BROAD Town ☆ Welcome to BROAD ！ © November 2005 1 © November 2005 2 Warm-up Knowledge • • • • • • • • • Absorption Cooling Theory How Absorption Cooling Works Why LiBr？ Energy efficiency Advantages Applications Central A/C system Standard Energy © November 2005 3 © November 2005 4 © November 2005 5 Absorption Cooling Theory making and keeping cooling surrounding special surrounding absorbing heat cooling source supply chiller ambient surrounding © November 2005 6 Absorption Cooling Theory condenser throttling device refrigerant cooling source 1. Getting cooling source supply evaporator driving device chiller refrigerant vapor Refrigerant evaporation Refrigerant make up 2.Maintaining cooling source © November 2005 Keep vacuum condition Absorbing refrigerant vapor 7 Absorption Cooling Theory In Evaporator: Refrigerant water sprays on the extended surface copper tubes of chilled water system Evaporation takes away heat from surroundings Water evaporates: 100 ℃ (212℉) under normal atmospheric pressure 760mm Hg (29.9in Hg) Water can also evaporate: at low temperatures & under vacuum conditions 4℃ (39℉) 6mm Hg (0.24in Hg) © November 2005 8 Absorption Cooling Theory 6mmHg 4 © November 2005 9 Absorption Cooling Theory In Absorber: • Lithium bromide has the ability to absorb water vapor – 63% LiBr solution at 41℃ has a strong affinity for water. Boiling point：1265℃ – Water is refrigerant – LiBr which is the refrigerant absorbent absorbs water vapor continuously and keeps the low pressure condition in the evaporator/absorber vessel – Refrigerant water is made up by condensation of the boiling solution heated by external heat source. © November 2005 10 Absorption Cooling Theory In Generator • External heat source (gas, oil, steam, hot water…) heats the solution – Concentrate it to ~63% (make up the refrigerant absorbent in Absorber) – Generate vapor (make up the refrigerant in Evaporator) © November 2005 11 Absorption Cooling Theory Generator Heat source strong solution weak solution © November 2005 Absorber Water vapour Evaporator cooling load 12 Absorption Cooling Theory Condenser LTG HTG (57mmHg) (57mmHg, 90℃) (690mmHg, 155℃) heating source 63%, 90℃ 63%, 155℃ HTHE LTHE 41℃ 38℃ 42℃ Absorber (6mmHg, 42℃) Evaporator (6mmHg, 4℃) © November 2005 57%, 38℃ 38℃ concentrated solution diluted solution refrigerant vapor refrigerant water cooling water chilled water 13 Absorption Cooling Theory Water vapour Generator Heat source Condenser strong solution Heat exchanger Water vapour weak solution cooling load Absorber Cooling water © November 2005 Evaporator 14 How Absorption Cooling Works © November 2005 15 How Absorption Cooling Works © November 2005 16 © November 2005 17 © November 2005 18 © November 2005 19 © November 2005 20 Why LiBr? . © November 2005 21 Why LiBr ? LiBr Physic Characteristics • LiBr: non-toxic, white crystal particles. Stable, odorless with salty taste in room temperature. • Its chemical characteristics are same as table salt (NaCI). • degenerative, non-volatile and decomposable in the atmosphere but soluble in water. • • • • • • © November 2005 molecular formula： LiBr relative molecular quality：86.844 appearance： white crystal particle density： 3464 kg/m3（25℃） melting point： 549℃ boiling point： 1265℃ 22 Why LiBr ? LiBr Solution’s Physic Characteristics • Solubility: soluble weight in 1L water under certain temperature and pressure. LiBr solubility: 111.2g at 20℃. Saturated solution / balanced state • Crystallization: crystal is to be separated out from saturated water solution when solute is greater than solubility. • Factors to cause crystallization: - temperature - concentration - flow velocity © November 2005 23 Why LiBr ? © November 2005 24 Why LiBr ? Additives • Corrosion Inhibitor - Lithium Chromate - Lithium Molybdate • Energy intensifier • iso-octanol © November 2005 25 Energy Efficiency Measurement of efficiency - Coefficient of Performance (COP) COP= energy out / energy input Primary energy efficiency - IPLV (Integrated Part Load Value) © November 2005 26 Advantages BROAD Absorption cooling offers important advantages • • • • • • • • • • Possibility and effectiveness for heat recovery applications Lower operating costs Reliable and low maintenance cost, longer lifespan Environmentally friendly More functions (and smaller footprint than an electric chiller with boiler) Sound primary energy efficiency Energy safety Safe, quite operation Initial costs quickly offset by energy savings National energy structure © November 2005 27 Energy Selection Applications Choosing an Energy Source for your Air Conditioning System • Energy conservation is an issue increasingly catching the public's attention. As larger portions of the globe race towards development, the strain on the environment and its resources is increasing. The global community has to make a greater effort to protect our future. Furthermore, using energy economically is a smart move for national economies and with regards to individual investments as well. Air conditioning systems are heavy consumers of energy. In evaluating a building's operational costs, it is almost a certainty that the energy used in the AC system covers a large percentage. The selection of a more appropriate energy source and energy saving air conditioning equipment can be key factors in reducing expenses for building owners/tenants. • BROAD recommends a series of proposals relating to energy source and air conditioning equipment selection. These proposals have been implemented numerous times, especially in the European and American markets. They are cutting-edge, yet also very practical. The investment payback period is short, and the system technologies are mature. © November 2005 28 Given a Heat Source, BROAD Can Provide Cooling Primary Energy Heat Equipment Heat Input Chiller Type Function Solar energy Parabolic trough solar collector ≥0.6MPa steam ≥160℃ hot water Direct-fired & steam type Direct-fired & hot water type CHW Geothermal heat (e.g. hot spring) N/A ≥75℃ hot water Single-stage hot water type C Natural gas Turbine 230-350℃ exhaust Single-stage exhaust type CH ≥400℃ exhaust Two-stage exhaust type Direct-fired & exhaust CHW Light oil Internal combustion engine ≥400℃ exhaust ≥90℃ jacket water Two-stage exhaust type Direct-fired & hot water & exhaust type CHW NG Town (coal) gas Town bed gas Coke-oven gas Bio-gas Light oil Bio-energy Fuel cell Thermal power station Industrial furnace Industrial boiler ≥400℃ exhaust ≥0.6MPa steam Two-stage exhaust type Two-stage steam type Direct-fired & exhaust type Direct-fired & steam type CHW Garbage Small garbage incinerator ≥400℃ exhaust Two-stage exhaust type CH Garbage incinerator & steam boiler Steam turbine ≥0.6MPa steam Two-stage steam type C © November 2005 29 Examples of Various Types of Energy-saving Systems © November 2005 30 Examples of Various Types of Energy-saving Systems © November 2005 31 Examples of Various Types of Energy-saving Systems © November 2005 32 Examples of Various Types of Energy-saving Systems © November 2005 33 Examples of Various Types of Energy-saving Systems © November 2005 34 Examples of Various Types of Energy-saving Systems © November 2005 35 Examples of Various Types of Energy-saving Systems © November 2005 36 Brief Introduction to Central Air Conditioning . © November 2005 37 Central A/C System Principle heat transfer by doors & windows ——Summer heat transfer by rooftop Air Con Sun Radiation heat transfer by floor heat transfer by wall © November 2005 38 Central A/C System Principle ——Winter heat transfer by doors & windows heat transfer by rooftop Air Con heat transfer by wall © November 2005 39 Central A/C System Central Air Con System Chiller Terminal System Central Air Conditioning System Water Pumps © November 2005 Cooling Tower Others 40 Central A/C System air… temperature/humidity/ flow… chiller provides heat/cold water Air-cooled heat pump Packaged Air Conditioner Absorption Chiller Chiller Screw Centrifugal Scroll Fan Coil air cools water… heat rejection (& balance) Open, Closed… Round, Square… Counterflow, Transverse… © November 2005 AHU Air Conditioner (terminal) A/C w. pump Hot w. pump Water pumps Cooling Tower Cooling w. pump 41 Central A/C System Other Elements • Water pipe (seamless, zinc-plated steel…) • Air duct (zinc-plated steel, glass fibre reinforced plastic…) • Water valve：regulate / cut off water flow • Air (wind) valve: regulate / cut off air (wind) flow • Water filter • Air filter • Insulation materials： reduce heat loss / prevent surface dewing / avoid scalding © November 2005 42 Standards Standards • JIS B 8622 • ARI 560-2000 • Chinese National Standard © November 2005 43 Energy Energy Sources • Types: conventional/new; primary/secondary; renewable/nonrenewable; clean/not clean • Measurements: kg,m3; kW, Btu, kcal; standard oil… • Quality: temperature/heat value/enthalpy/intensity Heating Value Natural Gas m3 Diesel kg Coke Oven Gas m3 m3 kg Power kWh kcal 8600 10400 4300 24600 12000 860 kWh 10 12 5 28.6 14 1 © November 2005 LPG 44
