The no. of Hydrogen atoms in the refrigerant R-12 is
Which one among the following eco- friendly refrigerants are used in many domestic and car air conditioning system ?
What is an azeotrope ?
The color of the flame of halides torch in a case of leakage of Freon refrigerant will change to
Wet bulb depression is zero, when relative humidity is equal to
Dry bulb temperature, wet bulb temperature and due-point temperature are same for which one of the following-
The main process which takes place in a desert cooler is-
For completely dry air total heat is-
The comfort chart is drawn between
In air conditioning system, effective temperature has been defined as
Alignment circle is marked on the Psychometric chart as-
COP of a carnot heat pump operating between -3oc and 27oc is
The choice of a refrigerant depends upon :
1. Refrigerating capacity
2. Type of compressor used (reciprocating, centrifugal or screw )
3. Service required (whether for air conditioning, cold storage or food freezing )
Which of the above statements is/are correct ?
The most suitable refrigeration system utilizing solar energy is :
In a vapour compression cycle, good refrigerant should have a
An absorption refrigeration system is supplied with energy Q1 in the form of heat at temperature T1, while it extracts energy Q3 as heat from a cold space at temperature T3. The ambient temperature is T2.Then the COP of the refrigerator is (ignoring the small amount of energy supplied in the pump.)
Consider the following statements :
1. COP of Ammonia absorption system is more than that of vapour compression system.
2. Ammonia absorption machines are preferable where waste heat is available from an existing source.
3. Absorption refrigerator has no moving part and hence needs little maintenance.
4. Th partial pressure of ammonia vapour varies, being high in the condenser and low in the evaporator.
Which of these statements are correct ?
The most suitable pair of refrigerant and absorbent combination for solar refrigerant is
In vapour absorption refrigeration system heating in generator is done at 1770C, refrigeration in evaporator is done at -30C and cooling in condenser is done at 270C. Then what will be the maximum COP of the system?
In a vapour absorption refrigeration, heat is rejected in
Oil separator is not required in refrigeration system If.
Consider the following statements in respect of a absorption refrigeration and vapour compression refrigeration system:
1. The former runs of low grade energy
2. The pumping work in the former is negligible since specific volume of strong liquid solution is small.
3. The latter uses an absorber while former uses a generator
4. The liquid pump alone replaces compressor of the latter.
Which of these statements are correct?
Consider the following statements regarding refrigerants:
1. Refrigerants NH3 is used in reciprocating compressors
2. Refrigerants CO2 is used in reciprocating compressors
3. Refrigerants R-11 is used in reciprocating compressors
Which of these statements are correct?
Consider the following statements:
1. Azeotrops are the mixtures of refrigerants and behave like pure substances.
2. Isomers refrigerants are compounds with the same chemical formula but have different molecular structures.
3. The formula n + p +q = 2m is used for unsaturated chloro-fluoro carbons compound (m , n, p and q are the number of atoms of carbon hydrogen, fluorine and chlorine respectively).
Which of these statements are correct?
Solar energy can be directly used in
