NON-CONVENTIONAL ENERGY RESOURCES AND UTILISATION 109elements of different age groups and temperatures. This leads to considerable increase in the heat trans-
fer coefficient.
After the technical discussion with the management and technical group in fertilizer industry,
various potential areas where this innovative heat exchanger can replace the existing heat exchangers
were identified. Some of which are: In Ammonia plants: Methanator feed preheater, CO 2 strip reboil/
shift effluent coolers feed gas, CO 2 stripper overhead trim cooler, Lean-solution Cooler (Air cooler),
CO 2 stripper condenser air cooler, CO 2 ejector steam generator, CO 2 ejector steam reboiler, NH 3 refrig-
eration condenser, Lean solution/BFW exchanger and in the Urea plants: Distillation pre-heater, HP
hydrolyser preheater and Distillation tower reboiler.
There is 15–20 percent improvement in heat transfer with 60–70 percent reduction in the ex-
changer area as compared to shell and tube heat exchanger. This device has two-fold advantage of
intensifying the convective transfer processes (i.e., increase heat and mass transfer coefficients) and also
provide increased transfer area per unit volume of space. It offers higher film-coefficient (i.e., the rate at
which heat is transferred through a wall from one fluid to another) and more effective use of available
pressure drop result in efficient and less expensive designs. The Innovative Heat Exchanger geometry
permits handling of high temperatures and extreme temperature differentials without high-induced stresses
or costly expansion joints. The compact size provides a distinct benefit and ease of fabrication and its
performance is substantially closer to plug flow system.
It can, not only work as a heat exchanger but also as inline mixer, separation devices and in
chemical reactors. It has a variety of applications: in coiled membranes blood oxygenators, kidney dialy-
sis devices due to their effectiveness in reducing concentration polarization, chemical reactors due to
increased residence time and minimized axial dispersion, heat exchangers, cryogenic systems, bio-sen-
sors, clean steam generators, natural gas heaters, freeze condensers, chromato graphic columns, sample
coolers and room heaters.
SOLVED EXAMPLES
Example 1. A nuclear fission reaction power plant converts energy in matter to electrical energy
by following energy chain
Energy in Thermal Mechanical Electrical
Matter Energy Energy Energy
Neglecting losses, how much matter is converted into electrical energy per day by a 10 mW
power plant?
Solution. Matter converted = Electrical Energy delivered
Energy delivered = Power × Time
Ee = (10 mW × 10^6 ) × (24 hr × 3600)
= (10^7 W) × (8.64 × 10^4 s)
Ee = 8.64 × 10^11 J
Electrical energy delivered = Matter converted into energy
E 0 = m 0 C^2
m 0 = E/C^2=11
828.64 10 J
(3 10 m/s)×
×= 9.6 × 10–4 kg→→ →