What are heat pumps and refrigerators (Definitions):-
A heat pump is used to transfer heat from an area at a lower temperature to an area at a higher temperature which is just the opposite of the natural flow of heat. Heat pumps can be used for both heating and cooling the system. For heating the system, it extracts heat from the surrounding and transfers it to the warmer area i.e. the system. Far cooling the system, it extracts heat from the system at a lower temperature and transfers it to the surrounding at a higher temperature.
The reverse flow of heat is not possible without any work input. For this, an energy input should be supplied in the form of work.
In the diagram, the pump is the system for which we need to know the energy balance equation.
Now the energy balance equation for a heat pump is:-
Now COP (Co-efficient Of Performance ) gives the measure of the performance of the heat pump.
The general equation for the co-efficient of performance is given below:-
So, the equation of co-efficient of performance for the heat pump becomes,
A refrigerator is one of the most commonly used appliances in this world. It can be found in almost every home and in many commercial places.
A refrigerator consists of an insulated chamber and a heat pump system.
The main function of the refrigerator is to transfer heat from the interior at a lower temperature to the external surrounding which is at a higher temperature. In the interior of the refrigerator, the temperature is maintained below room temperature.
Refrigerators used mainly used to store and preserve perishable stems and cooling products like cold drinks, ice -cream, etc. The insulation in the refrigerator minimizes the heat exchange with the external environment.
For refrigeration, we need maximum cooling. Maximum cooling is achieved by maximum absorption or extraction of heat from the source.
The work done equation for a heat pump is the same as that of the refrigerator.
In refrigeration, we need maximum absorption of heat from the source. So, the coefficient of performance for refrigerators becomes,
Difference between refrigerator and heat pump: –
The main difference between heat pumps & refrigerators is their objectives. While the main purpose of a heat pump is to either provide heating or cooling by transferring heat from low temperature to high-temperature area. On the other hand, the refrigerator has only one main purpose i.e. to cool the interior by transferring heat from the environment at high temperature to the interior at low temperature.
Detailed difference between the refrigerator and the heat pump is given in the table below:-
|1) Heat Pump can operate in both heating and cooling modes by
# transferring heat from an area at a higher temperature to an area at a lower temperature or
# transferring heat from lower to higher temperatures.
|1) Refrigerators are used to cool and preserve perishable items such as food and beverages.
|2) Heat pumps are used in residential and commercial buildings or houses for heating or cooling or space. Heat pumps are also used in industrial processes where precise temperature control is required.
|2) Refrigerators are commonly used in households, shops, restaurants, and in many other places where small amounts of products are to be cooled or preserved.
|3) In a heat pump, the heated space acts as the high-temperature sink.
|3) Refrigerators are used to maintain a temperature of 0 to 10 degree Celsius which is appropriate for preserving perishable items without freezing them.
|4) In Heat Pump, the evaporator is located inside the room.
|4) In Refrigerators, the evaporator is located in an external space or outside room.
|5) Heat pump work in both ways –
i) for providing warmth it transfers heat from a lower temperature environment and transfers it to the inside area which is at a higher temperature.
ii) For cooling, it transfers heat from the inside area which is at a lower temperature to the environment outside which is at a higher temperature.
|5) Refrigerator works in a one-way refrigeration cycle and extracts heat from the interior and gives it to the external environment for creating and maintaining the lower temperature inside.
|6) In a heat pump, the main objective is to provide temperature control and provide heat or cool an area depending on the requirement.
|6) The heat extracted from the refrigerator’s interior is rejected by the environment through the condenser raising the overall temperature outside.
|7) In Heat Pump, the condenser is located in an external space or outside the room.
|7) In the Refrigerator, the condenser is located in the internal space or inside the room.
In this article, we studied about different differences and similarities between the refrigerator and the heat pump.
Both appliances operate based on the same principle of thermodynamics by transferring heat from colder areas to warmer areas.
Both heat pumps and refrigerators use the refrigeration cycle and working fluid (refrigerant) for their respective processes.
Besides the similarities, both appliances serve different objectives.
So, we can conclude that the basics of the working of a heat pump and refrigerator are the same but serve differe