SHORT TERM TEST FOR SOLAR DOMESTIC HOT WATER SYSTEMS - EXPERIMENTAL RESULTS AND LONG TERM PERFORMANCE PREDICTION

1988 ◽  
pp. 732-736 ◽  
Author(s):  
R. Kübler ◽  
M. Ernst ◽  
N. Fisch
Keyword(s):  
Performance Prediction ◽  
Water Systems ◽  
Hot Water ◽  
Experimental Results ◽  
Short Term ◽  
Domestic Hot Water ◽  
Short Term Test ◽  
Long Term Performance ◽  
Term Performance

A Performance Prediction Methodology for Integral Collection-Storage Solar Domestic Hot Water Systems

1985 ◽  
Vol 107 (4) ◽  
pp. 265-272 ◽  
Author(s):  
A. Zollner ◽  
S. A. Klein ◽  
W. A. Beckman
Keyword(s):  
Performance Prediction ◽  
Prediction Method ◽  
Water Systems ◽  
Test Methods ◽  
Hot Water ◽  
Climatic Data ◽  
Domestic Hot Water ◽  
Long Term Performance ◽  
Term Performance ◽  
A Performance

A performance prediction methodology is developed which is applicable to most commercially available integral collection-storage passive solar domestic hot water systems. A computer model of a general ICS component was created to be compatible with the transient simulation program TRNSYS[3], and was used to develop and verify the simpler monthly performance prediction method. The method uses the system parameters from available test methods, monthly average climatic data, and load size to predict long term performance of ICS systems.

Polymers for Solar Domestic Hot Water: Long-Term Performance of PB and Nylon 6,6 Tubing in Hot Water

2004 ◽  
Vol 126 (1) ◽  
pp. 581-586 ◽  
Author(s):  
Chunhui Wu ◽  
Susan C. Mantell ◽  
Jane Davidson
Keyword(s):  
Creep Compliance ◽  
Hot Water ◽  
Master Curves ◽  
Burst Strength ◽  
Domestic Hot Water ◽  
Nylon 6,6 ◽  
Creep Modulus ◽  
Long Term Performance ◽  
Term Performance

Polymers offer a lightweight, low cost option for solar hot water system components. Key to the success of polymer heat exchanger components will be the long term mechanical performance of the polymer. This is particularly true for heat exchangers in which one of the fluids is pressurized hot water. For domestic hot water systems, polymer components must not fail after many years at a constant pressure (stress levels selected to correspond to 0.55 MPa in a tube) when immersed in 82°C potable water. In this paper, the long term performance of two potential heat exchanger materials, polybutylene and nylon 6,6, is presented. Two failure mechanisms are considered: failure caused by material rupture (as indicated by the hydrostatic burst strength) and failure caused by excessive deformation (as indicated by the creep modulus). Hydrostatic burst strength and creep modulus data are presented for each material. Master curves for the creep compliance as a function of time are derived from experimental data. These master curves provide a mechanism for predicting creep modulus as a function of time. A case study is presented in which tubing geometry is selected given the hydrostatic burst strength and creep compliance data. This approach can be used to evaluate properties of candidate polymers and to design polymer components for solar hot water applications.

scholarly journals Comparison of Short-Term Testing and Long-Term Monitoring of Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (4) ◽  
pp. 274-280
Author(s):  
S. B. Beale
Keyword(s):  
Water Systems ◽  
Hot Water ◽  
Testing Time ◽  
Short Term ◽  
Solar Simulator ◽  
Good Correspondence ◽  
Domestic Hot Water ◽  
Solar Fraction ◽  
Load Schedule

This paper reports on the results of a comparison between short-term indoor testing and long-term outdoor monitoring of solar domestic hot water systems. Five solar-preheat systems were monitored under side-by-side conditions of irradiance and load, for a period of two years. The systems were then tested according to a standard day test, using a solar simulator, and a load schedule identical to that imposed on each system during the monitoring. The systems were found to deliver 19.7 MJ–25.8 MJ daily in the test, compared to a two-year average of 19.1 MJ–26.0 MJ (1.5 to 2.0 GJ/m2 annually) outdoors. System rank was reasonably well preserved. Comparison of results on the basis of efficiency and solar fraction suggests that good correspondence exists between long-term outdoor results and those of indoor testing, at least for systems with stable controllers. Selected systems were also tested at different load schedules and radiation levels. Methods of predicting the performance of a solar-preheat system from the results of a standard day test are discussed, and the possibility of reducing testing time to a single day is explored.

The Long-Term Performance of Nuclear Waste Forms: Natural Materials - Three Case Studies

1992 ◽  
Vol 294 ◽  
Author(s):  
Rodney C. Ewing
Keyword(s):  
Case Studies ◽  
Nuclear Waste ◽  
Experimental Results ◽  
Waste Form ◽  
Short Term ◽  
Waste Forms ◽  
Long Term Performance ◽  
Term Performance ◽  
Nuclear Waste Forms

ABSTRACTNatural materials may be used to advantage in the evaluation of the long-term performance of nuclear waste forms. Three case studies are presented: (I) radiation effects in ceramic waste forms; (II) corrosion products of U02 under oxic conditions; (III) corrosion rate of nuclear waste glasses. For each case, a natural phase which is structurally and chemically analogous to the waste form is identified and used to evaluate the long-term behavior of a nuclear waste form. Short-term experimental results are compared to the observations made of analogous natural phases. The three case studies illustrate that results may range between providing fundamental data needed for the long-term evaluation of a waste form to only providing qualitative data of limited use. Although in the most rigorous view the long-term behaviour of a phase cannot be predicted, the correspondence between short-term experimental results and observations made of natural phases provides confidence in the “predicted” behavior of the waste form. The strength of this approach rests with the degree to which a mechanistic understanding of the phenomenon is attained.

Dynamic Solar Domestic Hot Water Testing

1990 ◽  
Vol 112 (2) ◽  
pp. 98-101 ◽  
Author(s):  
W. Spirkl
Keyword(s):  
Test Procedure ◽  
Dynamic Test ◽  
Hot Water ◽  
Domestic Hot Water ◽  
Water Testing ◽  
Naturally Occurring ◽  
Correlation Models ◽  
Long Term Performance ◽  
Term Performance

A dynamic test procedure for SDHW systems is presented, which generalizes correlation models to the nonstationary case. It is shown that testing can be performed with an accuracy comparable to stationary models. The dynamic procedure is more flexible in testing, since any load and radiation profiles are explicitly taken into account including the ones naturally occurring. The parameters are identified using filter and least squares technique. Long-term performance is predicted with the same model used for testing. The method is applied to experimental data of four different systems.

Long Term Performance of PE4710 Materials in Disinfectant Treated Nuclear Raw Water Systems

2013 ◽  
Author(s):  
Alexander M. Summe ◽  
Douglas P. Munson ◽  
Kenneth Oliphant ◽  
Sarah Chung
Keyword(s):  
Power Plants ◽  
Slow Crack Growth ◽  
Life Time ◽  
Water Systems ◽  
Superior Performance ◽  
Mechanical Degradation ◽  
Service Water ◽  
Long Term Performance ◽  
Term Performance

Degradation of service water systems is a major issue facing nuclear power plants and many plants will require repair or replacement of existing carbon steel piping components. High-density polyethylene (HDPE) has been used in non-safety service water systems for over ten years and has demonstrated superior performance. However, there still exist knowledge gaps around material properties, inspectability, and long-term performance. Specifically, there is a lack of insight on the aging of HDPE piping in disinfectant treated service water systems. This paper summarizes the methodology and results of predicting the expected life time of HDPE piping exposed to oxidizing biocides in numerous end-use scenarios. The aging mechanism of concern is Stage III Chemical-Mechanical degradation, where the polymer is oxidized by biocides and then experiences slow crack growth (SCG). An Aging Model is used to provide general predictions of pipe service life. The results were analyzed for trends and limiting or sensitive operating parameters were identified. For most applications, the specific resin used in the model demonstrated good performance for lifetimes of well over 40 years.

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