The advantages of the steam turbine over steam engine are listed below

1. Steam turbine can run at high speed, it also has a wide range of operating speed.
2. There are no reciprocating parts in a steam turbine, so there is no balancing problem.
3. Fewer moving parts - The mechanism of turbine is simple and do not have links like piston, piston head etc. the operation of turbine quiet and smooth.

Read: Construction and working of Babcock and Wilcox boiler

Advantages and application of Babcock and Wilcox boiler

• The draught loss of Babcock and Wilcox boiler is minimum
• Very high steam generation capacity 20,000 to 40,000 kg/hr
• Inspection during operation is possible.
• Defective tubes can replace readily.
• All portion of Babcock and Wilcox boiler is accessible to inspection, cleaning, and repairing.
• Rapid circulation of water can be made.
• Very quick steaming. This boiler has ability to raise the temperature of water quickly, so they are suitable were to meet sudden demands.

Babcock and Wilcox boiler construction

Babcock and Wilcox boiler is a type of water tube boiler designed by an American firm Babcock & Wilcox. This single drum boiler used when the pressure above 10 bar and capacity of more than 7000kg of stem per hour is required. These are designed to stationary as well as marine purpose.

Introduction to the Air Refrigerator working on reversed Carnot cycle

In these type of refrigerator, a reversed Carnot cycle is considered. For a heat engine, the highest possible efficiency is achieved by the Carnot cycle. Similarly in refrigeration cycle highest possible coefficient of performance is obtained when the system is working on reversed Carnot cycle. However, it is not possible to make an engine operating on the Carnot cycle, or it is not possible to make a refrigerating system working on reversed Carnot cycle. This hypothetical heat cycle is used as a standard of comparison.

- Air Refrigerator working on Bell-Coleman cycle with PV and TS diagram (reversed Brayton or Joule Cycle)
- Mechanism and working of a vapour compression refrigeration system - with PV And TS diagram

Cooling load

Cooling load is defined as the average rate at which the heat is removing from the cold space by refrigeration equipment. Similar to the unit of refrigeration it is also expressed in Ton of refrigeration (TR).  The building design, internal equipment, occupants, and outdoor weather conditions may affect the cooling load. Following are the common sources of heat that contribute to the cooling load of refrigeration equipment.

Unit of refrigeration

Rating for Refrigeration indicates the rate of removal heat. The unit of refrigeration is expressed in terms of ton of refrigeration (TR). One ton of refrigeration is defined as the amount of refrigeration effect (heat transfer rate) produced during uniform melting of one ton (1000kg) of ice at 0°C to the water at the 0°C in 24 hours.

The above figure shows simple vapour compression refrigeration system. In this type of refrigerator, refrigerant undergoes phase changes. It consists of following components.

Fig shows a schematic diagram of Bell-Coleman refrigerator (reverse Brayton or joule cycle). This refrigeration system components consists of a compressor, cooler, Expander, and refrigerator. In this process, heat absorption and rejection follows at the constant pressure; the compression and expansion of process are isentropic.

 

Earlier split cycle engine never matched the efficiency and performance of the conventional IC engine. The main challenges related to the previous split cycle engine are

• Poor breathing (low volumetric efficiency)
• Low thermal efficiency

Poor breathing (low volumetric efficiency)

Read: Centrifugal compressor parts and its function

Centrifugal compressor working on Bernoulli’s fluid dynamic principle. Bernoulli’s principle derived from conservation of energy. In a centrifugal compressor, an additional kinetic energy imparted to the fluid by rotating impeller. Then this kinetic energy gets converted into pressure energy at diffuser.

In a centrifugal compressor, the impeller is connected to a shaft driven by any mechanism. The rotating impeller draws air through the inlet at the center of the impeller and guides the air towards the periphery. During this movement, impeller increases the kinetic energy of air.

At the periphery, the air is guided through a stationary passage known as diffuser where its velocity kinetic energy decreases. According to Bernoulli's law reduction in a velocity cause increase in pressure of the fluid, that is kinetic energy is converted into pressure energy.

Read: Difference between positive displacement compressor and dynamic compressor