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The effect of weather on the moisture content of milled peat; Saeaen vaikutus jyrsoeskosteuteen

Abstract

The model `DRYPEAT`, developed in this study, simulates the cahnges in the moisture content of a milled peat layer thus giving an estimate of the progress and length of a harvest run. The model, which is proposed for operational use in peat harvesting, was derived using the simulation results of a detailled physical model and weather data measured at the Hoeystoesensuo production site. The forcing variable used in this model is potential evaporation. The key variable of the model was the drying efficiency defined as the ratio of the change per unit time in the water content of the milled peat layer and the rate of potential evaporation. The drying efficiency depended non-linearly on the volume moisture content and linearly on the layer thickness of the milled peat. The physical model, the DRYPEAT model and the gravimetric measurements of the moisture content gave similar and realistic results on the progress of the harvest run. As the DRYPEAT model was calibrated agains the physical model, the results of the two models were quite similar. The future development of the DRYPEAT model lies on the improvements in the parametrization of the physical model. The emphasis in this study was to evaluate the  More>>
Authors:
Heikinheimo, M; Koskela, T [1] 
  1. Finnish Meteorological Inst., Helsinki (Finland)
Publication Date:
Dec 01, 1991
Product Type:
Technical Report
Report Number:
VTT-OPT-39
Reference Number:
SCA: 010300; PA: FI-92:003007; SN: 92000719983
Resource Relation:
Other Information: DN: OPTIMITURVE Research Programme; PBD: Dec 1991
Subject:
01 COAL, LIGNITE, AND PEAT; PEAT; MOISTURE; DRYING; SIMULATION; HARVESTING; WEATHER; EVAPORATION; MATHEMATICAL MODELS; 010300; PREPARATION
OSTI ID:
10141558
Research Organizations:
Technical Research Centre of Finland, Jyvaeskylae (Finland). Combustion and Thermal Engineering Lab.
Country of Origin:
Finland
Language:
Finnish
Other Identifying Numbers:
Other: ON: DE92506481; CNN: Project KTM-275/881/87; ISBN 952-9500-37-8; TRN: FI9203007
Availability:
OSTI; NTIS (US Sales Only)
Submitting Site:
FI
Size:
29 p.
Announcement Date:
Jul 05, 2005

Citation Formats

Heikinheimo, M, and Koskela, T. The effect of weather on the moisture content of milled peat; Saeaen vaikutus jyrsoeskosteuteen. Finland: N. p., 1991. Web.
Heikinheimo, M, & Koskela, T. The effect of weather on the moisture content of milled peat; Saeaen vaikutus jyrsoeskosteuteen. Finland.
Heikinheimo, M, and Koskela, T. 1991. "The effect of weather on the moisture content of milled peat; Saeaen vaikutus jyrsoeskosteuteen." Finland.
@misc{etde_10141558,
title = {The effect of weather on the moisture content of milled peat; Saeaen vaikutus jyrsoeskosteuteen}
author = {Heikinheimo, M, and Koskela, T}
abstractNote = {The model `DRYPEAT`, developed in this study, simulates the cahnges in the moisture content of a milled peat layer thus giving an estimate of the progress and length of a harvest run. The model, which is proposed for operational use in peat harvesting, was derived using the simulation results of a detailled physical model and weather data measured at the Hoeystoesensuo production site. The forcing variable used in this model is potential evaporation. The key variable of the model was the drying efficiency defined as the ratio of the change per unit time in the water content of the milled peat layer and the rate of potential evaporation. The drying efficiency depended non-linearly on the volume moisture content and linearly on the layer thickness of the milled peat. The physical model, the DRYPEAT model and the gravimetric measurements of the moisture content gave similar and realistic results on the progress of the harvest run. As the DRYPEAT model was calibrated agains the physical model, the results of the two models were quite similar. The future development of the DRYPEAT model lies on the improvements in the parametrization of the physical model. The emphasis in this study was to evaluate the effects of layer thickness of the milled layer on the drying time. Increasing layer thickness from 20 to 30 mm increased the drying time (from 70 % moisture content to 40 %) from 22 hours to 32 hours or 1.5 fold under the constant rate of 0.4 mm/h potential evaporation. Increasing the layer thickness from 20 mm to 40 mm the drying time doubled.}
place = {Finland}
year = {1991}
month = {Dec}
}