Outdoor Test Cell Research Articles

The use of outdoor test cells for thermal and solar building research within the PASSYS project

The CEC research project PASSYS (PASsive Solar Components and SYStems Testing, 1986–1992) is using high-grade outdoor test cells for testing the thermal and solar performances of building components as well as for model validation purposes. The test facilities are highly standardized: identical test cells, equipped with the same sensors, heating and cooling system and data acquisition hardware and software, are installed at 12 test sites throughout Europe, applying the same test method. A severe quality assurance policy is being developed in order to ensure reliable and comparable results. This paper describes the objectives, organization and main themes of the project. Two further papers report results.

Estimating thermal parameters of outdoor test cells

A method for recursive identification of thermal parameters of outdoor test cells using monitoring data is presented. The method is based on a statistical autoregressive model (ARMAX-model). The heat loss coefficient and the effective solar aperture are obtained as rational polynomials of the parameters in the model. Dynamic thermal properties are obtained as the harmonic response to sinusoidal outdoor temperatures, solar irradiation and auxiliary energy inputs. An application of the method to data from a replicated experiment gave reproducible results. Another application of the method to data from a factorial experiment gave expected results.

Evaluation of Leachate Generation at the Montour, Pennsylvania, Fly Ash Test Cell

ABSTRACTThe Pennsylvania Power & Light Company, in cooperation with the Electric Power Research Institute, is studying leachate generation at a large outdoor test cell of compacted coal combustion fly ash constructed at the Montour Steam Electric Station in north-central Pennsylvania. The test cell design is identical to that of the plant's active dry fly ash disposal facility. Leachate initially generated at the test cell contained concentrations of chromium and selenium approximately ten times above EPA's assigned Maximum Contaminant Levels (MCL's) for drinking water. Concentrations of these two parameters have since decreased approximately five-fold. Similar reductions have occurred in the concentrations of several of the other trace metals measured in the leachate. The dominant reaction mechanisms controlling leachate composition were examined in an attempt to explain these and other observations. Deterministic chemical modeling was performed to aid in the interpretation of the data. The dynamics of leachate generation were also examined through an evaluation of the infiltration and redistribution of moisture.

Leachate Composition at an Experimental Test Cell of Coal Combustion Fly Ash

ABSTRACTIn an effort to characterize the waste streams at a typical utility fly ash landfill, a large outdoor test cell of compacted fly ash was constructed in 1984 at the Pennsylvania Power & Light Company's Montour Steam Electric Station. The test cell is a scaled-down version of the active dry fly ash disposal facility at the plant and includes a liner, a leachate collection system, and surface water runoff perimeter drains. It is 100 feet by 100 feet at the base and 10 feet high with 2:1 vertical:horizontal side slopes, giving a top area of 60 feet by 60 feet. The test cell is instrumented to measure precipitation, infiltration, surface runoff, unsaturated flow, evapotranspiration and leachate drainage. This paper presents a preliminary evaluation of the chemical composition of leachate generated from the test cell during the first year of leachate production. Leachate samples are periodically collected from a concrete sump to which the leachate collection system drains. Leachate first appeared in the sump in October 1985, approximately one year after the test cell was constructed. Samples are analyzed for pH, specific conductance, 22 metals, and 10 ions. The concentrations of parameters present in the test cell leachate are compared to drinking water standards and to standard laboratory extraction results. Parameters not detected in the leachate are also identified. The preliminary findings of the leachate monitoring effort are providing valuable information on the initial quality of leachate generated under field conditions. This data will be useful in the design of leachate control systems, wastewater treatment facilities and ground water monitoring programs for future ash disposal operations.

The Effect of Waste Water Reuse in Cold Regions on Land Treatment Systems

AbstractThe effect on ground water quality and soils and vegetation of treatment and disposal of municipal/industrial waste water on land in cold regions was investigated using six outdoor test cells. Winter application of waste water was feasible even at very cold air temperatures (<0.0°C) at the New Hampshire test site. High NO3‐N concentrations were observed in all treatments (5–15 cm/week) in both soils in early summer. This was explained as leaching of NH4‐N stored over the winter months after its oxidation to NO3 in early spring. Over the 12‐mo period of study, removal of organic C, BOD, suspended solids, fecal coliform bacteria, and phosphorus by the two soil types used (a Windsor sandy loam and a Charlton silt loam) was essentially complete. These had very little or no effect on ground water quality. The principal mechanism for nitrogen removal was found to be plant uptake, which was seasonally dependent. Application of 15− cm of secondary effluent per week to a sandy loam soil was not feasible because of the presence of > 10 mg/liter NO3‐N in the leachate for > 9 mo/year. Application of salts for road deicing during winter resulted in relatively higher concentrations of salts and Cl in the ground for a short period of time. No efforts were made to apply waste water according to plant need. Preapplication treatment is not necessary for the renovation of waste water by the soil‐plant systems. Movement of applied heavy metals to a depth of 15–30 cm in the high treatment soil was thought to be a result of a drop in soil pH resulting from this treatment. In all other treatments, heavy metals were confined to the top 15 cm of the soil.