c) Low electrical and thermal conductivity Like air, it is perfectly safe. Ans: c. 65. Q. How dry chemical powder extinguishes fire ? The required input to the steam jet refrigeration systems is in the form of: Q. The function of a compressor in a vapour compression refrigeration system is to: a) To maintain the required low-side pressure in the evaporator, b) To maintain the required high-side pressure in the condenser, c) To circulate required amount of refrigerant through the system. Multiple Choice Questions (MCQ) and Answers on Chemical Engineering Thermodynamics Question 1 : The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. B. Cooling An Amount Of Water At Low Pressure. Steam-Jet Chiller Integrated with SLIC System Incorporation of a steam-jet refrigeration system into a SLIC requires addition of an evaporator chamber, the steam-jet ejector, and a condenser for rejecting heat to ambient. 2. c) Q. D. None of the above View Answer. Q. From the thermodynamic standpoint, water is a very good refrigerant since it has a high latent heat of evaporation and it is cheap, nontoxic, nonflammable, and available in unlimited quantities. The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft (a) 1/2 (b) 1 (c) 2 (d) 4 (e) 8. A steam jet refrigeration system can operate steadily at boiler temperature of 90 °C. which is the ratio of refrigerating effect produced to the work of compression. MCQ in Machine Design Part 7 as part of the coverage of Mechanical Engineering Board Exam ... Arc produced by two tungsten electrodes into which a jet of hydrogen is directed. B. One ton of the refrigeration is (A) The standard unit used in refrigeration problems (B) The cooling effect produced by melting 1 ton of ice (C) The refrigeration effect to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours (D) The refrigeration effect to produce 1 ton of ice at NTP conditions Although superheating adds more energy to the steam in the form of heat there is no effect on pressure, which is determined by the rate at which steam is drawn from the boiler and the pressure settings of the safety valves. Ans: b. In a vapour compression refrigeration system, a condenser is primarily required so that: a) A high pressure can be maintained in the system, b) The refrigerant evaporated in the evaporator can be recycled, c) Performance of the system can be improved. 5. Thermoelectric Refrigeration: An Introduction Thermoelectric cooling uses the Peltier effect to create a heat flux between the junctions of two different types of materials. Water is more suitable against fire in wood, paper and textiles. Q. e. Steam and vapor jet refrigeration systems (Section 1.3.5) f. Thermoelectric refrigeration systems (Section 1.3.6), and g. Vortex tubes (Section 1.3.7) At the end of the lesson the student should be able to: 1. Q. Refrigeration by Using Liquid Gasses. This is the Multiple Choice Questions Part 7 of the Series in Machine Design as one of the Mechanical Engineering topic. Introduction. 4 show typical performance curves of a steam jet refrigeration cycle , . C. Chimney draught. Here a jet of air is used to cool the water when passed through the reducing section with the help of fan. In steam jet refrigeration systems, water can be used as the refrigerant. The draught produced by a steam jet issuing from a nozzle placed in the chimney,is called..... A. 64. StudySite.org, Best online Subjective, Objective questions, MCQ's solution, best for any competitive examination provide best online coaching The input required for the pump is typically less than 1% of the heat supplied to the boiler, thus, the actual COP may be given as: (1) COP = refrigeration effect at the evaporator heat input at the boiler Fig. B.Decreses Your Comments. Ans: c. 2. The effect of friction in the nozzle _____ dryness fraction of steam. In Cascade refrigeration, cooling effect is produced by (a) Latent heat (b) Total heat (c) Sensible heat (d) None (Ans:a) The ratio of COP of a two stage Cascade refrigeration system vs three stage cascade system is (a) < 1 (b) > 1 (a) = 1 (d) None (Ans: a) In a 2 stage cascade refrigeration system, cooling effect occurs in the (a) one evaporator • The load variations does not effect the performance of a vapour absorption system. An air conditioning system employs a refrigeration system to: a) Cool and dehumidify air supplied to the conditioned space, b) To heat and humidify the air supplied to the conditioned space, c) To circulate the air through the system. 7 Steam Jet Refrigeration. Hence a considerable drop in air temperature is obtained, and more steam associated with air is condensed resulting in reducing both steam lost and vacuum pump power. distillation systems. Steam-Jet Chiller Integrated with SLIC System Incorporation of a steam-jet refrigeration system into a SLIC requires addition of an evaporator chamber, the steam-jet ejector, and a condenser for rejecting heat to ambient. c) Q. Ans. Also, higher steam pressure will be possible than with saturated steam, enabling the steam to carry more energy. Ans: d. 40. These systems were applied successfully to refrigeration. The units of _____ and COP are the same. out cooling applications reducing the use of electrical energy. The aim of this research is to investigate the possibility to run a steam jet ejector on boiler temperatures below 100 °C. Abstract This paper first presents the results from an experimental study of a conventional steam jet ejector refrigeration system and compares the performance with the … Correct Answer The required input to the steam jet refrigeration systems is in the form of: a) Mechanical energy. Refrigerants - MCQs with Answers Q1. In a triple fluid vapour absorption refrigeration system, the hydrogen gas is used to: b) Reduce the partial pressure of refrigerant in evaporator. For the same draught produced the power of induced draught fan as compared to forced draught fan is (a) less (b) more (c) same (d) not predictable. Next . Change ), You are commenting using your Google account. Ans. B. Cooling An Amount Of Water At Low Pressure. This effect is commonly used in camping and portable coolers and for cooling electronic components and small instruments. 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