Thermodynamic design data for absorption heat pump systems operating on ammonia—water—Part II. Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia—water absorption systems for heating. The interaction of operating temperatures has been illustrated graphically.     

The effect of oil on the performance of heat pumps and refrigerators—II. Experimental results

The results of a prolonged investigation of the influence of the lubricating oil Shell Clavus 68 on the performance of an R12-based refrigeration-heat pump system are presented. The strategy is discussed for deciding if a given series of data collected at 10s intervals adequately represents the chosen experimental conditions and results are presented under both transient and steady state conditions. The effects of oil on evaporator capacity, coefficient of performance, heat transfer rates, evaporator outlet superheat stability, refrigerant mass flow rate, evaporator pressure drop and compressor discharge temperature are discussed, and the experimental results are compared with a theoretical analysis. Finally, it is shown that under certain (albeit unlikely) conditions, it is possible for both the evaporator and condensor to act as heat rejectors.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium chloride—Part II. Heating

Derived thermodynamic design data including Carnot coefficients of performance, enthalpy based coefficients of performance and flow ratios for possible combinations of operating temperatures for absorption heat pump systems operating on water-lithium chloride for heating are presented. The variations of the derived data with operating temperatures are illustrated graphically. The data obtained for the water-LiCl pair are compared with published data for the water-LiBr pair for identical conditions of temperatures.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-water—Part I. Cooling

The free choice of operating temperature in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia—water absorption systems for cooling. The interaction of operating temperatures have been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-sodium thiocyanate—II. Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia-sodium thiocyanate absorption systems for heating. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-lithium nitrate—Part two. Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy-based coefficients of performance have been presented for ammonia-lithium nitrate absorption systems for heating. The interactions of operating temperatures have been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium chloride—Part one. Cooling

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. For a given combination of temperatures, the concentrations in the absorber and the generator are fixed automatically. This determines the flow ratio. Therefore for any particular working pair, the coefficient of performance is related to the flow ratio.Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalphy based coefficients of performance have been presented for a water-lithium chloride absorption system for cooling. The interaction of operating temperatures has been illustrated graphically. The data obtained are also compared with published data for the water-lithium bromide absorption system under identical conditions.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium iodide—part II. Heating

Derived thermodynamic design data, including Carnot coefficients of performance and enthalpy-based coefficients of performance (for heating) with and without an economizer heat exchanger for possible combinations of operating temperatures are calculated for a system in which water is used as a working fluid and aqueous lithium iodide solution as absorbent. The effects of operating temperatures as well as economizer heat exchanger on the performance of an absorption heat pump are illustrated graphically.     

The effect of oil on the performance of heat pumps and refrigerators—part one. Experimental test facility

Details are given of a computer-controlled experimental test-bed which allows detailed investigations to be made of the influence of lubricating oil on the performance of refrigeration plant. The general nature of the observed effects are discussed and some preliminary results are presented. These demonstrate both how the test-rig can be used to record transient phenomena, and how the data can subsequently be analyzed to produce charts of system performance under closely specified experimental conditions. A high degree of reproducibility is reported, with consistent data being collected over periods of several months.     

Thermodynamic design data for absorption heat transformers—part III. Operating on water-lithium iodide

Derived thermodynamic design data, including Carnot coefficients of performance, enthalpy-based coefficients of performance with and without an economizer heat exchanger and flow ratios for possible combinations of operating temperatures, are calculated for absorption heat transformers operating on a system in which water is used as the working fluid and aqueous lithium iodide solution as absorbent. The effects of operating temperatures as well as economizer heat exchanger on the performance of the absorption heat transformer are illustrated graphically.     

Thermodynamic design data for absorption heat transformers—part four. operating on ammonia-lithium nitrate

The Gibbs phase rule and the thermodynamic properties of the working pair limit the choice of operating temperatures. For any combination of temperatures, the concentrations in the absorber and the generator and hence the flow ratios are fixed. For any particular working pair, the coefficient of performance is related to the flow ratio.Tables of possble combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have beenpresented f for absorption heat transformers operating on ammonia-lithium nitrate. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-sodium thiocyanate—III. Simultaneous cooling and heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamics propertie of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia-sodium thiocyanate absorption systems for simultaneous cooling and heating. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic study of advanced absorption heat transformers—II. Double absorption configurations

A thermodynamic analysis has been carried out to study the performance of double absorption heat transformers (DAHT) assuming water/lithium bromide as the working fluid. The performance of single (SSHT) and two stage heat transformers (TSHT) analyzed in Part I, was compared with the performance of double absorption heat transformers (DAHT) under the same operating conditions. The results showed that single stage heat transformers (SSHT) were the simplest and most efficient. Greater absorber temperatures were reached with two stage heat transformers (TSHT). However, these systems were in general less efficient than the others and technically the most complex. Double absorption heat transformers (DAHT) were technically simpler than two stage heat transformers (TSHT) and may reach absorber temperature as high as these systems.     

Numerical procedures and their practical application in PV modules’ analyses. Part II: Useful fractions and APE

The article regards aspects of PV modules tested with the use of natural sunlight. The analysis of spectral structure of solar energy resources in southern Poland, carried out on the basis of meteorological data originating from SolarLab PW Wrocław and AGH Kraków, Poland [1] was used in the article. It is a continuation of the article: Analysis of solar energy resources in southern Poland for photovoltaic applications [1], describing the method to determine spectral parameters of average photon energy (APE) and useful fraction (UF) with the use of a solar radiation spectrum simulator. This article, however, includes an experimental presentation of their impact on PV conversion of modules with different absorbers. Theory and practice of the measurements were described with the use of spectral parameters such as: UF, APE. Their influence on the efficiency of modules’ photovoltaic conversion with various spectral characteristics of absorbers was presented. The most recent methods described, which characterise the structure of solar energy resources such as annual distributions of APE and UF, have not been commonly used yet in Poland and other countries, even though they most precisely define adjustment of the spectral factor to the selected PV module.Practical application of UF, in detection of absorber type used in the tested PV module/cell is demonstrated in the final part of the article.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-sodium thiocyanate—I. Cooling

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia-sodium thiocyanate absorption systems for cooling. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-lithium nitrate—part three. Simultaneous cooling and heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy-based coefficients of performance have been presented for ammonia-lithium nitrate absorption systems for simultaneous cooling and heating. The interactions of operating temperatures have been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium iodide—part I. Cooling

The operating temperatures in the absorption heat pump system fix the absorber and the generator concentration for a given working pair. Derived thermodynamic design data, including Carnot coefficients of performance and enthalpy-based coefficients of performance, with and without an economizer heat exchanger for possible combinations of operating temperatures, are presented for water-lithium iodide absorption systems for cooling. The effects of operating temperatures as well as economizer heat exchanger on the performance of an absorption cooler are illustrated graphically.     

On the performance of advanced absorption heat transformers—II. The double absorption configuration

An innovative heat transformer can be derived from the TSHT discussed in Part I. Its configuration is essentially based on a serial arrangement of the two absorbers (“double absorption heat transformer”, DAHT) and allows a drastic reduction of the number of items necessary for the TSHT.The performance of a DAHT operated with the water-sulphuric acid system was computed by means of a lumped-parameter mathematical model and expressed in terms of the four indexes of performance previously used for the TSHT examined in Part I. The results show that the DAHT reaches its optimum performance at values of gross temperature lift intermediate between those optimal for the SSHT and the TSHT, respectively.     

Use of Defined Solid Angle Absolute β Counting for Environmental Radioanalytical Purposes Part II. Applications

Abstract

Three practical applications of the defined solid angle absolute β counting (DSAABC) method using end-window Geiger-Müller counter are presented. ⁹⁰Sr and ¹⁴⁷Pm nuclides were determined in filtered aerosol samples collected in Debrecen, Hungary, immediately after the Chernobyl accident. Development of an active method is in progress in order to determine radon and thoron daughters attached to airborne aerosols. Indoor concentrations were measured by this method in Ajka, Hungary, where radioactive industrial wastes were used as building materials. Determination of ⁹⁰Sr and ¹⁴⁷Pm in hot particles of Chernobyl origin, collected in Kiev, Ukraine, is in progress. The relation to the application of the DSAABC method is treated in detail and some results are presented.