Heat Calculations of Water Cooling Tower

Annotation: The article discusses the thermal calculation of the cooling tower. In the calculation, the specific air flow rate, the number of sections and the structural size of the tower are determined, according to the calculated value, energy-efficient methods are determined. Keywords: cooling tower, fan, specific air enthalpy, diagram I-d, relative humidity, aerodynamic resistance, thermometer. Аннотация: В статья рассмотрено тепловая расчёт градирня. В расчёта определено удельная расход воздуха, число секция и конструктивный размер градирня, по вычисленных величина определяется энергоэффективный методы. Ключевые слова: градирня, вентилятор, удельная энтальпия воздуха, диаграмма I-d, относительная влажность, аэродинамическое сопротивление, термометр.

Method and tools for determining heat transfer coefficients in organic liquids and solutions

The paper presents a method, tools and a newly developed algorithm for experimentally determining heat transfer coefficients in organic liquids and solutions. This work is made relevant by the problem of development of a new generation of aerospace technology. In this connection, improvements have been made to the pulse method of determining heat transfer coefficients that is based on the use of a micron-thick film sensor. The measurement setup was modified. A math model was constructed for the measuring sensor. Algorithms were developed for conducting the experiment and processing measurement results to determine heat transfer coefficients. Experimental uncertainties were analyzed. The paper provides results of experimental studies on certain organic liquids. The authors believe that the material presented in the paper will find application in research conducted at research institutions, engineering offices and universities, among researches, postgraduates and students. Key words: thermal and physical characteristics, organic liquids and their solutions, film-type electrical resistor, thin-film temperature sensor, voltage pulse, resistance thermometer, irregular heat transfer regime.

Challenges for In-Flight Calibration of Thermal Infrared Instruments for Earth Observation

Satellite instruments operating in the thermal infrared wavelength range >3 µm provide information for applications such as land surface temperature (LST), sea surface temperatures (SST), land surface emissivity, land classification, soil composition, volcanology, fire radiative power, cloud masking, aerosols, and trace gases. All these instruments are dependent on blackbody (BB) calibration sources to provide the traceability of the radiometric calibration to SI (Système International d’Unités). A key issue for flight BB sources is to maintain the traceability of the radiometric calibration from ground to orbit. For example, the temperature of the BB is measured by a number of precision thermometers that are calibrated against a reference Standard Platinum Resistance Thermometer (SPRT) to provide the traceability to the International Temperature Scale of 1990 (ITS-90). However, once calibrated the thermometer system is subject to drifts caused by on-ground testing, the launch and space environments. At best the uncertainties due to thermometer ageing can only be estimated as there is no direct method for recalibrating. Comparisons with other satellite sensors are useful for placing an upper limit on calibration drifts but do not themselves provide a traceable link to the SI. In this paper, we describe we describe some of the technology developments, including phase change cells for use as reference standards, thermometer readout electronics and implementation of novel coatings, that are in progress to enhance the traceability of flight calibration systems in the thermal infrared.