In a condenser of a power plant, the steam condenses at a temperature of $${60^ \circ }C.$$ The cooling water enters at $${30^ \circ }C$$ and leaves at $${45^ \circ }C.$$ The logarithmic mean temperature difference $$(LMTD)$$ of the condenser is

For the same inlet and outlet temperatures of hot and cold fluids, the Log mean temperature Difference $$(LMTD)$$ is

The practice to use steam on the shell side and cooling water on the tube side in condensers of steam power plant is because

In shell and tube heat exchanger, baffles are mainly used to