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Mammoth Product Training. Evaporative Condensing. EVAPORATIVE CONDENSING. What is it?. Condensers. Condensers in refrigeration systems reject the heat absorbed by the refrigerant in the evaporator & the compressor KW (heat of compression)
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Mammoth Product Training Evaporative Condensing
EVAPORATIVE CONDENSING What is it?
Condensers • Condensers in refrigeration systems reject the heat absorbed by the refrigerant in the evaporator & the compressor KW (heat of compression) • Three typical Condenser types: Air, Water and Evaporative cooled
The Power of Evaporation • The Thermodynamic Properties of Water at Saturation • Latent heat of vaporization = 1036 btu/lb H2O • Water changing state from liquid to gas at 100f absorbs 1036 btu/lb
Evaporative Cooling Vs Evaporative Condensing • Both systems use evaporation of water to cool. • Evap cooling --- cools room air. • Evap Condensing ---cools refrigerant gas, no moisture is added to the space.
Evaporative Condenser Construction • Draw Through Design. • Stainless Steel Housings and Sump. • Prime Copper Tube Bundle.
EVAPORATIVE CONDENSING How it works.
How It Works • Water is sprayed over a finless condenser coil • Evaporation assists in the rejection of condenser heat to the atmosphere
Why Evaporative Condensing? • 30% to 40% less compressor KW consumed than air cooled condensing • Less Air over coil, therefore quieter than air cooled condensing • Less coil required so less space on roof for equipment than air cooled.
ASHRAE Systems and Equipment Handbook • “In comparison with an air-cooled condenser, an evaporative condenser requires less coil surface and airflow to reject the same heat, or alternatively, greater operating efficiencies can be achieved by operating at a lower condensing temperature”
ASHRAE Systems and Equipment Handbook • “Also, evaporative condensers typically provide lower condensing temperatures than the cooling tower/water-cooled condenser because the heat and mass transfer steps (between the refrigerant and the cooling water and between the water and ambient air) are more efficiently combined in a single piece of equipment”
Evaporative Condensing ARI - WB = 75 SCT = 95 to 105 F SET = 45 F 88 F
ASHRAE Systems and Equipment Handbook • “Evaporative condensers reduce the water pumping and chemical treatment requirements associated with cooling tower/refrigerant condenser systems”
Water Consumption • Evaporated water of 1.6 gph/ton • Nominal bleed rate of ½ evaporation rate • Total water consumption of 2.4 gph/ton
ASHRAE Systems and Equipment Handbook • “Evaporative condensers are, therefore, the most compact for a given capacity”
How It Works • Condensing temperature becomes a function of the ambient wet bulb temp • The wet bulb depression under the dry bulb temperature, typically 15 to 30 degrees, leads to lower condensing temps than with air-cooled condensing • Design condensing temperatures range from 90 to 105 degrees
Corresponding Pressure for R-22 Condensing Temp of 100F = 200psig Evaporative Condenser Corresponding Pressure for R-22 Condensing Temp of 130F = 300psig Air-cooled Condenser
Reduced Connected kW Wire Size # 350 MCM Wire Size # 2/0 Typical 100 TonAir Cooled Condenser205 Operating Amps 135 kW Typical 100 Ton Evap Cooled Condenser157 Operating Amps 103 kW
Where Can Evaporative Condensing be Used? • Base design is for 75 degree wet bulb temperatures • Only a few locations have up to a 81 degree design wet bulb • Can be used anywhere cooling towers are used • Appropriately applied everywhere
Advantages over Air Cooled Packages • Better Acoustics • Because evap condensers move less air than air cooled units they typically are quieter. • In many areas Lot line noiseis becoming a real issue. • Greater Compressor Life • Evap Condensing Compressors work at lower pressures compared to Compressors applied to Air Cooled Condensers and therefore should last longer
Advantages over Air Cooled Packages • Typically a Smaller Footprint • Because evap condensers move less air than air cooled units they typically are smaller.
Evap Condensing - Benefits: • Lower amp draw • With lower amperage required, evap condensing can be used for applications with limited existing power supply
Lower Operating Cost • 30-40% less compressor kW consumed than air-cooled condensing • Can compete favorably with centrifugal chilled water systems • Reduced kW is the result of lower condensing temperatures
Evaporative CondenserConstruction Details Desirable Design Features: • Ease of Serviceability • Corrosion Resistance • Long Life • Reliability • Quiet Operation • Pleasing Aesthetics
Evaporative CondenserConstruction Details To prevent the possibility of water getting into the building, use a continuously welded stainless steel pan under the sump
Evaporative CondenserConstruction Details Utilize a fully welded, double sloped stainless steel sump
Evaporative CondenserConstruction Details Interlocking stainless panels with no fasteners on the inside
Evaporative CondenserConstruction Details Stainless coil supports
Evaporative CondenserConstruction Details Stainless and ABS tube sheets
Evaporative CondenserConstruction Details Evap condenser coil in the sump
Evaporative Condenser Construction Details • Spray Tree Assembly
Evaporative CondenserConstruction Details • Moisture Eliminator
Evaporative CondenserConstruction Details • Direct Drive Condenser Fans • All Stainless Steel Mounting Frame
Evaporative Condensing • Latest design enhancements • Ultraline evap condensers now available up to 350 tons • Penthouse up to 600 tons in a single sump • Sump basin is double-sloped to be self-draining • All water-side components made of non-corrosive materials - even fan venturis are stainless steel • Condensers fans hinged for easy service access • Basin inlet opens up easily for complete access • Air and water flow increased for even greater efficiency
Water Treatment Objectives • CONTROL and BALANCE of WATER CHEMISTRY • to MINIMIZE: • CORROSION • SCALE • BIOFOULING • USE of WATER • and to MAXIMIZE: • HEAT TRANSFER
Chemical Treatment • Inhibitor- reduces scale and corrosion • Biocide- alternate between two to prevents biological contamination • Chemical pumps- inject chemical into sump • Controller- monitors water and activates chemical pumps and bleed