number of problems, the most important of which is an increase in the combustion intensity. High local heat fluxes on the surfaces of the cylinder head, piston and liner are one of the main reasons that reduce the operational reliability of boosted marine diesel engines. The reliability of the calculated estimate of the thermal and stress-strain state of parts that form the combustion chamber is mainly determined by the correctness of setting the local boundary conditions from the part of the working medium. Taking into account that the share of convective heat flux in the total heat exchange reaches, on average, 60 - 70% for a working cycle, it becomes obvious the urgency of developing reliable computational and theoretical methods for determining the velocity fields of the working medium in the combustion chamber of marine diesel engines. The purpose of this article is to further improve the mathematical model of local convective heat transfer in the combustion chamber of a high-speed marine diesel engine. It is shown that the external flow of the working medium in the combustion chamber can be described by the Euler equations. The velocity fields of the working medium as a function of the angle of rotation of the crankshaft obtained by the numerical method are shown. Isotherms and isobars of the working medium are given, which allow a more in-depth analysis of the physics of the convective heat transfer process in the combustion chamber of a high-speed marine diesel engine.

Conjugate Heat Transfer Characteristics of Double Wall Cooling on a Film Plate With Gradient Thickness

2021 ◽  
Author(s):  
Juan He ◽  
Qinghua DENG ◽  
Weilun Zhou ◽  
Wei He ◽  
Tieyu Gao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Double Wall

Performance Calculation of a TBD234V12 Diesel Engine with STC

2012 ◽  
Vol 157-158 ◽  
pp. 1075-1078
Author(s):  
Yang Wang ◽  
Yin Yan Wang ◽  
Fan Shi ◽  
Xin Guang Li
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Computer Model ◽  
High Speed ◽  
Marine Diesel Engine ◽  
High Speed Diesel ◽  
Turbocharging System ◽  
Marine Diesel ◽  
Performance Calculation ◽  
Good Agreement

A computer model for a TBD234V12 marine high-speed diesel engine with 2 turbocharger(2TC) is built on GT-POWER. For validating the computer model, a calculation to the conventional turbocharging system has been done firstly, and the results show good agreement with experimental data. The computer model has then been used for predictive studies of the diesel engine with the proposed STC system on the mapping characteristics. From these results, it can be seen that the STC system can not only improve the part load performance of the diesel engine obviously, but also enlarge the operating range of the marine diesel engine.

Experimental Comparison on the Multi-Hole Steam Spraying Condensation Heat Transfer Characteristics

2018 ◽  
Author(s):  
Yuhao Zhang ◽  
Daogang Lu ◽  
Bin Ouyang ◽  
Yonglong Yuan
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Experimental Results ◽  
Experimental Comparison ◽  
Pressurized Water Reactor ◽  
Heat Transfer Characteristics ◽  
Pressurized Water ◽  
Transfer Characteristics ◽  
Passive Safety System ◽  
Contact Condensation

In the third generation pressurized water reactor AP1000 plant, the Automatic Depressurization System (ADS) is one of the most important passive safety system. As the steam continues to discharge into the IRWST, the high-temperature and high-pressure steam condenses in the IRWST intensely and rapidly. In the present work, multi-hole spargers DCC experimental bench has been built to study the condensation and mixing phenomena in the accidental depressurization events in AP1000. The key parameters including the temperature, velocity, and flow patterns are monitored by the thermocouples, PIV technique, and high speed camera, etc. Based on the experimental results, the heat transfer characteristics of the steam-jet Direct Contact Condensation (DCC) in the ADS depressurization process were analyzed. The experimental comparison shows that the spraying steam behaviors are closely related to the steam mass flux, which determined the ejection patterns. The spraying steam is condensed rapidly in the core region with the flow regime locating in chugging, transitional chugging, and stable ejection stages. The 88-hole experimental results fit well with Fukuda’s condensation oscillation correlations, whereas the 2-hole experimental results are slightly lower than the values predicted by traditional single hole correlation.

Sign in / Sign up

Export Citation Format

Share Document