A. direct mixing of hot and cold fluids B. a complete separation between hot and cold fluids C. flow of hot and cold fluids alternately over a surface D. generation of heat again and again E. indirect transfer. The reason behind this is that both streams flow in different sections for a rotary regenerator and one fluid enters and leaves one matrix at a time in a fixed-matrix regenerator. Some can have input powers as low as 2-3 W. Large systems, such as those used for cooling the superconducting magnets in particle accelerators are more often called cryogenic refrigerators. In regenerator type heat exchanger, heat transfer takes place by (a) direct mixing of hot and cold fluids (b) a complete separation between hot and cold fluids (c) flow of hot and cold fluids alternately over a surface (d) generation of heat again and again (e) indirect transfer. The concept of overall coefficient of heat transfer is used in case of heat transfer by (a) conduction     (b) convection (c) radiation (d) conduction and convection (e) convection and radiation. This type includes the following: (a) Regenerator (b) Recuperators or surface exchangers. In regenerator type heat exchanger, heat transfer takes place by_____? It may also be referred to as a run-around loop, a pump-around coil or a liquid coupled heat exchanger. Relative Direction of Motion of Fluids: Stefan Boltzmann law is applicable for heat transfer by, 80. Required fields are marked *. Ans: c, 77. If What you looking for is not here, you may send a request to modify articles, Notes, and Content modification, Feedback, Suggestions here (Team will reply as early as Possible ):  Contact Form or Using Whatsapp, © 2020 Copyright Learn Mechanical Engineering, Heat and Mass Transfer MCQ Objective Question and Answers Part 3, (a) radiant heat is proportional to fourth power of absolute temperature, (b) emissive power depends on temperature, (c) emissive power and absorptivity are constant for all bodies, (d) ratio of emissive power to absorptive power is maximum for perfectly black body. According to Stefan-Boltzmann law, ideal radiators emit radiant energy at a rate proportional to (a) absolute temperature (b) square of temperature (c) fourth power of absolute temperature (d) fourth power of temperature (e) cube of absolute temperature. Ans: d, 95. Ans: d, 97. A regenerative heat exchanger, or more commonly a regenerator, is a type of heat exchanger where heat from the hot fluid is intermittently stored in a thermal storage medium before it is transferred to the cold fluid. The device can easily be controlled and maintained. Instrumentation is used to monitor and control the process plant in the oil, gas and petrochemical industries. Convection is usually the dominant form of heat transfer in liquids and gases. This site uses Akismet to reduce spam. Heat transfer takes place as one fluid flows inside the tubes while the … The first regenerator was invented by Rev. The energy distribution of an ideal reflector at higher temperatures is largely in the range of (a) shorter wavelength (b) longer wavelength (c) remains same at all wavelengths (d) wavelength has nothing to do with it (e) none of the above. The unit of Stefan Boltzmann constant is, 78. The heat transfer will take place mainly by (a) convection       (b) free convection (c) forced convection (d) radiation (e) radiation and convection. A heat exchanger is a device used to transfer heat between two or more fluids. Privacy Policy. Usually the application will use this process cyclically or repetitively. HMT MCQ Objective : Part 1 |  Part 2 |  Part 3, (a) radiant heat is proportional to fourth power of absolute temperature (b) emissive power depends on temperature (c) emissive power and absorptivity are constant for all bodies (d) ratio of emissive power to absorptive power is maximum for perfectly black body (e) ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body. A cooling-specific thermal wheel is sometimes referred to as a Kyoto wheel. Your email address will not be published. When a hot fluid flows through the cell, heat from the fluid is transferred to the cell wells, and stored there. [1]. Depending on the radiating properties, body will be transparent when (a) p = 0, x = 0 and a = 1 (b) p=l,x = 0,anda = 0 (c) p = 0, T= l,anda = 0 (d) X = 0, a + p = 1 (e)     a = 0,x + p= 1. Robert Stirling in 1816, and is also found as a component of some examples of his Stirling engine. In regenerator type heat exchanger, heat transfer takes place by (a) direct mixing of hot and cold fluids (b) a complete separation between hot and cold fluids (c) flow of hot and cold fluids alternately over a surface (d) generation of heat again and again (e) indirect transfer.