scholarly journals Experimental Performance of Solar Receivers Designed to Use Oil as a Heat Transfer Fluid

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
J. S. P. Mlatho
Keyword(s):  
Heat Transfer ◽  
Low Cost ◽  
Thermal Studies ◽  
Experimental Tests ◽  
Heat Transfer Fluid ◽  
Flow Meter ◽  
Positive Displacement ◽  
Displacement Pump ◽  
Parabolic Dish ◽  
Parabolic Dish Concentrator

A parabolic dish concentrator (PDC) has been designed to be used for charging a thermal energy storage (TES) that is for indirect cooking purpose. Three different receivers have been designed, fabricated, and their performance tested experimentally. The three designs are Volumetric Flask (VF), Volumetric Box (VB), and Conical Tube (CT) receivers. The receivers have been fabricated to use oil as a heat transfer fluid. Of the three designs, the CT receiver has the highest efficiency for a given flow rate, thus making it the best receiver. A positive displacement pump was also designed and constructed for the experimental tests. The pump is used to drive the oil through the receivers and also to act as a flow meter. Thus a low-cost and high-temperature positive displacement pump and a flow meter have been designed and fabricated for use in solar thermal studies.

Thermal Performance of Solar Parabolic Dish Concentrator with Hetero-Conical Cavity Receiver

2015 ◽  
Vol 787 ◽  
pp. 197-201 ◽  
Author(s):  
V. Thirunavukkarasu ◽  
M. Cheralathan
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
High Efficiency ◽  
Heat Transfer Fluid ◽  
Solar Collectors ◽  
Metal Tube ◽  
Conical Cavity ◽  
Concentrated Solar Energy ◽  
Parabolic Dish ◽  
Parabolic Dish Concentrator

Concentrated solar collectors have high efficiency as compared to flat plate and evacuated tube solar collectors. Cavity receivers are mainly used on the parabolic dish concentrators and tower type concentrator systems. The heat transfer surfaces of cavity receiver are composed by coiled metal tube. Heat transfer fluid flows in the internal spaces of coiled metal tube, and the external surfaces would absorb the highly concentrated solar energy. This paper explains the thermal performance of parabolic dish concentrator system with hetero-conical cavity receiver. The experimental analysis was done during the month of April 2014 on clear sunny days at Chennai [Latitude: 13.08oN, Longitude: 80.27oE] to study its thermal performance.

scholarly journals Ray Tracing Study of Optical Characteristics of the Solar Image in the Receiver for a Thermal Solar Parabolic Dish Collector

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Saša R. Pavlovic ◽  
Velimir P. Stefanovic
Keyword(s):  
Ray Tracing ◽  
Low Cost ◽  
Optical Design ◽  
Solar Concentrator ◽  
Solar Collectors ◽  
Focal Distance ◽  
Medium Temperature ◽  
Parabolic Dish ◽  
Parabolic Dish Concentrator ◽  
Temperature Levels

This study presents the geometric aspects of the focal image for a solar parabolic concentrator (SPC) using the ray tracing technique to establish parameters that allow the designation of the most suitable geometry for coupling the SPC to absorber-receiver. The efficient conversion of solar radiation into heat at these temperature levels requires a use of concentrating solar collectors. In this paper detailed optical design of the solar parabolic dish concentrator is presented. The system has diameter D=3800 mm and focal distance f=2260 mm. The parabolic dish of the solar system consists of 11 curvilinear trapezoidal reflective petals. For the construction of the solar collectors, mild steel-sheet and square pipe were used as the shell support for the reflecting surfaces. This paper presents optical simulations of the parabolic solar concentrator unit using the ray tracing software TracePro. The total flux on the receiver and the distribution of irradiance for absorbing flux on center and periphery receiver are given. The goal of this paper is to present the optical design of a low-tech solar concentrator that can be used as a potentially low cost tool for laboratory scale research on the medium-temperature thermal processes, cooling, industrial processes, polygeneration systems, and so forth.

Experimental Study of a Novel Thermal Storage System Using Sands With High-Conductive Fluids Occupying the Pores

2014 ◽  
Author(s):  
Jingxiao Han ◽  
Ben Xu ◽  
Peiwen Li ◽  
Anurag Kumar ◽  
Yongping Yang
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Low Cost ◽  
Storage System ◽  
Solid Material ◽  
Thermal Storage ◽  
Heat Transfer Fluid ◽  
Large Capacity ◽  
Conductive Fluid ◽  
Media System

Because of the capability of large capacity thermal storage, concentrated solar power (CSP) technology is getting more attentions in the recent years. The energy storage allows power generation using solar energy during the late afternoon and evening time. For a large capacity of thermal energy storage, a dual-media system is typically adopted for reducing the use of the heat transfer fluid (HTF), which is usually expensive. In a dual-media system, the solid material must have large heat capacity and be inexpensive. One type of configuration for a dual-media system is that HTF flowing in pipes which are imbedded into the solid material. The present study considers sands, a major component of concrete, as low-cost solid thermal storage materials. The novel approach is that the sand is saturated with high thermal conductive fluid. Compared to using concrete for thermal storage, this method avoids issues of heat transfer degradation associated with the mismatch of thermal expansion of pipes and concrete. Since only sands are porous materials and the heat transfer performance is low, a high conductive fluid (XCELTHERM® 600 hot oil) was used to saturate sands, which then forms a new thermal storage material that can have better heat transfer. Results of thermal storage process with sands only and with the oil-saturated sands are presented and discussed.

Gas Turbimes for High-Specific-Output Industrial Heat-Transfer Equipment

1972 ◽  
Vol 186 (1) ◽  
pp. 205-220
Author(s):  
E. Kellett
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Gas Turbines ◽  
Low Cost ◽  
Heat Transfer Fluid ◽  
Transfer Rates ◽  
High Heat Transfer ◽  
Pressurized Combustion

The incompatibility of the dual role of air as a combustion and heat-transfer fluid is apparent in the unbalance of convective heat transfer in a water boiler. Pressurized combustion has, since the middle of the nineteenth century, been postulated as a means of increasing the gas-side convective heat transfer to more nearly correspond with the water-side rate. Gas turbines, in the form of turbine-driven supercharged boilers, have been made, but without significant commercial success, in Europe and America. Modern gas turbines are employed in total-energy systems but because of the premium value of their shaft power output, additional heat exchangers must have the minimum pressure loss and therefore conventional heat-transfer criteria apply. Small turbine-driven superchargers are now mass produced for automotive diesel engines and particularly with the availability of natural gas the feasibility of pressurized combustion by their use justifies re-appraisal. Although these turbochargers have little value as gas-turbine power units the margin of turbine output over compressor power absorption can be employed to improve heat-exchanger convective heat-transfer rates significantly. The provision of a second compressor in the rotor system enables a stoichiometric air and gaseous fuel charge to be induced into a simple pre-mixed combustor thus preserving the low-cost aspect of the turbocharger and providing improved control and safety in a very durable gas-turbine device. The addition of a simple after-burner allows total combustion at relatively low excess air rates. The arguments leading to the foregoing design are presented and some of the more important product developments are described. Examination of the wider application potential of such low-cost turbomachinery indicates prospects for their employment in diverse uses particularly where high heat-transfer rates are desirable.

scholarly journals Heat Transfer Augmentation of Concentrated Solar Absorber Using Modified Surface Contour

2021 ◽  
Vol 11 (1) ◽  
pp. 24-33
Author(s):  
Ramalingam Senthil ◽  
Arvind Chezian ◽  
Zackir Hussain Ajmal Arsath
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Cavity Surface ◽  
Solar Absorbers ◽  
Surface Contour ◽  
Parabolic Dish ◽  
Plain Surface ◽  
Surface Modified

This work aims to compare the cavity surface contour’s thermal performance to that of the solar absorber’s plain surface contour for Scheffler type parabolic dish collectors. The absorber is tested for the temperature range up to 600°C without working fluid and 180°C with the working fluid. The modified absorber surface's thermal performance is compared with the flat surface absorber with and without heat transfer fluid. The peak temperature reached by the surface modified absorber (534°C) is about 8.6% more than that of the unmodified absorber (492°C) during an outdoor test without fluid. The energy efficiency of cavity surface absorber and plain surface absorber are 67.65% and 61.84%, respectively. The contoured cavity surface produces a more uniform temperature distribution and a higher heat absorption rate than the plain surface. The results are beneficial to the design of high-temperature solar absorbers for concentrated solar collectors.

scholarly journals The Influence of Water and Mineral Oil on Volumetric Losses in the Displacement Pump for Offshore and Marine Applications

2019 ◽  
Vol 26 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Paweł Śliwiński
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Water Pump ◽  
Positive Displacement ◽  
Oil Pump ◽  
Influence Of Water ◽  
Displacement Pump ◽  
Marine Applications

Abstract In this paper, volumetric losses in a positive displacement pump supplied with water and mineral oil are described and compared. The experimental tests were conducted using a prototype of a satellite pump (with a non-circular tooth working mechanism). In this paper, the sources of volumetric losses in this pump are characterized. On this basis, a mathematical model of these losses has been presented. The results of the calculation of volumetric losses according to the model are compared with the results of the experiment. Experimental studies have shown that the volumetric losses in the water pump are even 3.2 times greater than the volumetric losses in the oil pump. It has been demonstrated that the mathematical model describing the volumetric losses both in the water pump and in the oil pump is quite good. It has been found that the results from the loaded pump simulation (at ∆p=25MPa and ant n=1500rpm) differ from the results of the experiment by no more than 5% both for oil and water.

scholarly journals Demonstration and analysis of a steam reforming process driven with solar heat using molten salts as heat transfer fluid

2022 ◽  
Vol 334 ◽  
pp. 01004
Author(s):  
Alberto Giaconia ◽  
Giampaolo Caputo ◽  
Primo Di Ascenzi ◽  
Giulia Monteleone ◽  
Luca Turchetti
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Steam Reforming ◽  
Molten Salts ◽  
Experimental Validation ◽  
Low Cost ◽  
Water Electrolysis ◽  
Pilot Scale ◽  
Heat Transfer Fluid ◽  
Hydrogen Availability

Solar reforming of biogas or biomethane represents an example hydrogen production from the combination of renewable sources such as biomass and solar energy. Thanks to its relatively low-cost and flexibility, solar-reforming can represent a complementary source of hydrogen where/when the demand exceeds the green hydrogen availability from water electrolysis powered by PV or wind. Molten salts can be used as heat transfer fluid and heat storage medium in solar-driven steam reforming. The main units of the process have been developed at the pilot scale and experimentally tested in a molten salt experimental loop at ENEA-Casaccia research center: a molten salt heater and a molten salt membrane reformer. After experimental validation, techno-economic studies have been carried out to assess the solar reforming technology on commercial scale and exploitation opportunities have been analysed.

Miniature Pump for Treatment of Refractory Ascites Based on Local Magnetic Actuation

2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Nicolo Garbin ◽  
Patrick Doyle ◽  
Byron Smith ◽  
Jesse G. Taylor ◽  
Mubashir H. Khan ◽  
...  
Keyword(s):  
Low Cost ◽  
Magnetic Coupling ◽  
Daily Basis ◽  
Refractory Ascites ◽  
Alignment Algorithm ◽  
Magnetic Actuation ◽  
Magnetic Field Sensors ◽  
Positive Displacement ◽  
Displacement Pump ◽  
Transjugular Portosystemic Shunt

This paper presents the design, fabrication, and experimental validation of a novel low-cost implantable pump for the treatment of refractory ascites (RA) based on local magnetic actuation (LMA). A reciprocating positive displacement pump displaces liquid unidirectionally through magnetic coupling with a magnetic controller placed on the outside of the patient's body. The proposed solution is intuitive to use given an alignment algorithm that exploits externally placed magnetic field sensors (MFS). The implantable device has a catheter-like shape, is electronic free (no on-board battery), has low fabrication cost (<8 USD), and is able to generate a flow-rate of 3.65 L/h while effectively pumping fluids with various viscosity (1–5.5 cP). RA is commonly treated via costly paracentesis or invasive surgical placement of a transjugular portosystemic shunt (TIPS). The proposed solution can be implanted with minimally invasive techniques and can be used on a daily basis to drain a set amount of liquid, without requiring recurrent hospital visits.

scholarly journals Effect of the phase change material in a solar receiver on thermal performance of parabolic dish collector

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 2803-2812 ◽  
Author(s):  
Ramalingam Senthil ◽  
Marimuthu Cheralathan
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Exergy Efficiency ◽  
Heat Transfer Fluid ◽  
Solar Radiation Intensity ◽  
Chloride Hexahydrate ◽  
Parabolic Dish ◽  
Solar Receiver ◽  
Change Material

In this work, the use of phase change material in the circular tank solar receiver is proposed for a 16 m2 Scheffler parabolic dish solar concentrator to improve the heat transfer in the receiver. Magnesium chloride hexahydrate with melting temperature of 117?C is selected as the phase change material in the annular space of the receiver with rectangular fins inside the phase change material. Experimental work is carried out to analyze heat transfer from the receiver to heat transfer fluid with and without phase change material in the inner periphery. Energy and exergy efficiency are determined from the measurements of solar radiation intensity, receiver temperature, surroundings temperature, heat transfer fluid inlet and outlet temperatures, storage tank temperature, and wind speed. The experiments were conducted in SRM University, Chennai, India (latitude: 13? 5? N, longitude: 80?16? E) in April 2014. Use of phase change material in receiver periphery increased energy efficiency by 5.62%, exergy efficiency by 12.8% and decreased time to reach the boiling point of water by 20% when compared with the receiver without phase change material.

The Pumping Dynamics of a Positive Displacement Pump Employing Self-Acting Valves

1990 ◽  
Vol 112 (4) ◽  
pp. 748-754 ◽  
Author(s):  
K. A. Edge ◽  
P. N. Brett
Keyword(s):  
Pressure Fluctuations ◽  
Experimental Tests ◽  
General Purpose ◽  
Operating Conditions ◽  
Cylinder Pressure ◽  
Valve Timing ◽  
Inlet Valve ◽  
Positive Displacement ◽  
Displacement Pump ◽  
Valve Dynamics

The paper describes a general purpose digital computer model for the analysis of the pumping dynamics of positive displacement pumps employing self-acting valves. This model is verified by comparison with experimental tests on a diaphragm separator pump. Predicted and simulated cylinder pressure transients and inlet and delivery valve dynamics are compared over the complete pumping cycle. Close agreement between theory and experiment is achieved. The induction performance of the pump is examined in detail and the effects of operating conditions on volumetric efficiency are presented. The effect of inlet valve timing on delivery manifold pressure fluctuations is also discussed.

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