In cars, the coolant cools down the engine and prevents overheating. By absorbing heat from the engine,the coolant becomes heated. The coolant is then cooled down by the radiator. A primitive car radiatorcan be considered an unmixed crossflow heat exchanger where cold air from the outside serves as coldfluid that cools down the hot coolant. Assume the average specific heat of air and the coolant are,respectively, 1007 J/kg-K and 3300 J/kg.K. The coolant enters the radiator at 120°C and exits at 50°C.The mass flow rate of the coolant is 0.4 kg/s. The air intake temperature is 20°C and you measuredthe outlet temperature of the air to be 40°C. What is the effectiveness of this radiator? What is theUA of this radiator? Effectiveness and NTU relationships for common heat exchangersEffectiveness as a function of NTU and Cr:Parallel flow:Counter flow:One shell and 2, 4, ... tube passes":n shells and 2n, 4n, ... tube passes*:Cross-flow both unmixed:Cross-flow* Cmar on mixed side:Cross-flow* Cmin on mixed side:All heat exchangers with C, = 0:NTU as a function of e and Cr:Parallel flow:Counter flow:One shell and 2, 4, ... tube passest:n shells and 2n, 4n, ... tube passes¹:Cross-flow both unmixed:Cross-flow" Cmaz on mixed side:Cross-flow* Cmin on mixed side:€ =All heat exchangers with Cr = 0:€ ==1 - exp[-NTU (1 + Cr)]1+ Cr1- exp[-NTU (1 - Cr)]1 - C, exp[-NTU (1 — Cr)]'NTU1+ NTU'when C₂ = 1€1 = 21+ C₂ + (1+C²) ¹1/²€ =1€ == [(²₁₁ ²¹+ )" - ¹] [(²¹²¹)" - c]'1-€1€1Use ₁ and NTU₁ from Eqn. 4€ = 1- expFNTU=(1 - exp{-C, [1 - exp(-NTU)]})NTU=€ = 1 - exp[-C₂¹ (1 - exp[-CrNTU])]€ = 1- exp(- NTU)=[(+)₁ NTU0.22 [exp(-C, NTU0.78) - :1+ exp-NTU₁ (1+ -C²) ¹/21- exp -NTU₁ (1+C²) ¹/2]C₂²-1¹n (6--11),InCrIn [1 - € (1 + Cr)]1+ Cr1 when C₁ = 1€NTU₁ = (1 + C²)-¹/2 In€1 =when Cr < 1F-1F-CrSolve Eqn. 6 numericallyNTU - InNTU=-NTU = nx NTU₁, use NTU₁ is from Eqn. 13 with €₁ as1/n= (Cr-1) ¹/F =1Crln (1-ɛ)when Cr < 1(E = 1).- In [1 + / - In (1 - eCr)]E =2 − (1+Cr)(1+C2) ¹1/2In [Cr In (1 e) + 1](1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(16)NTU=(17)1: If it is only a one-shell heat exchanger, € = ₁ and NTU = NTU₁. If there are n shells, use the ₁ and NTU₁ calculated based on oneshell formulation and calculate final and NTU for the entire heat exchanger. Also note, number of tubes does not directly feature in theseequations, they come in via the total area calculation.*: Single pass crossflow heat exchangers(13)(14)(15)

Answered: Image /qna-images/answer/7a3664ed-5f27-417f-9977-9fdf8e39da6f.jpg

In cars, the coolant cools down the engine and prevents overheating. By absorbing heat from the engine, the coolant becomes heated. The coolant is then cooled down by the radiator. A primitive car radiator can be considered an unmixed crossflow heat exchanger where cold air from the outside serves as cold fluid that cools down the hot coolant. Assume the average specific heat of air and the coolant are, respectively, 1007 J/kg-K and 3300 J/kg.K. The coolant enters the radiator at 120°C and exits at 50°C. The mass flow rate of the coolant is 0.4 kg/s. The air intake temperature is 20°C and you measured the outlet temperature of the air to be 40°C. What is the effectiveness of this radiator? What is the UA of this radiator?

In cars, the coolant cools down the engine and prevents overheating. By absorbing heat from the engine, the coolant becomes heated. The coolant is then cooled down by the radiator. A primitive car radiator can be considered an unmixed crossflow heat exchanger where cold air from the outside serves as cold fluid that cools down the hot coolant. Assume the average specific heat of air and the coolant are, respectively, 1007 J/kg-K and 3300 J/kg.K. The coolant enters the radiator at 120°C and exits at 50°C. The mass flow rate of the coolant is 0.4 kg/s. The air intake temperature is 20°C and you measured the outlet temperature of the air to be 40°C. What is the effectiveness of this radiator? What is the UA of this radiator?

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Related questions

Q: 3. A hydrocarbon stream is to be cooled from 200°F to 130°F using 10,800 lb/h of water with a range…

Q: and leaves at 32 0.078 bar. The velocity of circulating w d and 1.25 mm thickness. Taking the e

A: From the steam table, the enthalpy of the steam water at the inlet and outlet of the condenser…

Q: 2. In the counter flow heat exchanger, the water at 20°C is used to cool the liquid from 80°C to…

Q: Superheated steam from the boiler expands in the turbine from inlet pressure p₁ of 50 bar and…

A: According to our guidelines, we are supposed to answer the 1st three sub parts. Please repost other…

Q: What is the difference between a single stream and a two-stream heat exchanger?

A: Single stream heat exchanger: A single stream heat exchanger is a device that transfers heat between…

Q: Im struggling and I have exam tomorrow! Help idk how to do it

Q: alculate the power in the compressor, W(kW) Calculate the power-heat in the exchanger, Q(kW)…

A: Given data is

Q: Shown below is a heat exchanger used to cool down the liquid in the tube. The shell is well…

Q: Consider a water-to-water counterflow heat exchanger with these specifications. Hot water enters at…

Q: The cold storage room is maintained at T; = -70 °C by two stage vapor-compression refrigeration…

A: hg

Q: An aircraft air conditioner is to be optimized to achieve minimum first cost. During the day the…

Q: The cold storage room is maintained at T; = -70 °C by two stage vapor-compression refrigeration…

Concept explainers

Heat Exchangers

Heat exchangers are the types of equipment that are primarily employed to transfer the thermal energy from one fluid to another, provided that one of the fluids should be at a higher thermal energy content than the other fluid.

Heat Exchanger

The heat exchanger is a combination of two words ''Heat'' and ''Exchanger''. It is a mechanical device that is used to exchange heat energy between two fluids.

Question

In cars, the coolant cools down the engine and prevents overheating. By absorbing heat from the engine,
the coolant becomes heated. The coolant is then cooled down by the radiator. A primitive car radiator
can be considered an unmixed crossflow heat exchanger where cold air from the outside serves as cold
fluid that cools down the hot coolant. Assume the average specific heat of air and the coolant are,
respectively, 1007 J/kg-K and 3300 J/kg.K. The coolant enters the radiator at 120°C and exits at 50°C.
The mass flow rate of the coolant is 0.4 kg/s. The air intake temperature is 20°C and you measured
the outlet temperature of the air to be 40°C. What is the effectiveness of this radiator? What is the
UA of this radiator?

Effectiveness and NTU relationships for common heat exchangers
Effectiveness as a function of NTU and Cr:
Parallel flow:
Counter flow:
One shell and 2, 4, ... tube passes":
n shells and 2n, 4n, ... tube passes*:
Cross-flow both unmixed:
Cross-flow* Cmar on mixed side:
Cross-flow* Cmin on mixed side:
All heat exchangers with C, = 0:
NTU as a function of e and Cr:
Parallel flow:
Counter flow:
One shell and 2, 4, ... tube passest:
n shells and 2n, 4n, ... tube passes¹:
Cross-flow both unmixed:
Cross-flow" Cmaz on mixed side:
Cross-flow* Cmin on mixed side:
€ =
All heat exchangers with Cr = 0:
€ =
=
1 - exp[-NTU (1 + Cr)]
1+ Cr
1- exp[-NTU (1 - Cr)]
1 - C, exp[-NTU (1 — Cr)]'
NTU
1+ NTU'
when C₂ = 1
€1 = 21+ C₂ + (1+C²) ¹1/²
€ =
1
€ =
= [(²₁₁ ²¹+ )" - ¹] [(²¹²¹)" - c]'
1-
€1
€1
Use ₁ and NTU₁ from Eqn. 4
€ = 1- exp
F
NTU=
(1 - exp{-C, [1 - exp(-NTU)]})
NTU=
€ = 1 - exp[-C₂¹ (1 - exp[-CrNTU])]
€ = 1- exp(- NTU)
=
[(+)₁ NTU0.22 [exp(-C, NTU0.78) - :
1+ exp-NTU₁ (1+ -C²) ¹/2
1- exp -NTU₁ (1+C²) ¹/2]
C₂²-1¹n (6--11),
In
Cr
In [1 - € (1 + Cr)]
1+ Cr
1 when C₁ = 1
€
NTU₁ = (1 + C²)-¹/2 In
€1 =
when Cr < 1
F-1
F-Cr
Solve Eqn. 6 numerically
NTU - In
NTU=-
NTU = nx NTU₁, use NTU₁ is from Eqn. 13 with €₁ as
1/n
= (Cr-1) ¹/
F =
1
Cr
ln (1-ɛ)
when Cr < 1
(E = 1).
- In [1 + / - In (1 - eCr)]
E =
2 − (1+Cr)
(1+C2) ¹1/2
In [Cr In (1 e) + 1]
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(16)
NTU=
(17)
1: If it is only a one-shell heat exchanger, € = ₁ and NTU = NTU₁. If there are n shells, use the ₁ and NTU₁ calculated based on one
shell formulation and calculate final and NTU for the entire heat exchanger. Also note, number of tubes does not directly feature in these
equations, they come in via the total area calculation.
*: Single pass crossflow heat exchangers
(13)
(14)
(15)

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

Step 2

Step 3

Step 4

Step 5

Trending now

This is a popular solution!

Step by step

Solved in 5 steps with 5 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

Similar questions

Q1) A heat exchanger is to be designed to heat 32/68 mixture of ethylene glycol and water from 24 ᵒC to 55 ᵒC by a hot water stream from 79 ᵒC to 42 ᵒC. Flow rate of cold stream is 20 kg/s. Inlet pressure for both stream is 50 psi and the maximum pressure drop of 10 psi for cold stream and 8 psi for hot water are permissible. Report valid assumptions made for the design and give required justification. Estimate Heat Transfer, Corrected LMTD, Tube bundle diameter (Using TEMA standards and Codes) and Tube cross sectional area Heat transfer coefficient Overall heat transfer coefficient Pressure Drop (Shell side & Tube Side)
A gas turbine cycle with two stage of compression and two stage of expansion, the overall pressure ratio is 9, air enters each stage of compression at 298 K and each stage of turbine at 1200 K. Determine the thermal efficiency of the cycle under the following conditions:- 1- no heat exchanger is used. 2- ideal regenerator is used
A counterflow heat exchanger operates with hot liquid entering at 200° C and leaving at 160°C. The liquid to be heated enters at 40°C and leaves at 140°C. What is the log mean temperature difference between the hot and cold liquids?
Superheated steam from the boiler expands in the turbine from inlet pressure p₁ of 50 bar and temperature 7 of 487 °C to condenser pressure p2 of 18 kPa. In the condenser, the steam condenses to saturated water. The isentropic efficiency of the turbine ns is 78.0 %. The mass flow of steam 9m,h is 140 kg/s. In the boiler, heat flow rate to the circulating fluid (water/steam) is 458 MW. Read from h,s-diagram and calculate: 1. Enthalpy of the superheated steam h kJ/kg (with zero decimal accuracy) 2. Enthalpy of the steam at turbine outlet after isentropic expansion h₂s kJ/kg (with zero decimal accuracy) 3. Enthalpy of the steam at turbine outlet h₂ kJ/kg (with zero decimal accuracy) 4. Turbine power Pt MW (with one decimal accuracy) 5. Steam content at the turbine outlet X2 kJ/kg (with two decimal accuracy) 6. Enthalpy after condenser h3 kJ/kg (with zero decimal accuracy) 7. Thermal power of condenser Qc 8. Thermal efficiency of the plant n MW (with one decimal accuracy) % (with one…
iii) the exit area of the nozzle. Take Cp = 1.005 kJ/kg-K and R=287 J/kg-K Q.B3. A heat engine operates between two reservoirs at 400°C and 30°C. Half the power produced by the heat engine is used to drive a Carnot heat pump that removes heat from the cold surroundings at 2°C and transfers it to a house maintained at 27°C. The heat engine is absorbing heat at a rate of 5 kJ/s. i) Draw the complete schematic of the device ii) Determine the thermal efficiency of the heat engine iii) Determine the coefficient of performance of the heat pump iv) Determine the rate of heat loss from the house. v) Determine the minimum rate of heat extraction by the heat pump, and vi) the total rate of heat rejection.