СЪДЪРЖАНИЕ
- С. Стойкова. Платформа за локално обучение на големи езикови модели
- П. Петков. Приложение на диференциалната тополoгия в инженерните науки. Кратък обзор
- енергийни системи
М. Хаджийски, Н. Делийски, Н. Тумбаркова, Д. Ангелски, П. Вичев, К. Атанасова. Изчисляване и апроксимиране със софтуера Table Curve 2D на енергията, необходима за размразяване на трупи - П. Кесова, И. Бачкова. Обзор на интелигентни референтни рамки, архитектури и модели в системите за енергиен мениджмънт
- 90-годишен юбилей на акад. Васил Сгурев
Key Words: Logs; Table Curve 2D; frozen bound water; frozen free water; defrosting; energy consumption.
Abstract. A mathematical description of the thermal energy Qw-defr required for the complete defrosting of logs, i.e. for the complete melting of the ice in them, formed in the wood in winter by the natural freezing of both free and bound water in it, using the software package Table Curve 2D has been presented. This package allows for the selection of equations, which provide the best similarity between the calculated with them values of Qw-defr during thermal treatment of logs containing ice and the respective data obtained experimentally or using an adequate temperature-energy model of Qw-defr. An approach for computing the energy required for heating to defrost logs subjected to thermal treatment before their subsecuent mechanical processing was applied. The approach is based on the use of two personal models. With the help of the non-stationary model, the defrosting times of beech logs with a diameter of 0.4 m, initial temperatures of –1 °C, –10 ˚C, –20 °C, –30 °C, –40 °C, and moisture content u of 0.4 kg∙kg-1, 0.6 kg∙kg-1, and 0.8 kg∙kg-1 were determined at operating temperatures in the boiling or steaming equipment equal to 80 °C. For different combination of the specified three values of the moisture content and five values of the initial log temperature there are significant differences between the amount of both free and bound frozen water in the logs, which ensures sufficiently large differences between the calculated values of the energy required for defrosting of the logs.
