3 rd Annual CHAMPS Developers Workshop

Transcription

1 Syracuse University Department of Mechanical and Aerospace Engineering L.C. Smith College of Engineering and Computer Science Building Energy and Environmental Systems Laboratory ( 3 rd Annual CHAMPS Developers Workshop Combined Heat, Air, Moisture and Pollutants (CHAMPS) Transport in Building Environmental Systems June 19-2, 26, Syracuse University, Syracuse, New York Room 246/2 Link Hall An Extension of CHAMPS-Envelope to Single-Zone Building Enclosure Simulations Dr. John Grunewald Research Associate Syracuse University

2 Syracuse University Department of Mechanical and Aerospace Engineering L.C. Smith College of Engineering and Computer Science Building Energy and Environmental Systems Laboratory ( Presentation Overview: Governing balance equations CHAMPS application examples Extension to single/multi-zone building enclosure simulations Application of the CHAMPS model to predict the mold fungus formation - project outline

3 Governing balance equations Conserved quantities E ρ t = x Generally E = general extensive quantity k E ( jk ) e.g. m mass U I S internal energy linear momentum entropy in case of CHAMPS Heat, air, moisture and pollutant transport processes m m m m U v w a p vapor mass liquid water mass air mass pollutant mass internal energy

4 Governing balance equations Convective and diffusive fluxes Generally E ρ t = x k E ( jk ) convection-diffusion equation j = j + j E E E k k, conv k, diff j E k, conv total E-flux convective E-flux j E k, diff diffusive E-flux in case of CHAMPS Independent CHAMPS-fluxes moisture mass m wat, l+ g mwat, g mwat, g mwat, l ρ t = j + j + j REV k, conv k, diff k, conv xk 1 water vapor diffusion flux (kg/m 2 s) air mass m air, g mair, g ρ t REV = x k j k, conv pollutant mass m voc, l+ g mvoc, g mvoc, g mvoc, l ρ t = j + j + j REV k, conv k, diff k, conv xk 2 voc diffusion flux (kg/m 2 s) internal energy ρ = j + j t U U U REV k, conv k, diff x k

5 Governing balance equations Elimination of dependent fluxes mwat, g mwat, g mg k, conv = k, conv j c j mair, g mair, g mg k, conv = k, conv j c j 3 9 introduced by balance equations 7 eliminated + 3 newly introduced = 5 independent 1. water vapor diffusion flux (kg/m 2 s) 2. voc diffusion flux (kg/m 2 s) Independent CHAMPS-fluxes mvoc, g mvoc, g mg k, conv = k, conv j c j mwat, l mwat, l ml k, conv = k, conv j c j mvoc, l mvoc, l ml k, conv = k, conv mass concentrations in liquid phase (kg/kg liq phase ) U mg ml k, conv = g k, conv + l k, conv j c j j u j u j j wat, g, = j + h j + h j U Q k, diff k, diff 5 4 mass concentrations in gas phase (kg/kg gas phase ) m specific internal energy of gas and liquid phases (J/kg) mvoc g wat, g k, diff voc, g k, diff specific enthalpy of water vapor and gaseous voc (J/kg) 3. convective gas flux (kg/m 2 s) 4. convective liquid water flux (kg/m 2 s) 5. heat conduction flux (W/m 2 )

6 Governing balance equations Numerical solution (Semi-discretisation discretisation,, Finite Control Volume Method - CVM) iterative solution Balance equations describe change of state variables by divergence of fluxes E ρ t = x k E ( jk ) Fluxes depend on state variables S = f E ( ρ ) (, ) { θl l g wat, g voc, g } with S =, p, p, p, c, T,... E j = f S S Decomposition algorithm

7 CHAMPS application examples 1. Hygrothermal performance of heavy wall constructions The Rijksmuseum Amsterdam Museum for Art and History Sculptures Costumes Weapons Coins Treasures Handicraft Furniture Graphics Paintings

8 CHAMPS application examples 1. Hygrothermal performance of heavy wall constructions Reconstruction of the Rijksmuseum Amsterdam Questions: Which insulation material? Which thickness? Drying behaviour? Prevention of condensation? Risk of mould growth? Risk of rain penetration and frost damage? How to design details? Position of paintings?

9 CHAMPS application examples 1. Hygrothermal performance of heavy wall constructions inside outside 1. Existing construction without insulation sun radiation temperature long wave radiation 2. Cellular glass insulation 1mm Clay plaster 3mm Cellular glass 4mm Glue mortar 3. Calcium silicate insulation 1mm Lime cement plaster 3mm Calcium silicate 4mm Glue mortar 44 mm insulation 48 mm historical brick 12 mm clinker humidity wind rain Weather data from Amsterdam (1964/65, from the ARUP Company) Long wave radiation from nearest location (Bremen) Rain fall data from nearest location (Bremen) (amount of rain adjusted to monthly mean values of Amsterdam)

10 CHAMPS application examples Results: Moisture fields after 2 days drying after 5 years drying Existing construction, Water content in Vol% Existing construction, Water content in Vol% Cellular glass, Water content in Vol% 2 [d] Cellular glass, Water content in Vol% Calcium 14 silicate, 13.5 Water content 12 in Vol% Calcium 14.5 silicate, Water 13content 12.5 in Vol% [d]

11 CHAMPS application examples 2. Example construction to study air flow effects construction slightly changed according to lab requirements air flow air flow Reprinted with permission from

12 CHAMPS application examples 2. Example construction to study air flow effects Heat, Air and Moisture Performance of Building Envelope Systems Computer modelling of air leakage effects of lightweight wall constructions Heat, Air and Moisture Performance of Building Envelope Systems Computer modelling of air leakage effects of lightweight wall constructions Exfiltration Relative Humidity in in % [h] m3/h Exfiltration Temperature in in C C [h] m3/h DELPHIN 4 DELPHIN 4 26 by John Grunewald, Department of Mechanical and Aerospace Engineering, Syracuse University 26 by John Grunewald, Department of Mechanical and Aerospace Engineering, Syracuse University

13 CHAMPS application examples 3. First VOC diffusion and convection test high VOC concentration in indoor air exfiltration flux = 1 m 3 /h coupled heat, air, moisture and pollutant simulation top air flow + VOC air flow + VOC outside T = 1 C RH = 8 % low VOC conc. inside T = 2 C RH = 5 % high VOC conc. bottom

14 CHAMPS application examples 3. First VOC diffusion and convection test Location in [m] Temperature in C Location in [m] Relative Humidity in % Location in [m] VOC density in kg/m3 top top top time h 5 h 2 h 5 h 1 h bottom bottom bottom.5.1 Location in [m].5.1 Location in [m].5.1 Location in [m]

15 Extension to single/multi-zone building enclosure simulations Moisture balance of a room single zone solution Processes to be considered Moisture production in the room (e.g. caused by inhabitants and their activities) Vapor diffusion between room and envelope walls Air exchange between inside and outside and other rooms due to ventilation Assumptions Perfect mixing of indoor air (one room node)...

16 Extension to single/multi-zone building enclosure simulations Moisture balance of a room single zone solution Processes to be considered Moisture production in the room (e.g. caused by inhabitants and their activities) Vapor diffusion between room and envelope walls Air exchange between inside and outside and other rooms due to ventilation Assumptions Perfect mixing of indoor air (one room node)... Moisture balance of a room dm vap, room dt nwalls mvap mvap mvap prodvroom jdiff, i Awall, i ρ nchangevroom i= 1 = σ + + Production Diffusion Ventilation iterative solution Further sources and sinks that can be included Air cleaner/dehumidifier effects (negative production) Vapor exchange between room and furniture (carpets, curtains) Condensation/drying on surfaces without moisture buffer capacity m σ V j vap, room mvap prod room mvap diff, i A n wall, i ρ m vap change Moisture mass of the indoor air (kg) Moisture production density (kg/m 3 s) Room volume (m 3 ) Vapor diffusion fluxes (kg/m 2 s) Wall areas (m 2 ) Vapor density difference (kg/m 3 ) Air change rate (1/h)

17 Extension to single/multi-zone building enclosure simulations Coupling to CHAMPS envelope single zone solution Simulation start internal coupling = extension of the existing code (performance) Main integration loop Output integration loop Single step integration loop Adjust time step (based on convergence history) Compose and LU factorize Jacobian (as infrequently as possible) Iterate RHS of Newton/BDF scheme until converged Update climatic data for calculation of boundary conditions Calculate state variables Calculate fluxes Calculate divergences solve room balance current coupling in previous version (DELPHIN4) Converged solution Output time point reached Write output data Simulation end solve room balance loss of accuracy in solution gain of flexibility in coupling External coupling possible! (e.g. multi-zone building simulation, CONTAM)

18 Extension to single/multi-zone building enclosure simulations Multi-zone solution Heat and moisture (temperature and relative humidity) DLL or separate program Make use of CVODE integrator

19 Extension to single/multi-zone building enclosure simulations Multi-zone solution Heat and moisture (temperature and relative humidity) DLL or separate program In-house solution: make use of CVODE integrator Moisture and heat balances of N rooms: dm dt vap, room nwalls mvap mvap mvap prodvroom jdiff, i Awall, i ρ nchangevroom i= 1 j= 1.. N = σ + + Production Diffusion Ventilation m σ V j vap, room mvap prod room mvap diff, i A n wall, i ρ m vap change Moisture mass in the indoor air (kg) Moisture production density (kg/m 3 s) Room volume (m 3 ) Vapor diffusion fluxes (kg/m 2 s) Wall areas (m 2 ) Vapor density difference (kg/m 3 ) Air change rate (1/h) du dt room nwalls nwindows U Q Q mair vap, room prodvroom jcond, i Awall, i jrad, i Awindow, i uairρ nchangevroom hvap i= 1 i= 1 dt j= 1.. N = σ Production Conduction Radiation Ventilation Enthalpy dm U σ j room U prod Q cond, i Internal energy of the indoor air (J) Energy production density (J/m 3 s) Heat conduction fluxes (W/m 2 ) j Q rad, i u m ρ h vap air air Heat radiation fluxes (W/m 2 ) Specific internal energy difference (J/kg) Air mass density (kg/m 3 ) Specific vapor enthalpy (J/kg)

20 Extension to single/multi-zone building enclosure simulations Coupling to CHAMPS envelope - Multi-zone solution Wall integrator Single step integration loop Single step integration loop Adjust internal time step (based on convergence history) Compose and LU factorize Jacobian (as infrequently as possible) Room integrator Iterate RHS of Newton/BDF scheme until converged Update climatic data for calculation of boundary conditions Calculate state variables of walls Calculate fluxes of walls Calculate divergences Converged solution Time step, solve room balances Fluxes of loss of accuracy in solution walls gain of flexibility in coupling Adjust internal time step (based on convergence history) Compose and LU factorize Jacobian External (as coupling infrequently possible as possible)! (e.g. multi-zone building simulation, CONTAM) Iterate RHS of Newton/BDF scheme until converged Update climatic data for calculation of ventilation/radiation Calculate state variables of rooms (RH, T) Make use of precalculated fluxes of walls Calculate production, diffusion, ventilation, sources/sinks Converged solution Interface updated after each time step State variables of rooms

21 Extension to single/multi-zone building enclosure simulations Single-zone simulation example Location and history of the Kumamoto castle Constructed by the Kato Clan in 167. Later handed over to the Hosokawa Clan. In 1877, large parts of the castle were destroyed in that civil war. Most of the present castle buildings are reconstructions dating from the 196s. The interior of the castle is a modern museum. With permission from and in co-operation with

22 Extension to single/multi-zone building enclosure simulations Inside views of the Kumamoto castle There is an exhibition of a historical wooden ship. The ship is exhibited in a case box construction. The case box construction has been built inside the Kumamoto castle. wooden ship

23 Extension to single/multi-zone building enclosure simulations Boundary conditions Heat and vapor exchange between construction elements and outdoor air and between construction elements and indoor air Volume = 4 m 3 Existing construction Concrete Plywood Glass Applied insulation Humirite Caparite Harmonite wooden ship Air ventilation

24 Extension to single/multi-zone building enclosure simulations Wall-room coupling Floor Wall Beam Ceiling Column Lower Beam Existing construction Concrete Plywood Glass Indoor air, V = 4 m 3 Construction Building Insulation Wall element material thickness area Floor 1 cm Concrete 2 cm Caparite 66.3 m 2 Wall 5 cm Concrete 2 cm Humirite 56.7 m 2 Beam 2 cm Concrete 2 cm Humirite 26.5 m 2 Ceiling 3 cm Plywood 2 cm Humirite 62.6 m 2 Column 3 cm Concrete 2 cm Harmonite 24.9 m 2 Lower Beam 15 cm Concrete 2 cm Harmonite 21.9 m 2 Applied insulation Humirite Caparite Harmonite Room (indoor air) is connected to the internal surfaces of building elements. The shape of the room can be arbitrary, just its volume is significant. The building elements have to be discretized. Vertical alignment of floor and ceiling plays no role. To align all building elements in the same direction allows an all-in-one 1D-simulation and will make the simulation run faster.

25 Extension to single/multi-zone building enclosure simulations Numerical modelling using DELPHIN4 software Floor Wall Beam Ceiling Column Lower Beam The building elements are discretized in the construction workspace of DELPHIN4. Volume of the room Initial RH of the room Internal T data Air change rate External T data External RH data Moisture production in the room The room data are specified in the room definition dialog.

26 Extension to single/multi-zone building enclosure simulations Comparison of measurement and simulation,, case without insulation Time Mar 23 Apr 23 May 23 Jun 23 Jul 23 Aug 23 Sep 23 Oct 23 Nov 23 Dec 23 Jan 24 Feb 24

27 Application of the CHAMPS model to predict the mold fungus formation Goal develop strategies to minimize the exposure to insalubrious conditions related to fungal growth and reproduction Objectives predict the interior boundary conditions (the microclimate) in much higher precision calculate the probability of mold fungus formation as function of the construction design give practical recommendations how to improve the construction design Methodology - Project outline - Extension to single/multi-zone building enclosure simulations Coupling to Isopleth-Model Isopleth systems for spore germination of the mould fungi Aspergillus restrictus (on the left) and Aspergillus versicolor (on the right)

28 Syracuse University Department of Mechanical and Aerospace Engineering L.C. Smith College of Engineering and Computer Science Building Energy and Environmental Systems Laboratory ( 3 rd Annual CHAMPS Developers Workshop Combined Heat, Air, Moisture and Pollutants (CHAMPS) Transport in Building Environmental Systems June 19-2, 26, Syracuse University, Syracuse, New York Room 246/2 Link Hall An Extension of CHAMPS-Envelope to Single-Zone Building Enclosure Simulations Dr. John Grunewald Research Associate Syracuse University