PhD Thesis - Energy Systems Research Unit - University of Strathclyde

functions of hot water circuit inlet temperatures;Stage 2 - An expression for the chiller’s refrigerating power output is derivedas a function of all of the water circuit inlet temperatures; andStage 3 - The thermal capacities of the chiller model constituents areidentified.The data required to calibrate the chiller (see Table 3.8) is derived from two sources:Some of the parameters such as the highest and lowest permissible high andlow pressure, the minimum chilled water protection temperature and theworking minimum hot water outlet temperature can be extracted directlyfrom manufacturer’s data sheets as these are typically listed to avoid anydamage being caused to the chiller. The high (p high ) and low (p low ) pressure curve coefficients (a 0 , a 1 , b 0 and b 1 ),the chiller’s refrigerating power output function (CH Power ) curve coefficients(d 0 , d 1 , d 2 and d 3 ), the thermal masses (M i , M j and M g ) and the mass weightedaverage specific heat values ( , and ) all require empirical data, obtainedfrom a three stage calibration process. Details on how these values can beobtained are given in Sections 3.3.5.1, 3.3.5.2 and 3.3.5.3.Table 3.8 lists the parameters that require calibration together with the respectivevalues obtained after calibrating the model with experimentally measured dataacquired for a 10 kW th absorption chiller developed by SK SonnenKlima GmbH [36,37]. The chiller is adequately sized to cater for a broad spectrum of residentialthermal loads.For the nodal parameters, alternative values obtained from a more pragmaticcalibration process are shown and compared to measured values later.116