A text book of refrigerarion and air-conditioning by R S Khurmi. Refrigeration and airconditionin by rs khurmi. Onkar Nath. Engineering. Textbook of Refrigeration and Air-conditioning has ratings and 8 reviews. For the students of B.E.;UPSC(Engg. Services); UPSC (Civil Services); Secti. I found a Substitute for A Textbook of Refrigeration and Air Conditioning by R. S. Khurmi. This Substitute has all the Similar Topics Covered. Please get it from.
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Search the history of over billion web pages on the Internet. Ph ; , bangalore schandg roup. Nagor, Zone 1, Bhopal – Bapu Nagor, Jaipur -Phone: Road, trnakulam, KochlPh: Aminobad, Lucknow Ph: No, Pages 1 Introduction ?
Compound Vapour Compression Refrigeration Systems 5. Anx Evaporator ot Compressor Systems – 6. Vapour Absorption Refrigeration Systems 7. Condensers 10,1 Introduction Low Temperature Refrigeration Cryogenics Steam Jet Refrigeration System Psvchrometrv Cooling Load Estimafic i Ducts – Fans – Units International System of Units7, Kilogram. Standard Temperature and Ttextbook.
Types of Stored Energy. Specific Heats of a Gas. It also bt the process of reducing and maintaining the temperature of a body below the general temperature of its surroundings. In other words, the refrigeration means a continued extraction of heat from a body whose temperature is already below the temperature of its surroundings.
Thus in a refrigerator, heal is virtually being pumped from a lower temperature to a higher temperature. It is thus obvious that supply of power say electric motor is regularly required to drive a refrigerator.
Textbook of Refrigeration and Air-conditioning (M.E.)
The substance which works in a heal pump to extract heal from a cold body and to deliver it to a hot body is called a refrigerant. The refrigeration system is known to the man since the middle of nineteenth century.
The scientists, of the time, developed a few stray machines to achieve some pleasure. But it paved the way by inviting the attention of scientists for proper studies and research. They were able to build a reasonably reliable machine by the end of nineteenth century for refrigeration jobs.
But with the advent of efficient rotary compressors and gas turbines, the science of refrigeration reached the present height. Today it is used for the manufacture of ice and similar products. It is textnook widely used for the cooling of storage chambers in which perishable foods, drinks and medicines are stored. The refrigeration has also wide applications textbooi submarine ships, aircraft and rockets. These are known as: S, units has been revised to recognise all the S.
L units in industry and commerce. The conference has been entrusted with the task of prescribing definitions for various units of weights and measures, which are the very basis of science and technology today. These units are shown textbook Table 1. The triple point of water is taken as a fundamental fixed point having a ahd The implementation of ISO recommendations, in a country, is assisted by its organisation appointed for the purpose. We have already discussed that the fundamental units in S I, units for length, mass and time are metre, kilogram and textbook respectively.
But in actual practice, it is not necessary’ to express all lengths in metres, all masses in kilograms and all limes in seconds.
We shall, sometimes, use the convenient units, which are bu or divisions of our basic units in tens. As a typical example, reftigeration the metre is the unit of length, yet a small length of one-thousandth of a metre proves to be more convenient unit, especially in the dimensioning of drawings.
Such convenient units are formed by using a prefix in front of the basic units to indicate the multiplier. The full list of these prefixes is given in the following table, 1 Prefixes used in basic units.
Units The eleventh General Conference of Weights and Measures recommended only the fundamental and derived units for S. But it did not elaborate the rules for the usage of the units. Later on many scientists and engineers held a number of meetings for the style and usage of Si units. Some of the decisions of the meetings are as follows: For numbers having Five or more digits, the digits should be placed in groups of three separated by spaces instead of commas counting both to the left and right to abd decimal point, 2.
In a four digit number, the space is not required unless the four digit number is used in a column of numbers with five or more digits. A dash is to be used to separate units that are multiplied together. Plurals are never used with symbols. All symbols are written in small letters except the symbols derived from the proper names. For example, N for new ton and W for w r att.
The units with names of scientists should not start with conditioningg letter when written in full. For example, 90 newton and not 90 Newton. In certain countries, comma is still used as he decimal mark. The authors have tried to avoid such questions in the text of the book. Now let us discuss about the units.
We know that the fundamental units in 5. As a result khudmi this, wc find it quite convenient to use some standard abbreviations. This happens, because of the lack of clear understanding of the difference between mass and weight. The bj definitions of mass and weight should be clearly understood. A man whose mass is 60 kg weighs 58B.
But mass remains the same everywhere. The mass of a body is measured by direct comparison with a standard mass by using a lever balance. Since the pull varies with the distance of the body from the centre of the earth, therefore weight of the body will also vary with its position on the earth’s surface ar latitude and elevation. It is thus obvious, that the conditioninv is a force. Thus it is a definite amount of force. But, unfortunately, it has the same name as the unit of mass, The weight of a body is measured by the use of a spring balance, which indicates the varying tension in the spring as the body is moved from place to place.
The confusion in the units of mass and weight is eliminated, to a great extent, in S. In this system, mass Is taken in kg and weight in newtons. According to Newton’s Second Law of Motion, the applied force or impressed force is refriigeration proportional to the rate of change of momentum. Initial velocity of the body.
Final velocity of the body. For the sake of convenience, the unit of force adopted is such that it produces a unit acceleration to a body of unit mass, F – m a – Mass x Acceleration In S.
L system of units, the unit of force is called newton briefly written as N. Therefore, when the same body is moving with an acceleration of 9. It is thus obvious, that the gravitational or engineer’s units of force are limes the unii of force in the absolute or ST units. It is a region where our attention is focussed for studying a thermodynamic process, A little observation will show that a thermodynamic system has its boundaries and anything outside the boundaries is called its lum’uthiings as shown in Fig, l.
Full text of “A Textbook Of Refrigeration And Air Conditioning By R. S. Khurmi And J. K Gupta”
L These boundaries may be fixed like that of a tank enclosing a certain mass of compressed gas, or movable like the boundary of a certain volume of liquid in a pipe line, The thermodynamic systems may be classified into the following three groups: These systems are discussed, in detail, as follows: Closed thermodynamic system, A closed system is shown in Fig, 1. If heal is supplied to the cylinder from some external source, the temperature of the gas will increase and the piston will rise.
Thus, a closed system does not permit any mass transfer across its boundary, but it permits transfer of energy heal and work. In this system, the mass of the working substance crosses the boundary of the system.
Textbook of Refrigeration and Air Conditioning
Heat and work may also cross the boundary. The working substance crosses the boundary of the system as the low pressure L. Note; An open system may be referred to as control volume An open system is equivalent in every respect to a control volume, but the term open system is used throughout this text as it specifically implies that the system can have mass and energy crossing the system boundary.
X Isolated system, A system which is completely uninfluenced by the surroundings is called an isolated system. It is a system of fixed mass and no heat or work energy cross its boundary.
In other words, an isolated system docs not have transfer of either mass or energy heat or work with the surroundings.
Textbook of Refrigeration and Air Conditioning : R. S. Khurmi :
An open system with its bby known as an universe is an example of an isolated system, Note; The practical examples of isolated system are rare.
The concept of this system is particularly useful in formulating the principles derived from the Second Law of Thermodynamics. Note; Thermodynamics deals with hose quantities also which are not properties of any system. For example, when there is a flow of energy between a system and its surroundings, ihc energy [ran.