Heat Exchangers

A condenser is used as a heat exchanger in a large steam power plant in which steam is condensed to liquid water. The condenser is a shell and tube heat exchanger which consists of 1 shell and 20,000 tubes. Water flows t...

Consider a counter-flow heat exchanger with the inlet temperatures of two fluids (1 and 2) being T 1, in = 300 K and T 2, in = 350 K. The heat capacity rates of the two fluids are C 1 = 1000 W/K and C 2 = 400 W/K, and th...

Saturated vapor at 200 °C condenses to saturated liquid at the rate of 150 kg/s on the shell side of a heat exchanger (enthalpy of condensation h fg = 2400 kJ/kg). A fluid with C p = 4 kJ-kg -1 K -1 . enters at 100 °C on...

During open-heart surgery, a patient’s blood is cooled down to 25 °C from 37 ° C using a concentric tube counter-flow heat exchanger. Water enters the heat exchanger at 4 ° C and leaves at 18 ° C. Blood flow rate during...

Saturated steam at $${100^ \circ }C$$ condenses on the outside of a tube. Cold fluid enters the tube at $${20^ \circ }C$$ and exits at $${50^ \circ }C.$$ The value of the Log Mean Temperature Difference $$(LMTD)$$ is ___...

In a counter-flow heat exchanger, water is heated at the rate of $$1.5kg/s$$ from $$\,40{}^ \circ C\,$$ to $$\,80{}^ \circ C\,$$ by an oil entering at $$\,120{}^ \circ C\,$$ and leaving at $$\,60{}^ \circ C\,$$. The spec...

Consider a parallel-flow heat exchanger with area $${A_p}$$ and a counter-flow heat exchanger with area $${A_c}.$$ In both the heat exchangers, the hot stream flowing at $$1$$ $$kg/s$$ cools from $$80{}^ \circ C$$ to $$5...

For a heat exchanger, $$\Delta {T_{\max }}$$ is the maximum temperature difference and $$\Delta {T_{\min }}$$ is the minimum temperature difference between the two fluids. $$LMTD$$ is the log mean temperature difference....

Saturated vapor is condensed to saturated liquid in a condenser. The heat capacity ratio is $${c_r} = {{{c_{\min }}} \over {{c_{\max }}}}.$$ The effectiveness $$(s)$$ of the condenser is.

A balanced counter-flow heat exchanger has a surface area of $$20\,\,{m^2}$$ and overall heat transfer coefficient of $$20$$ $$W/{m^2}$$-$$K$$. Air $$\left( {{C_p} = 1000J/kg - K} \right)$$ entering at $$0.4$$ $$kg/s$$ a...

In a concentric counter flow heat exchanger, water flows through the inner tube at $${25^ \circ }C$$ and leaves at $${42^ \circ }C$$. The engine oil enters at $${100^ \circ }C$$ and flows in the annular flow passage. The...

In a heat exchanger, it is observed that $$\Delta {T_1} = \Delta {T_2},$$ where $$\Delta {T_1}$$ is the temperature difference between the two single phase fluid streams at one end and $$\Delta {T_2}$$ is the temperature...

A double-pipe counter-flow heat exchanger transfers heat between two water streams. Tube side water at $$19$$ liter/s is heated from $${10^ \circ }C$$ to $${38^ \circ }C$$. Shell side water at $$25$$ liter/s is entering...

Water $$\left( {{C_p} = 4.18\,kJ/kg.K} \right)$$ at $${80^ \circ }C$$ enters a counter flow heat exchanger with a mass flow rate of $$0.5kg/s.$$ Air $$\left( {{C_p} = 1\,kJ/kg.\,K} \right)$$ enters at $${80^ \circ }C$$ w...

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 $$(LM...

In a parallel flow heat exchanger operating under steady state, the heat capacity rates (product of specific heat at constant pressure and mass flow rate) of the hot and cold fluid are equal. The hot fluid, flowing at $$...

The $$LMTD$$ of a counter flow heat exchanger is $${20^ \circ }C$$. The cold fluid enters at $${20^ \circ }C$$ and the hot fluid enters at $${100^ \circ }C$$. Mass flow rate of the cold fluid is twice that of the hot flu...

In a counter flow heat exchanger, hot fluid enters at $${65^ \circ }C$$ and cold fluid leaves at $${30^ \circ }C.$$ mass flow rate of the hot fluid is $$1$$ $$Kg/s$$ and that of cold fluid is $$2$$ $$kg/s$$. Specific hea...

Hot oil is cooled from $${80^ \circ }C$$ to $${50^ \circ }C$$ in an oil cooler which uses air as the coolant. The air temperature rises from $${30^ \circ }C$$ to $${40^ \circ }C$$. the designer uses a $$LMTD$$ value of $...

In a condenser, water enters at $${30^ \circ }C$$ and flows at the rate $$1500$$ $$Kg/hr.$$ The condensing steam is at a temperature of $${120^ \circ }C$$ and cooling water leaves the condenser at $${80^ \circ }C$$. Spec...

In a counter flow heat exchanger, for the hot fluid the heat capacity $$= 2kJ/kg$$ $$K,$$ mass flow rate $$= 5 kg/s,$$ inlet temperature $$ = {150^ \circ }C$$, outlet temperature $$ = {100^ \circ }C$$. For the cold fluid...

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

Air enters a counter-flow heat exchanger at $${7^ \circ }C$$ and leaves at $${40^ \circ }C$$. Water enters at $${30^ \circ }C$$ and leaves at $${50^ \circ }C$$. The $$LMTD$$ in deg $$C$$ is

Two fluids, $$A$$ and $$B$$ exchange heat in a counter-current heat exchanger. Fluid $$A$$ enters at $${420^ \circ }C$$ and has a mass flow rate of $$1$$ $$kg/s.$$ Fluid $$B$$ enters at $${20^ \circ }C$$ and also has a m...

A hot fluid at $${200^ \circ }C$$ enters a heat exchanger at a mass flow rate of $${10^4}\,\,kg/hr.$$ Its specific heat is $$2000$$ $$J/kg$$-$$K.$$ It is to be cooled by another fluid entering at $${25^ \circ }C$$ with a...

In certain $$HE,$$ both the fluids have identical mass flow rate-specific heat product. The hot fluid enters at $${76^ \circ }C$$ and leaves at $${47^ \circ }C$$ and the cold fluid entering at $${28^ \circ }C$$ leave at...

In a certain double pipe heat exchanger hot water flows at a rate of $$50,000$$ $$kg/h$$ and gets cooled from $${95^ \circ }C$$ to $${65^ \circ }C$$. At the same time $$50,000$$ $$kg/h$$ of cooling water at $${30^ \circ...

A counter flow heat exchanger is to heat air entering at $${400^ \circ }C$$ with a flow rate of $$6$$ $$kg/s$$ by the exhaust gas entering at $${800^ \circ }C$$ with a flow rate of $$4$$ $$kg/s$$. The overall heat transf...

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

Two streams of fluid of unit constant specific heats and unit mass flow rate exchange thermal energy in an adiabatic heat exchanger. The inlet temps of hot and cold streams are $${300^ \circ }C$$ and $${30^ \circ }C$$ re...

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

A one shell pass, one tube-pass heat exchanger, has counter flow configuration between the shell side and tube side fluids. The total number of tubes within the heat exchanger is $$10$$ and the tube dimensions are $$ID=1...

A double pipe counter flow heat exchanger is to be designed to cool $$12000$$ $$kg/hr$$ of an oil of specific heat $$1.95$$ $$kJ/kgK$$ from $$\,85{}^ \circ C$$ to $$\,55{}^ \circ C$$ by water entering the heat exchanger...

A shell and tube heat exchanger is to be designed for heating pressurized water by means of hot gasses which get cooled the data are as follows Temp of water at the inlet $$ = \,80{}^ \circ C$$ Temp of the water at the o...