Browsing by Subject "air cooling"

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Access status: Open Access ,
Chłodzenie powietrza małogabarytowymi wodnymi chłodnicami ścianowymi
(Wydawnictwa AGH, 2005) Filek, Krzysztof; Franczuk, Waldemar; Łuska, Piotr; Nowak, Bernard; Roszkowski, Janusz
The results of measurements of cooling water temperature and temperature and humidity of cooled air, which were taken in longwall no. 3 of seam no. 502 at part J in »Śląsk« Colliery during the operation of a unit consisting of 4 small-sized diaphragm water air coolers (these are the first units of this kind in Poland) are presented in this paper. Themeasurement results of heat power for each air-cooler, temperature and specific humidity of cooled air were compared to calculation results, which were obtained on the basis of the equations presented in the paper. The research was conducted for two variants of air-coolers’ connection to a water pipe – in series (variant A) and in series – parallel (variant B). The results of calculations and measurements are presented in the tables and the graphs. The conducted research allows to determine that total heat power of four air-coolers is within limits 120130 kW. The greater power of the system with a series-parallel coolers’ connection can be observed in the form of a slightly lower air temperature in the longwall, behind the outlet of the longwall air temperature was reduced by 2.2°C (variant A) and 2.8°C (variant B) in comparison with the situation without cooling.
Access status: Open Access ,
Moc cieplna wymienników górniczej sprężarkowej chłodziarki powietrza
(Wydawnictwa AGH, 2009) Nowak, Bernard; Filek, Krzysztof
This article applies to mine compression refrigerator of air. In this article, work of refrigerator with or without inner regenerative heat exchanger (subcooler) is considered. The equations are given, from which thermal powers of evaporator, condenser and subcooler of refrigerator are determined. Focused character of all elements of refrigerator is assumed (expect specified, compressor and expansion valve also). For refrigerator with subcooler, system compound with 12 algebraic equations is received, in which unknowns are: temperature and humidity of cooled air, temperature of water after the condenser and temperature of refrigerant in five characteristic points of its circulation and ariolity degree of refrigerant of evaporator's inlet. For refrigerator without subcooler, the system is composed of 9 equations with the same as before unknowns, with the exception of 3 equations refer to subcooler.
Access status: Open Access ,
Wymiana ciepła między powietrzem a zimną wodą w rurociągu zabudowanym w ślepym wyrobisku
(Wydawnictwa AGH, 2005) Filek, Krzysztof; Mikołajczyk, Władysław
If we want to use a water diaphragm cooler of air in a dead-end heading, cold water must be brought into it through a pipeline. Heat capacity of such a cooler depends on the temperature of water supplied to it. Locating 7 a water pipeline in a heading, in which warm air flows, leads to an increase in the temperature of water in pipe and is higher at the inlet of a cooler than at the inlet of pipeline. This article presents equations of air enthalpy balance in the dead end heading (without water vapor condensation on the external surface of the pipe) and cold water flowing through an insulated pipeline to the cooler of air as well as equations describing heat flow through the side wall of a pipeline from air to water. A set of equations of air and water enthalpy was solved analytically, giving distributions of air and water temperatures along the heading and, later on, using the dependences describing heat transmission through the wall of a pipe. Both distributions of temperatures of internal and external sides of pipe in the heading and the distribution of elementary heat flow exchanged between air and water are given. A calculation example, whose solution – distributions of the values mentioned above along the heading are shown in the form of graphs, was presented. An increase in temperature of cold water in a pipeline was also presented.