Air-Cooled Condensers

Transcription

1 CH-RACCTB APR 2015 Replaces CH-RACCTB April 2011 Air-Cooled Condensers Technical Guide Models WSS

2 Table of Contents Features & Options...2 Condenser Selection Performance Data...5 Dimensional Data...5 Dimensional Diagrams...6 Specifications...7 WSS air-cooled condensers are available from 1 through 26 ton models. They are designed for efficient performance and low maintenance. Design Features Horizontal or vertical air discharge Attractive aluminum housing Multi-circuiting at no additional charge Energy efficient fan motors with internal overload protection and permanently lubricated ball bearings Motors wired to a common junction box Coated steel fan guards Fully baffled fan sections to prevent windmilling Available Options 2 Available Factory Options mounted head pressure control valves (consult factory) Temperature or pressure activated fan cycling kits 2 Control power transformer for fan cycling kits (230V standard) Alternate control voltages (115V or 24V) for fan cycling kits Polyester finned or copper fins on condenser coil Industrial coil coatings available (consult factory) Single phase fan motors available on all models Three phase motors available on models /3/60 motors available on models Sealtite wiring on models Variable speed fan motor options available on models (consult factory) 2015 Heatcraft Refrigeration Products, LLC

3 CONDENSER SELECTION Capacity for air-cooled condensers are based on total heat of rejection (THR) at the condenser. THR is equal to net refrigeration at the evaporator (compressor capacity) plus the energy input into the refrigerant by the compressor (heat of compression). The heat of compression will vary depending on the compressor manufacturer, type of compressor and the operating conditions of the compressor. Whenever possible, it is recommended that you obtain the heat of compression value from the compressor manufacturer. If this is not available, the THR can be estimated using the following formula: THR = (Compressor Capacity) * (Heat of Compression Factor, Tables 1 & 2) Table 1 contains heat of compression factors for suction-cooled compressors and Table 2 contains factors for open drive compressors. For refrigeration systems beyond the range of Tables 1 and 2, use the following equations to estimate THR: Table 1. Heat of Compression Factor for Suction-Cooled Compressors Suction Temp. F Condensing Temperature F Open Compressors: THR = Compressor Capacity (BTUH) + (2545) * (Brake Horsepower, BHP) Table 2. Heat of Compression Factor for Open Drive Compressors Suction-Cooled Compressors: THR = Compressor Capacity (BTUH) + (3413 * KW) The condenser capacity is affected by its altitude. If the condenser location is above sea level, an additional correction is required to the THR, as follows: THR (altitude) = THR* altitude Correction Factor, Table 3 The condenser capacity is affected by the refrigerant used in the project. If the refrigerant is not R-404A or R-507A, an additional correction is required to the THR, as follows: THR (refrigerant) = THR Refrigerant Correction Factor, Table 4 Evaporator Condensing Temperature F Temp. F

4 Step 1: Estimate Condenser THR Obtain compressor heat of rejection from compressor manufacturer or calculate condenser THR estimate by multiplying compressor capacity by heat of compression factor from Tables 1 or 2 at given operating conditions. THR = Compressor Capacity *Heat of Compression Factor Step 2: Correct for Altitude If condenser location is above sea level, correct for altitude by multiplying condenser THR by altitude correction factor from Table 3. THR = THR (from Step 1) *Altitude Correction Factor Step 3: Correct for Refrigerant Type If condenser is using a refrigerant other than R-404A/R-570A, correct for alternate refrigerant by dividing condenser THR by refrigerant capacity factor from Table 4. Step 5: Condenser Selection Condenser capacities for 60 Hz operation are in Table 5. Condenser capacities are given in MBH. Convert capacity from Step 3 to MBH by dividing by 1,000. Condenser capacities are given at 10 F, 15 F, 20 F and 30 F condenser T.D. conditions. If Condenser T.D. from Step 4 matches one of these columns, use that column. Otherwise, divide the calculated MBH by the calculated design condenser T.D. from Step 4 and use the 1 F column. Using the appropriate column, read down until you locate a value equal to or slightly larger than the value calculated. Then read horizontally to the left to obtain condenser model number. THR (MBH) = THR (from Step 3) 1,000 THR (MBH/ T.D.) = THR (MBH) Calculated Design Condenser T.D. Step 6: Calculate Actual Condenser T.D. and Condensing Temperature Actual condenser T.D. can be calculated by dividing the design THR by the 1 F T.D. Condenser T.D. Rating. THR = THR (from Step 2) Refrigerant Capacity Factor Actual T.D. = THR (MBH) (Rating at 1 F) Step 4: Calculate Design Condenser T.D. Design Condenser T.D. = Condensing Temp. Ambient Temp. Actual condensing temperature can be calculated by adding the actual condenser T.D. to the design ambient temperature. Actual Condensing Temp. = Ambient Temperature + Actual T.D. Table 3. Altitude Correction Factors Table 4. Refrigerant Capacity Factor Altitude Correction Factor , , , , , , , Refrigerant Capacity Factor R R-134A 0.99 R-407A 0.98* R-407C 0.94* R-407F 0.98* R-410A 1.02 *Correction factors based on midpoint condensing temperature. 4 4

5 CONDENSER PERFORMANCE Table 5. Performance Data for 60 Hz. Total Heat of Rejection MBH kcal/hr WSS Model R404A/R507 1 F T.D. 10 F T.D. 15 F T.D. 20 F T.D. 30 F T.D. 1 C T.D. 6 C T.D. 8 C T.D. 12 C T.D. 17 C T.D. Max. Feeds Available , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Table 6. Performance Data for 50 Hz. WSS Model Total Heat of Rejection kcal/hr R404A/R507 1 C T.D. 6 C T.D. 8 C T.D. 12 C T.D. 17 C T.D ,900 2,500 3,700 5, ,200 2,900 4,400 6, ,500 3,300 5,000 7, ,900 5,100 7,700 10, ,000 8,000 11,900 16,900 8 Max. Feeds Available 040 1,640 9,800 13,100 19,600 27, ,990 11,900 15,900 23,900 33, ,490 14,900 19,900 29,800 42, ,860 17,100 22,900 34,300 48, ,270 19,600 26,100 39,200 55, ,280 25,700 34,300 51,400 72, ,630 27,800 37,000 55,500 78, ,430 32,600 43,400 65,100 92,

6 DIMENSIONAL DATA Diagram 1. Dimensions for WSS Models 1 through 3 2 7/16 62mm 27 5/8 700mm 7/16 Diameter Hole 11mm mm 15 1/4 390mm 8 200mm 9/16 14mm 31 1/4 790mm 37 1/2 950mm 2 51mm mm mm 13/32 x 1/2 Slots 6mm x 13mm Unit legs are removable from units installed for horiziontal air 2 51mm Diagram 2. Dimensions for WSS Models 5 through 26 with Vertical Air Flow 43 1,090mm A Optional External Electrical Box 24 1/2 620mm mm mm 21 1/2 550mm mm 7/8 Diameter Holes 22mm 9 230mm E 8 200mm 1 25mm Diagram 3. Dimensions for WSS Models 5 through 26 with Horizontal Flow 43 1,090mm 2 1/2 64mm 37 1/2 950mm 42 1/2 1,080mm 7/8 Diameter Holes 22mm 9 230mm A E 1 25mm 6 6

7 CONDENSER SPECIFICATION / CONDENSER FAN CYCLING Table 7. Specifications WSS Models CFM/m³h No. Fan Dia. In./mm Motor Data HP 1 FLA 1 HP 2 FLA 2 HP 3 FLA / / / / /3 2.6/1.3 1/ / /3 2.6/1.3 1/ / /3 5.2/2.6 1/ / /3 5.2/2.6 1/ / /3 5.2/2.6 1/ / /3 5.2/2.6 1/ / /3 7.8/3.9 1/ / /3 7.8/3.9 1/ / /3 7.8/3.9 1/ Motor voltage /1/60; 1075 RPM 2 Motor voltage /3/60; 1140 RPM 3 Motor Voltage 575/3/60; 1140 RPM Note: WSS available in 115/1/60 voltage; WSS Models Dimensions Inches/mm Connections ODS (In.) A E Inlet Oulet Max. Feeds Avail. Approx. Net Wt. Lbs./kg /8 3/ /8 5/ /8 5/ /8 7/ /8 7/ (2) 1-1/8 (2) 7/ (2) 1-1/8 (2) 7/ (2) 1-1/8 (2) 7/ (2) 1-3/8 (2) 1-1/ (2) 1-5/8 (2) 1-1/ (2) 1-5/8 (2) 1-1/ (2) 1-5/8 (2) 1-1/ Condenser Fan Cycling WSS models 010 to 026 condensers are available with either ambient or pressure activated fan cycling packages. Head pressure can be controlled by varying the air flow across the coil in response to changes in ambient temperatures or refrigerant pressures. See Table 8 below for minimum ambients for fan cycling. Table 8. Minimum Ambient for Fan Cycling (90 º F./32 º C. Condensing Temperature) Design T.D. WSS Models Fans 30 F. / 17 C. 25 F. / 15 C. 20 F. / 12 C. 15 F. / 8 C. 10 F. / 6 C. 49, 61, 70, , 113,

8 2175 West Park Place Blvd. Stone Mountain, GA Phone: Fax: heatcraftrpd.com Since product improvement is a continuing effort, we reserve the right to make changes in specifications without notice. CH-RACCTB APR 2015