Analysis on Effect of Heat Bridge to Heat Transfer of Refuge Chamber’s Shell

2011 ◽  
Vol 211-212 ◽  
pp. 624-628 ◽  
Author(s):  
Hai Feng Fang ◽  
Shi Rong Ge ◽  
Ming Song
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Heat Transfer Process ◽  
Direct Connection ◽  
Analysis Method ◽  
Indirect Connection ◽  
Method Effect ◽  
Connection Type ◽  
Reduce Energy Consumption ◽  
Heat Bridge

In order to improve the heat-insulating capability of the refuge chamber’s shell and reduce energy consumption of the cooling system, the horizontal cylindrical mobile refuge chamber for coal mine was taken as the research object. By selecting two connection types between the inner shell and the outer shell for calculation, which were direct connection type and indirect connection type, and comparing these with the connectionless heat transfer, the heat transfer process in the refuge chamber subjected to thermal loadings of constant temperature was respectively discussed with numerical analysis method. Effect of heat bridges to heat transfer of the refuge chamber’s shell was analyzed. The analysis results showed that the average heat flux through direct connection heat bridge and indirect connection heat bridge had respectively increased by 668% and 30% than that of the connectionless heat transfer. The influencing scope of the former was larger than the latter’s. And more heat entered the refuge chamber through the direct connection heat bridge. Therefore, the indirect connection type should be used in the design of the refuge chamber’s shell.

Research on Heat-Transfer Process of the Radiant Ceiling Cooling System

2012 ◽  
Vol 512-515 ◽  
pp. 2171-2174 ◽  
Author(s):  
Quan Ying Yan ◽  
Ran Huo ◽  
Li Li Jin
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Cooling System ◽  
Numerical Models ◽  
Cooling Water ◽  
Lower Surface ◽  
Cooling Capacity ◽  
Heat Transfer Process ◽  
Lower Surface Temperature ◽  
Selection Of

Physical and numerical models of the radiant ceiling cooling system were built and numerically simulated. The results showed that the lower the temperature of cooling water is, the lower surface temperature the ceiling has, and the bigger the cooling capacity is. The bigger the depth of tubes is, the higher the surface temperature and the smaller the cooling capacity. The differences are not evident. The bigger the distance of tubes is, the bigger the surface temperature is and the smaller the cooling capacity is. The diameter of tubes has a few influences on the surface temperature and the cooling capacity. Results in this paper can provide basis and guide for the design of the project, the selection of parameters and the feasibility of the system.

Heat transfer process of R600a spray cooling system

2015 ◽  
Vol 27 (7) ◽  
pp. 71001
Author(s):  
徐洪波 Xu Hongbo ◽  
钱春潮 Qian Chunchao ◽  
邵双全 Shao Shuangquan ◽  
田长青 Tian Changqing ◽  
司春强 Si Chunqiang
Keyword(s):  
Heat Transfer ◽  
Transfer Process ◽  
Cooling System ◽  
Spray Cooling ◽  
Heat Transfer Process

scholarly journals ANALYSIS OF DETERMINING CRITICAL COMPONENTS USING FMECA METHOD IN SEAWATER PUMP OF DIESEL GENERATOR CATERPILLAR 3412

JOURNAL ASRO ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 124
Author(s):  
Saiful Hasan ◽  
Erpan Sahiri ◽  
Suprayitno Suprayitno ◽  
Endin Tri Hartanto
Keyword(s):  
Heat Transfer ◽  
Transfer Process ◽  
Preventive Maintenance ◽  
Cooling System ◽  
Heat Transfer Process ◽  
Failure Model ◽  
Diesel Generator ◽  
Component Reliability ◽  
Operational Conditions ◽  
Critical Components

The seawater pump on the Caterpillar 3412 Diesel Generator is one of the important component to make the Diesel generator can work well. This section serves to circulate seawater for the heat transfer process. The seawater pump is part of a cooling system of the engine which keeps the engine temperature from being too overheat. Seawater pumps with continuous operational conditions, resulting in reduced component reliability. This study applies the FMECA method to identify opportunities for failure at the seawater pump. From the calculation of FMECA, it is obtained an assessment of the level of risk from a failure model that can give priority scale to preventive maintenance that can be done in the future. FMECA analysis of 27 components in seawater pump on the Diesel Generator, found 7 components that had RPN values above the average. The following are the 4 components with the highest RPN value, namely Shaft (7C-3493) RPN value 420,44; Key (175-6716) RPN value 300,31; Bearing Inner (4M-6107) RPN value 285 and Bearing Roller (3N-8463) RPN value 253,13. Components that have high RPN values require more attention, such as routine checks and periodic maintenance.Keyword: Seawater pump, Caterpillar 3412 Diesel Generator, FMECA, RPN.

scholarly journals Research on High-Pressure Hydrogen Pre-Cooling Based on CFD Technology in Fast Filling Process

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2208
Author(s):  
Sen Li ◽  
Jinxing Guo ◽  
Xin Lv ◽  
Teng Deng ◽  
Bo Cao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Transfer Process ◽  
Volume Fraction ◽  
Cooling System ◽  
Operating Cost ◽  
Heat Transfer Process ◽  
Inlet Temperature ◽  
Filling Process ◽  
Pressure Hydrogen

In the fast filling process, in order to control the temperature of the vehicle-mounted storage tank not to exceed the upper limit of 85 °C, it is an effective method to add a hydrogen pre-cooling system upstream of the hydrogenation machine. In this paper, Fluent is used to simulate the heat transfer process of high-pressure hydrogen in a shell-and-tube heat exchanger and the phase change process of refrigerant R23. The accuracy of the model is proven by a comparison with the data in the references. Using this model, the temperature field and gas volume fraction in the heat transfer process are obtained, which is helpful to analyze the heat transfer mechanism. At the same time, the influence of hydrogen inlet temperature, hydrogen inlet pressure, and refrigerant flow rate on the refrigeration performance was studied. The current work shows that the model can be used to determine the best working parameters in the pre-cooling process and reduce the operating cost of the hydrogen refueling station.

Comprehensive Reduction of Thermal Resistance in Air Cooled Condensers

2015 ◽  
Author(s):  
Ahmad Saleh ◽  
Jayanta Kapat
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Transfer Process ◽  
Cooling System ◽  
Ambient Air ◽  
Heat Transfer Process ◽  
Air Cooling ◽  
Total Thermal Resistance ◽  
Fin Efficiency

Restriction on water consumption is becoming an increasing problem for the power generation industry. As an alternative both to once-through cooling and to surface condenser/wet-cooling tower combination, utility companies and equipment manufacturers are considering, and even implementing, air-cooled condenser (ACC). However, the industry is quite reluctant to switch over to ACC for three important reasons: (a) lower power output, (b) higher capital cost, and (c) larger physical foot-print, all because of the same reason — it is not as efficient to transfer heat from condensing steam to air as it is to transfer to water. In other words, overall thermal resistance from condensing steam to the ambient air is significantly higher than to cooling water. To get a clear and full understanding of the heat transfer process occur in air-cooling condenser, Detailed mathematical equations were derived to model the heat transfer process through the fined-tubes of the ACC. The total thermal resistance model was analyzed and investigated to identify the design components with highest affect in the process. The paper proposes a viable cooling system based on novel heat pipe technology which addresses these problems. This technology employs boiling as the means to store and transfer heat energy. A detailed mathematical set of equations was derived to model the heat pipe thermal resistance. A comparison of the heat transfer performances of the ACC technology and the proposed method is presented. The proposed cooling system suggests a solution for each of the three components of the thermal resistance, the super-hydrophobic coating of the steam ducts internal surfaces increased the condensing heat transfer rate by an order of magnitude, the proposed design of the heat pipes improved the external heat transfer, and the installation mechanism improves the fin efficiency by eliminating the contact resistance between steam duct and the heat pipe.

Reciprocating Compressor Cylinder’s Cooling: A Numerical Approach Using CFD With Conjugate Heat Transfer

2014 ◽  
Author(s):  
Francesco Balduzzi ◽  
Giovanni Ferrara ◽  
Alberto Babbini ◽  
Riccardo Maleci
Keyword(s):  
Heat Transfer ◽  
Conjugate Heat Transfer ◽  
Best Practice ◽  
Cooling System ◽  
Numerical Technique ◽  
Heat Transfer Process ◽  
System Capacity ◽  
3D Analysis ◽  
Reciprocating Compressor ◽  
Discharge Temperature

The working cycle of a reciprocating compressor is characterized by heat generation, mainly due to compression transformation and friction phenomena. The main consequences are a reduction of the volumetric efficiency and an increase in the gas discharge temperature. Current regulations such as API618 for reciprocating compressors require a cylinder cooling system. Therefore, a proper design of the cooling circuit is needed in order to achieve the best balance between refrigerating potential and system capacity. A systematic methodology for the evaluation of the heat transfer process is essential and since experimental characterization of the circuit is complex and case-dependent, the use of a numerical technique is the most favorable and generalizable approach. Within this scenario, 3D analysis shows a great potential although several phenomena must be accounted for in order to accurately model the system. In this paper, a conjugate heat transfer (CHT) analysis on a double-acting water-cooled reciprocating compressor cylinder is presented, where the three-dimensional flow field of the water circuit and the thermal conduction inside the solid metal are solved simultaneously. The best practice for the imposition of consistent boundary conditions for the metal body is given with special attention to the heat transfer coefficient values for the suction and discharge gas chambers, the compression chamber and the external ambient. The assessment of the numerical methodology is completed with an investigation on the influence of wall roughness and buoyancy effects.

A Computer-Aided Cooling-Line Design System for Injection Molds

1990 ◽  
Vol 112 (2) ◽  
pp. 161-167 ◽  
Author(s):  
L. S. Turng ◽  
K. K. Wang
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Cooling System ◽  
Transient Heat Conduction ◽  
Heat Transfer Process ◽  
Design System ◽  
Cavity Surface ◽  
Transient Temperature ◽  
Numerical Predictions ◽  
Line Design

This paper presents a methodology for analyzing the heat-transfer process during the injection molding of plastics as an aid to mold design. A numerical scheme using the Boundary Element Method (BEM) with “zonal” approach has been developed to solve the quasi-steady temperature field and its normal derivative over the entire surface of the mold plates including the cavity wall as well as parting surface. In order to obtain a solution for the temperature field, a cycle-averaged heat-transfer coefficient is introduced from a transient heat-conduction analysis and applied as the boundary condition at the cavity surface. The numerical predictions as compared with the experimental data have shown that the cycle-averaged solution used in this study gives a reasonable representation of the transient temperature variation over the cavity surface. Based on the numerical predictions, the mold designer will be able to design a proper cooling-system for a mold to achieve better part quality and high productivity through more uniform cooling and shorter cycle time, respectively.

scholarly journals MODELING THE HEAT TRANSFER PROCESS IN REFRIGERATION UNITS USED IN THE OIL INDUSTRY

2019 ◽  
Vol 6 ◽  
pp. 57-62
Author(s):  
Ibrahim Abulfaz Gabibov ◽  
Rabiya Seydulla Nadjafkulieva ◽  
Sevinj Malik Abasova
Keyword(s):  
Heat Transfer ◽  
Transfer Process ◽  
Cooling System ◽  
High Heat ◽  
Heat Transfer Process ◽  
Gas Production ◽  
Pipeline System ◽  
Processing Plant ◽  
Associated Petroleum Gas ◽  
High Heat Transfer

Currently, the main volume of associated petroleum gas production in Azerbaijan is carried out at offshore fields. About 30 % of this volume is used for SOCAR’s own technological needs of the oil company (to maintain the level of oil production). And the rest are transported to onshore facilities and further for processing to a gas processing plant. Subsequently, dry and purified gas is sent through a gas pipeline system for use by the population, or to a network of trunk pipelines for further export. When gas is transferred to the gas lift system and ashore, it is compressed in compressors, as a result of which the temperature of the working agent rises. The latter dramatically reduces the level of operational safety of the entire process. Based on the foregoing, ensuring the required gas quality at the outlet of the compressor unit is an important and urgent task. Currently used in the gas cooling system, shell-and-tube type refrigeration units have several advantages: high heat transfer coefficient, operability in low and high pressure modes, simplicity of design and service. Along with this, these units are distinguished by large dimensions and high metal consumption, noise effect, vibration, etc. A new design of a heat exchanger for cooling associated petroleum gas at the outlet of gas motor compressors is proposed. Based on the modeling of the heat transfer process, mathematical models have been obtained that make it possible to adequately evaluate the cooling process in the proposed refrigeration device.

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