What is parallel flow in heat exchanger?
A parallel flow pattern, also referred to as a cocurrent flow, is one in which the shellside and tubeside fluids flow in the same direction. This is widely seen in double-pipe heat exchangers and can be replicated in shell and tube heat exchangers as well, according to Bright Hub Engineering.
What is the formula for effectiveness of 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 are parallel flow and counter flow 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.
What is parallel flow in fluid mechanics?
Mathematically, a parallel flow is one in which the velocity does not vary in the direction of the flow.
How does parallel flow differ from counter flow?
In the parallel-flow arrangement, the hot and cold fluids enter at the same end, flow in the same direction, and leave at the same end. counter-flow arrangement. In the counter-flow arrangement, the fluids enter at opposite ends, flow in opposite directions, and leave at opposite ends.
How do we determine the total discharge through parallel pipes?
Explanation: Total discharge in parallel pipes are determined by adding the discharges so developed in individual pipes. If Q1 is the discharge through pipe 1 and Q2 is the discharge through pipe 2. Then the total discharge through parallel pipes is equal to Q1+Q2.
How do you calculate heat transfer between two liquids?
We know that heat transfer is calculated by equation Q=m×Cp×ΔT.
What is the maximum efficiency for parallel flow heat exchanger?
What is the maximum efficiency for parallel flow heat exchanger? Explanation: No matter how large the exchanger be or how high be the flow of overflow at transfer coefficient, the maximum efficiency for parallel flow heat exchanger is 5%.
What are the advantages of parallel flow heat exchanger?
While less efficient, the main advantage of parallel heat exchangers is that the exit temperature of the two fluids, and therefore their energies, will be closer to one another than they would be in counter-flow exchangers.
What is NTU and HTU?
H = height of transfer units (HTU) – dimension of length. The number of transfer units (NTU) required is a measure of the difficulty of the separation. A single transfer unit gives the change of composition of one of the phases equal to the average driving force producing the change.
What do you mean by flow through parallel pipes?
Pipes are said to be in parallel when they are so connected that the flow from a pipe branches or divides into two or more separate pipes and then reunite into a single pipe.
What is parallel flow heat exchanger theory?
Parallel flow heat exchanger theory Heat exchanger is defined as a steady flow adiabatic open system. Flow of both fluids (hot fluid and cold fluid) are in the same direction to exchange heat between. It is a categorized as direct transfer type heat exchanger in which fluids do not have any physical contact between them.
What are the disadvantages of a parallel flow heat exchanger?
The temperature profiles of the two heat exchangers indicate two major disadvantages in the parallel-flow design. The large temperature difference at the ends causes large thermal stresses. The temperature of the cold fluid exiting the heat exchanger never exceeds the lowest temperature of the hot fluid.
What are the different types of flow paths in a heat exchanger?
The most common arrangements for flow paths within a heat exchanger are counter-flow and parallel flow. 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…
What is the direction of flow in a parallel flow exchanger?
In a parallel flow exchanger, both fluids in the heat exchanger flow in the same direction. Figure 9 represents the directions of fluid flow in the parallel and counter-flow exchangers.