The paper deals with assessment of thermal fields and temperature changesin ground massif with horizontal heat exchanger used as a heat source for a heatpump. Temperatures in the zone of the horizontal ground exchanger are comparedwith temperatures in a reference land. Changes of heat potential of the soil duringthe heating period are also assessed. Possibilities of recovery of thermal potentialof the ground massif when utilizing vertical and horizontal exchangers are analyzedin the opening part of the paper. The results of the first verification indicatedthat average temperatures in the horizontal planes of the ground massif did not differconsiderably with distance from the exchanger tube. Differences in averagetemperatures in reference and experimental lands confirmed sufficient heat potentialof the ground massif even at the peak of the heating period. The differences inaverage temperatures reached up to 6.51 K in the end of the heating period whileat the beginning of the heating period, the differences in average temperaturesdropped to 1.35 K. The differences between maximum and minimum temperaturesin the zone of the ground exchanger reached up to 1.9 K at the peak of the heatingperiod and rose to 3.9 K at the beginning and end of the heating period. The firstresults of our measurements ...
The article is devoted to temperature changes in the ground massif with the horizontal heat exchanger as an energy source for a heat pump. The article was aimed at analyzing temperature changes in the ground massif with the horizontal heat exchanger at the beginning, in the course of and at the end of the heating sea-son. Another aim was to analyze temperature differences in the area of the horizon-tal exchanger and the reference lot. The heat flow utilized in the evaporator of heat pump was extracted from the ground exchanger (nominal output at the condenser was 10.5 kW). Temperatures of the ground massif with the horizontal heat ex-changer were measured in its plane in depths of 0.75 m, 0.5 m and 0.25 m. The temperature inside the ground massif on the reference lot and ambient parameters were measured as well. It is obvious that the difference of energetic potentials in-side the ground massif with the heat exchanger and on the reference lot is insig-nificant at the beginning of the heating season. During the heating season, the dif-ference of ground massif energetic potentials increases; at the end it is constant. The difference of temperatures in horizontal planes was not significant at ...
Artykuł dotyczy określenia energochłonności czterech podstawowych grup w chowie trzody chlewnej. W wyniku pomiarów eksploatacyjnych oraz analiz teoretycznych uzyskano jednostkowe zużycie energii w odniesieniu do poszczególnych czynności wykonywanych w ramach produkcyjnego cyklu technologicznego. Opracowano proste zależności matematyczne, określające zależność jednostkowego zużycia energii od normatywnych bądź zalecanych wartości eksploatacyjnych dla danej grupy trzody chlewnej. Dokonano również oceny wzajemnych zależności jednostkowego zużycia energii w poszczególnych grupach zabiegów roboczych. ...
The behaviour of carob (Ceratonia siliqua L.) powder relevant to its densification at low pressure was determined given different equipment aspect ratios (0.5, 1.0 and 1.5) and varying rates of deformation (5.5, 10 and 14.5 mm min-1). The effects of both parameters were examined through the analysis of variance and trends were fitted to observed mechanical responses using standard regression technique. Both aspect ratio and the time rate of deformation had highly significant effects on the material's response to load. Strain rate and specific power requirement were power functions of the equipment's aspect ratio, at all rates of deformation. These findings furnish insights on mechanical response in compressed food powders which are applicable in modelling related food handling and processing systems. ...
Bulk, porous oil-bearing materials acquire various degrees of densification under varying influences of equipment and process parameters with direct bearings on yield during compressive abstraction of oil from such materials. Effects of both aspect ratio and compression cycle on the course of densification were investigated. Mechanical response and oil expression indices were analysed for variances and treatment means were compared using Duncan's multiple range test. All influence factors had significant effects on mechanical response and oil yield. Significant improvements in achievable deformation and specific energy demand were obtained through repeated induction of compressive stress; compression cycle correlated positively with both deformation and energy demand. Margin for the expenditure of energy became wider as pressure ratio at the oil point became lower. This study reveals that performance of compression schemes may be significantly enhanced through careful application of the pressure ratio. ...
W publikacji przeprowadzono analizę oddziaływania parametrów termicznych na egzergię strumienia strat cieplnych, egzergetyczną i cieplną sprawność płytowego rekuperatora powietrze - powietrze przy stałych objętościowych strumieniach ogrzewanego i chłodzonego powietrza. Wyniki badań i ich analiza potwierdziły zależności między egzergią strumieni strat cieplnych a wartościami temperatur zasilania, wzrostem wykorzystania ciepła z ochładzanego powietrza i spadkiem przenikania ciepła z ochładzanego do ogrzewanego powietrza wraz ze wzrostem różnicy temperatur na zasilaniu. Potwierdzono również zależność między cieplną a całkowitą energetyczną sprawnością. ...
