Solar Absorption Cooling / Heating System for the Intelligent Workplace Ming Qu Sophie Masson Dr. David Archer IWESS Workshop Oct.4,2006 page1
Introduction IW solar cooling/heating system One -axis solar trough Parabolic Trough Solar Collectors Natural Gas TO LOAD HX-1 Intelligent Workplace Absorption Chiller Cooling tower CMP TK-1 Cooling tower The initial solar heating and cooling system Page2
Introduction Intelligent workplace 577"(17500mm) 394"(12000mm) Solar Collectors Building North 15 Location of chiller and control box The Robert L. Preger Intelligent Workplace latitude: North 40.26 longitude: 79.56 Orientation: 15 deviation to east from the south area:650 m2 (7,000 ft2) 9@159" (9@ 4800 mm) IW Solar Field Plan Feb.21 10:50am / 1:10pm 16 175"(5310mm) Dec.21 9:10am / 2:50pm Jan.21 8:50am / 3:10pm Feb.21 8:00am / 3:50pm 12 South zone area: 245 m2 (2,637 ft2) 9 offices and 1 conference space 30 people PTSC Orientation E-W axis Page3
Introduction Parabolic trough solar collector (PTSC) Module 12m Each module includes parabolic trough reflector receiver pipe, surface treated steel support structure single axis drive 4 modules, total 52.44 m2 Installed in series Piping length:85m Page4
Introduction Dual fired D.E absorption chiller 16 kw (4.55 tons) hot water driven or natural gas fired LiBr/H2O, sorbent; water, refrigerant double effect COP 1.0~1.2 at the rated condition cooling, heating modes heating efficiency 0.8~0.95 Page5
Introduction Solar cooling / heating system 2 52.4 m^2 solar collector field 3 50% propylene glycol Natural Gas TO LOAD HX-1 50% in volume of propylene glycol constant flow P1 1 8 CMP TK-1 Cooling water 4 16 kw 2E Absorption Chiller cooling tower 5 7 6 CHW at 7.8C / HW57.2C CHW at 14C / HW50C Solar field pressure Solar field temperature Cooling 0.85Mpa (123psi) >T_ HTR (155C) Heating 0.4Mpa (58psi) > 130C P&ID Diagram of Solar Thermal System (pressurized aqueous solutions of propylene glycol) CHW/HW supply/return 7C/14C 57C/50C Page6
Accomplishment Design and procurement Mass & Energy balance cal. Preliminary design Equipment delivery Engineering construction draw. Page7
Accomplishment System construction and installation Page8
PTSC mathematic model η =η opt thermalloss q& thermalloss q& i q & = q& + q& + q& SolAbs _ g rad _ g _ sky cond _ g conv _ g _ air q & + q& = q& + q& q & = q& + q& cond _ g conv _ a rad _ a conv _ g _ air cond _ bracket rad _ g _ sky q& cond _ sup q& q& SolAbs_ g q& SolAbs_ a q& cond _ a q& rad _ a _ g q& conv _ fluid conv _ a _ g q& cond_ g Accomplishment q& rad _ g _ sky q& conv _ g _ air q & = q& + q& + q& + q& SolAbs _ a conv _ a rad _ a cond _ a cond _ bracket T (in C) At a fixed Y Y T At a fixed X q & = q& cond _ a conv _ fluid X Y R_ cond_sup T base R_ conv_a_g R_ conv_g_air T f R_ conv_f T a1 R_ cond_a T T a2 g1 R_ rad_a_g The thermal network R_ cond_g T g2 R_ rad_g_sky T air T sky fluid X sky ambient air absorber tube glass envelope ambient air sky T > T a _ out > Ta _ in > T fluid > Tg _ in > Tg _ out > T sky Page9
Accomplishment Predicted PTSC performance 0.6 0.59 Efficiency 0.55 0.5 0.45 0.4 0.35 0.3 Syltherm 800 Incident Angle =0 insolation 1100 W/m^2 insolation 1000 W/m^2 insolation 900 W/m^2 insolation 800 W/m^2 insolation 700 W/m^2 insolation 600 W/m^2 insolation 500 W/m^2 insolation 400 W/m^2 Efficiency 0.57 0.55 0.53 0.51 6 m^3/h 7 m^3/h 8 m^3/h 9 m^3/h 10 m^3/h 11 m^3/h 12 m^3/h 13 m^3/h Syltherm 800 Incident Angle =0 Direct normal solar radition 900 W/m^2 0.25 0 50 100 150 200 250 300 350 400 Average Operation Temeprature Above Ambient (oc) BROAD PTSC Efficiency vs Temp & Insolation at 0 Incident Angle 0.49 0 50 100 150 200 250 300 350 400 Average Operation Temeprature Above Ambient (oc) Efficiency 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 Incident angle = 0 Incident angle = 10 INcident angle = 20 Incident angle = 30 Incident angle = 40 Incident angle = 50 Syltherm 800 Direct normal solar radiaiton I_dn=900W/m^2 0 50 100 150 200 250 300 350 400 Average Operation Temeprature Above Ambient (oc) BROAD PTSC Efficiency vs Temp & Incident Angle Percent of energy to total collected 0.65 0.6 0.55 0.5 0.45 Insolation = 900 W/m^2 Incident angle =0 Optical losses vacuum Air 0.4 0 50 100 150 200 250 300 350 400 Solar collector efficiency & air in the annular space Average Operation Temperature Above Ambient (oc) Page10
Accomplishment Predicted energy accounting by model Page11
Accomplishment Preliminary system simulation BUILDING SIMULATION Conditioned fresh air T, RH, air change rate Weather data Occupancy schedule Equipment schedule Lighting schedule Season schedule Cooling set point T,RH Heating set point T,RH SEMCO air units Intelligent Workplace IW T, RH IIW sensible heating / cooling loads IW heating / cooling loads control hot heat transfer fluid Heat from burned gas Pressure relife valve diverter weather in Pittsburgh One -axis solar trough SOLAR COLLECTION LOOP Dual 2E abs. chiller LOAD LOOP Pump_solar mixer Pump_load SOLAR ENERGY SUPPLY SYSTEM SIMULATION Information flow of TRNSYS simulation Page12
Estimated IW solar system performance by system simulation Accomplishment IW solar cooling and heating system might cover 39-50% of cooling load and 5-30% heating based on the system simulation. Page13
Accomplishment System also designed for experiments TO LOAD Parabolic Trough Solar Collectors Heat exchanger HX-2 Pump S4 HX-1 Installed HX-2 to Natural Gas Absorption Chiller Validate PTSC model Evaluate system simulations CMP TK-1 Pump S5 Cooling water Cooling tower Compare absorption chiller vs HX for space heating Page14
Where are we? suggestions Completed system installation Commissioned the system, solar field has be operated at above 150C driving 16kW D.E absorption chiller. Where are we going? Integration with cooling and heating devices Integration of energy supply systems like solar energy, bio-diesel energy supply system System simulation including the integration of various energy supply systems to help design. Economic of solar cooling and heating System design, evaluation of a given application Questions? Page15
Accomplishment Experiments to validate PTSC model Measure PTSC efficiency optical efficiency (no thermal loss) at various elevated temperature at different incidence angle Thermal loss at various elevated temperature through piping Heat capacity T1 HX2 HX1 connect to CHW grid F1 F3 F4 V10 V3 V4 Page16
Experiments to evaluate system simulation Measure system performance for daily or seasonal operation Different load profile Solar radiation control strategy Accomplishment GIVEN HX2, chiller HX1 T7 Connect to CHW grid Load=F4*Cp*(T7-T8) Load 16 kw F1 F3 F4 Time T8 V10 V3 V4 Page17