Optimization in refrigeration systems
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The document discusses the optimization of refrigeration systems, detailing the design process and the need for energy conservation through innovative concepts. It formulates optimization problems, emphasizing the importance of minimizing costs while considering various constraints and system variables. Case studies illustrate the optimization of components like chillers and condenser coils, while also highlighting eco-design principles and energy-saving strategies for air conditioning.
![Optimum Design of a Refrigeration
System -- problem formulation
Min TCs = FCe + FCc + RCe + RCc +Rcco
TCs= ΣNte(i) Lte Cct +Σ Ntc(i) Ltc Cct + [K Mwe PDe +
K Mwc PDc + 0.746 (BHP) ] Ckw Lh
Variables : Lte , Nte( 1,2) ; Ltc , Ntc (1,7)
No of passes, Fin design, tube layout, etc
Constraints: :
Qe = Qer
; Mwe = Mwer, Twic = Twicr ; Qc = Qcr
Max Vel of water < Vr; Tube lengths within bounds](https://image.slidesharecdn.com/optimizationinrefrigerationsystems-140101055157-phpapp02/85/Optimization-in-refrigeration-systems-8-320.jpg)
Optimization in refrigeration systems
- 2. Synopsis The design Process Need for Optimization How Energy Conservation – innovative concepts
- 3. The Design Process Traditional approach Design of a window air-conditioner What is the basis of choosing ? Condenser Temperature Evaporator temperature No. of Rows Tube diameter
- 4. The Design Process Condenser temp Compressor Power Consumption Condenser size Evaporator Tube Dia Pressure gradient Surface Area / frontal area ? Heat transfer coefficient ? ? Effective temp difference
- 5. Why Optimization ? Increasing Competition Increasing energy costs Stringent energy standards Ecological considerations Availability of computational tools
- 6. Formulation of an Optimization Problem Three basic steps : Objective function Variables Constraints Special features of thermal system Optimization Nature of variables—discrete + continuous We may want to optimize only some equipment NOT the whole system
- 8. Optimum Design of a Refrigeration System -- problem formulation Min TCs = FCe + FCc + RCe + RCc +Rcco TCs= ΣNte(i) Lte Cct +Σ Ntc(i) Ltc Cct + [K Mwe PDe + K Mwc PDc + 0.746 (BHP) ] Ckw Lh Variables : Lte , Nte( 1,2) ; Ltc , Ntc (1,7) No of passes, Fin design, tube layout, etc Constraints: : Qe = Qer ; Mwe = Mwer, Twic = Twicr ; Qc = Qcr Max Vel of water < Vr; Tube lengths within bounds
- 12. Optimizing a Component Case Study 40 TR DX Chiller Min. initial cost design SN No of tubes shell dia baffle cut 1 12 16 20 24 30 1.28 .24 32 32 32 34 2 16 16 17 21 Obj fn pr. at entry psi 1452 77.5 1.07 .324 998 78.7
- 13. Optimizing a Component Case Study: Condenser coil of an AC Min initial cost design Design variable No of Rows No of Ckts Tube Length Tube O/ D Tubes/row Heat Transfer Pressure Drop Base Cost Initial Design 2 2 .585 m 7 mm 23 5080 W 1.0166 bar Rs 6377 Optimize d Design 2 3 .594 m 7 mm 21 5090 W .8438 bar Rs 5940
- 14. ECO – Design of Refrigeration Equipment Life cycle analysis based on emissions
- 15. Reducing Energy Consumption What should be the thermostat settings of a Window AC ? Do we need to maintain 24oC indoors ? Experience of Air conditioned trains . Comfort research shows PPD for 24oC is the same as for 27.2oC. Impact of high outdoor temperatures and short duration of occupancy on “optimal” indoor temperatures
- 16. Reduce Energy Consumption through Innovative Concepts Using stratification to reduce cooling load Window AC + Table fan Regenerative evaporative cooling for “hotdry” climates : “Green AC” Regenerative Evaporative cooling based cool chests for vegetable & fruit retail outlets Desiccant based cooling
- 17. Reduce Energy Consumption through innovative concepts Combining multiple uses -- Customized A/C Solutions e.g. for kitchens, hostels, restaurants Air conditioning, cold water, hot water Multiple indoor and outdoor unit split AC Fuzzy Control + variable speed control for energy saving Variable dead-band thermostats Personal AC
- 18. Reduce Energy Consumption through innovative concepts LPG based AC / refrigerator Bio-mass/Bio-gas energized cold chests for rural areas Low cost Domestic refrigerator without freezer Consumer education
- 19. Thank you !