Theoretical Analysis of a Water Desalination System Using Low Grade Solar Heat

Solar Energy ◽  
2003 ◽  
Author(s):  
S. Al-Kharabsheh ◽  
D. Yogi Goswami
Keyword(s):  
Theoretical Analysis ◽  
Heating System ◽  
Operating Conditions ◽  
Water Desalination ◽  
Low Grade ◽  
Solar Heat ◽  
Evaporation And Condensation ◽  
Condenser Temperature ◽  
Low Grade Heat ◽  
Natural Means

Theoretical analysis of a solar desalination system utilizing an innovative new concept, which uses low-grade solar heat, is presented. The system utilizes natural means of gravity and atmospheric pressure to create a vacuum, under which liquid can be evaporated at much lower temperatures and with less energy than conventional techniques. The uniqueness of the system is in the way natural forces are used to create vacuum conditions and its incorporation in a single system design where evaporation and condensation take place at appropriate locations without any energy input other than low grade heat. The system consists of solar heating system, an evaporator, a condenser, and injection, withdrawal, and discharge pipes. The effect of various operating conditions, namely, withdrawal rate, depth of water body, temperature of the heat source, and condenser temperature were studied. Numerical simulations show that the proposed system may have distillation efficiencies as high as 90% or more. Vacuum equivalent to 3.7 kPa (abs) or less can be created depending on the ambient temperature at which condensation will take place.

Theoretical Analysis of a Water Desalination System Using Low Grade Solar Heat

2004 ◽  
Vol 126 (2) ◽  
pp. 774-780 ◽  
Author(s):  
S. Al-Kharabsheh ◽  
D. Yogi Goswami
Keyword(s):  
Theoretical Analysis ◽  
Heating System ◽  
Operating Conditions ◽  
Water Desalination ◽  
Low Grade ◽  
Solar Heat ◽  
Evaporation And Condensation ◽  
Condenser Temperature ◽  
Low Grade Heat ◽  
Natural Means

Theoretical analysis of a solar desalination system utilizing an innovative new concept, which uses low-grade solar heat, is presented. The system utilizes natural means of gravity and atmospheric pressure to create a vacuum, under which liquid can be evaporated at much lower temperatures and with less energy than conventional techniques. The uniqueness of the system is in the way natural forces are used to create vacuum conditions and its incorporation in a single system design where evaporation and condensation take place at appropriate locations without any energy input other than low grade heat. The system consists of solar heating system, an evaporator, a condenser, and injection, withdrawal, and discharge pipes. The effect of various operating conditions, namely, withdrawal rate, depth of water body, temperature of the heat source, and condenser temperature were studied. Numerical simulations show that the proposed system may have distillation efficiencies as high as 90% or more. Vacuum equivalent to 3.7 kPa (abs) or less can be created depending on the ambient temperature at which condensation will take place.

The Study of Heat Consumption Systems of Buildings with Heat Pump

2016 ◽  
Vol 856 ◽  
pp. 297-302 ◽  
Author(s):  
Anna Tsynaeva ◽  
Katerina Tsynaeva
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Heating System ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Heat Consumption ◽  
Low Grade ◽  
Consumption System ◽  
Low Grade Heat

Systems of heat consumption of the building with heat pump that uses low-grade heat source are investigated. Effectiveness of heat consumption systems with heat pump is concluded effective for severe climatic conditions prevailing in Russia. Characteristics of heat consumption system with heat pump and the traditional heating system are compared. In this case the heat pump is used the warmth of the environment, that is why considered operating conditions for the autumn and spring. Low inertia of heat systems with heat pump compared to traditional ones during autumn and spring proved.

Experimental adsorption water desalination system utilizing activated clay for low grade heat source applications

2021 ◽  
Vol 43 ◽  
pp. 103219
Author(s):  
Ehab S. Ali ◽  
Ahmed A. Askalany ◽  
K. Harby ◽  
Mohamed Refaat Diab ◽  
Bahgat R.M. Hussein ◽  
...  
Keyword(s):  
Heat Source ◽  
Water Desalination ◽  
Low Grade ◽  
Experimental Adsorption ◽  
Low Grade Heat

Meanline Analysis and CFD Study of a Radial Inflow Turbine With Vaneless Distributor for Low Temperature Organic Rankine Cycle

2020 ◽  
Author(s):  
M. Deligant ◽  
S. Braccio ◽  
T. Capurso ◽  
F. Fornarelli ◽  
M. Torresi ◽  
...  
Keyword(s):  
Energy Demand ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Low Grade ◽  
Heat Sources ◽  
Turbine Wheel ◽  
Good Efficiency ◽  
Low Grade Heat

Abstract The Organic Rankine Cycle (ORC) allows the conversion of low-grade heat sources into electricity. Although this technology is not new, the increase in energy demand and the need to reduce CO2 emissions create new opportunities to harvest low grade heat sources such as waste heat. Radial turbines have a simple construction, they are robust and they are not very sensitive to geometry inaccuracies. Most of the radial inflow turbines used for ORC application feature a vaned nozzle ensuring the appropriate distribution angle at the rotor inlet. In this work, no nozzle is considered but only the vaneless gap (distributor). This configuration, without any vaned nozzle, is supposed to be more flexible under varying operating conditions with respect to fixed vanes and to maintain a good efficiency at off-design. This paper presents a performance analysis carried out by means of two approaches: a combination of meanline loss models enhanced with real gas fluid properties and 3D CFD computations, taking into account the entire turbomachine including the scroll housing, the vaneless gap, the turbine wheel and the axial discharge pipe. A detailed analysis of the flow field through the turbomachine is carried out, both under design and off design conditions, with a particular focus on the entropy field in order to evaluate the loss distribution between the scroll housing, the vaneless gap and the turbine wheel.

scholarly journals Porous evaporators with special wettability for low-grade heat-driven water desalination

2021 ◽  
Author(s):  
Zhigao Zhu ◽  
Ying Xu ◽  
Yifei Luo ◽  
Wei Wang ◽  
Xiaodong Chen
Keyword(s):  
Robust Stability ◽  
Water Desalination ◽  
Low Grade ◽  
Porous Interface ◽  
Low Grade Heat

Design of novel special wettable evaporators with robust stability for high-performances porous interface distillation.

scholarly journals ENVIRONMENTALLY SAFE USAGE OF HYDROPOWER POTENTIAL BY HYDROTHERMAL POWER SUPPLY SYSTEMS

2019 ◽  
pp. 67-75
Author(s):  
S. Goshovskyi ◽  
O. Zurian
Keyword(s):  
Heat Pump ◽  
Energy Systems ◽  
Hydrothermal Systems ◽  
Heat Energy ◽  
Operating Conditions ◽  
Small Rivers ◽  
Low Grade ◽  
Hydropower Potential ◽  
Environmentally Safe ◽  
Low Grade Heat

The article contains the results of scientific research and design work related to environmentally safe usage of hydropower potential of the small rivers of the Dnieper basin. The innovative design solutions for extraction of low-grade heat energy of water and systems for its transformation into energy convenient for consumption were offered. It was established that use of renewable low-grade energy of soil is widely used in environmentally safe and economically sound power systems. At the same time hydropower potential is not widely used in hydrothermal heat pump systems. It was proved that existing hydrothermal systems are not always adjusted to actual operating conditions and object location. The evidence was provided that the scientific approach to development of appropriate configuration of hydrothermal collector, to methodology of their optimal mounting and to efficiency determination depending on operating conditions is quite topical issue. The scientific novelty of the new process approach is use of special design of water collector that has modular configuration and consists of several functionally related water sondes. The efficiency of hydrothermal system was scientifically proved. The paper describes the results of experimental research of efficiency of hydrothermal heat pump system where the low-grade heat energy of water is used as a renewable primary heating energy source for functioning of the heat pump. The authors have developed experimental hydrothermal and geothermal heat pump systems to conduct the research. Both collector and ground section of the system have mounted sensors of temperature, pressure and coolant flow velocity. The software for archiving and visualization of obtained data was developed. The research procedure was developed. As part of study, observation data were received and performance efficiency of geothermal and hydrothermal systems was calculated. The comparative analysis of energy systems depending on used renewable energy source was carried out. The conclusion was made that use of hydrothermal heat pump systems is environmentally safe. The data obtained as part of study have great scientific and applied significance for engineering of heat pump energy systems using hydropower potential of the small rivers.

scholarly journals Recovery of Low-Grade Heat (Heat Waste) from a Cogeneration Unit for Woodchips Drying: Energy and Economic Analyses

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 501 ◽  
Author(s):  
Tilia Dahou ◽  
Patrick Dutournié ◽  
Lionel Limousy ◽  
Simona Bennici ◽  
Nicolas Perea
Keyword(s):  
Waste Heat ◽  
Point Of View ◽  
Operating Conditions ◽  
Low Grade ◽  
Drying Time ◽  
Financial Gain ◽  
Return Water ◽  
Economic Analyses ◽  
The Right ◽  
Low Grade Heat

The aim of this paper is to improve the operating share of a biomass cogeneration unit by using unavoidable heat waste heat recovered from a district network heating used for drying woody biomass’ return water (law-grade temperature heat). The optimal operating conditions of a drying unit added to the system were estimated from an energy and a financial point of view, applying four objective functions (drying time, energy consumption, energy balance, and financial performance of the cogeneration unit). An experimental design methodology used heat for the implementation of these functions and to obtain an operating chart. Numerical modelling was performed to develop a simulation tool able to illustrate the unsteady operations able to take into account the available waste heat. Surprisingly, the model shows that the right strategy to increase the financial gain is to produce more warm water than necessary and to consequently dispose higher quantities of unavoidable heat in the network’s return water, which heat up the drying air at a higher temperature. This result contrasts with the current approaches of setting-up cogeneration units that are based on the minimization of the heat production.

Performance Evaluation of a Turbine Used in a Regenerative Organic Rankine Cycle

2012 ◽  
Author(s):  
Maoqing Li ◽  
Jiangfeng Wang ◽  
Lin Gao ◽  
Xiaoqiang Niu ◽  
Yiping Dai
Keyword(s):  
Flow Rate ◽  
Rotational Speed ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Axial Flow ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Low Grade ◽  
Low Grade Heat

Due to environmental constraints, the Organic Rankine Cycle (ORC) is widely used to generate electricity from low grade heat sources. In ORC processes, the working fluid is an organic substance, which has a better thermodynamic performance than water for low grade heat recovery. The design of the turbine which is the key component in the ORC system strongly depends on the operating conditions and on the scale of the facility. This paper presents an experimental study on a prototype of an axial-flow turbine integrated into a regenerative ORC system with R123 as working fluid. The power output is 10kW scale, and the single-stage turbine is selected. The turbine is specially designed and manufactured, and a generator is connected to the turbine directly. In the experiment, the turbine is tested under different inlet pressure conditions (0.6–1.5MPa), different inlet temperature conditions (80–150°C) and different flow rate conditions. The experimental data such as the pressures, temperatures of the turbine inlet and outlet, flow rate, rotational speed, and electrical power generation are analyzed to find their inner relationships. During the test, the turbine rotational speed could reach more than 3010 r/min, while the design rotational speed is 3000 r/min. The isentropic efficiency of the turbine could reach 53%. The maximum electrical power generated by the turbine-generator is 6.57KW. From the test data the peak value of the temperature difference between the inlet and the outlet of the turbine is 53 °C, and the expansion ratio reaches about 11. The computational fluid dynamics (CFD) solvers is also used to analyze the performance of the turbine. The distributions of the pressure, Mach number, and static entropy in the turbine flow passage component are examined and the reasons are also obtained. This study reveals the relationships between the performance of the axial-flow turbine and its inlet and outlet vapor conditions. The experiment results and the CFD results lay a foundation for using this type turbine in the ORC systems which product electrical power from a few KW to MW.

Inherently safe pool-type reactor as a generator of low-grade heat for district heating, air conditioning and salt water desalination

1997 ◽  
Vol 173 (1-3) ◽  
pp. 167-174 ◽  
Author(s):  
E.O. Adamov ◽  
Yu.M. Cherkashov ◽  
A.A. Romenkov ◽  
V.I. Mikhan ◽  
V.I. Semenikhin
Keyword(s):  
Air Conditioning ◽  
Salt Water ◽  
District Heating ◽  
Water Desalination ◽  
Low Grade ◽  
Type Reactor ◽  
Low Grade Heat ◽  
Pool Type

scholarly journals Using a Partially Evaporating Cycle to Improve the Volume Ratio Problem of the Trilateral Flash Cycle for Low-Grade Heat Recovery

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 515
Author(s):  
Kai-Yuan Lai ◽  
Yu-Tang Lee ◽  
Ta-Hua Lai ◽  
Yao-Hsien Liu
Keyword(s):  
Thermal Efficiency ◽  
Saturation Temperature ◽  
Volume Ratio ◽  
High Volume ◽  
Operating Conditions ◽  
Low Grade ◽  
Pinch Point ◽  
Operational Conditions ◽  
Cycle System ◽  
Low Grade Heat

This study examined the trilateral flash cycle characteristics (TFC) and partially evaporating cycle (PEC) using a low-grade heat source at 80 °C. The evaporation temperature and mass flow rate of the working fluids and the expander inlet’s quality were optimized through pinch point observation. This can help advance methods in determining the best design points and their operating conditions. The results indicated the partially evaporating cycle could solve the high-volume ratio problem without sacrificing the net power and thermal efficiency performance. When the system operation’s saturation temperature decreased by 10 °C, the net power, thermal efficiency, and volume ratio of the trilateral flash cycle system decreased by approximately 20%. Conversely, with the same operational conditions, the net power and thermal efficiency of the partially evaporating cycle system decreased by only approximately 3%; however, the volume ratio decreased by more than 50%. When the system operating temperature was under 63 °C, each fluid’s volume ratio could decrease to approximately 5. The problem of high excessive expansion would be solved from the features of the partially evaporating cycle, and it will keep the ideal power generation efficiency and improve expander manufacturing.

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