3.27 An elemental solid has a heat capacity of 1 J/mole-K. What is the atomic weight of the element?
Chap. 4 Heat Engines, Power Cycles, and the Thermodynamics of Open Systems
4.1 Heat Engines 1
4.1.1 Single device - sequential states - ideal gas 2
4.1.2 Four devices - circulating fluid - water 4
4.1.3 The First law for heat engines 5
4.2 The Second Law applied to heat-engine cycles 5
4.3 The Carnot Cycle 7
4.4 Thermodynamics of open systems 9
4.4.1 The First law for open (flow) systems 10
4.4.2 The Second Law for open systems 12
4.4.3 Reversible Work of a Flow System 13
4.5 Practical power cycles 13
4.5.1 The Rankine cycle - a steam power plant 14
4.5.2 The Brayton cycle - a gas turbine 20
4.4 Flow Devices Without Shaft Work 23
4.6.1 Orifice or valve - water 24
4.6.2 Nozzle- ideal gas 24
4.7 Summary: properties of flow devices 26
In Sect. 1.9, it was noted that the First law regards heat and work as completely interchangeable; if a certain number of Joules of heat added to a system increases the internal energy of a body by, say, AU, the same number of Joules of work performed on the body would produce the same AU. In addition, work can be completely converted to heat, as everyday experience with friction attests. However, the reverse is not true; heat cannot be completely transformed into work. This limitation, which is a consequence of the Second law, is best demonstrated by studying the properties of heat engines.
A heat engine is a system operating in a cycle that receives heat from a high-temperature source (called a reservoir) and produces useful work. However, since the efficiency of conversion must be less than 100%, some of the input heat is rejected to a cold reservoir. Figure 4.1 shows a schematic of a heat engine/heat pump and their associated thermal reservoirs.
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Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.