Question

An expansion tank is a necessity in a chilled water cooling network because:

1. The network is a closed loop system
2. It allows for the variation in temperature of chilled water in the chilled water circuit
3. Both A & B
4. None of the above

Answer 1

Ans. We know that domestic refrigerator and chiller used to cool water ( chilled water cooling network ) works on simple vapour compresion refrigeration cycle.

It consists of following components:

1. Evaporator

2. Compressor

3. Condenser

4. Expansion device

In this mainly four process occurs :

Process 1-2- Reversible adiabatic compresion

Process 2-3- Constant pressure heat rejection

Process 3-4- irreversible expansion (throttling)

Process 4-1- constant pressure heat addition.

In expansion process refrigerant which is expanded isentropically in the expansion tank must be cool enough to absorb heat from surrounding. So it is desired to provide expansion tank in chilled water cooling network.

This will allow expansion and then following with heat addition to complete one cycle.

Hence the network is a closed loop system.

It allows for variation in temperature of chilled water in the chilled water circuit due to a process of heat addition we control the temperature of chilled water circuit. Also expansion tank is necessary in vapour compresion refrigeration system. Generally throttle expansion is performed due to its very simple and cheap cost.

We can also use capillary tubes, constant pressure expansion valve, thermostatic expansion valve as desired.

Hence Option C is correct.

Option a & b alone are incorrect because these two statement are true for chilled water circuit.