scholarly journals HEAT BALANCE RESEARCH OF 3MW MARINE WIND TURBINE'S ENGINE ROOM

2012 ◽  
Vol 19 ◽  
pp. 362-373
Author(s):  
NA KANG ◽  
YANLONG JIANG ◽  
NIANYONG ZHOU ◽  
HONG SHI ◽  
ZHILI LIU ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Wind Turbine ◽  
Heat Balance ◽  
Heat Load ◽  
Cooling System ◽  
Turbine Cooling ◽  
Engine Room ◽  
Wind Turbine System ◽  
Volume Method ◽  
The Heat Balance

The increment of heat load in Wind Turbine's engine room could cause the system shut down. In this paper the heat balance of Wind Turbine's engine room is investigated according to the structure of the engine room, environmental operating requirements as well as heat-dissipating of different components of a 3MW Wind Turbine System. The heat load of the engine room is analyzed and the physical model is developed based on finite volume method. After that, the temperature distribution of the cabin is obtained under different conditions with/without the jet unit. The temperature distribution in engine compartments with different number and the arrangement of jet units is compared in this paper. Based on the analysis, the cabin cooling design is carried out to achieve the purpose of stopping heat gathering and keeping heat balance of the cabin. This work puts forward the heat balance maintenance and completes the corresponding research, which could be helpful for the optimization of large-capacity Wind Turbine cooling system.

scholarly journals Numerical and experimental study of pyrophoric activated metal Mg surface combustion characteristics

2018 ◽  
Vol 5 (5) ◽  
pp. 172064
Author(s):  
Hesong Huang ◽  
Zhongxiang Tong ◽  
Chaozhe Wang ◽  
Biao Wang
Keyword(s):  
Temperature Distribution ◽  
Heat Balance ◽  
High Speed ◽  
Difficult Problem ◽  
Combustion Mechanism ◽  
Thermal Imager ◽  
Balance Equations ◽  
Adiabatic Wall ◽  
The Heat Balance ◽  
Infrared Thermal Imager

The combustion of multi-hole pyrophoric activated metal is solid combustion and the combustion mechanism is quite complex, which is a difficult problem to be solved. Once the pyrophoric activated metal is exposed to air, the oxygen diffuses to the interior of the activated metal within plenty of holes and reacts with it, which enlarges the contact area with oxygen. Consequently, the whole combustion is vigorous and the temperature rises rapidly. To study the combustion mechanism of the chaff, the surface heat balance equation is established in this work by taking Mg as the activated metal. To solve this equation, the chaff adiabatic wall temperature distribution is computed by computational fluid dynamics in the presence of high-speed airflow. Then, the chaff surface temperature distribution is obtained by solving the heat balance equations. Finally, numerical and experimental results obtained via an infrared thermal imager are compared to demonstrate the effectiveness of the established equation.

The heat balance of sheep standing in the sun

1957 ◽  
Vol 8 (3) ◽  
pp. 271 ◽  
Author(s):  
CHB Priestley
Keyword(s):  
Heat Balance ◽  
Heat Load ◽  
The Body ◽  
Wave Radiation ◽  
The Sun ◽  
Convective Heat Loss ◽  
Radiation Exchange ◽  
Long Wave ◽  
The Heat Balance ◽  
Long Wave Radiation

An extension is made of Lee's (1950) original discussion of the heat balance of sheep exposed to a tropical sun. Methods are given for calculating the two quantities, convective heat loss and long-wave radiation exchange, which automatically compensate to a large extent for the added heat load. There appear to be advantages in distinguishing between the heat balance of the fleece and that of the body of the sheep, and this provides a method of estimating the heat conducted to the body as a consequence of the insolation.

Dynamic Analysis on Energy-Saving Effect of Distributed Cooling System in TBS

2014 ◽  
Vol 472 ◽  
pp. 1047-1051
Author(s):  
Tian Jian Yang ◽  
Yang Li
Keyword(s):  
Dynamic Analysis ◽  
Energy Saving ◽  
Dynamic Simulation ◽  
Heat Balance ◽  
Air Conditioning ◽  
Cooling System ◽  
Balance Model ◽  
Saving Effect ◽  
The Heat Balance

In order to evaluate the energy-saving effect of Distributed Cooling System (DCS) analytically, the heat balance model of DCS in a TBS is established and then dynamic simulation is employed. The numeral results show that DCS has much better energy-saving effect than traditional air conditioning (AC) and the energy-saving effect is steady all year round.

scholarly journals Aspects of adapting the cooling installation in a food cold storage system to the applicable f-gas regulations

2021 ◽  
pp. 30-42
Author(s):  
Filip BRAŃSKI ◽  
Adam RUCIŃSKI
Keyword(s):  
Cold Storage ◽  
Heat Balance ◽  
Main Part ◽  
Cooling System ◽  
Storage System ◽  
Operating Parameters ◽  
Alternative Refrigerant ◽  
System Reconstruction ◽  
Cold Store ◽  
The Heat Balance

The paper presents the methodology of the analysis of the cooling system reconstruction in a food cold store under the regulations applicable from the beginning of 2020. They result from the so-called the F-Gas Act concerns the use of refrigerants with a low environmental impact. First, the elements of the existing regulations on the use of refrigerants were discussed. This part of article focus mainly on the F-Gas Act and the regulations it entails. Then, the refrigerants used so far in refrigeration systems were compared with substitutes, which were the only ones that have been approved for use since 2020, thanks to the low GWP index. Their properties are briefly described, along with the benefits (primarily for the environment) of their use. The main part of the work is the analysis of the reconstruction of the cooling system to use an alternative refrigerant. During the work, the construction of the cold storage was analyzed together with the system currently working in analysed location. Then, the heat balance was calculated, thanks to which it was possible to determine the demand for cold. Than, several refrigerants that meet the latest standards and application regulations were selected. Their operating parameters were examined, the possible variants of use were compared in relation to the determined demand for cooling and the most important operational features were summarized.

Performance and Affection Analysis on Cooling Module in the Vehicle Working Conditions

2014 ◽  
Vol 472 ◽  
pp. 348-352
Author(s):  
He Chang ◽  
Xiu Min Yu ◽  
Jing Hua Lv ◽  
Ming Zhou ◽  
Ge Li
Keyword(s):  
Simulation Model ◽  
Thermal Management ◽  
Working Conditions ◽  
Heat Balance ◽  
Air Conditioning ◽  
Cooling System ◽  
Balance Test ◽  
Simulation Results ◽  
Cooling Module ◽  
The Heat Balance

Cooling module simulation for vehicle has been built according to the heat balance test, and the simulation results are compared with the test data to verify the authenticity of the module. This simulation model provides an effective platform for vehicle thermal management analysis. Module is used to simulate the air conditioning running and to find how different ambient temperaturesto effect the performance of the cooling module. The air conditioning working and ambience temperaturewhichis significantly influence the performance of the cooling system.

An Approximate Analysis of the Temperature Conditions in a Journal Bearing. Part II: Application

1984 ◽  
Vol 106 (2) ◽  
pp. 237-244 ◽  
Author(s):  
J. W. Lund ◽  
J. Tonnesen
Keyword(s):  
Temperature Distribution ◽  
Heat Balance ◽  
Journal Bearing ◽  
Pressure Profile ◽  
Design Parameters ◽  
Experimental Measurements ◽  
Approximate Analysis ◽  
Bearing Sleeve ◽  
The Heat Balance ◽  
Bearing Part

To test the validity of the theory, described in Part I of this investigation, calculations are performed for a cylindrical, two-axial groove journal bearing over a range of loads and speeds. The results give the temperature distribution in the lubricant film and in the bearing sleeve, the journal surface temperature, the heat balance for the bearing, the journal center eccentricity, and the film pressure profile. The calculated results are compared with experimental measurements, and although significant discrepancies are observed, the overall agreement is satisfactory, considering the usual tolerance effects and the uncertainties in defining some of the design parameters

Nano Fluids for Improving Efficiency in Wind Turbine Cooling System

2014 ◽  
Vol 984-985 ◽  
pp. 784-791
Author(s):  
C. P. Christin Raj ◽  
S.A. Ananthapuri Surendran ◽  
B. Amjathkhan ◽  
J.Antony Baksi Metilda ◽  
S.Eben Devaraj ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Wind Turbine ◽  
High Efficiency ◽  
Waste Heat ◽  
Cooling System ◽  
Colloidal Suspensions ◽  
Heat Transfer Fluid ◽  
Turbine Cooling

In order to reduce the entry of moisture, salt, sand and other external contaminations into the nacelle and also to reduce the fan noise which reaches the exterior, in this work a study of an innovative cooling system for off-shore wind turbine has been carried out. The new cooling technique is based on the use of nanofluids (engineered colloidal suspensions of nanoparticles in a base fluid). Nanofluids allow to increase the thermal conductivity of fluids and so to reduce the heat exchange surface and the heat transfer fluid flow rate due to the increased heat capacity. To reduce the amount of nanofluids circulating in the cooling system, the performance of a two-stage cooling circuit has been investigated. The first circuit takes the heat out of the generator and of the accessories whereas the second circuit, coupled with the first via an heat exchanger, dissipates the heat into the ambient. For the second circuit two options have been investigated. In the first solution the waste heat is dispersed using the tower as dissipator whereas in the second option the waste heat is exchanged with a titanium heat exchanger using marine water as heat transfer fluid.Both solutions assure high efficiency of heat exchange, long technical life expectancy and limited maintenance requirements.Keywords: Wind turbine, nanofluid, cooling system.

scholarly journals Logistic Heat Integral Methods for the One-Phase Stefan Problem

2011 ◽  
Vol 2011 ◽  
pp. 1-13
Author(s):  
O. P. Layeni ◽  
A. M. Adegoke
Keyword(s):  
Temperature Distribution ◽  
Boundary Conditions ◽  
Stefan Problem ◽  
Heat Balance ◽  
Time Dependent ◽  
Integral Methods ◽  
The One ◽  
The Heat Balance ◽  
Moving Front

Logistic versions of the heat balance integral and refined integral methods are introduced. A benchmark with a one-phase Stefan problem under constant and time-dependent boundary conditions shows remarkable accuracy at estimating temperature distribution and position of the moving front.

scholarly journals BIURO PATALPOS ŠILUMOS PRITEKIŲ TYRIMAS / INVESTIGATION OF HEAT GAINS IN AN OFFICE

2018 ◽  
Vol 10 (0) ◽  
pp. 1-6
Author(s):  
Laura Juršėnaitė ◽  
Violeta Motuzienė
Keyword(s):  
Heat Balance ◽  
Energy Demand ◽  
Information Technologies ◽  
Cooling System ◽  
Internal Heat ◽  
Energy Performance ◽  
Experimental Simulation ◽  
Maximum Heat ◽  
Room Model ◽  
The Heat Balance

Increasing the energy efficiency of buildings, heat losses through envelope and infiltration become very low, therefore, the proportion of the heat gains in the heat balance of the building increases. Due to their abundance of computer equipment, intensive lighting and the abundance of employees the information technologies’ (IT) staff offices are characterized by high internal heat gains. Formally, such offices are not distinguished when designing the building and its energy performance, values of internal heat gains are the same as for usual offices. Insufficient attention to the detailed differentiation of the heat gains may lead to the inadequate assessment of the energy performance of the building, insufficient design power of the cooling system. The aim of this work is to determine the influence of internal heat gains on the heat balance of a existing IT office. The heat gains are initially determined experimentally and compared with the values calculated in accordance with STR 2.01.02:2016, the room model is calibrated in the IDA ICE software, which is used to analyze building’s annual energy demand sensitivity to internal heat gains. It was defined that in the case of maximum heat gains, the experimental internal heat gain are 63–81% higher than the ones, calculated in accordance with norms. The annual heating demand is 31% lower, and the cooling demand is 56% higher according to the experimental simulation compared to standardized simulation results. Santrauka Didinant pastatų energinį naudingumą, šilumos nuostoliai per atitvaras ir dėl infiltracijos tampa nykstamai maži, todėl pastato šilumos balanse didėja vidiniams šilumos pritekiams tenkanti dalis. Dideliais vidiniais šilumos pritekiais pasižymi informacinių technologijų (IT) personalo biurai dėl juose gausiai naudojamos kompiuterinės įrangos, intensyvaus apšvietimo bei darbuotojų gausos. Formaliai tokie biurai, projektuojant pastatą ir jo energinį naudingumą, nėra išskiriami, jiems taikomos tokios pačios vidinių pritekių vertės kaip ir įprastiems biurams. Nepakankamas dėmesys išsamesniam šilumos pritekių diferencijavimui gali lemti tai, kad pastato naudingumas bus įvertintas netinkamai, vėsinimo sistemos bus suprojektuotos nepakankamos galios (projektinei šildymo galiai šilumos pritekiai įtakos neturi). Šio darbo tikslas yra nustatyti vidinių šilumos pritekių įtaką realaus IT biuro patalpos šilumos balansui. Šilumos pritekiai pradžioje nustatomi eksperimentiniu būdu ir lyginami su dydžiais, apskaičiuotais pagal STR 2.01.02:2016 standartą, patalpos modelis kalibruojamas IDA ICE programoje, kurioje atliekama pastato metinių energijos poreikių priklausomybės nuo vidinių šilumos pritekių parametrinė analizė. Nustatyta, kad maksimalūs paros eksperimentiniai vidiniai pritekiai yra 63–81 % didesni nei apskaičiuoti pagal reglamentą, metiniai šildymo poreikiai pagal eksperimentinius duomenis yra 31 % mažesni, o vėsinimo poreikiai 56 % didesni lyginant su gautais taikant normines pritekių vertes.

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