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Presentation on Building a Robust Refrigeration System By P. Sudhir Kumar Frick India Limited What is a Cold Store ? A Cold store is a building or a group of buildings with thermal insulation and a refrigeration system, in which various perishable foodstuffs can be stored for various lengths of times in set conditions of temperature and humidity, thus slowing the deterioration and spoilage that would occur in a natural environment. In some countries cold stores are known as refrigerated warehouses. TYPE OF COLD STORES : PRE-COOLING COLD ROOMS LARGE COLD STORAGES FROZEN STORES IQF/BLAST FREEZING PLATE FREEZING HIGH HUMIDITY CHAMBERS CONTROLLED ATMOSPHERE COLD STORES Planning A Cold Store SITE PRODUCTS STORAGE CONDITIONS MATERIAL HANDLING REFRIGERATION SYSTEMS SELECTION OF SITE A. FACTORS Geographical Economic Factor B. CONSIDERATIONS Proximity to Rail/Roads Possibility of later expansions Water and Power supply Availability of Work Force MAINTAINAING A COLD STORE FOR FINANCIAL VIABILITY Multipurpose Cold Stores Operation round the year Ordinary Single Product Store Operation only for part of a year How a Refrigeration Plant is to be designed ? Capacity of Plant Refrigerant Type of Cooling Direct Secondary Selection of refrigeration equipment Choosing the Right refrigerant Why Ammonia ? Less expensive to install Easy to operate Highly reliable Easy to modify or expand Safe Self-Alarming Environmental issue and natural refrigerants Depletion of Ozone Layer Global Warming Montreal Protocol (1987) Kyoto Protocol (1997) CFC : Fazed out in 1996 Requires : Reduction 6% of green house gases compared to 1990 level (First target annual : 2008~2012) HCFC : Regulation starts in 2004 to be fazed out by 2020 Regulated gases : 3 gases such as HFC Recovery and disposal of Fluoro-carbon (Freon) law : Refrigerants CFC, HCFC, HFC PRTR :Aw (Chemical Control promotion law ) : HCFC22, HCFC123, EG Brine etc. Utilization of natural refrigerants Comparision of refrigerant characteristics 100 years Safety Group COP ratio Refrigeration Capacity Discharge Pressure MPa Discharge Temp. 0C .055 1700 A1 1 1 1.53 57.5 HFC-R134a 0 1300 A1 0.99 0.91 1.02 44.5 HFC-R404A 0 3870 A1/A1 0.89 0.68 1.83 44.8 HFC-R407C 0 1650 A1/A1 0.99 0.99 1.64 53.6 HFC-R410A 0 1980 A1/A1 0.93 1.0 2.41 57.2 HFC-R507A 0 3850 A1 0.88 0.65 1.88 44.4 R717(Ammonia) 0 <1 B2 1.04 6.90 1.55 93.3 R290(Propane) 0 3 A3 0.97 1.71 1.37 44.2 R600a(Isobutane) 0 3 A3 1.01 1.66 0.53 40.0 R744(CO2) 0 1 A1 0.63 0.85 9.0 72.0 Refrigerant HCFC-R22 OD P GWP Tc/Te = 40/00C (Sc = Sh=00C) (Calculated by REFPROP V6.01) ODP : Ozone Depletion Potential COP and Refrigeration capacity ratios are compared with R22 GWP : Global Warming Potential Discharge pressure at discharge temperature of 400C Safety group is according to AHRAE standard safety group 34 A: Lower Toxicity, B : Higher toxicity 1: Nonflammable, 2: Flame resistant 3: Inflammable Ammonia – A Natural Refrigerants Ammonia is a colourless gas that liquefies under pressure and has a pungent odour. Ammonia is considered a natural refrigerant because it occurs in nature’s material cycles. Ammonia is also an ideal refrigerant from a climate protection point of view It contributes neither to ozone depletion nor to global warming . Ammonia has no ozone depletion potential (ODP = 0) and no direct greenhouse effect (GWP = 0). Ammonia is combustible only to a limited degree; its ignition energy is 50 times higher than that of natural gas Source : eurammom-information No.2/August 2005 Ammonia – A Natural Refrigerants Thermodynamic properties :means that its indirect global warming potential is also very low. Plants that use ammonia as opposed to other refrigerants have a better TEWI (Total Equivalent Warming Impact). The TEWI is the sum of the direct global warming impact – caused by the refrigerant lost through leakage and recovery Source : eurammom-information No.2/August 2005 EQUIPMENT FOR THE REFRIGERATION SYSTEM COMPRESSORS CONDENSERS EVAPORATORS RECIRCULATION SYSTEMS AUTOMATION Most Popular & Successful Compressors are : Rotary Twin Screw Compressor Package Reciprocating Compressors Frick India high Speed Reciprocating compressors Capacity Range : 108.9kW to 864 kW CFM Range : 99.4 to 796 Frick India Limited Advantages of High speed Reciprocating Compressors Latest advancement in refrigeration compressor technology now manufactured and assembled in India. Runs at 730 rpm to 1200 rpm. High efficiency and high performance. Smooth unloading system for power saving. Low vibration and noise. Tolerance measured in light bands rather than thousandths of inches. Advance filter removes 95% of contaminants as small as 3 micron in size. Oil pressure is maintained even at very low suction pressure. Double bellows shaft seal. Installation can be done almost anywhere, even at top floor. EVAPORATORS Horizontal Discharge Vertical Discharge CONDENSERS Evaporative Condenser Evaporative Condenser • Less Space, no civil work required. • Less Connected pump & fan motor.(at least 50%) • Combination of S/T Condenser & Atmospheric Condenser. • Run at lower condensing Temp – means BKW / TR of Compressor come down and it will reduce the power cost Ammonia Re-Circulation Systems Superb refrigerant distribution Lower inlet liquid temperature Cut down capital costs Low maintenance Protection of compressors from liquid slugs Tremendous power saving in operation. Advantages of using Re-circulation System Automation system For Refrigeration Plant Controlled Parameters Ease of Operation Flexible Load Power Saving Automation in Refrigeration Plant Operation. Total Plant Control. centralized temperature recorder and interlocking electric circuit for various process controls can be interlocked to your PC/PLC Additional advantageous of VFD drive When an induction motor is connected to a full voltage supply, it draws several times ( up to about 6 times) its rated current. As the load accelerates, the available torque usually drops a little and then rises to a peak while the current remains very high until the motor approaches full speed. By contrast, when a VFD starts a motor, it initially applies a low frequency and voltage to the motor. The starting frequency is typically 2 Hz or less. Thus starting at such a low frequency avoids the high inrush current that occurs when a motor is started by simply applying the utility (mains) voltage by turning on a switch. After the start of the VFD, the applied frequency and voltage are increased at a controlled rate or ramped up to accelerate the load without drawing excessive current. This starting method typically allows a motor to develop 150% of its rated torque while the VFD is drawing less than 50% of its rated current from the mains in the low speed range. A VFD can be adjusted to produce a steady 150% starting torque from standstill right up to full speed. FRICK INDIA LIMITED SAFETY IN COLD STORE FIRE SAFETY Causes of Fire Potential Hazards Fire Prevention in protecting the cold store Fire prevention and fire safety equipment Fire precautions SAFETY FROM ACCIDENTS General precautions Preventing accidents due to poor design Precaution against getting trapped in a freezing room Precaution against refrigerant leak Water safety measures Visit us at : www.frickweb.com Please contact : [email protected] THANK YOU