# Chapter 6 Energy Equation for a Control Volume

 To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Chapter 6 Energy Equation for a Control Volume Conservation of Mass and the Control Volume Closed systems: The mass of the system remain constant during a process. Control volumes: Mass can cross the boundaries, and so we must keep track of the amount of mass entering and leaving the control volume. 1

2 A control volume is a volume in space in which one has interest for a particular study or analysis. The surface of this control volume is referred to as a control surface and always consists of a closed surface. The size and shape of the control volume are completely arbitrary and are so defined as to best suit the analysis to be made. The surface may be fixed, or it may move so that it expands or contracts.

3 Conservation of mass: Mass, like energy, is a conserved property, and it cannot be created or destroyed during a process. The rate of change of mass inside the control volume can be different from zero if we add or take a flow of mass out as Rate of change inout or dm dt cv m i m e

4 Mass and Volume Flow Rates Definition of average velocity Volume flow rate Mass flow rate The average velocity V avg is defined as the average speed through a cross section. The volume flow rate is the volume of fluid flowing through a cross section per unit time. 4

5 The First Law of Thermodynamics for a Control Volume The first law of thermodynamics for a control mass Or time rate form E Q W CM E E1 1Q 1W The fluid flowing across the control surface enters or leaves with an amount of energy per unit mass as 1 e u V g Z Whenever a fluid mass enters a control volume at state i, or exits at state e, there is a boundary movement work. Some work is required to push the mass into or out of the control volume. This work is known as the flow work, or flow energy

6 Total Energy of a Flowing Fluid Total energy per unit mass associated with the flow of mass is 1 1 The extension of the first law of thermodynamics from e Pv u Pv V g Z h V g Z E Q W CM Or Or Q W E m ( h ke pe) m ( h ke pe) cv cv cv e e i i

7 For the general control volume we may have several entering or leaving mass flow rates, so a summation over those terms is often needed. The final form of the first law of thermodynamics then becomes As the kinetic and potential energy terms per unit mass appear together with the enthalpy in all the flow terms, a shorter notation is often used 1 1 htot h V g Z hstag h V defining the total enthalpy and the stagnation enthalpy. The shorter equation then becomes

8 The Steady State Process The term steady implies no change with time. We say that a person is running at a steady speed of 5 km per hour, as shown in Figure, if the speed does not change with time. d CV dt 0 A person running at a steady speed of 5 km per hour. The properties of the flow is not changed with time. However, the properties need not be the same in all points of the flow

9 A steady-flow process is concerned primarily with the properties of the fluid entering and leaving the control volume. A steady-state process is primarily interested in the spatial distribution of properties, particularly temperature. Since this is an introductory book we will use the term steady-state process for both. Consider a certain set of assumptions that lead to a reasonable model for this type of process, which we refer to as the steady-state process. 1. The control volume does not move relative to the coordinate frame.

10 . The state of the mass at each point in the control volume does not vary with time. So during a steady-flow process, the total amount of mass contained within a control volume does not change with time (m CV = constant). Then the conservation of mass principle requires that the total amount of mass entering a control volume equal the total amount of mass leaving it. For steady-flow processes, we are interested in the amount of mass flowing per unit time, that is, the mass flow rate. For multiple inlets and exits Conservation of mass principle for a twoinlet one-outlet steady-flow system. Since dm cv dt 0

11 Energy Analysis of Steady-flow Systems Many engineering systems such as power plants operate under steady conditions. Under steady-flow conditions, the fluid properties at an inlet or exit remain constant (do not change with time). Under steady-flow conditions, the mass and energy contents of a control volume remain constant.

12 The First Law of Thermodynamics for a Control Volume The total energy content E of the control volume remain constant for a steady state process so de cv 0 dt and the First Law of Thermodynamics for a steady state process First Law Q W m h m h : cv cv e tot, e i tot, i 3. As for the mass that flows across the control surface, the mass flux and the state of this mass at each discrete area of flow on the control surface do not vary with time. The rates at which heat and work cross the control surface remain constant.

13 Many of the applications of the steady-state model are such that there is only one flow stream entering and one leaving the control volume. For this type of process Single stream First Law: Q W m( h h ) where cv cv tot, e tot, i First Law q w h : tot ie Q m cv q and w W m cv

14 Examples of Steady State Process A number of examples of steady-state processes in which there is one fluid stream entering and one leaving the control volume or more than one fluid stream.

15 Heat Exchanger A steady-state heat exchanger is a simple fluid flow through a pipe or system of pipes, where heat is transferred to or from the fluid. The fluid may be heated or cooled, and may or may not boil, liquid to vapor, or condense, vapor to liquid. Tubular heat exchanger.

16 A heat exchanger can be as simple as two concentric pipes. The heat transfer associated with a heat exchanger may be zero or nonzero depending on how the control volume is selected. Mass and energy balances for the adiabatic heat exchanger in the figure is: 16

17 EXAMPLE 6.3 Consider a water-cooled condenser in a large refrigeration system in which R-134a is the refrigerant fluid. The refrigerant enters the condenser at 1.0 MPa and 60 C, at the rate of 0. kg/s, and exits as a liquid at 0.95 MPa and 35 C. Cooling water enters the condenser at 10 C and exits at 0 C. Determine the rate at which cooling water flows through the condenser. It is reasonable to assume that both kinetic and potential energy changes are negligible. We note that the work is zero, and we make the other reasonable assumption that there is no heat transfer across the control surface. Therefore, the first law, m h m h i i e e Using the subscript r for refrigerant and w for water, we write m ( h ) m ( h ) m ( h ) m ( h ) r i r w i w r e r w e w

18 by considering entire heat exchanger as a control volumes From the R-134a and steam tables, we have (h i ) r = kj/kg, (h i ) w = 4.00 kj/kg (h e ) r = kj/kg, (h i ) w = kj/kg Solving the above equation for m w the rate of flow of water, we obtain ( hi he ) r mw mr kg / s ( h h) e i w by considering two separate control volumes, one having the flow of R-134a across its control surface and the other having the flow of water across its control surface The heat transfer for the control volume involving R-134a is calculated first Q m ( h h ) 0.*( ) kw cv r e i r This is also the heat transfer to the other control volume, for which Qcv kw Q m ( h h ) cv w e i w mw kg / s

19 Nozzles and Diffusers A nozzle is a steady-state device whose purpose is to create a high-velocity fluid stream at the expense of the fluid's pressure. Nozzles and diffusers are shaped so that they cause large changes in fluid velocities and thus kinetic energies. A steady state diffuser is a device constructed to decelerate a high velocity fluid in a manner that results in an increase in pressure of the fluid. In essence, it is the exact opposite of a nozzle. 19

20 Nozzles There is no means to do any work - there are no moving parts. There is little or no change in potential energy and usually little or no heat transfer. Diffusers The assumptions are similar to those for a nozzle, with a large kinetic energy at the diffuser inlet and a small, but usually not negligible, kinetic energy at the exit being the only terms besides the enthalpies remaining in the first law.

21 EXAMPLE 6.4 Steam at 0.6 MPa and 00 C enters an insulated nozzle with a velocity of 50 m/s. It leaves at a pressure of 0.15 MPa and a velocity of 600 m/s. Determine the final temperature if the steam is superheated in the final state and the quality if it is saturated. he Wcv 0 Qcv 0 The first law yields h i V V i e he kj / kg *1000 *1000 The two properties of the fluid leaving that we now know are pressure and enthalpy, and therefore the state of this fluid is determined. Since h e is less than h g and greater than at h f 0.15 MPa (Sat. Temp. 111 C), the quality is calculated. h h xh *6.5 x e = 0.99 f fg x e

22 Throttle A throttling process occurs when a fluid flowing in a line suddenly encounters a restriction in the flow passage. This may be a plate with a small hole in it, as shown in Figure. it may be a partially closed valve protruding into the flow passage, or it may be a change to a tube of much smaller diameter, called a capillary tube. The pressure drop in the fluid is often accompanied by a large drop in temperature, and for that reason throttling devices are commonly used in refrigeration and airconditioning applications.

23 Consider fluid flowing through a one-entrance, one-exit porous plug. The fluid experiences a pressure drop as it flows through the plug. No net work is done by the fluid. Assume the process is adiabatic and that the kinetic and potential energies are neglected; then the conservation of mass and energy equations become

24 The temperature of an ideal gas does not change during a throttling (h = constant) process since h = h(t). During a throttling process, the enthalpy of a fluid remains constant. But internal and flow energies may be converted to each other.

25 EXAMPLE 6.5 Consider the following process, in which ammonia is the refrigerant. The ammonia enters the expansion valve at a pressure of 1.50 MPa and a temperature of 35 C, Its pressure on leaving the expansion valve is 91 kpa. Calculate the quality of the ammonia leaving the expansion valve. We can use standard throttling process analysis and assumptions. The first law reduces to h h From the ammonia tables we get h i = kj/kg (The enthalpy of a slightly compressed liquid is essentially equal to the enthalpy of saturated liquid at the same temperature.) i h h x * e i e x % e e

26 Turbine A turbine is a rotary steady-state machine whose purpose is to produce shaft work at the expense of the pressure of the working fluid. Two general classes of turbines are steam turbines, in which the steam exiting the turbine passes to a condenser, where it is condensed to liquid, and gas turbines, in which the gas usually exhausts to the atmosphere from the turbine. Q W m( h h ) cv cv tot, e tot, i

27 EXAMPLE 6.6 The mass rate of flow into a steam turbine is 1.5 kg/s, and the heat transfer from the turbine is 8.5 kw. Determine the power output of the turbine. Q W m( h h ) Q 8.5kW cv cv tot, e tot, i From the steam tables, h i = kj/kg V i 50 g Zi Inlet 1.5 kj / kg *1000 6* kj / kg 1000 cv Outlet Similarly, for the exit h e = kj/kg and V e kj / kg *1000 3* g Ze 0.09 kj / kg 1000 Therefore, substituting into first law, we obtain

28 Q W m( h h ) cv cv tot, e tot, i 1 1 Q W m h V g Z h V g Z cv cv [( ) e ( ) i] *[( ) W cv Wcv ( )] 678. kw

29 Compressor and Pump The purpose of a steady-state compressor (gas) or pump (liquid) is the same: to increase the pressure of a fluid by putting in shaft work

30 EXAMPLE 6.7 The compressor in a plant receives carbon dioxide at 100 kpa, 80 K, with a low velocity. At the compressor discharge, the carbon dioxide exits at 1100 kpa, 500 K, with velocity of 5 m/s and then flows into a constant-pressure aftercooler (heat exchanger) where it is cooled down to 350 K. The power input to the compressor is 50 kw. Determine the heat transfer rate in the aftercooler. q h3 h kj / kg Q mq 0.45* kw cool Here we assume q = 0 and V 1 = 0, so, getting h from Table q w h tot ie 1 5 w h h1 V kj / kg 000 W c 50 m 0.45 kg / s w 03.8

31 The Transient Process Many processes of interest in thermodynamics involve unsteady flow. For example, filling of closed tanks or discharge from closed. We call this process the transient process, for convenience, recognizing that our model includes specific assumptions that are not always valid. 1. The control volume remains constant relative to the coordinate frame.. The state of the mass within the control volume may change with time, but at any instant of time the state is uniform throughout the entire control volume (or over several identifiable regions that make up the entire control volume). 3. The state of the mass crossing each of the areas of flow on the control surface is constant with time although the mass flow rates may be time varying. 4. The rates at which heat and work cross the control surface remain constant.

32 The overall process occurs during time t. At any instant of time during process, the continuity equation is dm dt cv m m 0 e where the summation is over all areas on the control surface through which flow occurs. Integrating over time t gives the change of mass in the control volume during the overall process i dmcv dt ( m m 1) dt cv The total mass leaving the control volume during time t is 0 and the total mass entering the control volume during time is 0 t t m dt e m dt i m m e i Therefore, for this period of time t, we can write the continuity equation for the transient process as ( m m ) m m 0 1 cv e i

33 In writing the first law of the transient process at any instant of time during the process: Q W E m h m h cv cv cv e tot, e i tot, i Since at any instant of time the state within the control volume is uniform, the first law for the transient process becomes d V Qcv Wcv m u g Z me htot, e mi htot, i dt cv Let us now integrate this equation over time t, during which time we have t t 0 Q dt 0 i tot, i i cv Q V m h dt m h g Z i t V m u g Z dt 0 cv cv t t 0 W dt cv W V m h dt m h g Z 0 e tot, e e V V m u g Z m1 u g Z 1 cv cv e

34 Therefore, for this period of time t, we can write the first law for the transient process as V V Qcv Wcv mu g Z m1 u g Z 1 V V me h g Z mi h g Z As an example of the type of problem for which these assumptions are valid and above equation is appropriate e cv i

35 EXAMPLE 6.11 Steam at a pressure of 1.4 MPa and temperature of 300 C is flowing in a pipe (Figure 6.14). Connected to this pipe through a valve is an evacuated tank. The valve is opened and the tank fills with steam until the pressure is 1.4 MPa, and then the valve is closed. The process takes place adiabatically and kinetic energies and potential energies are negligible. Determine the final temperature of the steam. V V Qcv Wcv mu g Z m1 u g Z 1 V V me h g Z mi h g Z e i We note that Qcv 0 Wcv 0, m e = 0, and (m 1 ) c.v. = 0. We further assume that changes in kinetic and potential energy are negligible. Therefore, the statement of the first law for this process reduces to mihi mu From the continuity equation for this process mi m Therefore, combining the continuity equation with the first law, hi u From the steam tables we obtain h i = u = kj/kg cv

36 Since the final pressure is given as 1.4 MPa, we know two properties at the final state and therefore the final state is determined. The temperature corresponding to a pressure of 1.4 MPa and an internal energy of kj/kg is found to be 45 C.

### Sheet 5:Chapter 5 5 1C Name four physical quantities that are conserved and two quantities that are not conserved during a process.

Thermo 1 (MEP 261) Thermodynamics An Engineering Approach Yunus A. Cengel & Michael A. Boles 7 th Edition, McGraw-Hill Companies, ISBN-978-0-07-352932-5, 2008 Sheet 5:Chapter 5 5 1C Name four physical

### CO 2 41.2 MPa (abs) 20 C

comp_02 A CO 2 cartridge is used to propel a small rocket cart. Compressed CO 2, stored at a pressure of 41.2 MPa (abs) and a temperature of 20 C, is expanded through a smoothly contoured converging nozzle

### DET: Mechanical Engineering Thermofluids (Higher)

DET: Mechanical Engineering Thermofluids (Higher) 6485 Spring 000 HIGHER STILL DET: Mechanical Engineering Thermofluids Higher Support Materials *+,-./ CONTENTS Section : Thermofluids (Higher) Student

### Chapter 7 Energy and Energy Balances

CBE14, Levicky Chapter 7 Energy and Energy Balances The concept of energy conservation as expressed by an energy balance equation is central to chemical engineering calculations. Similar to mass balances

### ME 201 Thermodynamics

ME 0 Thermodynamics Second Law Practice Problems. Ideally, which fluid can do more work: air at 600 psia and 600 F or steam at 600 psia and 600 F The maximum work a substance can do is given by its availablity.

### UNIT 2 REFRIGERATION CYCLE

UNIT 2 REFRIGERATION CYCLE Refrigeration Cycle Structure 2. Introduction Objectives 2.2 Vapour Compression Cycle 2.2. Simple Vapour Compression Refrigeration Cycle 2.2.2 Theoretical Vapour Compression

### C H A P T E R T W O. Fundamentals of Steam Power

35 C H A P T E R T W O Fundamentals of Steam Power 2.1 Introduction Much of the electricity used in the United States is produced in steam power plants. Despite efforts to develop alternative energy converters,

### ES-7A Thermodynamics HW 1: 2-30, 32, 52, 75, 121, 125; 3-18, 24, 29, 88 Spring 2003 Page 1 of 6

Spring 2003 Page 1 of 6 2-30 Steam Tables Given: Property table for H 2 O Find: Complete the table. T ( C) P (kpa) h (kj/kg) x phase description a) 120.23 200 2046.03 0.7 saturated mixture b) 140 361.3

### PG Student (Heat Power Engg.), Mechanical Engineering Department Jabalpur Engineering College, India. Jabalpur Engineering College, India.

International Journal of Emerging Trends in Engineering and Development Issue 3, Vol. (January 23) EFFECT OF SUB COOLING AND SUPERHEATING ON VAPOUR COMPRESSION REFRIGERATION SYSTEMS USING 22 ALTERNATIVE

### THERMODYNAMICS TUTORIAL 5 HEAT PUMPS AND REFRIGERATION. On completion of this tutorial you should be able to do the following.

THERMODYNAMICS TUTORIAL 5 HEAT PUMPS AND REFRIGERATION On completion of this tutorial you should be able to do the following. Discuss the merits of different refrigerants. Use thermodynamic tables for

### Lesson. 11 Vapour Compression Refrigeration Systems: Performance Aspects And Cycle Modifications. Version 1 ME, IIT Kharagpur 1

Lesson Vapour Compression Refrigeration Systems: Performance Aspects And Cycle Modifications Version ME, IIT Kharagpur The objectives of this lecture are to discuss. Performance aspects of SSS cycle and

### An analysis of a thermal power plant working on a Rankine cycle: A theoretical investigation

An analysis of a thermal power plant working on a Rankine cycle: A theoretical investigation R K Kapooria Department of Mechanical Engineering, BRCM College of Engineering & Technology, Bahal (Haryana)

### Mohan Chandrasekharan #1

International Journal of Students Research in Technology & Management Exergy Analysis of Vapor Compression Refrigeration System Using R12 and R134a as Refrigerants Mohan Chandrasekharan #1 # Department

### Optimal operation of simple refrigeration cycles Part I: Degrees of freedom and optimality of sub-cooling

Computers and Chemical Engineering 31 (2007) 712 721 Optimal operation of simple refrigeration cycles Part I: Degrees of freedom and optimality of sub-cooling Jørgen Bauck Jensen, Sigurd Skogestad Department

### Engineering Problem Solving as Model Building

Engineering Problem Solving as Model Building Part 1. How professors think about problem solving. Part 2. Mech2 and Brain-Full Crisis Part 1 How experts think about problem solving When we solve a problem

### Refrigeration and Airconditioning Prof. M. Ramgopal Department of Mechanical Engineering Indian Institute of Technology, Kharagpur

Refrigeration and Airconditioning Prof. M. Ramgopal Department of Mechanical Engineering Indian Institute of Technology, Kharagpur Lecture No. # 22 Refrigeration System Components: Compressor (Continued)

### Condensers & Evaporator Chapter 5

Condensers & Evaporator Chapter 5 This raises the condenser temperature and the corresponding pressure thereby reducing the COP. Page 134 of 263 Condensers & Evaporator Chapter 5 OBJECTIVE QUESTIONS (GATE,

### Development of a model for the simulation of Organic Rankine Cycles based on group contribution techniques

ASME Turbo Expo Vancouver, June 6 10 2011 Development of a model for the simulation of Organic Rankine ycles based on group contribution techniques Enrico Saverio Barbieri Engineering Department University

### 2004 Standard For Performance Rating Of Positive Displacement Refrigerant Compressors And Compressor Units

2004 Standard For Performance Rating Of Positive Displacement Refrigerant Compressors And Compressor Units ANSI/AHRI Standard 540 (formerly ARI Standard 540) IMPORTANT SAFETY RECOMMENDATIONS ARI does not

### Chapter 3.4: HVAC & Refrigeration System

Chapter 3.4: HVAC & Refrigeration System Part I: Objective type questions and answers 1. One ton of refrigeration (TR) is equal to. a) Kcal/h b) 3.51 kw c) 120oo BTU/h d) all 2. The driving force for refrigeration

### High Speed Aerodynamics Prof. K. P. Sinhamahapatra Department of Aerospace Engineering Indian Institute of Technology, Kharagpur

High Speed Aerodynamics Prof. K. P. Sinhamahapatra Department of Aerospace Engineering Indian Institute of Technology, Kharagpur Module No. # 01 Lecture No. # 06 One-dimensional Gas Dynamics (Contd.) We

### FREESTUDY HEAT TRANSFER TUTORIAL 3 ADVANCED STUDIES

FREESTUDY HEAT TRANSFER TUTORIAL ADVANCED STUDIES This is the third tutorial in the series on heat transfer and covers some of the advanced theory of convection. The tutorials are designed to bring the

### Transient Analysis of Integrated Shiraz Hybrid Solar Thermal Power Plant Iman Niknia 1, Mahmood Yaghoubi 1, 2

Transient Analysis of Integrated Shiraz Hybrid Solar Thermal Power Plant Iman Niknia 1, Mahmood Yaghoubi 1, 2 1 School of Mechanical Engineering, Shiraz University, Shiraz, Iran 1, 2 Shiraz University,

### PERFORMANCE ANALYSIS OF VAPOUR COMPRESSION REFRIGERATION SYSTEM WITH R404A, R407C AND R410A

Int. J. Mech. Eng. & Rob. Res. 213 Jyoti Soni and R C Gupta, 213 Research Paper ISSN 2278 149 www.ijmerr.com Vol. 2, No. 1, January 213 213 IJMERR. All Rights Reserved PERFORMANCE ANALYSIS OF VAPOUR COMPRESSION

### Energy Analysis and Comparison of Advanced Vapour Compression Heat Pump Arrangements

Energy Analysis and Comparison of Advanced Vapour Compression Heat Pump Arrangements Stuart Self 1, Marc Rosen 1, and Bale Reddy 1 1 University of Ontario Institute of Technology, Oshawa, Ontario Abstract

### Waste Heat Recovery through Air Conditioning System

International Journal of Engineering Research and Development e-issn: 2278-067X, p-issn : 2278-800X, www.ijerd.com Volume 5, Issue 3 (December 2012), PP. 87-92 Waste Heat Recovery through Air Conditioning

### C. starting positive displacement pumps with the discharge valve closed.

KNOWLEDGE: K1.04 [3.4/3.6] P78 The possibility of water hammer in a liquid system is minimized by... A. maintaining temperature above the saturation temperature. B. starting centrifugal pumps with the

### EJECTOR AIR REMOVAL SYSTEMS ENGINEERING DATA BULLETIN # PVS-80025201-ARS PAGE 1 OF 5

BULLETIN # PVS-80050-ARS PAGE OF 5 GENERAL Air Removal Systems generally consist of dual 00% (twin-element) ejecrs, single 00% surface-type inter- & aftercondensers, suction & discharge isolation valves

### Rusty Walker, Corporate Trainer Hill PHOENIX

Refrigeration 101 Rusty Walker, Corporate Trainer Hill PHOENIX Compressor Basic Refrigeration Cycle Evaporator Condenser / Receiver Expansion Device Vapor Compression Cycle Cooling by the removal of heat

### Analytical Study of Vapour Compression Refrigeration System Using Diffuser and Subcooling

IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-issn: 2278-1684,p-ISSN: 2320-334X, Volume 11, Issue 3 Ver. VII (May- Jun. 2014), PP 92-97 Analytical Study of Vapour Compression Refrigeration

### The final numerical answer given is correct but the math shown does not give that answer.

Note added to Homework set 7: The solution to Problem 16 has an error in it. The specific heat of water is listed as c 1 J/g K but should be c 4.186 J/g K The final numerical answer given is correct but

### LG Electronics AE Company, Commercial Air Conditioning

www.lgeaircon.com New concept Ecofriendly Highefficiency Heating solution Total heating & Hot water Solution for MULTI V LG Electronics AE Company, Commercial Air Conditioning 2 Yeouidodong, Yeongdeungpogu,

### COURSE TITLE : REFRIGERATION AND AIR CONDITIONING COURSE CODE : 4029 COURSECATEGORY : A PERIODS/WEEK : 5 PERIODS/SEMESTER : 90 CREDITS : 4 OBJECTIVES

COURSE TITLE : REFRIGERATION AND AIR CONDITIONING COURSE CODE : 4029 COURSECATEGORY : A PERIODS/WEEK : 5 PERIODS/SEMESTER : 90 CREDITS : 4 TIME SCHEDULE MODULE TOPICS PERIODS 1 Introduction 22 Principles

### Dynamic Process Modeling. Process Dynamics and Control

Dynamic Process Modeling Process Dynamics and Control 1 Description of process dynamics Classes of models What do we need for control? Modeling for control Mechanical Systems Modeling Electrical circuits

### Refrigeration Basics 101. By: Eric Nelson

Refrigeration Basics 101 By: Eric Nelson Basics Refrigeration is the removal of heat from a material or space, so that it s temperature is lower than that of it s surroundings. When refrigerant absorbs

### Characteristics of Evaporators

Characteristics of Evaporators Roger D. Holder, CM, MSME 10-28-2003 Heat or Energy In this paper, we will discuss the characteristics of an evaporator coil. The variance of the operational condenses of

### Comparing Air Cooler Ratings Part 1: Not All Rating Methods are Created Equal

Technical Bulletin By Bruce I. Nelson, P.E., President, Colmac Coil Manufacturing, Inc. Comparing Air Cooler Ratings Part 1: Not All Rating Methods are Created Equal SUMMARY Refrigeration air coolers (evaporators)

### New Trends in the Field of Automobile Air Conditioning

New Trends in the Field of Automobile Air Conditioning E. Janotkova and M. Pavelek Department of Thermomechanics and Environmental Engineering Brno University of Technology, 61669 Brno, Czech Republic

### Troubleshooting HVAC/R systems using refrigerant superheat and subcooling

Troubleshooting HVAC/R systems using refrigerant superheat and subcooling Application Note Troubleshooting and servicing refrigeration and air conditioning systems can be a challenging process for both

### VACUUM REFRIGERATION SYSTEMS

VACUUM REFRIGERATION SYSTEMS CHILL VACTOR The Croll-Reynolds CHILL-VACTOR is a chiller that uses a vapor flashing process. Water has a pressure-temperature relationship which is its boiling point. If its

### AS COMPETITION PAPER 2007 SOLUTIONS

AS COMPETITION PAPER 2007 Total Mark/50 SOLUTIONS Section A: Multiple Choice 1. C 2. D 3. B 4. B 5. B 6. A 7. A 8. C 1 Section B: Written Answer Question 9. A mass M is attached to the end of a horizontal

### C H A P T E R F I V E GAS TURBINES AND JET ENGINES

169 C H A P T E R F I V E GAS TURBINES AND JET ENGINES 5.1 Introduction History records over a century and a half of interest in and work on the gas turbine. However, the history of the gas turbine as

### We will try to get familiar with a heat pump, and try to determine its performance coefficient under different circumstances.

C4. Heat Pump I. OBJECTIVE OF THE EXPERIMENT We will try to get familiar with a heat pump, and try to determine its performance coefficient under different circumstances. II. INTRODUCTION II.1. Thermodynamic

### CPX/HT Series. REFRIGERATED AND HIGH TEMPERATURE DRYER 12 to 2400 CFM. High-performance products. Designed for you!

CPX/HT Series REFRIGERATED AND HIGH TEMPERATURE DRYER 12 to 2400 CFM High-performance products. Designed for you! COMPRESSED AIR WATER CONTAMINATION Atmospheric air contains water in vapor form in different

### ORC TURBOGENERATOR TYPE CHP - Organic Rankine Cycle Turbogenerator fed by thermal oil, for the combined production of electric energy and heat -

Doc. : 08C00031_e Date : 10.02.2009 Page : 1 / 9 ORC TURBOGENERATOR TYPE CHP - Organic Rankine Cycle Turbogenerator fed by thermal oil, for the combined production of electric - (Preliminary) Doc. : 08C00031_e

### Evaluation Of Hybrid Air- Cooled Flash/Binary Power Cycle

INL/CON-05-00740 PREPRINT Evaluation Of Hybrid Air- Cooled Flash/Binary Power Cycle Geothermal Resources Council Annual Meeting Greg Mines October 2005 This is a preprint of a paper intended for publication

### SECTION 5 COMMERCIAL REFRIGERATION UNIT 22 CONDENSERS

SECTION 5 COMMERCIAL REFRIGERATION UNIT 22 CONDENSERS UNIT OBJECTIVES After studying this unit, the reader should be able to explain the purpose of the condenser in a refrigeration system. describe differences

### Steam System Efficiency. Bill Lumsden Leidos Engineering

Steam System Efficiency Bill Lumsden Leidos Engineering Steam System Efficiency Steam System Efficiency Key Take-aways: Review of the properties of ice, water, and steam Learn the basics of steam trap

### ASHRAE Boston Chapter Meeting Designing AC Refrigeration Systems Lessons Learned February 11, 2014

ASHRAE Boston Chapter Meeting Designing AC Refrigeration Systems Lessons Learned February 11, 2014 Explanation of the refrigeration cycle. Compressors. Benefits and operating characteristics. -Reciprocating

### 18 Q0 a speed of 45.0 m/s away from a moving car. If the car is 8 Q0 moving towards the ambulance with a speed of 15.0 m/s, what Q0 frequency does a

First Major T-042 1 A transverse sinusoidal wave is traveling on a string with a 17 speed of 300 m/s. If the wave has a frequency of 100 Hz, what 9 is the phase difference between two particles on the

### Energy Procedia Energy 00 Procedia (2011) 000 000 14 (2012) 56 65

Available online at www.sciencedirect.com Available online at www.sciencedirect.com Energy Procedia Energy 00 Procedia (2011) 000 000 14 (2012) 56 65 Energy Procedia www.elsevier.com/locate/procedia ICAEE

### Comparison of fin-and-tube interlaced and face split evaporators with flow maldistribution

Downloaded from orbit.dtu.dk on: Nov 06, 2015 Comparison of fin-and-tube interlaced and face split evaporators with flow maldistribution and compensation Kærn, Martin Ryhl; Elmegaard, Brian; Larsen, L.F.S.

### A Comparison of an R22 and an R410A Air Conditioner Operating at High Ambient Temperatures

R2-1 A Comparison of an R22 and an R410A Air Conditioner Operating at High Ambient Temperatures W. Vance Payne and Piotr A. Domanski National Institute of Standards and Technology Building Environment

### COGENERATION. This section briefly describes the main features of the cogeneration system or a Combined Heat & Power (CHP) system. 36 Units.

COGENERATION 1. INTRODUCTION... 1 2. TYPES OF COGENERATION SYSTEMS... 2 3. ASSESSMENT OF COGENERATION SYSTEMS... 10 4. ENERGY EFFICIENCY OPPORTUNITIES... 14 5. OPTION CHECKLIST... 16 6. WORKSHEETS... 17

### Increasing the evaporation temperature with the help of an internal heat exchanger

Increasing the evaporation temperature with the help of an internal heat exchanger A. TAMBOVTSEV (a), H. QUACK (b) (a,b) Technische Universität Dresden, D-01062, Dresden, Germany (a) Fax: (+49351) 463-37247,

### Steam Generation Efficiency Module Blowdown Losses Section

Steam End User Training Steam Generation Efficiency Module Blowdown Losses Section Slide 1 Blowdown Losses Module This section will discuss blowdown loss and its affect on boiler efficiency. [Slide Visual

### The Second Law of Thermodynamics

Objectives MAE 320 - Chapter 6 The Second Law of Thermodynamics The content and the pictures are from the text book: Çengel, Y. A. and Boles, M. A., Thermodynamics: An Engineering Approach, McGraw-Hill,

### SECTION 5 COMMERCIAL REFRIGERATION UNIT 21 EVAPORATORS AND THE REFRIGERATION SYSTEM

SECTION 5 COMMERCIAL REFRIGERATION UNIT 21 EVAPORATORS AND THE REFRIGERATION SYSTEM UNIT OBJECTIVES After studying this unit, the reader should be able to Define high-, medium-, and low-temperature refrigeration.

### = 1.038 atm. 760 mm Hg. = 0.989 atm. d. 767 torr = 767 mm Hg. = 1.01 atm

Chapter 13 Gases 1. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. Gases have volumes that depend on their conditions, and can be compressed or expanded by

### Condensate Treatment Solutions. CTS Series Eliminator II Oil-Water Separators

Condensate Treatment Solutions CTS Series Eliminator II Oil-Water Separators 2 Condensate Treatment Solutions A Cleaner Environment & Reduced Disposal Costs Compressed air is compressed and discharged

### The Development of Heat Pump Water Heaters Using CO 2 Refrigerant

The Development of Heat Pump Heaters Using CO 2 Refrigerant Shigeharu TAIRA* * DAIKIN Industries, Ltd., 1000-2 Aza-Ohtani, Okamoto-cho, Kusatsu, Shiga 525-8526 Abstract heating consumes about one-third

### AIRAH Refrigeration (in HVAC) Back to Basics. For the First Time

AIRAH Refrigeration (in HVAC) Back to Basics For the First Time Terms of Reference What this session is NOT about Detailed Refrigeration Design Detailed analysis of various Refrigants properties Comparison

### TEST REPORT #44. System Drop-in Tests of Refrigerant R-32 in Single Packaged Vertical Heat Pump (SPVH)

Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Low-GWP Alternative Refrigerants Evaluation Program (Low-GWP AREP) TEST REPORT #44 System Drop-in Tests of Refrigerant R-32 in Single Packaged

### TOPIC: 191004 KNOWLEDGE: K1.01 [3.3/3.5] Which one of the following contains indications of cavitation in an operating centrifugal pump?

KNOWLEDGE: K1.01 [3.3/3.5] P21 Which one of the following contains indications of cavitation in an operating centrifugal pump? A. Low flow rate with low discharge pressure. B. Low flow rate with high discharge

### Initial Experiments of a Novel Liquid Desiccant Dehumidifier for Industrial and Comfort Air Conditioning Systems

Abstract Initial Experiments of a Novel Liquid Desiccant Dehumidifier for Industrial and Comfort Air Conditioning Systems M. Jaradat, R. Heinzen, U. Jordan, K. Vajen Kassel University (Germany), Institute

### Comparison of Spherical and Membrane Large LNG. Carriers in Terms of Cargo Handling

GASTECH 2005 Comparison of Spherical and Membrane Large LNG Carriers in Terms of Cargo Handling Author Co-authors Kiho Moon, Chief Researcher Daejun Chang, Senior Researcher Donghun Lee, Researcher Hyundai

### Transient Performance Prediction for Turbocharging Systems Incorporating Variable-geometry Turbochargers

22 Special Issue Turbocharging Technologies Research Report Transient Performance Prediction for Turbocharging Systems Incorporating Variable-geometry Turbochargers Hiroshi Uchida Abstract Turbocharging

### Nirvana. Cycling Refrigerated Dryers

Nirvana Cycling Refrigerated Dryers Nirvana Cycling Refrigerated Dryers Reliability Is Our Design Ingersoll Rand's Nirvana Cycling Refrigerated Dryer provides reliability like no other dryer in its class:

### Short Communication Design Analysis of Combined Gas-Vapour Micro Power Plant with 30 kw Air Turbine

Pol. J. Environ. Stud. Vol. 23, No. 4 (2014), 1397-1401 Short Communication Design Analysis of Combined Gas-Vapour Micro Power Plant with 30 kw Air Turbine Marian Piwowarski*, Krzysztof Kosowski** Faculty

### Total Heat Versus Sensible Heat Evaporator Selection Methods & Application

Total Heat Versus Sensible Heat Evaporator Selection Methods & Application Scope The purpose of this paper is to provide specifying engineers, purchasers and users of evaporators in industrial refrigeration

### Solving Problems in Food Engineering

Solving Problems in Food Engineering Stavros Yanniotis, Ph.D. Author Solving Problems in Food Engineering Stavros Yanniotis, Ph.D. Department of Food Science and Technology Agricultural University of Athens

### Cooling kw 5.2 6.0 7.1 Heating kw 5.65 6.35 7.75

Specifications COOLING ONLY / HEAT PUMP 005 006 007 Capacity (Eurovent) Cooling kw 5.2 6.0 7.1 Heating kw 5.65 6.35 7.75 Nominal input (Eurovent) Cooling kw 1.89 2.35 2.95 Heating kw 1.97 2.24 2.83 EER

### Pushing the limits. Turbine simulation for next-generation turbochargers

Pushing the limits Turbine simulation for next-generation turbochargers KWOK-KAI SO, BENT PHILLIPSEN, MAGNUS FISCHER Computational fluid dynamics (CFD) has matured and is now an indispensable tool for

### Putting a chill on global warming

Carbon capture and storage Putting a chill on global warming SABINE SULZER SULZER PUMPS MARKUS DUSS SULZER CHEMTECH Whenever fuel is burned, carbon dioxide (CO ) is emitted into the atmosphere. The subsequent

### A car air-conditioning system based on an absorption refrigeration cycle using energy from exhaust gas of an internal combustion engine

A car air-conditioning system based on an absorption refrigeration cycle using energy from exhaust gas of an internal combustion engine G Vicatos J Gryzagoridis S Wang Department of Mechanical Engineering,

### A Performance Comparison of Vapour Compression Refrigeration System Using Eco Friendly Refrigerants of Low Global Warming Potential

International Journal of Scientific and Research Publications, Volume 2, Issue 9, September 2012 1 A Performance Comparison of Vapour Compression Refrigeration System Using Eco Friendly Refrigerants of

### Validation of a vapour compression refrigeration system design model

AMERICAN JOURNAL OF SCIENTIFIC AND INDUSTRIAL RESEARCH 2011, Science Huβ, http://www.scihub.org/ajsir ISSN: 2153-649X doi:10.5251/ajsir.2011.2.4.504.510 Validation of a vapour compression refrigeration

### Contents and Nomenclature

DX Coils Contents and Nomenclature Nomenclature... 1 Evaporator Coil Types EN... 2 EF... 2 ER... 2 EJ... 3 EK... 3 Evaporator Construction Connections... 4 Tubing... 4 Headers... 5 Tube Supports... 5 Coil

### Percent per Degree Rule of Thumb for Refrigeration Cycle Improvement

7 Percent per Degree Rule of Thumb for Refrigeration Cycle Improvement Steve Doty, PE, CEM sdoty@csu.org ABSTRACT A value of 1-1.5% power reduction per degree Fahrenheit (F) has been used successfully

### ENGINEERING INFORMATION Hot water and steam service

ENGINEERING INFORMTION Hot water and steam service WHT IS STEM? Like other substances, water can exist in the form of a solid, when we call it ice; as a liquid when we call it water or as a gas when we

### Theoretical Study on Separate Sensible and Latent Cooling Air-Conditioning System

Purdue University Purdue e-pubs International Refrigeration and Air Conditioning Conference School of Mechanical Engineering 2008 Theoretical Study on Separate Sensible and Latent Cooling Air-Conditioning

### Module 1 : Conduction. Lecture 5 : 1D conduction example problems. 2D conduction

Module 1 : Conduction Lecture 5 : 1D conduction example problems. 2D conduction Objectives In this class: An example of optimization for insulation thickness is solved. The 1D conduction is considered

### Flashing and Cavitation

As seen in the Summer 2015 issue of MAGAZINE BACK TO BASICS A high-power boiler burner in a co-generation plant Flashing and Cavitation Some of the following questions may seem unrelated, but they all

### Commercial Hot Water. Make a difference...

Commercial Hot Water Make a difference... heat S O L A R pumps The Company Quantum Energy Technologies The Quantum story is based on innovation and the quest to harness renewable energy to produce sustainable

### Performance Test of Solar Assisted Solid Desiccant Dryer

Performance Test of Solar Assisted Solid Desiccant Dryer S. MISHA 1,2,*, S. MAT 1, M. H. RUSLAN 1, K. SOPIAN 1, E. SALLEH 1, M. A. M. ROSLI 1 1 Solar Energy Research Institute, Universiti Kebangsaan Malaysia,

### Water Contamination and Water Removal in Industrial Ammonia Refrigeration Systems

Water Contamination and Water Removal in Industrial Ammonia Refrigeration Systems By Ray Ficker, PE Effects of Water Contamination Water contamination in an industrial ammonia refrigeration system can

### Investigations of a Long-Distance 1000 MW Heat Transport System with APROS Simulation Software

th International Conference on Structural Mechanics in Reactor Technology (SMiRT ) Espoo, Finland, August 9-4, 9 SMiRT -Division 3, Paper 56 Investigations of a Long-Distance MW Heat Transport System with

### Design and Fabrication of Vapour Absorption Refrigeration System [Libr-H 2 0]

International OPEN ACCESS Journal Of Modern Engineering Research (IJMER) Design and Fabrication of Vapour Absorption Refrigeration System [Libr-H 2 0] Mohd Aziz Ur Rahaman 1, Md. Abdul Raheem Junaidi 2,

### KINGDOM OF SAUDI ARABIA SAUDI ARABIAN STANDARDS ORGANIZATION SASO. SAUDI STANDARD DRAFT No. 3457/2005

KINGDOM OF SAUDI ARABIA SAUDI ARABIAN STANDARDS ORGANIZATION SASO SAUDI STANDARD DRAFT No. 3457/2005 NON-DUCTED AIR CONDITIONERS AND HEAT PUMPS TESTING AND RATING PERFORMANCE This standard is developed

### Pressurized Water Reactor B&W Technology Crosstraining Course Manual. Chapter 9.0. Integrated Control System

Pressurized Water Reactor B&W Technology Crosstraining Course Manual Chapter 9.0 Integrated Control System TABLE OF CONTENTS 9.0 INTEGRATED CONTROL SYSTEM... 1 9.1 Introduction... 1 9.2 General Description...

### Energy savings in commercial refrigeration. Low pressure control

Energy savings in commercial refrigeration equipment : Low pressure control August 2011/White paper by Christophe Borlein AFF and l IIF-IIR member Make the most of your energy Summary Executive summary

### WEEKLY SCHEDULE. GROUPS (mark X) SPECIAL ROOM FOR SESSION (Computer class room, audio-visual class room)

SESSION WEEK COURSE: THERMAL ENGINEERING DEGREE: Aerospace Engineering YEAR: 2nd TERM: 2nd The course has 29 sessions distributed in 14 weeks. The laboratory sessions are included in these sessions. The

### Daikin Altherma hybrid heat pump. The natural combination

Daikin Altherma hybrid heat pump The natural combination Daikin Altherma hybrid heat pump, the natural combination Why choose Daikin Altherma hybrid heat pump? What the customer wants: more energy efficient

### MAKING MODERN LIVING POSSIBLE. Refrigeration - an introduction to the basics REFRIGERATION & AIR CONDITIONING DIVISION. Lecture

MAKING MODERN LIVING POSSIBLE Refrigeration - an introduction to the basics REFRIGERATION & AIR CONDITIONING DIVISION Lecture Automatic Controls and Compressors for refrigeration Automatic controls for

### Lecture 6 - Boundary Conditions. Applied Computational Fluid Dynamics

Lecture 6 - Boundary Conditions Applied Computational Fluid Dynamics Instructor: André Bakker http://www.bakker.org André Bakker (2002-2006) Fluent Inc. (2002) 1 Outline Overview. Inlet and outlet boundaries.

### The First Law of Thermodynamics

Thermodynamics The First Law of Thermodynamics Thermodynamic Processes (isobaric, isochoric, isothermal, adiabatic) Reversible and Irreversible Processes Heat Engines Refrigerators and Heat Pumps The Carnot

### Energy Efficient Ammonia Heat Pump. Energy and Climate Refrigeration and Heat Pump Technology

Energy and Climate Refrigeration and Heat Pump Technology Energy Efficient Ammonia Heat Pump PSO no. 342-059 Claus Madsen Bastiaan Pijnenburg Henning Schumann Grindorf Rolf Christensen Bjarne D. Rasmussen

### Technical Thermodynamics

Technical Thermodynamics Chapter 2: Basic ideas and some definitions Prof. Dr.-Ing. habil. Egon Hassel University of Rostock, Germany Faculty of Mechanical Engineering and Ship Building Institute of Technical