--- title: "Boiler: definition and applications" subject: "Applied Thermodynamics" chapter: 1 key: "semester_3/applied_thermodynamics:boiler-definition-applications" source: https://www.bctengineer.com/q/semester_3/applied_thermodynamics/boiler-definition-applications site: BCT Engineering --- # Boiler: definition and applications Applied Thermodynamics · Chapter 1: Boilers - Asked in: year not given, 5 marks - Video: [What is a Boiler and How does It Work?](https://www.youtube.com/watch?v=fk3DjD9gSsk) — RealPars - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_3/applied_thermodynamics/boiler-definition-applications - Whole chapter: https://www.bctengineer.com/md/semester_3/applied_thermodynamics/chapter-1 ## Question Define a boiler. State the main applications of steam boilers and the factors that govern the selection of a boiler for a given duty. ## Short answer A boiler is a closed pressure vessel generating steam above atmospheric pressure from water using heat from fuel. Main applications are power generation, process heating, space heating, and mobile steam engines. Selection depends on working pressure, steam quantity/quality, fuel type and cost, floor area, load pattern, feedwater quality, and efficiency/cost. ## Answer #### Definition A **boiler** (steam generator) is a closed pressure vessel in which water is heated by the heat of burning fuel (or another heat source) to generate steam at a pressure higher than atmospheric. #### Applications - Power generation: steam for turbines in thermal power plants. - Process heating in industries: sugar mills, textile, paper, dairy, chemical and food industries. - Space heating and hot-water supply in hospitals, hotels and large buildings. - Steam locomotives and ships (mobile boilers). - Sterilisation, cooking and cleaning (autoclaves, laundries). - Driving steam engines and steam hammers. #### Factors governing selection 1. Working pressure and quantity of steam required (kg/h). 2. Quality of steam: wet, dry saturated or superheated. 3. Type and cost of fuel available (coal, oil, gas, biomass, husk). 4. Floor area and head room available. 5. Load pattern: steady or fluctuating; quick steaming needed or not. 6. Quality of feed water available. 7. Initial cost, running cost, maintenance cost and ease of inspection. 8. Efficiency and statutory safety requirements. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is a boiler according to the answer? A. A closed pressure vessel in which water is heated to generate steam at a pressure above atmospheric B. An open tank that heats water to exactly 100 °C at atmospheric pressure C. A machine that converts steam into mechanical work D. A device that condenses steam back into feed water Answer: A. A boiler is a closed pressure vessel that generates steam above atmospheric pressure using heat from burning fuel or another source. (Key point: Boiler definition) 2. Which of the following is a main application of steam boilers? A. Directly cooling cold-storage rooms B. Steam for turbines in thermal power plants C. Compressing air for pneumatic tools D. Generating electricity in solar panels Answer: B. Boilers supply steam to turbines for power generation, as well as process heating and space heating. (Key point: Applications) 3. Which set of factors governs the choice of a boiler for a given duty? A. Only the colour and shape of the shell B. Only the chimney height and the brand of the maker C. Working pressure, quantity and quality of steam, fuel available, floor area and load pattern D. Only the ambient temperature and the humidity Answer: C. Selection depends on pressure, steam quantity and quality, fuel, space, load pattern, feed water, costs and safety rules. (Key point: Selection factors) 4. A plant has a fluctuating load and needs steam quickly. Which selection factor does this relate to? A. Type of fuel B. Statutory safety requirements C. Head room available D. Load pattern (steady or fluctuating, quick steaming needed) Answer: D. The answer lists load pattern, including whether quick steaming is needed, as a selection factor. 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