Why Is Carnot Cycle Not Possible In Heat Pump And Refrigerator?

reversed Carnot cycle pv and Ts diagram

Read: COP of air refrigerator working on reversed carnot cycle with PV and Ts diagram

In working of refrigerator, the term Carnot cycle represents the reversed Carnot cycle. As we know that, between the fixed temperature limits, a heat engine operating on Carnot cycle give highest possible efficiency. Similarly, a refrigerator working on reversed Carnot cycle give the highest possible coefficient of performance. Even though no heat engine and refrigerator used Carnot cycle. This is because that the isentropic process of Carnot cycle requires a high speed of air while the isothermal process of Carnot cycle requires extremely slower speed. This large variation in speed of air is simply not possible.

COP Of Air Refrigerator Working On Reversed Carnot Cycle with PV and Ts Diagram

reversed carnot cycle pv diagram ts diagram

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

What Is Refrigeration Load? Cooling Load, Heating Load

chair pillow radiation curtain window

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.

What is Unit of refrigeration or Rating for Refrigeration - Derivation

refrigeration shop

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 (100kg) of ice at 0°C to the water at the 0°C in 24 hours.

Air Refrigerator Working On Bell-Coleman Cycle with PV and TS Diagram (Reversed Brayton or Joule Cycle)

bell coleman diagram

Fig shows a schematic diagram of Bell-Coleman refrigerator (reverse Brayton or joule cycle). It 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.