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NTU Relation:
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The NTU (Number of Transfer Units) relation for a double pipe counter flow heat exchanger with Cmax mixed and Cmin unmixed provides a mathematical relationship between the number of transfer units, heat capacity ratio, and effectiveness of the heat exchanger. It is used to analyze and design heat exchangers.
The calculator uses the NTU relation formula:
Where:
Explanation: This formula calculates the number of transfer units based on the heat capacity ratio and effectiveness of the heat exchanger for the specific configuration where Cmax is mixed and Cmin is unmixed in a counter flow arrangement.
Details: The NTU method is crucial for heat exchanger design and analysis as it provides a direct relationship between heat exchanger effectiveness, heat capacity ratio, and the size of the heat exchanger represented by NTU.
Tips: Enter heat capacity ratio (0 ≤ C ≤ 1) and effectiveness (0 ≤ ε ≤ 1) as dimensionless values. Both values must be within their valid ranges for accurate calculation.
Q1: What does NTU represent in heat exchanger analysis?
A: NTU represents the non-dimensional heat transfer size or thermal size of the exchanger, defined as the ratio of overall thermal conductance to the smaller heat capacity rate.
Q2: What is the range of heat capacity ratio C?
A: The heat capacity ratio C ranges from 0 to 1, where C = Cmin/Cmax.
Q3: What is effectiveness in heat exchanger terminology?
A: Effectiveness is defined as the ratio of the actual heat transfer to the maximum possible heat transfer.
Q4: When is this specific NTU relation applicable?
A: This relation is specifically for double pipe counter flow heat exchangers where Cmax fluid is mixed and Cmin fluid is unmixed.
Q5: What are the limitations of this calculation?
A: This calculation assumes steady-state operation, constant fluid properties, and neglects heat losses to the surroundings. It is specific to the given heat exchanger configuration.