Water Cooler condenser, Bottle Cooler and Deep freezer
WATER-COOLED CONDENSERS
- 1. Definition & Function
- A water-cooled condenser is a heat exchanger that removes heat from refrigerant vapor using water instead of air. It is more efficient than air-cooled condensers, especially in large commercial applications.
- 2. Types of Water-Cooled Condensers
| Type | Construction & Working | Application |
|---|---|---|
| Shell and Tube | Refrigerant flows inside tubes, water flows around them, heat is transferred | Used in large HVAC systems & industrial refrigeration |
| Shell and Coil | Refrigerant in shell, water flows through coiled tubes, compact design | Used in water coolers, small industrial plants |
| Double Pipe | Water and refrigerant flow in opposite directions inside pipes | Small-scale applications, limited capacity |
- 3. Capacity Calculation Factors
- Water flow rate
- Condensing temperature
- Heat load
- Efficiency of heat transfer
- 4. Descaling & Maintenance
- Scale buildup (Ca & Mg deposits) reduces efficiency → Regular descaling required
- Cleaning methods: Chemical descaling, brushing, flushing with acid solution
- Check water flow rate & quality to prevent corrosion
EVAPORATIVE CONDENSERS
- 1. Function
- A combination of air-cooled & water-cooled condenser
- Uses water spray + airflow to remove heat
- Ideal for hot climates
- 2. Construction & Working
- Water is sprayed over condenser coils containing hot refrigerant vapor
- Fans blow air over the water, causing it to evaporate → Cools refrigerant
- Remaining water recirculates through the system
- 3. Applications
- Used in large cooling systems, industrial refrigeration, and HVAC
- More energy-efficient than water-cooled condensers
LIQUID RECEIVER & DRIER
- 1. Liquid Receiver (Function & Construction)
- Stores excess refrigerant to balance system operation
- Located after the condenser & before expansion valve
- Prevents refrigerant starvation during fluctuations
- 2. Drier (Types & Application)
- Removes moisture & dirt from refrigerant
- Types:
- Desiccant driers → Use silica gel/molecular sieves to absorb moisture
- Filter driers → Remove contaminants like dust, acid, and metal particles
VISIBLE COOLER & BOTTLE COOLER
- 1. Visible Cooler
- Used in shops, supermarkets, & beverage industries
- Glass door design for easy visibility of stored products
- Uses R-134a refrigerant instead of R-12 (CFC ban)
- 2. Bottle Cooler
- Used for cooling & storing bottles at low temperatures
- Horizontal design, often top-loading
- Rapid cooling feature
- 3. R-12 to R-134a Conversion
- R-12 (CFC) banned due to ozone depletion → Replaced with R-134a or hydrocarbons
- Precautions: Ensure compressor compatibility, change lubricant oil, check seals
DEEP FREEZER
- 1. Description & Function
- Used for freezing & storing food, ice cream, medical supplies
- Works on vapor compression refrigeration cycle
- 2. Construction & Working
- Outer cabinet (insulated) → Prevents heat transfer
- Evaporator coils → Absorb heat
- Compressor → Circulates refrigerant
- Expansion valve → Controls refrigerant flow
- 3. Specifications
- Temperature range: -18°C to -30°C
- Types:
- Chest freezers → Horizontal, more storage
- Upright freezers → Vertical, easy access
- 4. Maintenance & Troubleshooting
| Fault | Cause | Remedy |
|---|---|---|
| Freezer not cooling | Low refrigerant, blocked evaporator | Check refrigerant level, clean coils |
| Excessive ice buildup | Faulty defrost system | Inspect & repair defrost heater |
| Compressor runs continuously | Dirty condenser, thermostat issue | Clean condenser, check thermostat |
- This study guide provides quick revision notes for water-cooled condensers, evaporative condensers, visible coolers, bottle coolers, and deep freezers.
