Types of Refrigeration Systems including Vapour Absorption Refrigeration Cycle (VARC) and Water Combination Systems

In the Basic Refrigeration trade, understanding different types of refrigeration systems is essential for practical and industrial applications. The book “Basic Refrigeration” explains various refrigeration systems, including the widely used vapour compression system and the vapour absorption refrigeration cycle (VARC). It also introduces water-based combination systems used in specific applications.

Introduction to Refrigeration Systems

A refrigeration system is designed to remove heat from a space and maintain a low temperature. Different systems are used depending on the application, efficiency, and available energy sources.

Refrigeration systems are broadly classified based on their working principles and energy sources.

Types of Refrigeration Systems

The main types of refrigeration systems include:

• Vapour Compression Refrigeration System (VCRS)
• Vapour Absorption Refrigeration System (VARS or VARC)
• Air Refrigeration System
• Steam Jet Refrigeration System

Each system has its own advantages and applications.

Vapour Compression Refrigeration System (VCRS)

The vapour compression refrigeration system is the most commonly used system. It works on the principle of compression and expansion of refrigerant.

Main Components

• Compressor
• Condenser
• Expansion device
• Evaporator

This system is widely used in domestic refrigerators, air conditioners, and industrial cooling systems.

Vapour Absorption Refrigeration Cycle (VARC)

The vapour absorption refrigeration cycle (VARC) is an alternative to the vapour compression system. It uses heat energy instead of mechanical energy for operation.

Working Principle

In VARC, a refrigerant is absorbed by an absorbent and later separated using heat. The cycle involves absorption, pumping, heating, condensation, expansion, and evaporation.

Main Components

• Generator
• Absorber
• Pump
• Condenser
• Evaporator

Common Combinations

• Ammonia-Water System: Ammonia is refrigerant, water is absorbent
• Water-Lithium Bromide System: Water is refrigerant, lithium bromide is absorbent

These combinations are used based on temperature requirements and applications.

Advantages of VARC

• Uses low-grade heat energy
• Low maintenance
• Quiet operation

VARC is suitable for places where electricity is limited but heat energy is available.

Disadvantages of VARC

• Lower efficiency compared to VCRS
• Larger size and weight
• Higher initial cost

Despite these limitations, VARC is useful in specific applications.

Air Refrigeration System

The air refrigeration system uses air as the working fluid. It works on the principle of compression and expansion of air.

This system is mainly used in aircraft refrigeration systems.

Steam Jet Refrigeration System

The steam jet refrigeration system uses high-pressure steam to produce a cooling effect. It is used in large-scale industrial applications.

Water-Based Combination Systems

Water-based systems are used in combination with absorbents such as lithium bromide. These systems are commonly used in large air conditioning systems.

In these systems, water acts as a refrigerant, and lithium bromide acts as an absorbent. These systems are efficient for large cooling loads.

Comparison of VCRS and VARC

• VCRS uses mechanical energy; VARC uses heat energy
• VCRS has higher efficiency; VARC has lower efficiency
• VCRS is compact; VARC is larger in size

The choice of system depends on application and energy availability.

Applications of Refrigeration Systems

Refrigeration systems are used in:

• Domestic refrigerators
• Air conditioning systems
• Industrial cooling
• Cold storage and food preservation

Different systems are used based on requirements.

Importance of Refrigeration Systems

Refrigeration systems are essential for maintaining temperature-controlled environments. They help in preserving food, medicines, and industrial products.

Understanding different systems helps technicians select and maintain appropriate systems.

Conclusion

The study of different types of refrigeration systems, including vapour compression and vapour absorption systems, is essential for refrigeration students. Each system has its own advantages and applications.

The book “Basic Refrigeration” provides detailed knowledge of these systems. By understanding these concepts, students can develop technical skills and build a successful career in refrigeration and air conditioning.