The Effect of Using a Heat Recovery Absorber on the Performance and Operating Cost of the Solar Ammonia Absorption Cycles

1997 ◽  
Vol 119 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Saghiruddin ◽  
M. Altamush Siddiqui
Keyword(s):  
Economic Analysis ◽  
Flat Plate ◽  
Solar Collector ◽  
Heat Recovery ◽  
Theoretical Study ◽  
Operating Cost ◽  
Operating Conditions ◽  
Tubular Type ◽  
Ammonia Absorption ◽  
The Cost

Economic analysis of ordinary and evacuated tubular type flat-plate collectors have been carried out for operating absorption cycles with and without heat recovery absorber. Water-ammonia, NaSCN-NH3 and LiNO3-NH3 have been selected as the working fluids in the cycles. Use of a heat recovery absorber, in addition to the primary absorber in the conventional absorption cycles, lead to improvement in the system performances by about 20–30 percent in the H2O-NH3 and 33–36 percent in the NaSCN-NH3 and LiNO3-NH3 mixtures. Subsequently, there is a considerable amount of reduction in the cost of the solar collector required to operate them. For the set of operating conditions, in this theoretical study, the cost reduces to about 25 percent in the H2O-NH3 and 30 percent in the NaSCN and LiNO3-NH3 cycles.

Transient Considerations of Flat-Plate Solar Collectors

1974 ◽  
Vol 96 (2) ◽  
pp. 109-113 ◽  
Author(s):  
S. A. Klein ◽  
J. A. Duffie ◽  
W. A. Beckman
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Operating Conditions ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermal Capacitance ◽  
Flat Plate Solar Collector ◽  
Capacitance Effects

The effects of thermal capacitance in the modeling of the performance of a flat plate solar collector have often been neglected because of the computation involved. But because the solar collector is inherently exposed to continuously variable weather conditions, capacitance effects may be significant. To investigate these effects, three different models of flat-plate collectors have been investigated. The first, a quasi-steady-state model, simulates the performance of a collector of zero capacitance. The second model accounts for capacitance effects by assuming that a single value of thermal capacitance can be determined for the collector as a unit. The third model divides the collector into many isothermal segments, or nodes. For all three models the heat transfer coefficients are calculated as a function of operating conditions. The results show that, when hourly meteorological data are used, the zero-capacitance model is adequate.

Numerical Investigation of the Effects of Environmental Parameters and Geometry on Energy Absorption for an Open-type Water-cooled Flat-plate Solar Collector

2000 ◽  
Vol 122 (2) ◽  
pp. 56-62 ◽  
Author(s):  
B. Song ◽  
H. Inaba ◽  
A. Horibe
Keyword(s):  
Heat Flux ◽  
Flat Plate ◽  
Energy Absorption ◽  
Tilt Angle ◽  
Solar Collector ◽  
Water Film ◽  
Operating Conditions ◽  
Open Type ◽  
Type Water ◽  
Flat Plate Solar Collector

A two-dimensional mathematical model was developed for predicting the performance of an open-type water-cooled flat-plate solar collector, and solved numerically through an implicit finite difference method. The effects of various environmental and geometric conditions on energy absorption for the collector were investigated. The results predict that there is an optimum length and tilt angle for the absorbing plate for which the collector could obtain the highest solar energy absorptance. The latent heat flux of water evaporation can be 3 to 15 times larger than the sensible heat flux under normal operating conditions. The wind speed and the inlet water temperature have a large influence on the energy absorption of the collector. The effects of the solar incident flux, the atmospheric humidity and temperature, the absorbing plate tilt angle and length, and the water film thickness on the temperature rise of the water film and/or the absorptance of the collector are clarified. The open-type flat-plate collector is suitable to operate at lower inlet water temperatures and in regions where the local latitude is in the range of 20°N-40°N, and the weather is humid and hot with low winds. [S0199-6231(00)00202-1]

scholarly journals Comparison of Solar Collector Testing Methods—Theory and Practice

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1340
Author(s):  
Paweł Obstawski ◽  
Tomasz Bakoń ◽  
Dariusz Czekalski
Keyword(s):  
Solar Collector ◽  
Dynamic Properties ◽  
Operating Cost ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Solar Heating ◽  
Theory And Practice ◽  
Steady State Condition ◽  
Hybrid Energy ◽  
Heating Installation

One of the most important problems of operating solar heating systems involves variable efficiency depending on operating conditions. This problem is more pronounced in hybrid energy systems, where a solar installation cooperates with other segments based on conventional carriers of energy or renewable sources of energy. The operating cost of each segment of a hybrid system depends mainly on the resulting efficiency of solar installation. For over 40 years, the procedures of testing solar collectors have been undergoing development, testing, comparison and verification in order to create a procedure that would allow determining the thermal behavior of a solar collector without performing expensive and complicated experimental tests, usually based on the steady state condition. The proper determination of the static and dynamic properties of a solar collector is of key significance, as they constitute a basis for the design of a solar heating installation, as well as a control system. It is therefore important to conduct simulating and operating tests enabling the performance of a comparative analysis intended to indicate the degree to which the static and dynamic properties of a solar collector depend on the method used for their determination. The paper compares the static and dynamic properties of a flat solar collector determined by means of various methods. Based on the produced results, it has been concluded that the static and dynamic properties of a collector determined using various methods may differ from each other even by 50%. This means that it is possible to increase the efficiency of a solar heating installation via the use of an adaptive control algorithm, enabling real-time calculation of the values of characteristic parameters of solar installation, e.g., the time constant under operating conditions.

scholarly journals Advance Exergo-Economic Analysis of a Waste Heat Recovery System Using ORC for a Bottoming Natural Gas Engine

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 267 ◽  
Author(s):  
Guillermo Valencia Ochoa ◽  
Jhan Piero Rojas ◽  
Jorge Duarte Forero
Keyword(s):  
Heat Exchanger ◽  
Economic Analysis ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Operating Conditions ◽  
Cost Rate ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

This manuscript presents an advanced exergo-economic analysis of a waste heat recovery system based on the organic Rankine cycle from the exhaust gases of an internal combustion engine. Different operating conditions were established in order to find the exergy destroyed values in the components and the desegregation of them, as well as the rate of fuel exergy, product exergy, and loss exergy. The component with the highest exergy destroyed values was heat exchanger 1, which is a shell and tube equipment with the highest mean temperature difference in the thermal cycle. However, the values of the fuel cost rate (47.85 USD/GJ) and the product cost rate (197.65 USD/GJ) revealed the organic fluid pump (pump 2) as the device with the main thermo-economic opportunity of improvement, with an exergo-economic factor greater than 91%. In addition, the component with the highest investment costs was the heat exchanger 1 with a value of 2.769 USD/h, which means advanced exergo-economic analysis is a powerful method to identify the correct allocation of the irreversibility and highest cost, and the real potential for improvement is not linked to the interaction between components but to the same component being studied.

scholarly journals Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Thomas Semenou ◽  
Daniel R. Rousse ◽  
Brice Le Lostec ◽  
Hervé F. Nouanegue ◽  
Pierre-Luc Paradis
Keyword(s):  
Mathematical Modeling ◽  
Solar Collector ◽  
Thermal Model ◽  
Heat Recovery ◽  
Significant Rise ◽  
Operating Conditions ◽  
Solar Irradiation ◽  
Combined Model ◽  
Air Mass ◽  
Collector Efficiency

Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC) with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC). The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20°K when the solar irradiation is high.

Heat Exchanger Theory Applied to the Design of Water- and Air-Heating Flat-Plate Solar Collectors

1988 ◽  
Vol 110 (2) ◽  
pp. 132-138 ◽  
Author(s):  
Gregory J. Kowalski ◽  
Arthur R. Foster
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flat Plate ◽  
Solar Collector ◽  
Operating Conditions ◽  
Solar Collectors ◽  
Heat Transfer Characteristics ◽  
Air Heating ◽  
Collector Efficiency ◽  
The Difference

A general method for the design of flat-plate solar collectors based on solar collector theory has been developed. It can be applied to both liquid- and air-heating solar collectors. The solar collector efficiency is determined by the product of the effectiveness (ε) and the insolation use factor (IUF). The effectiveness describes the heat transfer characteristics of the collector and is shown to be a function of a solar number of transfer units (SNTU) and a parameter ψ. For an air-heating collector, the ψ parameter equals the collector efficiency factor, while for a liquid-heating collector it must account for the difference between the plate and tube heat transfer areas. The effectiveness and SNTU parameters are similar to the effectiveness and NTU parameters used in heat exchanger design methods. The IUF is a measure of the operating conditions of the collector. It represents the difference between the transmittance-absorptance product and the ratio of the minimum heat loss to the insolation on the exterior cover. The relationship between the effectiveness and the SNTU parameter is general for all nonconcentrating collectors. One advantage of this method over the traditional Hottel-Whillier method is that it separates the heat transfer characteristics of the solar collector from its optical properties and the operating conditions.

scholarly journals Economic Analysis of Atomization Drying of Concentrated Solution Based on Zero Discharge of Desulphurization Wastewater

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 148
Author(s):  
Ning Zhao ◽  
Yongxin Feng ◽  
Debo Li ◽  
Limei Chen
Keyword(s):  
Sensitivity Analysis ◽  
Economic Analysis ◽  
Flue Gas ◽  
Treatment Cost ◽  
Operating Cost ◽  
Economic Benefits ◽  
Operating Conditions ◽  
Drying Process ◽  
Unit Load ◽  
Zero Discharge

With the improvement of environmental protection requirements, more and more attention has been given to desulphurization wastewater with zero discharge in coal power plants. Atomization drying is part of the main zero discharge technologies at present. Economic analysis of the atomization drying of desulphurization wastewater is beneficial to the formulation of an appropriate operation scheme and to the reduction of operation costs. The economic analysis and sensitivity analysis of different operating conditions such as unit load, the handling capacity of concentrates, and the temperature of the extracted flue gas in the atomization drying process of concentrated desulfurized wastewater were carried out in this paper. The main cost of the drying process came from the influence of flue gas extraction on the overall heat transfer in the boiler, resulting in the decrease in power generation revenue, which can reach more than 80%. The operating cost of auxiliary machinery was relatively low. The cost of treatment for per ton of concentrates increased first and then decreased with the increase in temperature of the extracted flue gas, and it decreased with the increase in the handling capacity of the concentrates. The effect of a unit load on the treatment cost was also related to the temperature of the extracted flue gas, and the optimal flue gas temperature increase to higher temperatures as the unit load decreased. The minimum treatment costs per ton of concentrate ranged from CNY 143.54/t to CNY 158.77/t under different unit loads. Sensitivity analysis showed that the temperature of the extracted flue gas had the greatest impact on treatment cost, and its sensitivity coefficient was 0.0834. The ways in which to improve economic benefits were discussed.

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