PsychroAn_tuto - Computational psychrometric analysis of HVAC systems: tutorials

Contents

Interactive web pages (using Voilà)

1. T01_moist_air_prop.ipynb Moist air properties.
2. T02_loads_winter.ipynb Thermal loads: winter.
3. T03_mix.ipynb Adiabatic mixing and isentalpic condensation.
4. T04_va_hum.ipynb Heating and vapor humidification.
5. T05_ad_hum.ipynb Heating and adiabatic humidification.
6. T06_cool Cooling with dehumidification.

Annex

• Design procedure for mass flow rate of supply air

Elementary processes

The models presented in the tutorials are formed by a system of equations constructed with blocks of elementary processes (Table 1).

Table 1. Models of the elementary processes (Ghiaus 2022).

Bibliography

Ghiaus, C. (2014). Linear algebra solution to psychometric analysis of air-conditioning systems. Energy, 74, 555-566. DOI: 10.1016/j.energy.2014.07.021

Ghiaus, C. (2016). Analyse psychrométrique des systèmes de climatisation. Revue générale du Froid & du Conditionnement d’air, pp.38-42. hal-03379788

Ghiaus, C. (2021). PsychroAn_cool: Psychrometric analysis of cooling systems as a control problem. In Journal of Building Performance Simulation (0.0.0, Vol. 15, Number 1, pp. 21–38). Zenodo. DOI: 10.5281/zenodo.5236450

Ghiaus, C. (2022) Computational psychrometric analysis as a control problem: case of cooling and dehumidification systems, International Journal of Building Performance Simulation, 15(1), pp. 21-38, DOI: 10.1080/19401493.2021.1995498, (open access preprint hal-03484064)

Support

• LaTeX/Mathematics

• LaTex Equations

• Latex Table generator

• Anaconda cheetsheet

• Jupyter Notebook cheatsheet

• NumPy for MATLAB users

Questions

1. What is a mathematical model of a physical process?
2. What is the difference between correlation and causation?
3. Define the inputs and the outputs of a physical system.
4. Define the inputs and the outputs of a computational model.
5. Based on the definition of the inputs and outputs of a physical system and the inputs and outputs of a computational model, define the direct problem.
6. Describe the inverse problem of model identification.
7. Describe the inverse problem of control.
8. Explain the citation: "Divide each difficulty into as many parts as is feasable and necessary to solve it" by René Descartes, Discourse on Method, 1637.
9. Explain the citation: "Whenever I run into a problem I can't solve, I always make it bigger. I can never solve it by trying to make it smaller, but if I make it big enough, I can begin to see the outlines of a solution." by Dwight David Eisenhower in the context of numerical simulation of physical systems.
10. Explain the type of inputs of numerical models used for simulation: know knowns, unknown knowns, known unknowns, unknown unknowns (Donald Rumsfeld or Rumsfeld matrix).
11. Define a white box, a black box and a gray box model.
12. What are the aims of the indoor climat control?
13. The functions of an Air Handling Unit (AHU).
14. Why the air vector becomes widly used in buildings?
15. Definition of enthalpy. Sensible enthalpy and latent enthalpy
16. Definition of moist air.
17. Saturation pressure of water vapor.
18. Humidity ratio (or absolute humidity); why is it important?
19. Relative humidity; why is it important?
20. Moist air enthalpy.
21. Dew temperature and dew point.
22. Dry bulb and wet bulb temperature.
23. Write the sensible heat balance and the latent heat balance of a thermal zone in steady-state.
24. Write the equations for the sensible and the latent load of a building in steady-state (considering the transfer through the walls, thermal bridges, by infltration and the auxiliary loads).
25. Write the equations for the sensible heat balance and the latent heat balance and represent the process on a psychrometric chart for:

• a thermal zone;
• a mixing process;
• a heating process;
• a dry cooling process;
• a cooling with dehumidification process;
• a vapor humidification process.
• an adiabatic humidification process.