scholarly journals Development and improvement of self-pumping boiling collector solar hot water storage system, June 1987--May 1988, in Colorado State University Solar House 3

1988 ◽  
Author(s):  
J. H. Davidson ◽  
H. A. Walker ◽  
G. O.G. Loef
Keyword(s):  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
State University ◽  
Colorado State University ◽  
Solar House

An Analytic Model of Stratification for Liquid-Based Solar Systems

1986 ◽  
Vol 108 (2) ◽  
pp. 105-110 ◽  
Author(s):  
K. DenBraven
Keyword(s):  
Temperature Distribution ◽  
Storage Temperature ◽  
Direct Calculation ◽  
Hot Water ◽  
Forced Flow ◽  
State University ◽  
Colorado State University ◽  
Liquid Storage ◽  
System Data ◽  
Solar House

Accurate modelling of solar air or liquid heating, cooling, or domestic hot water systems with storage generally requires an accounting of the stratification within such storage. Overall system performance may be significantly affected by the storage temperature distribution. Most current stratification models utilize a finite difference scheme for solution to the general equations. An analytic method to determine the temperature distribution has been derived for liquid storage within a solar system. In liquid storage, it is assumed incoming fluid enters at the location with the temperature closest to its own. Hence, the solution requires the possibility of a region within storage where there is no forced flow. In addition, ther may be collector loop flow, load loop flow, or both concurrently. Each of these cases has different boundary conditions, and each must be solved separately. Comparisons of the resulting calculations with system data for the Colorado State University Solar House I show good agreement. This suggests that inclusion of an analytic stratification model within a system simulation may be useful by allowing direct calculation of temperatures in stratified storage.

Experimental performance evaluation of a novel heat exchanger for a solar hot water storage system

2009 ◽  
Vol 86 (9) ◽  
pp. 1492-1505 ◽  
Author(s):  
Jayanta Deb Mondol ◽  
Mervyn Smyth ◽  
Aggelos Zacharopoulos ◽  
Trevor Hyde
Keyword(s):  
Performance Evaluation ◽  
Heat Exchanger ◽  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
Experimental Performance

Flow Rate Optimization of a Linear Concentrating Photovoltaic System

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Tony Kerzmann ◽  
Laura Schaefer
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Storage System ◽  
Water Storage ◽  
Heat Energy ◽  
Hot Water ◽  
Recovery Model ◽  
Waste Heat Recovery System ◽  
Recovery System

The world is facing an imminent energy supply crisis. In order to sustain and increase our energy supply in an environmentally conscious manner, it is necessary to advance renewable technologies. An area of recent interest is in concentrating solar energy systems that use very high efficiency solar cells. Much of the recent research in this field is oriented toward three dimensional high concentration systems, but this research focused on a two dimensional linear concentrating photovoltaic (LCPV) system combined with an active cooling and waste heat recovery system. The LCPV system serves two major purposes: it produces electricity and the waste heat that is collected can be used for heating purposes. There are three parts to the LCPV simulation. The first part simulates the cell cooling and waste heat recovery system using a model consisting of heat transfer and fluid flow equations. The second part simulates the GaInP/GaAs/Ge multijunction solar cell output so as to calculate the temperature-dependent electricity generation. The third part of the simulation includes a waste heat recovery model which links the LCPV system to a hot water storage system. Coupling the multijunction cell model, waste heat recovery model and hot water storage system model gives an overall integrated system that is useful for system design, optimization, and acts as a stepping stone for future multijunction cell photovoltaic/thermal (PV/T) systems simulation. All of the LCPV system components were coded in Engineering Equation Solver V8.425 (EES) and were used to evaluate a 6.2 kWp LCPV system under actual weather and solar conditions for the Phoenix, AZ, region. This evaluation was focused on obtaining an optimum flowrate, so as to produce the most electrical and heat energy while reducing the amount of parasitic load from the fluid cooling system pump. Under the given conditions, it was found that an optimal cooling fluid flowrate of 4 gal/min (2.52×10-4m3/s) would produce and average of 45.9 kWh of electricity and 15.9 kWh of heat energy under Phoenix conditions from July 10–19, 2005. It was also found that the LCPV system produced an average of $4.59 worth of electrical energy and displaced $0.79 worth of heat energy, while also displacing a global warming potential equivalent of 0.035 tons of CO2 per day. This simulation uses system input parameters that are specific to the current design, but the simulation is capable of modeling the LCPV system under numerous other conditions.

Domestic Hot Water Storage Tank: Design and Analysis for Improving Thermal Stratification

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Nathan Devore ◽  
Henry Yip ◽  
Jinny Rhee
Keyword(s):  
Heat Exchanger ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Reverse Flow ◽  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
Inlet Temperature ◽  
Domestic Hot Water ◽  
Water Storage Tank

Experimental designs for a solar domestic hot water storage system were built in efforts to maximize thermal stratification within the tank. A stratified thermal store has been shown by prior literature to maximize temperature of the hot water drawn from the tank and simultaneously minimize collector inlet temperature required for effective heat transfer from the solar panels, thereby improving the annual performance of domestic solar hot water heating systems (DSHWH) by 30–60%. Our design incorporates partitions, thermal diodes, and a coiled heat exchanger enclosed in an annulus. The thermal diodes are passive devices that promote natural convection currents of hot water upward, while inhibiting reverse flow and mixing. Several variations of heat exchanger coils, diodes and partitions were simulated using ansys Computational Fluid Dynamics, and benchmarked using experimental data. The results revealed that the optimum design incorporated two partitions separated by a specific distance with four diodes for each partition. In addition, it was discovered that varying the length and diameter of the thermal diodes greatly affected the temperature distribution. The thermal diodes and partitions were used to maintain stratification for long periods of time by facilitating natural convective currents and taking advantage of the buoyancy effect. The results of the experiment and simulations proved that incorporating these elements into the design can greatly improve the thermal performance and temperature stratification of a domestic hot water storage tank.

Optimal Control of Mass Flow Rates in Flat Plate Solar Collectors

1981 ◽  
Vol 103 (2) ◽  
pp. 113-120 ◽  
Author(s):  
R. C. Winn ◽  
C. B. Winn
Keyword(s):  
Optimal Control ◽  
Flat Plate ◽  
Flow Rate ◽  
State University ◽  
Colorado State University ◽  
Collector Efficiency ◽  
The Difference ◽  
Flat Plate Collector ◽  
Solar House ◽  
Bang Bang Control

The optimal flat plate collector fluid flow rate is determined for several combinations of objective functions and system models. The method of implementing the control strategy for one of the problems considered, that which maximizes the integral of the difference between the collected solar power and fluid moving power, is described. The performance of the solar energy collection system in Solar House II at Colorado State University using this optimal controller is discussed and compared with the same system using bang-bang control. In addition, the dependence of the collector efficiency factor on flow rate is considered and its effect on the optimal control is determined.

The experimental new hybrid solar dryer and hot water storage system of thin layer coffee bean dehumidification

2018 ◽  
Vol 115 ◽  
pp. 954-968 ◽  
Author(s):  
S. Deeto ◽  
S. Thepa ◽  
V. Monyakul ◽  
R. Songprakorp
Keyword(s):  
Thin Layer ◽  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
Coffee Bean ◽  
Solar Dryer

Domestic Hot Water Storage Tank: Design and Analysis for Improving Thermal Stratification

2012 ◽  
Author(s):  
Nathan Devore ◽  
Henry Yip ◽  
Jinny Rhee
Keyword(s):  
Heat Exchanger ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Reverse Flow ◽  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
Solar Panels ◽  
Domestic Hot Water ◽  
Water Storage Tank

Experimental designs for a solar domestic hot water storage system were built in efforts to maximize thermal stratification within the tank. A stratified thermal store has been shown by prior literature to maximize temperature of the hot water drawn from the tank while simultaneously increasing the temperature delta required for effective heat transfer from the solar panels, thereby improving the annual performance of domestic solar hot water heating systems (DSHWH) by 30%–60%. Our design incorporates partitions, thermal diodes, and a coiled heat exchanger enclosed in an annulus. The thermal diodes are passive devices that promote natural convection currents of hot water upwards, while inhibiting reverse flow and mixing. Several variations of heat exchanger coils, diodes and partitions were simulated using ANSYS Computational Fluid Dynamics, and benchmarked using experimental data. The results revealed that the optimum design incorporated two partitions separated by a specific distance with four diodes for each partition. In addition, it was discovered that varying the length and diameter of the thermal diodes greatly affected the temperature distribution. The thermal diodes and partitions were used to maintain stratification for long periods of time by facilitating natural convective currents and taking advantage of the buoyancy effect. The results of the experiment and simulations proved that incorporating these elements into the design can greatly improve the thermal performance and temperature stratification of a domestic hot water storage tank.

Sign in / Sign up

Export Citation Format

Share Document