scholarly journals LONG TERM PERFORMANCE PREDICTION FOR DHW SOLAR SYSTEMS BASED ON INPUT-OUTPUT TEST METHOD

1990 ◽  
pp. 487-491
Author(s):  
B. Bourges ◽  
A. Rabl ◽  
B. Leide ◽  
M.J. Carvalho ◽  
M. Collares-Pereira
Keyword(s):  
Performance Prediction ◽  
Test Method ◽  
Input Output ◽  
Solar Systems ◽  
Long Term Performance ◽  
Term Performance

The Input-Output Model for Solar Water Heaters: Model Errors and Long-Term Performance Estimate

1990 ◽  
Vol 112 (3) ◽  
pp. 161-168
Author(s):  
L. Kadi ◽  
B. Bourges ◽  
J. Adnot
Keyword(s):  
Test Method ◽  
Model Errors ◽  
Input Output ◽  
Solar Water ◽  
Water Heaters ◽  
Performance Estimate ◽  
Solar Water Heaters ◽  
Long Term Performance ◽  
Term Performance

Based on the experimentally observed linear relationship between the daily collected energy and the daily insolation, the development of a test method for the performance rating of solar water heaters is studied using both an analytical modeling of the daily performance and detailed simulation. This analysis has shown the existence of a general linear correlation between daily performance and external conditions (daily irradiation, ambient temperature, main’s water temperature, and storage initial temperature). Two approaches appeared possible for the long-term performance estimate and, for its simplicity, the statistical one was chosen for the definition of the European test method for solar water heaters, also known as the input-output test method.

A Method for Measuring the Creep Behavior of Pressurized Polymer Tubing

2001 ◽  
Author(s):  
Chunhui Wu ◽  
Susan C. Mantell ◽  
Jane H. Davidson
Keyword(s):  
Heat Exchanger ◽  
Strain Gage ◽  
Hot Water ◽  
Test Method ◽  
Hoop Strain ◽  
Dog Bone ◽  
Thin Walled ◽  
Long Term Performance ◽  
Term Performance

Abstract Polymer components have been proposed for use in domestic solar hot water heating systems. A polymer heat exchanger is under development for such systems. For heat transfer considerations, the heat exchanger will be comprised of many thin walled tubes. The heat exchanger must survive 10 years of service at high pressure (1.55 MPa) and high temperature (82°C). A novel method has been developed for evaluating the long term performance (creep) of the polymer tubing. Traditional creep testing, performed with dog bone test specimens can not be applied because the thin walled tubing has anisotropic material properties. Consequently, performance must be evaluated directly on the extruded tubing. The method entails wrapping a Constantan wire around the tube specimen to continuously record the hoop strain. For pressure loading of tubing, this method offers significant improvements over strain gage instrumentation. In this paper, the test method is described, an analysis of the strain transfer between the tubing and wire wrap is presented, and strain data for polypropylene tubing measured with a strain gage and wire wrap are compared. The data show that the wire measurement method can be successfully used for the characterization of long term mechanical behavior of polymer tubes.

The Use of Laboratory-Measured and Strain-Gauge Backcalculated Asphalt Stiffness for Rutting Performance Prediction

2019 ◽  
Vol 2673 (3) ◽  
pp. 323-333
Author(s):  
Erdem Coleri ◽  
John T. Harvey
Keyword(s):  
Performance Prediction ◽  
Strain Gauge ◽  
Asphalt Concrete ◽  
Laboratory Tests ◽  
Concrete Materials ◽  
Long Term Performance ◽  
Term Performance ◽  
The Impact

Laboratory tests are conducted with asphalt concrete materials to determine the expected in-situ performance. In addition, laboratory test results are commonly used in mechanistic-empirical design methods for material characterization to improve the predictive accuracy of the models. However, the effectiveness of laboratory tests in characterizing the long-term performance of asphalt concrete materials needs to be validated to be able to use the results for pavement design and long-term performance prediction. Inaccurate performance characterization and prediction can directly affect the decision-making process for pavement maintenance, rehabilitation, and reconstruction and result in unexpected early failures in the field. The major objective of this study is to determine the impact of using laboratory-measured asphalt stiffness on the prediction accuracy of mechanistic-empirical models. In addition, the effect of using linear-elastic modeling assumptions (layered elastic theory) and neglecting the nonlinearity of pavement response at high load levels (and/or at high strain levels for weaker structures) on the predicted rutting performance was determined. In this study, the effectiveness of the use of laboratory asphalt stiffness tests for in-situ asphalt stiffness characterization was determined by comparing the rutting performance predicted using laboratory-measured stiffness to rutting predicted using strain-gauge backcalculated stiffness. It was determined that laboratory tests are able to characterize the in-situ stiffness characteristics of the asphalt mix used in this study and the stiffness characterization process suggested in this study can provide reliable rutting performance predictions. Results of this study are only applicable to tested rubberized asphalt concrete mixtures.

scholarly journals NNWSI Waste Form Performance Test Development

1984 ◽  
Vol 44 ◽  
Author(s):  
John K. Bates ◽  
Thomas J. Gerding
Keyword(s):  
Performance Test ◽  
Test Development ◽  
Test Method ◽  
Waste Form ◽  
Analog Test ◽  
Waste Package ◽  
Long Term Performance ◽  
Term Performance

AbstractA test method has been developed to measure the release of radionuclides from the waste package under simulated NNWSI repository conditions, and to provide information concerning materials interactions that may occur in the repository. Data from 13 weeks of unsaturated testing are discussed and compared to that from a 13 week analog test. The data indicate that the waste form test is capable of producing consistent, reproducible results that will be useful in evaluating the role of the waste package in the long-term performance of the repository.

Sign in / Sign up

Export Citation Format

Share Document