Solar Loads Hvac Flow Simulation

Master in Engineering Design Computational Design

Report: ACADS Solar Collector

Group: Jos Gaspar

IN+ Center for Innovation, Technology and Policy Research, Instituto Superior Tcnico, Universidade Tcnica de Lisboa

October 2005

1. Introduction.

The goal of this work was to practice the COSMOS FloWorks (SolidWorks add-in). Its a promising tool to support the design process. Its simple and intuitive, but offers some problems on the object preparation for the simulation. It was time consuming because it was the first time that I used this application. To deliver this report on time I needed to simplify the model to overcome the difficulties I found without compromising the goals.

This experiment was pleasant. In the future it will be useful for my projects and career I work on the thermo fluids scholarship.

2. Work Description

The ACADS solar concept is explained to contextualize the model simulations. Next the solar collector was removed from the auditory room model and simplified. This action was essential to reduce complexity and to increase the computing capacity during the simulations.

Two models designed on SolidWorks software are presented: Real Model; Simplified Model. This indicates that later simplifications were made, because software errors were not solved. But the goals for this work were guaranteed.

The FloWorks is an application that simulates flows inside or outside de solids. Also it can simulate the turbulent or laminar flows, on a time-dependent form of the Navier - Stokes equations. It can also be applied for steady or unsteady problems. On this particular case a steady flow problem was considered. COSMOSFloworks starts the calculation from initial conditions defined by the user. The solver iterates on the variables until there is no appreciable change, i.e. the solution converges. The input-data was then introduced with the help of tutorials. This software has advanced features, to be explored by the student on other opportunities.

The most important results were the temperature distributions along the air flow movement through out the chambers. After data analysis some conclusions were made, resulting in a redesign of the concept.

3. ACADS Solar Concept

The ACADS system can be used on the classic spaces or in a new kind of spaces as purposed here. Some of the classic rooms can also be modified to retrieve more of the new features. The full concept is presented on append A. The air conditioning system is a hybrid between the mechanical system and a solar energy battery.

This space normally functions better with 100 % fresh air supply, to match the 8 L/s/person requirement (see append B). The disadvantage is the increased energy consumption to head the winter cold air. The solution is the air heat permutation between exhaust and inlet air. The efficiency permutation is about 50 %. The exhaust air carries heat from the people metabolism and solar energy retrieved by a solar collector placed behind the film projection screen. Also the collector is placed on the plenum that carries the air from the room to the building exterior.

The hybrid solution is also an organic one, because the two acclimatization systems work and complement themselves. Two extreme cases are:

- Solar energy not disposable: In this case, in a cloudy day its impossible to retrieve solar energy to heat the room. The mechanical heating system functions at full;

- Low room occupancy: The solar energy contribution to heat the air increases. The utilization of heat from the mechanical system decreases.

The space is well insulated to match the noise level requirement and the heat transmission thought the space is minimal adiabatic - (see append B). Also the energy gains trough the electric equipment is low. Basically, the whole heat gained by the space, is supplied from the spectators. This is an opportunity to use an air localized distribution system, based on the occupation distribution information, gathered from the ticket management system. The advantage of this solution is to carry the air only to the zones that need acclimatization, reducing the energy waste during the transportation and delivery operations, mainly for the solar case.

Other important observation is the good matching between the Auditory and Solar Heat Gain schedules (see Append D). When the solar energy is stronger, the auditory occupation is low, given an optimal match between zone heat requirement and solar energy, complemented by an air localized distributed system.

This concept needs more refinement. One of the tools to see more constraints that will improve de product by the redesign process is the flow simulation. The geometric model of the building was initially proposed to the simulation, but was complex and consumed resources and time. A new approach consisted on the model simplification and the establishment of new assumptions. The model was restricted to the solar collector, and the rest of the building considered adiabatic. Some limitations were also due to the lack of the student knowledge.

The software used to model the solar collector was the SolidWorks and the flow simulations were made with the FloWorks.

4. SolidWorks Model

4.1. Real Model

The concept model is presented on the append E. The spaces between the structural pillars are used to heat the air. Each space has nervures that increase the exposed collector area, hence increasing the efficiency of the heat transmission mechanisms radiation, conduction, convection. The room exhaust air enters at the top of the wall, and in contact with the spaces is reheated (first was heated on the room). After this process the air exits from the wall and enters on the return chamber. Two air handling units that operate on this chamber, have a device that exchanges the heat from the rejected air to the fresh air. The overall dimensions are not far away from the real. Only the nervure, inlet/outlet openings and glass windows parameters have to be refined.

4.2. Simplified Model

Problems occurred during FloWorks configuration and preparation for the simulation, manly on the nervures case. The model has to be simplified. The assumption was that the entire solar energy incident on the windows was effectively transmitted to the air flow. This is an ideal goal, but serves as a driver for subsequent design process. Remember that increasing efforts were made to obtain more results on the last few years leading, on the material research and products referred here.

5. FloWorks Input Data

5.1. Computational domain

The computational domain is a rectangular prism that encloses the model (see append F), for the 3D analysis. The computational domains boundary planes envelop the entire model, because the options Internal Flows and Heat Transfer in Solids were selected.

5.2. Boundary Conditions

Two kinds of boundary conditions were selected (see append G):

o Inlet volume flow boundary condition, applied on the Inlet Lids. In this case the volume flow was calculated for a room with low occupancy (20 persons) each with a requirement of 8 L/s/person. The temperature selected was 293.K (20 C) and the volume air flow for each inlet lid is about 0,0533 m3/s.

o Pressure boundary condition, applied on the outlet lids: the pressure value selected is the same as the pressure at the chamber entrance, because pressure losses were discarded.

5.3. Heat Sources

The volume source boundary condition type was considered to simulate the solar energy that enters the chambers (see append H). The heat generation rates were retrieved from the design day maximum solar heat gains (see append D), for a window orientation to South and on a typical day on January. The value selected was 375 W/m2. But due a multiplier factor (cloud clearance) of 0.47, the final result was 176 W/m2 (without the compensation due to the direct radiation incident angle). The total heat power delivered to the air is:

Total Heat Power [W] = 10384 = 3520 + 3344 + 3520

If the heat permutation has an efficiency of 50 % then the heat power transferred to the fresh air is 10384 * 0,5 = 5,2 kW. This is a good result since the heat power required at 12 PM is 5.3 KW and decreases to 16 PM. Then a match between the solar source power and the room power requirements exists:

o 12:00 PM (5.3 kW); o 13:00 PM (4.2 kW); o 14:00 PM (3.4 kW); o 15:00 PM (3.0 kW); o 16:00 PM (3.2 kW).

See append D for a better understanding of the hourly air system results for a typical Saturday, January 1.

5.4. Material Conditions

The material selected for the walls and windows were: insulation and glass.

5.5. Goals

The software initially considers any steady flow problem as a time-dependent problem. The solver module iterates on an internally determined time step to seek a steady state flow field, so it is necessary to have a criterion of determining that a steady state flow field is obtained, in order to stop the calculations. The criteria to stop the calculation are named Goals. These goals are the physical parameters of interest in the project. Then the Goals convergence is one of the conditions for finishing the calculation. The Goals used on this project are:

o GG Average Pressure: Static Pressure goal type; Average value calculation;

o GG Av Fluid Temperature: Temperature of fluid; Average value calculation;

o AVInletPressure: Static Pressure goal type; Average value calculation;

o OutletMassflowRate: Mass Flow Rate goal type;

o TempMinimaColector: Temperature of solid; Maximum Value calculation.

6. Results

The results are presented on the append I. On figures n 12 & 13, the air temperature varies 293 K (20 C) to 387 K (114 C). In some chamber places, the temperature rises to 450 K (177 C). The exit temperature is high and can damage de air handling units and conduits that operate on the under floor plenum. This happen for a low air volume flow (low room occupancy, see the schedules), because the air moves slowly and is exposed to the chamber heat more time than for increased air flows (increased occupancy levels). This case can be considered the worst for a variable air volume system with a solar energy collector.

The temperature distribution on the heat source can be seen on figure n 14. This distribution does not correspond to the real distribution of the window glass, because the radiation energy

that passes through the windows is the main energy that reaches the chamber. The rest of the energy real energy on the window - is absorbed, irradiated and conducted to the air. But the goal was to see the air flow distribution. But in the figure the decrease of temperature on the window as the air temperature increases can be seen. This is a numerical validation of the heat transfer mechanism between the heat source and the air.

The flow trajectories are presented on figure n 15 (Inlet Lid).

On figures n 16 to 19, are presented the behavior of the calculation process convergence of goal parameters vs. iterations. On the table it can be seen the final results for the goal parameters.

7. Conclusion

Some redesign has to be made. Two constrains are:

- The extreme air temperature generated by the collector, and delivered to the under floor plenum, can damage the equipment and materials and induce hazards like fire;

- The collector is useful only for the winter. On the summer its usefulness. So heat gains due the solar radiation on the summer need to be eliminated.

8. Redesign

To solve the constraints, the alterations made on the collector are:

- Registers installation at the bottom of the air chambers, to mix the exhaust air with fresh air to reduce the air temperature, mainly, for the low occupancies. The register sizing will be made to satisfy noise, pressure losses constrains. It will be motorized and controlled by the DDC system. In case of failure the register opens automatically spring return. Two or more Safety Thermostats will also be installed;

- Installation of an overhang to externally shade the windows. Shade dimensions are used together with the solar position data in HAP Hourly Analysis Software load calculations to determine the fraction of the window surface shaded by the overhang. The intent of the shading geometry is to eliminate the solar heat gain and solar load for the windows on the summer (on the summer the solar direct radiation angle relatively to the windows is higher than on the winter). If this passive solution solves partially the problem, then a hybrid solution must be used. A second exhaust air system must be installed to bypass the air flow to the collector chambers. At the same time the bottom register is opened to supply fresh air to the under floor plenum and to the collector chamber, to remove the heat.

- The material selection for the collector must correspond to the insulation and black body constraints;

- The windows characteristics for the collector are the same used on the commercial solar collectors (utilization of the best practices).

Appends

A ACADS Solar Concept

B Auditory Data

C Schedules

D Design Weather Parameters & Hourly Simulation Results

E SolidWorks Model

F Computational Domain

G Boundary Conditions

H Heat Sources

I Results

J Design Alterations

Append A ACADS Solar Concept

Figure n 1 ACADS Solar Concept

Figure n2 Air Entrance of the Solar Collector

Figure n 3 Solar Collector

Append B Auditory Data

Auditory

1. General Details: Floor Area ................................................ 266.0 m Avg. Ceiling Height ....................................... 6.0 m Building Weight ........................................ 634.7 kg/m

1.1. OA Ventilation Requirements: Space Usage ............. THEATERS: Auditorium OA Requirement 1 ........................................ 8.0 L/s/person OA Requirement 2 ...................................... 0.00 L/(s-m)

2. Internals: 2.1. Overhead Lighting: Fixture Type .................. Recessed (Unvented) Wattage ...................................................... 5.00 W/m Ballast Multiplier ......................................... 1.20 Schedule ................................ Light Auditory

2.2. Task Lighting: Wattage ...................................................... 0.00 W/m Schedule ................................................... None

2.3. Electrical Equipment: Wattage ...................................................... 0.00 W/m Schedule ................................................... None

2.4. People: Occupancy .................................................. 308 People Activity Level ............................. Seated at Rest Sensible ..................................................... 67.4 W/person Latent ......................................................... 35.2 W/person Schedule .............................. People Auditory

2.5. Miscellaneous Loads: Sensible .......................................................... 0 W Schedule ................................................... None Latent .............................................................. 0 W Schedule ................................................... None

3. Walls, Windows, Doors:

Exp. Wall Gross Area (m) Window 1 Qty. Window 2 Qty. Door 1 Qty. S 98.0 0 0 0

3.1. Construction Types for Exposure S

4. Roofs, Skylights: (No Roof or Skylight data).

5. Infiltration: Design Cooling ........................................... 0.00 L/s Design Heating ........................................... 0.00 L/s Energy Analysis ......................................... 0.00 L/s Infiltration occurs only when the fan is off.

6. Floors: Type ................................ Slab Floor On Grade Floor Area ................................................ 266.0 m Total Floor U-Value .................................. 0.550 W/(m-K) Exposed Perimeter ..................................... 66.0 m Edge Insulation R-Value ............................. 1.82 (m-K)/W

7. Partitions: (No partition data).

Exterior Wall - Auditory

Wall Details

Outside Surface Color ............................... Light Absorptivity ............................................... 0.450 Overall U-Value ........................................ 0.091 W/(m-K)

Wall Layers Details (Inside to Outside)

Thickness Density Specific Ht. R-Value Weight Layers mm kg/m kJ / (kg - K) (m-K)/W kg/m Inside surface resistance 0.000 0.0 0.00 0.12064 0.0 Revestimento - Madeira 20.000 550.0 0.88 0.86957 11.0 Isolamento Acstico 260.000 40.0 1.17 6.50000 10.4 Reboco Interior 10.000 1950.0 0.87 0.00869 19.5 Isolamento - Poliuretano 100.000 35.0 0.92 3.33333 3.5 Tijolo - 15cm 150.000 1900.0 0.84 0.13043 285.0 Reboco Exterior 10.000 1950.0 0.87 0.00869 19.5 Outside surface resistance 0.000 0.0 0.00 0.05864 0.0

Totals 550.000 -

11.02999 348.9

Roof - Auditory

Roof Details

Outside Surface Color ............................... Light Absorptivity ............................................... 0.450 Overall U-Value ........................................ 0.080 W/(m-K)

Roof Layers Details (Inside to Outside)

Thickness Density Specific Ht. R-Value Weight Layers mm kg/m kJ / (kg - K) (m-K)/W kg/m Inside surface resistance 0.000 0.0 0.00 0.12064 0.0 Revestimento - Madeira 20.000 550.0 0.88 1.84000 11.0 Isolamento - Acstico 400.000 40.0 0.92 10.00000 16.0 Lage 100.000 2300.0 0.84 0.05778 230.0 Impermeabilizao 10.000 1050.0 1.47 0.41082 10.5 Chapa de Zinco 6.000 7130.0 0.94 0.00054 42.8 Outside surface resistance 0.000 0.0 0.00 0.05864 0.0

Totals 536.000 -

12.48842 310.3

Door - Auditory - Exterior

Door Details: Gross Area ................................................... 2.3 m Door U-Value ........................................... 2.300 W/(m-K)

Glass Details: Glass Area ................................................... 0.0 m Glass U-Value .......................................... 3.293 W/(m-K) Glass Shade Coefficient ........................... 0.880 Glass Shaded All Day? ................................. No

Append C - Schedules

Light - Auditory (Fractional)

Hourly Profiles: 1:Diario

Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 10 10 100 0 0 0 0 0 0 0 0 0 0 50 100 10 10 100 10 10 100 10 10 100

8:Profile Eight Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 10 10 100 10 0 0 0 0 0 0 0 0 0 100 100 100 100 100 100 100 100 100 100 100

Assignments:

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Design 8 8 8 8 8 8 8 8 8 8 8 8

Monday 1 1 1 1 1 1 1 1 1 1 1 1 Tuesday 1 1 1 1 1 1 1 1 1 1 1 1

Wednesday 1 1 1 1 1 1 1 1 1 1 1 1 Thursday 1 1 1 1 1 1 1 1 1 1 1 1

Friday 1 1 1 1 1 1 1 1 1 1 1 1 Saturday 1 1 1 1 1 1 1 1 1 1 1 1

Sunday 1 1 1 1 1 1 1 1 1 1 1 1 Holiday 1 1 1 1 1 1 1 1 1 1 1 1

Thermostat - Auditory (Fan / Thermostat)

Hourly Profiles: 1:Termostato

Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value O O O U U U U U U U U U U U O O O O O O O O O O

2:Profile Two Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value O O O O O O O O O O O O O O O O O O O O O O O O

3:Profile Three Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value O O O O O O O O O O O O O O O O O O O O O O O O

4:Profile Four Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value O O O O O O O O O O O O O O O O O O O O O O O O

O = Occupied; U = Unoccupied

Assignments:


Monday 2 2 2 2 2 2 2 2 2 2 2 2 Tuesday 2 2 2 2 2 2 2 2 2 2 2 2


Friday 2 2 2 2 2 2 2 2 2 2 2 2 Saturday 3 3 3 3 3 3 3 3 3 3 3 3

Sunday 4 4 4 4 4 4 4 4 4 4 4 4 Holiday 4 4 4 4 4 4 4 4 4 4 4 4

People - Auditory (Fractional)

Hourly Profiles: 1:Monday

Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 50 50 0 0 0 0 0 0 0 0 0 0 0 0 0 50 50 0 80 80 0 100 100 0

2:Tuesday Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 30 30 0 0 0 0 0 0 0 0 0 0 0 0 0 10 10 0 20 20 0 30 30 0

3:Wednesday Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 40 40 0 0 0 0 0 0 0 0 0 0 0 0 0 10 10 0 20 20 0 40 40 0

4:Thursday Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 40 40 0 0 0 0 0 0 0 0 0 0 0 0 0 10 10 0 30 30 0 40 40 0

5:Friday Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 80 80 0 0 0 0 0 0 0 0 0 0 0 0 0 20 20 0 50 50 0 60 60 0

6:Saturday Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 80 80 0 0 0 0 0 0 0 0 0 0 0 0 0 30 30 0 50 50 0 80 80 0

7:Sunday Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 40 40 0 0 0 0 0 0 0 0 0 0 0 0 0 50 50 0 60 60 0 60 60 0

8:Profile Eight Hour 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Value 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

Assignments:


Monday 1 1 1 1 1 1 1 1 1 1 1 1 Tuesday 2 2 2 2 2 2 2 2 2 2 2 2


Friday 5 5 5 5 5 5 5 5 5 5 5 5 Saturday 6 6 6 6 6 6 6 6 6 6 6 6

Sunday 7 7 7 7 7 7 7 7 7 7 7 7 Holiday 6 6 6 6 6 6 6 6 6 6 6 6

Append D Design Weather Parameters & Hourly Simulation Results

Design Weather Parameters & MSHGs

Design Parameters:

City Name ................................................................................. Lisbon Location ................................................................................. Portugal Latitude ......................................................................................... 38.4 Deg. Longitude ........................................................................................ 9.1 Deg. Elevation ....................................................................................... 10.0 m Summer Design Dry-Bulb ............................................................. 32.0 C Summer Coincident Wet-Bulb ....................................................... 20.8 C Summer Daily Range .................................................................... 10.5 K Winter Design Dry-Bulb ................................................................... 3.5 C Winter Design Wet-Bulb .................................................................. 2.3 C Atmospheric Clearness Number ................................................... 1.00 Average Ground Reflectance ........................................................ 0.20 Soil Conductivity ......................................................................... 1.385 W/(m-K) Local Time Zone (GMT +/- N hours) ................................................ 0.0 hours Consider Daylight Savings Time ..................................................... No Simulation Weather Data ............................................... Lisbon (TRY) Current Data is .............................................................. User Modified Design Cooling Months .................................... January to December

Design Day Maximum Solar Heat Gains:

(The MSHG values are expressed in W/m )

Month N NNE NE ENE E ESE SE SSE S January 30.1 30.1 30.1 127.4 234.9 309.6 362.1 376.6 375.0 February 36.5 36.5 85.0 184.1 289.7 348.5 370.5 361.6 350.6

March 43.6 43.6 149.8 256.1 319.7 356.6 344.2 313.5 296.9 April 53.8 116.0 220.5 305.9 354.2 348.5 315.4 259.7 231.3 May 62.5 174.2 277.1 338.0 368.6 343.9 285.6 210.8 174.8 June 90.6 219.6 326.1 387.3 409.5 370.7 297.1 206.1 165.9 July 96.5 265.0 406.1 508.4 546.2 502.2 419.8 307.2 255.2

August 87.0 177.4 323.4 458.8 525.2 518.2 467.8 385.1 343.8 September 64.6 64.6 189.4 343.2 438.7 480.5 475.3 434.4 411.9

October 45.9 45.9 87.0 230.5 329.9 407.3 430.7 423.6 414.2 November 30.7 30.7 30.7 121.3 229.7 309.4 354.2 367.3 370.3 December 27.4 27.4 27.4 97.7 209.6 288.3 350.4 372.9 376.7

Month SSW SW WSW W WNW NW NNW HOR Mult January 373.9 356.6 316.3 228.4 130.5 30.1 30.1 209.3 0.47 February 362.1 370.9 343.8 290.1 195.8 76.8 36.5 276.6 0.47

March 316.6 348.6 353.7 326.7 249.2 153.1 43.6 338.7 0.47 April 260.7 315.6 352.0 353.3 300.9 225.2 112.9 403.7 0.50 May 211.1 285.3 344.9 367.3 340.3 278.2 172.2 448.0 0.53 June 206.9 295.6 373.2 405.0 392.3 328.2 213.7 510.3 0.60 July 309.3 418.0 509.8 538.9 509.7 414.6 254.0 667.1 0.80

August 388.0 469.1 523.0 524.7 447.8 337.0 172.0 609.9 0.77 September 433.7 474.4 481.9 437.2 343.8 192.4 64.6 467.9 0.67

October 423.3 431.8 408.7 334.1 222.5 97.8 45.9 331.1 0.57 November 369.9 356.2 303.5 231.9 119.1 30.7 30.7 209.4 0.47 December 371.5 350.2 290.3 210.3 90.1 27.4 27.4 181.1 0.47

Mult. = User-defined solar multiplier factor.

Table 1.1 Hourly Air System Simulation Results for Saturday, January 1

Hour

Central Cooling Coil

Load (kW)

Central Heating Coil Load

(kW) Supply Fan

(kW) Return Fan

(kW) Vent. Reclaim

Device (kW)

Lighting (kW)

Electric Equipment

(kW) 0000 0.0 2.8 1.8 0.5 0.0 0.2 0.0 0100 0.0 2.3 1.8 0.5 0.0 0.2 0.0 0200 0.0 7.5 1.8 0.5 0.0 1.6 0.0 0300 0.0 8.6 1.8 0.5 0.0 0.0 0.0 0400 0.0 8.8 1.8 0.5 0.0 0.0 0.0 0500 0.0 8.2 1.8 0.5 0.0 0.0 0.0 0600 0.0 8.4 1.8 0.5 0.0 0.0 0.0 0700 0.0 8.6 1.8 0.5 0.0 0.0 0.0 0800 0.0 8.1 1.8 0.5 0.0 0.0 0.0 0900 0.0 8.6 1.8 0.5 0.0 0.0 0.0 1000 0.0 8.0 1.8 0.5 0.0 0.0 0.0 1100 0.0 5.9 1.8 0.5 0.0 0.0 0.0 1200 0.0 5.3 1.8 0.5 0.0 0.0 0.0 1300 0.0 4.2 1.8 0.5 0.0 0.8 0.0 1400 0.0 3.4 1.8 0.5 0.0 1.6 0.0 1500 0.0 3.0 1.8 0.5 0.0 0.2 0.0 1600 0.0 3.2 1.8 0.5 0.0 0.2 0.0 1700 0.0 6.5 1.8 0.5 0.0 1.6 0.0 1800 0.0 4.6 1.8 0.5 0.0 0.2 0.0 1900 0.0 5.1 1.8 0.5 0.0 0.2 0.0 2000 0.0 8.4 1.8 0.5 0.0 1.6 0.0 2100 0.0 2.1 1.8 0.5 0.0 0.2 0.0 2200 0.0 1.7 1.8 0.5 0.0 0.2 0.0 2300 0.0 7.7 1.8 0.5 0.0 1.6 0.0 Total 0.0 141.0 43.8 11.0 0.0 10.1 0.0

Hourly Simulation Results for Saturday, January 1 (day 1) thru Saturday, January 1 (day 1)

0

1

2

3

4

5

6

7

8

9

k

W

Hour of Day00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Central Heating Coil Load (kW)

Figure n 4 Hourly Simulation Results

Location: Lisbon, Portugal

( Dry and Wet Bulb temperatures are expressed in C )

Hr January February March April May June

DB WB DB WB DB WB DB WB DB WB DB WB 0000 14.3 10.4 15.9 10.9 19.0 13.3 21.1 14.2 26.1 16.8 26.5 18.2 0100 14.0 10.3 15.5 10.7 18.6 13.1 20.7 14.1 25.7 16.7 26.2 18.0 0200 13.7 10.1 15.2 10.6 18.3 13.0 20.2 13.9 25.4 16.5 25.8 17.9 0300 13.4 9.9 14.9 10.4 18.0 12.8 19.9 13.7 25.1 16.4 25.6 17.8 0400 13.3 9.8 14.7 10.3 17.8 12.7 19.7 13.6 24.9 16.3 25.4 17.7 0500 13.2 9.8 14.6 10.3 17.7 12.7 19.6 13.6 24.8 16.3 25.3 17.7 0600 13.3 9.9 14.7 10.4 17.8 12.8 19.8 13.7 24.9 16.4 25.4 17.8 0700 13.6 10.1 15.1 10.5 18.2 12.9 20.2 13.8 25.3 16.5 25.8 17.9 0800 14.2 10.4 15.7 10.8 18.9 13.2 20.9 14.2 26.0 16.8 26.4 18.1 0900 15.0 10.8 16.7 11.3 19.8 13.6 21.9 14.6 26.9 17.1 27.2 18.5 1000 15.9 11.4 17.7 11.8 20.9 14.1 23.2 15.1 28.0 17.6 28.2 18.8 1100 16.9 11.9 18.9 12.3 22.2 14.6 24.5 15.7 29.2 18.0 29.4 19.3 1200 17.9 12.5 20.1 12.8 23.3 15.0 25.8 16.2 30.3 18.5 30.5 19.6 1300 18.6 12.8 20.9 13.2 24.2 15.4 26.8 16.6 31.2 18.8 31.3 19.9 1400 19.1 13.1 21.5 13.4 24.8 15.6 27.5 16.8 31.8 19.0 31.8 20.1 1500 19.3 13.2 21.7 13.5 25.0 15.7 27.7 16.9 32.0 19.1 32.0 20.2 1600 19.1 13.1 21.5 13.4 24.8 15.6 27.5 16.8 31.8 19.0 31.8 20.1 1700 18.7 12.9 21.0 13.2 24.3 15.4 26.9 16.6 31.3 18.8 31.3 20.0 1800 18.0 12.5 20.2 12.9 23.5 15.1 26.0 16.2 30.5 18.5 30.6 19.7 1900 17.2 12.1 19.3 12.5 22.5 14.7 24.9 15.8 29.6 18.2 29.7 19.4 2000 16.4 11.7 18.4 12.0 21.6 14.3 23.9 15.4 28.6 17.8 28.9 19.1 2100 15.8 11.3 17.6 11.7 20.8 14.0 23.0 15.0 27.8 17.5 28.1 18.8 2200 15.2 10.9 16.9 11.4 20.0 13.7 22.2 14.7 27.1 17.2 27.4 18.5 2300 14.7 10.7 16.3 11.1 19.5 13.4 21.5 14.4 26.5 17.0 26.9 18.3

Hr July August September October November December

DB WB DB WB DB WB DB WB DB WB DB WB 0000 26.8 18.0 27.4 19.2 26.9 18.7 25.4 17.5 18.4 13.5 14.1 10.6 0100 26.4 17.9 27.1 19.1 26.6 18.5 25.0 17.4 18.1 13.3 13.8 10.4 0200 26.1 17.7 26.8 19.0 26.3 18.4 24.5 17.2 17.7 13.2 13.5 10.3 0300 25.9 17.6 26.6 18.9 26.0 18.3 24.2 17.1 17.5 13.0 13.2 10.1 0400 25.7 17.5 26.5 18.8 25.9 18.2 24.0 17.0 17.3 12.9 13.1 10.0 0500 25.6 17.5 26.4 18.8 25.8 18.2 23.9 17.0 17.2 12.9 13.0 10.0 0600 25.7 17.6 26.5 18.8 25.9 18.3 24.1 17.1 17.3 13.0 13.1 10.1 0700 26.0 17.7 26.8 18.9 26.2 18.4 24.5 17.2 17.7 13.1 13.4 10.2 0800 26.6 18.0 27.3 19.1 26.8 18.6 25.2 17.5 18.3 13.4 14.0 10.5 0900 27.5 18.4 28.0 19.4 27.6 18.9 26.2 17.9 19.1 13.8 14.7 10.9 1000 28.4 18.8 28.9 19.7 28.5 19.3 27.5 18.3 20.1 14.3 15.6 11.4 1100 29.5 19.3 29.8 20.0 29.6 19.7 28.8 18.8 21.3 14.8 16.7 11.9 1200 30.5 19.8 30.7 20.4 30.6 20.1 30.1 19.3 22.4 15.3 17.6 12.3 1300 31.3 20.1 31.4 20.6 31.3 20.3 31.1 19.6 23.2 15.7 18.3 12.7 1400 31.8 20.3 31.8 20.7 31.8 20.5 31.8 19.8 23.7 15.9 18.8 12.9 1500 32.0 20.4 32.0 20.8 32.0 20.6 32.0 19.9 23.9 16.0 19.0 13.0 1600 31.8 20.3 31.8 20.7 31.8 20.5 31.8 19.8 23.7 15.9 18.8 12.9 1700 31.4 20.1 31.4 20.6 31.4 20.4 31.2 19.6 23.2 15.7 18.4 12.7 1800 30.7 19.8 30.8 20.4 30.7 20.1 30.3 19.3 22.5 15.4 17.7 12.4 1900 29.8 19.4 30.1 20.1 29.9 19.8 29.2 18.9 21.6 15.0 17.0 12.0 2000 29.0 19.1 29.4 19.9 29.1 19.5 28.2 18.6 20.8 14.6 16.2 11.6 2100 28.3 18.8 28.8 19.7 28.4 19.2 27.3 18.3 20.0 14.2 15.5 11.3 2200 27.6 18.5 28.2 19.5 27.8 19.0 26.5 18.0 19.3 13.9 14.9 11.0 2300 27.1 18.2 27.7 19.3 27.3 18.8 25.8 17.7 18.8 13.7 14.4 10.8

Append E SolidWorks Model

Figure n 5 Chambers of the Solar Collector Exterior Wall

Figure n 6 - Chambers of the Solar Collector Interior Wall

Figure n 7 Collector Chamber

Append F Computational Domain

Fig 8 - Computational Domain

Append G Boundary Conditions

Fig 9 - Outlet Lids

Pressure boundary condition Settings

Static Pressure 101325 Pa Temperature 291 K

Fig 10 - Inlet Lids

Inlet volume flow boundary condition

Settings

Volume flow rate normal to face 0.0533 m3/s Flow vectors direction Normal to Face Inlet Profile Uniform Approximate pressure 101325 Pa Temperature 293.2 K

Append H Heat Sources

Fig 11 - Heat Sources

Volume source boundary condition

Settings

Heat Generation Rate 3520 W


Settings



Settings


Append I Results

Fig 12 Air Flow Temperature Distribution- Rear View

Fig 13 - Air Flow Temperature Distribution Front View

Fig 14 Window Temperature Distribution Front View

Fig 15 Air Flow Trajectories

Colector3.SLDASM [ColectorSolar]

-200

0

200

400

600

800

1000

0 50 100 150 200 250 300 350 400

Iterations

T

e

m

p

e

r

a

t

u

r

e

o

f

S

o

l

i

d

[

K

]

TempMinimaColector

Fig 16 Collector Temperature Convergence


-0.25

-0.2

-0.15

-0.1

-0.05

00 50 100 150 200 250 300 350 400

Iterations

M

a

s

s

F

l

o

w

R

a

t

e

[

k

g

/

s

]

OutletMassflowRate

Fig 17 Mass Flow Rate Convergence


-50

0

50

100

150

200

250

300

350

400

0 50 100 150 200 250 300 350 400

Iterations

T

e

m

p

e

r

a

t

u

r

e

o

f

F

l

u

i

d

[

K

]

GG Av Fluid Temperature

Fig 18 Air Flow Temperature convergence


101324.95

101325

101325.05

101325.1

101325.15

101325.2

101325.25

0 50 100 150 200 250 300 350 400Iterations

S

t

a

t

i

c

P

r

e

s

s

u

r

e

[

P

a

]

GG Average PressureAVInletPressure

Fig 19 Static Pressure convergence


Goal Name Unit Value Averaged

Value Minimum

Value Maximum

Value Progress

[%] Use In Convergence Delta Criteria GG Average Pressure [Pa] 101325.0033 101325 101325 101325 100 Yes 1.43E-06 0.00506625 AVInletPressure [Pa] 101325.0056 101325 101325 101325 100 Yes 1.49E-06 0.00506625 GG Av Fluid Temperature [K] 357.501783 357.497 357.458 357.542 100 Yes 1.09E-02 16.7925202

OutletMassflowRate

[kg/s] -0.192472225 -0.192473 -0.192473 -0.192472 100 Yes 1.63E-07 0.000192472 TempMinimaColector [K] 869.3077499 868.85 867.875 870.135 100 Yes 3.54E-01 28.8611505

Iterations: 372

Append J Design Alterations

Fig 20 Collector Front Redesign

Fig 21 Collector Rear Redesign

Fig 22 - Collector Front View

Fig 23 - Collector Rear View

Fig 24 - Collector Lateral View

References

Carrier Hourly Analysis Program, Version 4.22 (Help information)

Cosmos FloWorks, Version 2004 (help and tutorial information)

Solar Loads Hvac Flow Simulation

Documents

Transcript of Solar Loads Hvac Flow Simulation