Kinetics of Propane Cracking Related to Its Use as a Heat-Transfer Fluid

2015 ◽  
Vol 29 (2) ◽  
pp. 711-716 ◽  
Author(s):  
Alan K. Burnham ◽  
Gregory J. Turk ◽  
James R. McConaghy ◽  
Leonard H. Switzer
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Fluid ◽  
Kinetics Of ◽  
Propane Cracking

Experimental Study on Thermal Characteristics of Finned Coil LHSU Using Paraffin as Phase Change Material

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Guansheng Chen ◽  
Nanshuo Li ◽  
Huanhuan Xiang ◽  
Fan Li
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Phase Change ◽  
Phase Change Material ◽  
Water Flow ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Heat Transfer Fluid ◽  
Latent Heat Storage ◽  
Change Material

It is well known that attaching fins on the tubes surfaces can enhance the heat transfer into and out from the phase change materials (PCMs). This paper presents the results of an experimental study on the thermal characteristics of finned coil latent heat storage unit (LHSU) using paraffin as the phase change material (PCM). The paraffin LHSU is a rectangular cube consists of continuous horizontal multibended tubes attached vertical fins at the pitches of 2.5, 5.0, and 7.5 mm that creates the heat transfer surface. The shell side along with the space around the tubes and fins is filled with the material RT54 allocated to store energy of water, which flows inside the tubes as heat transfer fluid (HTF). The measurement is carried out under four different water flow rates: 1.01, 1.30, 1.50, and 1.70 L/min in the charging and discharging process, respectively. The temperature of paraffin and water, charging and discharging wattage, and heat transfer coefficient are plotted in relation to the working time and water flow rate.

scholarly journals Numerical Evaluation of a HVAC System Based on a High-Performance Heat Transfer Fluid

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Cooling System ◽  
Electrical Energy ◽  
Simulation Software ◽  
Heat Transfer Fluid ◽  
Hvac System ◽  
Dynamic Simulations ◽  
Heating And Cooling ◽  
The University

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

scholarly journals Modification of a Solar Thermal Collector to Promote Heat Transfer inside an Evacuated Tube Solar Thermal Absorber

2021 ◽  
Vol 11 (9) ◽  
pp. 4100
Author(s):  
Rasa Supankanok ◽  
Sukanpirom Sriwong ◽  
Phisan Ponpo ◽  
Wei Wu ◽  
Walairat Chandra-ambhorn ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Small Scale ◽  
Medium Temperature ◽  
Change Behavior ◽  
Set Up ◽  
Evacuated Tube ◽  
Heating Medium

Evacuated-tube solar collector (ETSC) is developed to achieve high heating medium temperature. Heat transfer fluid contained inside a copper heat pipe directly affects the heating medium temperature. A 10 mol% of ethylene-glycol in water is the heat transfer fluid in this system. The purpose of this study is to modify inner structure of the evacuated tube for promoting heat transfer through aluminum fin to the copper heat pipe by inserting stainless-steel scrubbers in the evacuated tube to increase heat conduction surface area. The experiment is set up to measure the temperature of heat transfer fluid at a heat pipe tip which is a heat exchange area between heat transfer fluid and heating medium. The vapor/ liquid equilibrium (VLE) theory is applied to investigate phase change behavior of the heat transfer fluid. Mathematical model validated with 6 experimental results is set up to investigate the performance of ETSC system and evaluate the feasibility of applying the modified ETSC in small-scale industries. The results indicate that the average temperature of heat transfer fluid in a modified tube increased to 160.32 °C which is higher than a standard tube by approximately 22 °C leading to the increase in its efficiency by 34.96%.

scholarly journals Numerical Simulation of the Impact of the Heat Source Position on Melting of a Nano-Enhanced Phase Change Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1425
Author(s):  
Tarek Bouzennada ◽  
Farid Mechighel ◽  
Kaouther Ghachem ◽  
Lioua Kolsi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Commercial Code ◽  
Tube Position ◽  
The Impact ◽  
Change Material

A 2D-symmetric numerical study of a new design of Nano-Enhanced Phase change material (NEPCM)-filled enclosure is presented in this paper. The enclosure is equipped with an inner tube allowing the circulation of the heat transfer fluid (HTF); n-Octadecane is chosen as phase change material (PCM). Comsol-Multiphysics commercial code was used to solve the governing equations. This study has been performed to examine the heat distribution and melting rate under the influence of the inner-tube position and the concentration of the nanoparticles dispersed in the PCM. The inner tube was located at three different vertical positions and the nanoparticle concentration was varied from 0 to 0.06. The results revealed that both heat transfer/melting rates are improved when the inner tube is located at the bottom region of the enclosure and by increasing the concentration of the nanoparticles. The addition of the nanoparticles enhances the heat transfer due to the considerable increase in conductivity. On the other hand, by placing the tube in the bottom area of the enclosure, the liquid PCM gets a wider space, allowing the intensification of the natural convection.

Experimental studies on micro-channel heat sink with different heat transfer fluid

2021 ◽  
Author(s):  
M. P. Dhanishk ◽  
P. Selvakumar ◽  
V. Ashwin ◽  
P. N. ArunKumar
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Experimental Studies ◽  
Heat Transfer Fluid ◽  
Micro Channel

scholarly journals Comparison of Li2CO3-Na2CO3-K2CO3, KCl-MgCl2 and NaNO3-KNO3 as heat transfer fluid for different sCO2 and steam power cycles in CSP tower plant under different DNI conditions

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110119
Author(s):  
Kamran Mahboob ◽  
Awais A Khan ◽  
Muhammad Adeel Khan ◽  
Jawad Sarwar ◽  
Tauseef A Khan
Keyword(s):  
Heat Transfer ◽  
Power Plant ◽  
Rankine Cycle ◽  
Capacity Factor ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Incident Power ◽  
Steam Power ◽  
Power Cycles ◽  
Plant Configuration

This work presents the characteristics of a solar thermal tower power plant in two different places (Seville and Dubai) using three different HTFs (NaNO3-KNO3, KCl-MgCl2 and Li2CO3-Na2CO3-K2CO3) and three different power cycles (Rankine, sCO2 Recompression and sCO2 Partial cooling cycles). An indirect configuration is considered for the Gemasolar power plant. Detailed modelling is carried out for the conversion of incident power on the heliostat to the output electricity. Optimization of the cycle is carried out to determine the most promising cycle configuration for efficiency. The results showed that for the Gemasolar power plant configuration, the performance of the KCl-MgCl2 based plant was poorest amongst all. NaNO3-KNO3 based plant has shown good performance with the Rankine cycle but plant having Li2CO3-Na2CO3-K2CO3 as HTF was best for all three cycles. Partial cooling was the best performing cycle at both locations with all three HTFs. Placing the Seville Plant in Dubai has improved the efficiency from 23.56% to 24.33%, a capacity factor improvement of 21 and 52 GW additional power is generated. The optimization of the plant in Dubai has shown further improvements. The efficiency is improved, the Capacity factor is increased by 31.2 and 77.8 GW of additional electricity is produced.

scholarly journals Analysis and Comparison of Some Low-Temperature Heat Sources for Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1853 ◽  
Author(s):  
Pavel Neuberger ◽  
Radomír Adamovský
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Ambient Air ◽  
Heat Transfer Fluid ◽  
Heat Sources ◽  
Ground Heat Exchangers ◽  
Temperature Heat

The efficiency of a heat pump energy system is significantly influenced by its low-temperature heat source. This paper presents the results of operational monitoring, analysis and comparison of heat transfer fluid temperatures, outputs and extracted energies at the most widely used low temperature heat sources within 218 days of a heating period. The monitoring involved horizontal ground heat exchangers (HGHEs) of linear and Slinky type, vertical ground heat exchangers (VGHEs) with single and double U-tube exchanger as well as the ambient air. The results of the verification indicated that it was not possible to specify clearly the most advantageous low-temperature heat source that meets the requirements of the efficiency of the heat pump operation. The highest average heat transfer fluid temperatures were achieved at linear HGHE (8.13 ± 4.50 °C) and double U-tube VGHE (8.13 ± 3.12 °C). The highest average specific heat output 59.97 ± 41.80 W/m2 and specific energy extracted from the ground mass 2723.40 ± 1785.58 kJ/m2·day were recorded at single U-tube VGHE. The lowest thermal resistance value of 0.07 K·m2/W, specifying the efficiency of the heat transfer process between the ground mass and the heat transfer fluid, was monitored at linear HGHE. The use of ambient air as a low-temperature heat pump source was considered to be the least advantageous in terms of its temperature parameters.

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