## Mathematical modelling and validation of an absorption chiller containing recommendation and conclusion

### engineering

##### Description

ASSIGNMENT REQUIREMENTS

Question: Mathematical modelling and validation of an absorption chiller containing recommendation and conclusion

Overall aim of the assignment:

The main objective of this assignemnt is to highlight methods that can be adopted by potash mining industries for higher potash recovery, which translates to better crop yields and availability of higher quality food. This involves theoretical analysis of an absorption chiller taking into consideration geometry and operation parameters for optimal performance and higher yield of KCl.

I have done the initial part involving highlighting methods for higher potash recovery but now I need help with the theoretical analysis which is the mathematical modelling of absorption chillers. The chillers will provide cold water that will increase the recovery of KCl from the crystallization tank.

Background work done by me:

An absorption chiller consists of an evaporator, generator, absorber, condenser and heat exchanger.

The weak solution (refrigerant mixed with water) is collected in the absorber, and passed through the heat exchanger to the generator. The recycled heat from the system passes through the generator and separates the water from the refrigerant. The refrigerant flows back to the absorber and the water converts to vapor in the evaporator, flows to the condenser and then to a cooling tower. The cooling tower pipe has a lower air pressure than the condenser thus converting the vapor back to cold water. The water flows to the absorption chamber and continues the cycle carrying unwanted heat from the generator and cooling afterwards (https://goenergylink.com/blog/how-absorption-chillers-work/).

NOMENCLATURE

U - Heat transfer coefficient (W/m2.K)

Evap - Evaporator

Abs – Absorber

Gen – Generator

Cond – Condenser

Ref -  refrigerant

Ws- Weak solution

SS – Strong solution

Cp - Specific heat (kJ/kg.K)

ṁ - mass flow rate (kg/s)

X – Concentration

Q – heat transfer rate (kW)

T – temperature (°C)

HX – Heat exchanger

h- enthalpy (kJ/kg)

A – area (m2)