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Dynamic model of a heat pump with plate heat exchangers and ecological refrigerant
Strmiska, Pavel ; Řehák Kopečková, Barbora (referee) ; Pokorný, Jan (advisor)
For the optimization of a heat pump, there is a need to possess its dynamic model. One of the freely available tools for creating such a model is the language Modelica and its open-source compiler OpenModelica. The thesis aims to research options for creating dynamic models of refrigeration circuits with the ecological refrigerant R290 and its components in Modelica, to create the circuit and subsequently validate it using previously measured data. Models of basic components of heat pumps - compressor, condenser, evaporator and expansion valve are created in a way described in the thesis. A simplified model of a refrigerant loop is also created
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Validity of commercially available smartwatches when estimating energy expenditure
Kopecký, David ; Pokorný, Jan (referee) ; Řehák Kopečková, Barbora (advisor)
Metabolic rate is an energy quantity. Its value is a key input not only in thermophysiological models, but also in the calculation of heat stress indices or complex models predicting a person's thermal sensation. With the dynamic development of technology, sporttesters are able to estimate energy expenditure, among other things. It is a non-invasive method of estimating energy expenditure, or metabolic rate, using associated body functions to predict it. This work deals with the validity of the accuracy of metabolic rate estimation using the Garmin Fenix 6X Pro sporttester in comparison with indirect calorimetry. The accuracy of the metabolic rate estimation was tested for the activities of lying down, administrative work and cycling with regulated mechanical resistance of 100 and 150 W. 15 male subjects aged 28 ± 5 years, with a weight of 83.2 ± 13.5 kg and a height of 180 ± 7 cm participated in the study. In terms of the results, it is possible to observe a lower accuracy of prediction of metabolic rate for low-intensity activities, with the resulting MAPE being around 19-43 %. On the other hand, for activities with moderate activity, the prediction of the metabolic rate by the used sporttester proved to be sufficiently accurate, with a resulting MAPE in the range of 6–8 %.
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Dynamic model of a heat pump with plate heat exchangers and ecological refrigerant
Strmiska, Pavel ; Řehák Kopečková, Barbora (referee) ; Pokorný, Jan (advisor)
For the optimization of a heat pump, there is a need to possess its dynamic model. One of the freely available tools for creating such a model is the language Modelica and its open-source compiler OpenModelica. The thesis aims to research options for creating dynamic models of refrigeration circuits with the ecological refrigerant R290 and its components in Modelica, to create the circuit and subsequently validate it using previously measured data. Models of basic components of heat pumps - compressor, condenser, evaporator and expansion valve are created in a way described in the thesis. A simplified model of a refrigerant loop is also created
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Validity of commercially available smartwatches when estimating energy expenditure
Kopecký, David ; Pokorný, Jan (referee) ; Řehák Kopečková, Barbora (advisor)
Metabolic rate is an energy quantity. Its value is a key input not only in thermophysiological models, but also in the calculation of heat stress indices or complex models predicting a person's thermal sensation. With the dynamic development of technology, sporttesters are able to estimate energy expenditure, among other things. It is a non-invasive method of estimating energy expenditure, or metabolic rate, using associated body functions to predict it. This work deals with the validity of the accuracy of metabolic rate estimation using the Garmin Fenix 6X Pro sporttester in comparison with indirect calorimetry. The accuracy of the metabolic rate estimation was tested for the activities of lying down, administrative work and cycling with regulated mechanical resistance of 100 and 150 W. 15 male subjects aged 28 ± 5 years, with a weight of 83.2 ± 13.5 kg and a height of 180 ± 7 cm participated in the study. In terms of the results, it is possible to observe a lower accuracy of prediction of metabolic rate for low-intensity activities, with the resulting MAPE being around 19-43 %. On the other hand, for activities with moderate activity, the prediction of the metabolic rate by the used sporttester proved to be sufficiently accurate, with a resulting MAPE in the range of 6–8 %.
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