EJECTOR EXPANSION REFRIGERATION CYCLE (EERC)
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09-01-2011, 06:09 PM


EJECTOR EXPANSION REFRIGERATION CYCLE (EERC)
BY
RAGIL V R
S8, MECHANICAL
S.N.M.I.M.T, MALIANKARA


ABSTRACT
The ejector expansion refrigeration cycle (EERC) is a variant of the standard vapor compression cycle in which an ejector is used to recover part of the work that would otherwise be lost in the expansion valve. In initial testing EERC performance was poor, mainly due to thermodynamic nonequilibrium conditions in the ejector motive nozzle. Modifications were made to correct this problem, and significant performance improvements were found.
Ejector Cycle Refrigeration System is the brand name of DENSO world first ejector cycle technology which won the 2006 Environmental Protection Agency Climate Protection Award. This new technology reduces energy use and greenhouse gas emissions of vehicle air conditioning, refrigeration units and residential heat pumps.
When this technology is installed in a refrigeration unit and combined with other complementary breakthroughs in components and controls, it improves efficiency by more than 50%, leading to a 70% reduction in refrigerant emissions and a 60% reduction in carbon dioxide emissions.

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Contents
Chapter no Chapter name Page no
1 Introduction 7
2 Refrigeration 8
2.1 Unit of refrigeration 8
2.2 Methods of refrigeration 8
2.3 Types of Refrigeration systems 9
2.4 Basic Refrigeration Cycles 9
2.41 The Vapor-Compression Refrigeration Cycle 9
2.42 Ideal Vapor-Compression Refrigeration Cycle 10
2.43 Actual Vapor-Compression Refrigeration Cycle 12
3 Ejector refrigeration cycle 13
3.1 Reason for using ejector instead of expansion valve 14
3.2 Contents of techniques
16
3.3 Applications
20
3.4 Advantages
21
4 Conclusion 22
5 References 23

List of figures
Figure no Description Page no
2.421 Ideal Vapor-Compression Refrigeration Cycle and T-s diagram 11
2.422 The P-h diagram is another convenient diagram often used to illustrate the refrigeration cycle. 11
2.43 Actual Vapor-Compression Refrigeration Cycle 12
3.1 Ejector Cycle Refrigeration Cycle 13
3.11 An ejector 15
3.12 Line diagram showing the working cycle of ejector refrigeration system 16
3.21 Diagram showing the principle of an ejector 17
3.22 Ejector refrigeration cycle constitution 18
3.23 A variable ejector construction 19







List of tables
Table no Description Page no

CHAPTER 1
INTRODUCTION

The ejector expansion refrigeration cycle (EERC) is a variant of the standard vapor compression cycle in which an ejector is used to recover part of the work that would otherwise be lost in the expansion valve. In initial testing EERC performance was poor, mainly due to thermodynamic non-equilibrium conditions in the ejector motive nozzle. Modifications were made to correct this problem, and significant performance improvements were found.
Ejector Cycle Refrigeration System is the brand name of DENSO’s world first ejector cycle technology which won the 2006 Environmental Protection Agency (EPA) Climate Protection Award. This new technology reduces energy use and greenhouse gas emissions of vehicle air conditioning, refrigeration units and residential heat pumps.
When this technology is installed in a refrigeration unit and combined with other complementary breakthroughs in components and controls, it improves efficiency by more than 50%, leading to a 70% reduction in refrigerant emissions and a 60% reduction in carbon dioxide emissions.






Chapter 2
Refrigeration

Refrigeration is the process of removing heat from an enclosed space, or from a substance, and rejecting it elsewhere for the primary purpose of lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.
2.1 Unit of refrigeration
Commercial refrigerators in the US are mostly rated in tons. A much less common definition is: 1 tone of refrigeration is the rate of heat removal required to freeze a metric ton (i.e., 1000 kg) of water at 0 °C in 24 hours.
1 tone of refrigeration = 13,898 kJ/h = 3.861 Kw
2.2 Methods of refrigeration
• Non-cyclic refrigeration
• Cyclic refrigeration
o Vapor-compression cycle
o Vapor absorption cycle
o Gas cycle
• Thermoelectric refrigeration
• Magnetic refrigeration
• Other methods
• They include the Air cycle machine used in aircraft; the Vortex tube used for spot cooling, when compressed air is available; and Thermoacoustic refrigeration using sound waves in a pressurised gas to drive heat transfer and heat exchange.
2.3 Types of Refrigeration systems

• Cascade refrigeration systems
• Multistage compression refrigeration systems
• Multipurpose refrigeration systems
• Liquefaction of gases
• Gas Refrigeration Systems
• Absorption Refrigeration Systems
• Thermoelectric Refrigeration Systems
• Air conditioners
2.4 Basic Refrigeration Cycles
Refrigeration is the process of removing heat from an enclosed space, or from a substance, and rejecting it elsewhere for the primary purpose of lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.
2.41 The Vapor-Compression Refrigeration Cycle
The vapor-compression refrigeration cycle has four components: evaporator, compressor, condenser, and expansion (or throttle) valve. The most widely used refrigeration cycle is the vapor-compression refrigeration cycle. In an ideal vapor-compression refrigeration cycle, the refrigerant enters the compressor as a slightly superheated vapor at a low pressure. It then leaves the compressor and enters the condenser as a vapor at some elevated pressure, where the refrigerant is condensed as heat is transferred to cooling water or to the surroundings. The refrigerant then leaves the condenser as a high-pressure liquid. The pressure of the liquid is decreased as it flows through the expansion valve, and as a result, some of the liquid flashes into cold vapor. The remaining liquid, now at a low pressure and temperature, is vaporized in the evaporator as heat is transferred from the refrigerated space. This vapor then reenters the compressor.
The refrigerant enters the compressor Vapor-compression refrigeration cycles specifically have two additional advantages. First, they exploit the large thermal energy required to change a liquid to a vapor so we can remove lots of heat out of our air-conditioned space. Second, the isothermal nature of the vaporization allows extraction of heat without raising the temperature of the working fluid to the temperature of whatever is being cooled. This is a benefit because the closer the working fluid temperature approaches that of the surroundings, the lower the rate of heat transfer. The isothermal process allows the fastest rate of heat transfer. The cycle operates at two pressures, Phigh and Plow, and the statepoints are determined by the cooling requirements and the properties of the working fluid. Most coolants are designed so that they have relatively high vapor pressures at typical application temperatures to avoid the need to maintain a significant vacuum in the refrigeration cycle.

2.42 Ideal Vapor-Compression Refrigeration Cycle

Process Description
1-2 Isentropic compression
2-3 Constant pressure heat rejection in the condenser
3-4 Throttling in an expansion valve
4-1 Constant pressure heat addition in the evaporator


Fig 4.21 Ideal Vapor-Compression Refrigeration Cycle and T-s diagram



Fig 2.422 the P-h diagram is another convenient diagram often used to illustrate the refrigeration cycle.
2.43 Actual Vapor-Compression Refrigeration Cycle

The working fluid:
We have several working fluids available for use in refrigeration cycles. Four of the most common working fluids are available R-12, R-22, R-134, and ammonia. (Nitrogen is also available for very low temperature refrigeration cycles.) .




Chapter 3
Ejector Cycle Refrigeration System



Fig 3.1 Ejector Cycle Refrigeration Cycle
Ejector cycle is a high-efficiency refrigeration cycle with a significantly improved energy consumption rate, achieved by using a small injector called an ejector.
Refrigeration units with an ejector cycle increase energy efficiency by 60% compared to previous models.
An ejector cycle comprising: a compressor for compressing refrigerant; a high-pressure heat exchanger for radiating heat from high-pressure refrigerant discharged from the compressor; a low-pressure heat exchanger for evaporating low-pressure refrigerant after being decompressed; an ejector including a nozzle for decompressing and expanding the high-pressure refrigerant from the high-pressure heat exchanger; and a gas-liquid separator which separates refrigerant flowing from the ejector into gas refrigerant and liquid refrigerant, the gas-liquid separator having a gas refrigerant outlet connected to a refrigerant suction side of the compressor, and a liquid refrigerant outlet connected to a refrigerant inlet side of the low-pressure heat exchanger, wherein: the ejector further includes an outer wall portion for accommodating the nozzle; and the outer wall portion is disposed at an outer side of the nozzle to define a suction portion having a suction port from which gas refrigerant in the low-pressure heat exchanger is sucked, and a pressure-increasing portion in which gas refrigerant evaporated in the low-pressure heat exchanger is sucked by a high-speed refrigerant flow jetted from the nozzle while the gas refrigerant from the suction portion and refrigerant jetted from the nozzle are mixed, and a pressure of refrigerant to be sucked to the compressor is increased by converting expansion energy to pressure energy; and at least a part of the outer wall portion is made of an insulation material.
In conventional refrigerating units, refrigerant is heated in the compressor and then cooled through exposure to outside air through the condenser. The cooled refrigerant is cooled further through expansion in the expansion valve, reducing the refrigerant pressure. Finally, cooled refrigerant lowers the temperature inside the refrigerator as it passes through the evaporator.

3.1 Reason for using ejector instead of expansion valve
Using an expansion valve, however, creates a vortex in the refrigerant during the expansion process, causing a loss of energy. That's why the new cycle uses an ejector instead of an expansion valve. The ejector injects and expands high-pressure refrigerant at high speed, and uses the energy that previously was lost to increase the compressor suction pressure. The ejector also works as a pump. As a result, the power required for the compressor in an ejector cycle can be reduced to two thirds of the power needed in a conventional cycle using an expansion valve.
Compared to an expansion valve cycle with a similar refrigeration capacity, the overall weight of the new cycle is reduced by 40 percent. The reduction is due to the remarkable miniaturization of the compressor, condenser, and evaporator. This weight reduction increases fuel efficiency by 60 percent and decreases carbon dioxide emissions by 60 percent, which contributes to environmental preservation.


Fig 3.11 an ejector

The refrigerant that runs through the ejector is in a gas and liquid mixture called "two-phase flow." In the past, there was no technology to analyze the complicated flow of two-phase refrigerant, and promoting the efficiency of the ejector itself had been viewed as nearly impossible.
In ejector cycle carbon dioxide, Freon, carbon hydride is used as the refrigerant.


Fig 3.12 line diagram showing the working cycle of ejector refrigeration system

In this ejector cycle, high-temperature high-pressure refrigerant discharged from a compressor 1 is cooled and condensed in a condenser 2. High-pressure refrigerant from the condenser 2 is decompressed in a nozzle of an ejector 4 and is mixed with gas refrigerant sucked from an evaporator 3. Refrigerant flowing out of an outlet of the ejector 4 is introduced into a gas-liquid separator 5 to be separated into gas refrigerant and liquid refrigerant. Gas refrigerant from the gas-liquid separator 5 is introduced to the compressor 1 and liquid refrigerant from the gas-liquid separator 5 is introduced to the evaporator 3 to be evaporated in the evaporator 3.
3.2 Contents of techniques
In a conventional refrigeration cycle, the refrigerant loses part of its kinetic energy in the expansion valve since energy is wasted as heat in generating a vortex in the decompression-expansion process.
Among its physical properties, CO2 refrigerant loses larger amounts of energy compared with usual fluorocarbon refrigerants.
Hence refrigeration cycle that effectively recovers the wasted energy, and thus improves coefficient of performance (COP).
An ejector is used in place of a conventional expansion valve, and an accumulator located downstream from the ejector. The ejector itself consists of a nozzle, mixing unit, and diffuser

Fig 3.21 diagram showing the principle of an ejector
The refrigerant flowing into the nozzle (drive flow) is decompressed at the nozzle to draw the refrigerant from the evaporator (intake flow).
The drive flow and intake flow are mixed until they are homogenized in the mixing unit, reducing the flow velocity and increasing the pressure of the mixture.
The mixture further reduces velocity when it passes through the diffuser with its larger passage, further increasing the pressure. The new ejector refrigeration cycle thus uses the kinetic energy of the refrigerant to increase the pressure, thereby supplementing the power of the compressor.
To secure the required discharge temperature by absorbing heat into the refrigerant, we combined the features of an external heat exchanger and internal heat exchanger by positioning them downstream from the accumulator

Fig 3.22 Ejector refrigeration cycle constitution
The external heat exchanger absorbs heat in the air whereas the internal heat exchanger exchanges heat with the high-side pressure refrigerant.
The external heat exchanger functions most effectively when the feed water temperature is low, whereas the internal heat exchanger is more effective for high temperature feed water.
The ejector efficiency is influenced mainly by its nozzle. An ejector nozzle includes a "throat" and an "exit." The throat adjusts the refrigerant flow rate to assure the required heating capacity and maintains a high-side pressure for high COP, while the exit has a large effect on ejector efficiency. Hence a unique flow restriction mechanism that optimally controls the cross-sectional areas of the throat and exit simultaneously

Fig 3.23 A variable ejector construction






3.3 Applications
Refrigeration application Short descriptions Typical refrigerants used
Domestic refrigeration Appliances used for keeping food in dwelling units R-600a, R-134a

Commercial refrigeration Holding and displaying frozen and fresh food in retail outlets R-134a, R-404A, R-507

Food processing and cold storage Equipment to preserve, process and store food from its source to the wholesale distribution point R-134a, R-407C, R-410A, R-507

Industrial refrigeration Large equipment, typically 25 kW to 30 MW, used for chemical processing, cold storage, food processing and district heating and cooling R-134a, R-404A, R-507, R-717

Transport refrigeration Equipment to preserve and store goods, primarily foodstuffs, during transport by road, rail, air and sea R-134a, R-407C, R-410A

Electronic cooling Low-temperature cooling of CMOS circuitry and other components in large computers and servers R-134a, R-404A, R-507

Medical refrigeration R-134a, R-404A, R-507

Cryogenic refrigeration Ethylene, Helium


3.4 Advantages
• Very mature technology.
• Relatively inexpensive.
• The overall weight of the ejector cycle is reduced by 40 percent than the conventional refrigeration cycle.
• Increase fuel efficiency by 60 percent
• Decreases carbon dioxide emissions by 60 percent, which contributes to environmental preservation.
• Can be driven directly using mechanical energy (water, car/truck motor) or with electrical energy.


Chapter 4
Conclusion

Alongside our development of the new variable ejector refrigeration cycle technology, we also improved the compressor and CO2-water heat exchanger designs. As a result, there is an increase in 30% heating capacity and a COP approximately 20% higher than conventional type.


Chapter 5
References


 denso-europe.com
 patentstorm.us
 jsme.org
 coolingdevice.net
 Refregeration and Air Conditioning by R.S kurmi

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TARUP777
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17-01-2011, 12:54 AM

Respected Sir,
The report doc which you have uploaded has password protection. May i know the password please.

thank you.
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17-01-2011, 09:40 AM

the password is "seminar and presentationproject and implimentations" (please remove double quote)
Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
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18-07-2011, 08:04 PM

do you have eerc ppt?
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18-07-2011, 09:01 PM

pls uplaod ppt for this
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19-07-2011, 09:50 AM


you can refer these page details of " EJECTOR EXPANSION REFRIGERATION CYCLE (EERC)"link bellow
topicideashow-to-ejector-expansion-refrigeration-cycle-eerc
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30-03-2014, 05:19 PM

(17-01-2011, 09:40 AM)project topics Wrote: the password is "seminar and presentationproject and implimentations" (please remove double quote)

this password not working..
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31-03-2014, 09:30 AM

To get full information or details of EJECTOR EXPANSION REFRIGERATION CYCLE please have a look on the pages

topicideashow-to-ejector-expansion-refrigeration-cycle-eerc

if you again feel trouble on EJECTOR EXPANSION REFRIGERATION CYCLE please reply in that page and ask specific fields in EJECTOR EXPANSION REFRIGERATION CYCLE
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