Azri punya
Abstract
In this experiment, each of our groups is required to conduct an experiment
based on the distributed test rig by the lecturer. The test rig concentric tube heat
exchanger is a simple heat exchanging mechanism containing if 1 heater, valves
to configure the flow pattern, and 2 flow rate valve controller to control the flow
rate for heated and pipe water. By alternating the pattern of the heat exchanger
valves, we would be able to obtain different set data and thus comparing the
efficiency, temperature profile, and log mean temperature different of parallel
and counter flow condition. Also by using a new way of approach in collecting the
data, which is virtual instrument, allowed us to save a lot of time and gained a
better advantages to prepare for the future industrial needs. A total time of 6
weeks have been used to master and complete this project fully. In the end of
the project, we can utilise the knowledge gain in this experiment and apply in the
daily life by apply in with the highest effectiveness in manipulating the water
temperature to a required range for the best performance on every need.
INTRODUCTION
A heat exchanger are commonly used in practice, and engineer often finds
himself in a position to select a heat exchanger that will archieve a specific
teamperature change in a fliud stream of known mass flow rate, or to predict the
outlet teamperature of the hot and cold fluid streams in a specific heat
exchanger. In application, heat exchanger is device that efficiently transfers
heat from a warmer fluid to a colder fluid. A device we are probably all familiar
with is the automobile radiator. Other applications for heat exchangers are found
in heating and air conditioning systems. Heat exchangers are categorized in
many ways, but the two most common practices are, by the method of
construction, and by the flow arrangements. The analysis for designing an
effective heat exchanger is very important; after all who'd want to be caught on
the side of a deserted desert road with an overheated engine!
After we have learned how to analyze conduction and convection heat transfer in
various systems with different geometries. This information, however, is not very
useful unless it can be applied to practical situations. For this reason we shall
devote this experiment to a prototypical application of heat transfer analysis
known as a heat exchanger.
In this experiment we will study a concentric tube heat exchanger with parallel
and counter flow. For the analysis of this heat exchanger we will need to find
important quantities such as the heat transfer coefficient, power emitted,
absorbed, and lost, the log mean temperature difference, and the overall
efficiency to compare the two types of flow.
The variables that affect the performance of a heat exchanger are the fluids’
physical properties, the fluids’ mass flow rates, the inlet temperature of the
fluids, the physical properties of the heat exchanger materials, the configuration
and area of the heat transfer surfaces, the extent of scale or deposits on the heat
transfer surfaces, and the ambient conditions.
In this project, we are required to run experiment on concentric tube heat
exchanger test rig to determine its effectiveness and rate of heat transfer in
different settings. To aid in obtaining data, we will be using 4 thermocouple
censors on each flow tube. To analyze data obtained, we will be using DASYlab.
LITERATURE REVIEW
Heat exchanger
A heat exchanger is a piece of equipment built for efficient heat transfer from
one medium to another without affecting the other properties of the medium.
The medium is separated by a solid wall, so that they can never mix. They are
widely used in space heating, refrigeration, air conditioning, power plants,
chemical plants, petroleum refineries, natural gas processing and sewage
treatment.
The hot water is pumped through a pipe to an insulated tube for which heat will
be exchanged. The actual heat exchange takes place in the insulated tubing for
which cold water flows concentricity around the hot water tube in two different
flow arrangements. These two arrangements, parallel and counter flow, can be
changed by opening and closing certain valves within the network of hot and
cold water tubing. Each flow arrangement is shown on a diagram located on the
front panel. It is worthwhile to note that the temperature at cold-in changes to
temperature at cold-out when a counter flow arrangement is used. The same
situation applies to the temperature at cold-out, which changes to temperature
cold-in for the counter flow.
The other readings remain the same. The flow rates can be adjusted for both
cold and hot water by turning the valve knobs on the right side of the panel.
Thermometers are located at the inlet, exit and middle of the insulated heat
exchanger tubing for both hot and cold water.
For efficiency, heat exchangers are designed to maximize the surface area of
wall between two walls. In some cases, fin or corrugations will be added to
further increase the efficiency.
Tube exchanger
Shell and tube heat exchangers consist of a series of tubes. One set of
these tubes contain the fluid that must be either heated or cooled. The second
fluids runs over the tubes that are being heated or cooled to act as a exchanger
agent.
OBJECTIVE
i)
ii)
iii)
To compare the effectiveness between parallel flow and counter flow
heat transfer and choose the most effective.
To study the effect of volume flowrate to the performance of the heat
transfer.
To study the effect of inlet temperature to the effectiveness of the heat
tranfer .
Methodology
The test rig is bench-mounted and contained as a unit. This concentric tube heat
exchanger in this experiment is able to operate in either parallel flow or counter
flow just by simply open and close the valves. The heat exchanger is in U shape
2 pass type. The outer surface of the tubes is insulated. Eight k-typed
thermocouples are installed at the tube of the heat exchanger as the sensors for
this experiment. For hot water tube (inner), 2 thermocouples located at the first
and second mixing inlet and 2 thermocouples located at first and second mixing
outlet, and same configuration for the cold water tube (outer). Thus four different
kinds of temperatures will be measured accurately from inlet to outlet for both
hot and cold water. At each end of both hot water and cold water tube was
installed with flow rate valve controller so that different flow rate can be
obtained.This apparatus has a tank with a heater inside to heat water to a
specified temperature. The temperature setting is adjusted at the thermostat on
the front panel. Once the water is heated to the desired temperature it is
transferred by a water pump next to the tank. On the pump there is a knob which
varies the pump pressure.
In this experiment, each of our groups is required to conduct an experiment
based on the distributed test rig by the lecturer. The test rig concentric tube heat
exchanger is a simple heat exchanging mechanism containing if 1 heater, valves
to configure the flow pattern, and 2 flow rate valve controller to control the flow
rate for heated and pipe water. By alternating the pattern of the heat exchanger
valves, we would be able to obtain different set data and thus comparing the
efficiency, temperature profile, and log mean temperature different of parallel
and counter flow condition. Also by using a new way of approach in collecting the
data, which is virtual instrument, allowed us to save a lot of time and gained a
better advantages to prepare for the future industrial needs. A total time of 6
weeks have been used to master and complete this project fully. In the end of
the project, we can utilise the knowledge gain in this experiment and apply in the
daily life by apply in with the highest effectiveness in manipulating the water
temperature to a required range for the best performance on every need.
INTRODUCTION
A heat exchanger are commonly used in practice, and engineer often finds
himself in a position to select a heat exchanger that will archieve a specific
teamperature change in a fliud stream of known mass flow rate, or to predict the
outlet teamperature of the hot and cold fluid streams in a specific heat
exchanger. In application, heat exchanger is device that efficiently transfers
heat from a warmer fluid to a colder fluid. A device we are probably all familiar
with is the automobile radiator. Other applications for heat exchangers are found
in heating and air conditioning systems. Heat exchangers are categorized in
many ways, but the two most common practices are, by the method of
construction, and by the flow arrangements. The analysis for designing an
effective heat exchanger is very important; after all who'd want to be caught on
the side of a deserted desert road with an overheated engine!
After we have learned how to analyze conduction and convection heat transfer in
various systems with different geometries. This information, however, is not very
useful unless it can be applied to practical situations. For this reason we shall
devote this experiment to a prototypical application of heat transfer analysis
known as a heat exchanger.
In this experiment we will study a concentric tube heat exchanger with parallel
and counter flow. For the analysis of this heat exchanger we will need to find
important quantities such as the heat transfer coefficient, power emitted,
absorbed, and lost, the log mean temperature difference, and the overall
efficiency to compare the two types of flow.
The variables that affect the performance of a heat exchanger are the fluids’
physical properties, the fluids’ mass flow rates, the inlet temperature of the
fluids, the physical properties of the heat exchanger materials, the configuration
and area of the heat transfer surfaces, the extent of scale or deposits on the heat
transfer surfaces, and the ambient conditions.
In this project, we are required to run experiment on concentric tube heat
exchanger test rig to determine its effectiveness and rate of heat transfer in
different settings. To aid in obtaining data, we will be using 4 thermocouple
censors on each flow tube. To analyze data obtained, we will be using DASYlab.
LITERATURE REVIEW
Heat exchanger
A heat exchanger is a piece of equipment built for efficient heat transfer from
one medium to another without affecting the other properties of the medium.
The medium is separated by a solid wall, so that they can never mix. They are
widely used in space heating, refrigeration, air conditioning, power plants,
chemical plants, petroleum refineries, natural gas processing and sewage
treatment.
The hot water is pumped through a pipe to an insulated tube for which heat will
be exchanged. The actual heat exchange takes place in the insulated tubing for
which cold water flows concentricity around the hot water tube in two different
flow arrangements. These two arrangements, parallel and counter flow, can be
changed by opening and closing certain valves within the network of hot and
cold water tubing. Each flow arrangement is shown on a diagram located on the
front panel. It is worthwhile to note that the temperature at cold-in changes to
temperature at cold-out when a counter flow arrangement is used. The same
situation applies to the temperature at cold-out, which changes to temperature
cold-in for the counter flow.
The other readings remain the same. The flow rates can be adjusted for both
cold and hot water by turning the valve knobs on the right side of the panel.
Thermometers are located at the inlet, exit and middle of the insulated heat
exchanger tubing for both hot and cold water.
For efficiency, heat exchangers are designed to maximize the surface area of
wall between two walls. In some cases, fin or corrugations will be added to
further increase the efficiency.
Tube exchanger
Shell and tube heat exchangers consist of a series of tubes. One set of
these tubes contain the fluid that must be either heated or cooled. The second
fluids runs over the tubes that are being heated or cooled to act as a exchanger
agent.
OBJECTIVE
i)
ii)
iii)
To compare the effectiveness between parallel flow and counter flow
heat transfer and choose the most effective.
To study the effect of volume flowrate to the performance of the heat
transfer.
To study the effect of inlet temperature to the effectiveness of the heat
tranfer .
Methodology
The test rig is bench-mounted and contained as a unit. This concentric tube heat
exchanger in this experiment is able to operate in either parallel flow or counter
flow just by simply open and close the valves. The heat exchanger is in U shape
2 pass type. The outer surface of the tubes is insulated. Eight k-typed
thermocouples are installed at the tube of the heat exchanger as the sensors for
this experiment. For hot water tube (inner), 2 thermocouples located at the first
and second mixing inlet and 2 thermocouples located at first and second mixing
outlet, and same configuration for the cold water tube (outer). Thus four different
kinds of temperatures will be measured accurately from inlet to outlet for both
hot and cold water. At each end of both hot water and cold water tube was
installed with flow rate valve controller so that different flow rate can be
obtained.This apparatus has a tank with a heater inside to heat water to a
specified temperature. The temperature setting is adjusted at the thermostat on
the front panel. Once the water is heated to the desired temperature it is
transferred by a water pump next to the tank. On the pump there is a knob which
varies the pump pressure.