What is countercurrent flow in heat exchanger?
A counter-flow heat exchanger is one in which the direction of the flow of one of the working fluids is opposite to the direction to the flow of the other fluid. In a parallel flow exchanger, both fluids in the heat exchanger flow in the same direction.
How do you calculate effective heat exchanger?
How do I determine the effectiveness of a heat exchanger?
- From fluid’s properties, calculate the maximum (qmax) and actual heat transfer (q).
- Determine the ratio between the heat capacities of the fluids, Cr = Cmin / Cmáx.
- Calculate the effectiveness as the ratio of the heats, ε = q/qmax.
What is counter current principle?
A biological mechanism in which there is an exchange of a substance between fluids flowing in opposite directions. Engineers have known that efficient and almost complete heat or other exchange could be achieved between two fluids flowing in opposite directions in separate tubes.
What is meant by counter current?
: a current flowing in a direction opposite that of another current.
What is Q MCP ∆ T used for?
The amount of heat gained or lost by a sample (q) can be calculated using the equation q = mcΔT, where m is the mass of the sample, c is the specific heat, and ΔT is the temperature change.
Is UA constant for a heat exchanger?
constant (UA). Heat exchanger analyses usually involve the process of determining the UA required for the process to operate and comparing that to the UA available. The UA required is normally determined based only on thermodynamics.
Why is it called countercurrent exchanger?
Because the blood flow through these capillaries is very slow, any solutes that are reabsorbed into the bloodstream have time to diffuse back into the interstitial fluid, which maintains the solute concentration gradient in the medulla. This passive process is known as countercurrent exchange.
What is the purpose of the counter current exchange?
The purpose of counter current exchange is to maintain a concentration gradient between the two fluids in order to maximize movement from one fluid to the other. The opposite of counter current exchange occurs in concurrent exchange when two fluids flow in the same direction.
What is the correct formula for the rate of heat transfer q from a surface of body?
Exercise Questions :: Steady and Unsteady Heat Transfer
| What is the correct formula for the rate of heat transfer (q) from a surface of body of the area A to the surrounding fluid, when surface of the body is at temperature Ts and the surrounding fluid is | |
|---|---|
| B. | q = h A (Ts – T∞) |
| C. | q = (h/k) A (Ts – T∞) |
| D. | q = (1/h) A (Ts – T∞) |
Why is a countercurrent heat exchanger more efficient?
Counter flow heat exchangers are inherently more efficient than parallel flow heat exchangers because they create a more uniform temperature difference between the fluids, over the entire length of the fluid path.