TEST 2

What is a heat exchanger? (Choose the correct answers):
1. A device that can provide or remove heat from one place.
2. A device that allows the transfer of heat from a hotter fluid to another in less hot.
3. An instrument that measures the amount of heat that exists in the environment.
4. A device that physical-chemical methods to measure the heat of two fluids.
A shell and tube heat exchanger 1-4 mean (choose the correct answers):
1. The cooling fluid circulates 4 times inside the shell and the hot fluid through a tube once.
2. The warm fluid circulates inside the tubes 4 times and 1 time for cooling the fluid inside the shell.
3. The warm fluid circulates 4 times inside the shell and the fluid cooling tubes for 1 time.
4. The cooling fluid circulates inside the tubes 4 times and 1 time for hot fluid inside the shell.
The exchangers are direct contact (choose the correct answers):
1. Evaporators
2. Regenerators
3. Plates
4. Cooling towers
The calculation of the double tube heat exchangers, what hypothesis used for calculating?
1. The convection coefficient (h) are not a function of temperature.
2. Not working with stationary regime.
3. The global coefficient of heat passage (U) is a function of temperature.
4. It works with adiabatic conditions.
The configurations of heat exchangers can be (choose the correct answers):
1. Parallel
2. Cross flow
3. Counter
4. Cold flow
The equations of thermal balance (choose the correct answers):
1. You can not proposed if any of the fluid has a phase change.
2. Must be proposed for each fluid.
3. They referred to the inner or external tube inside.
4. You can not proposed, is just enough to propose the general equation of heat step.
The general equation of heat was propose (select the correct answers):
1. When the area of heat exchange going referenced to the outer tube inside.
2. When the area of heat exchange going referenced to the inner tube inside
3. Only by the configuration a counter.
4. Only for heat exchangers shell and tube very complex.
In the diagrams of distribution of temperature if C1< C2 (choose the correct answers):
1. The only configuration possible is in parallel.
2. The only configuration possible is in counter.
3. Both parallel and counter, ∆t1< ∆t2.
4. Both parallel and counter, ∆t1> ∆t2.
How to solve a design problem with the method of F Factor? (Choose the correct answers).
1. Only with the graph of F factor for the given configuration, and solving for rough estimate.
2. Directly applying the general equation of heat step.
3. Applying the general equation of heat step, the area isolated by the previous calculations and using the factor graph of F.
4. Only the graph with the factor F for the given configuration.
To solve a problem E-NTU method for heat (choose the correct answers):
1. Must be consider the two equations of thermal balance.
2. You should not consider the two equations of thermal balance.
3. It is only necessary to have the E-NTU graph for the given configuration.
4. To use the graphic to calculate NTU, Z is not necessary to calculate it.

TEST 2

GENERAL TEST OF HEAT EXCHANGERS