TimTaiLieu.vn - Tài liệu, ebook, giáo trình, đồ án, luận văn

Since the percent theoretical air is known, the N2 balance gives B. The H balance gives G. Then the C and O balances give two equations that relate the remaining three unknowns D, E, and F. Therefore, we need one more equation. To obtain this last equation relating the mole numbers of the products, we assume that the products are in chemical equil...

32 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 757 | Lượt tải: 0

Fuels are usually composed of some compound or mixture containing carbon, C, and hydrogen, H2. Examples of hydrocarbon fuels are CH4 Methane C8H18 Octane Coal Mixture of C, H2, S, O2, N2 and non-combustibles Initially, we shall consider only those reactions that go to completion. The components prior to the reaction are called reactants an...

52 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 831 | Lượt tải: 0

We will be concerned with the mixture of dry air and water vapor. This mixture is often called atmospheric air. The temperature of the atmospheric air in air-conditioning applications ranges from about –10 to about 50oC. Under these conditions, we treat air as an ideal gas with constant specific heats. Taking Cpa = 1.005 kJ/kgK, the enthalpy of ...

45 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 843 | Lượt tải: 0

The discussions in this chapter are restricted to nonreactive ideal-gas mixtures. Those interested in real-gas mixtures are encouraged to study carefully the material presented in Chapter 12. Many thermodynamic applications involve mixtures of ideal gases. That is, each of the gases in the mixture individually behaves as an ideal gas. In this sect...

23 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 774 | Lượt tải: 0

The equations that relate the partial derivatives of properties P, v, T, and s of a simple compressible substance to each other are called the Maxwell relations. They are obtained from the four Gibbs equations. The first two of the Gibbs equations are those resulting from the internal energy u and the enthalpy h.

40 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 773 | Lượt tải: 0

The vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. The above figure shows the objectives of refrigerators and heat pumps. The purpose of a refrigerator is the removal of heat, called the cooling load, from a low-temperature medium. The purpose of a heat pump is the trans...

20 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 717 | Lượt tải: 0

We consider power cycles where the working fluid undergoes a phase change. The best example of this cycle is the steam power cycle where water (steam) is the working fluid. Carnot Vapor Cycle

41 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 751 | Lượt tải: 0

Our study of gas power cycles will involve the study of those heat engines in which the working fluid remains in the gaseous state throughout the cycle. We often study the ideal cycle in which internal irreversibilities and complexities (the actual intake of air and fuel, the actual combustion process, and the exhaust of products of combustion amon...

71 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 957 | Lượt tải: 0

The energy content of the universe is constant, just as its mass content is. Yet at times of crisis we are bombarded with speeches and articles on how to “conserve” energy. As engineers, we know that energy is already conserved. What is not conserved is exergy, which is the useful work potential of the energy. Once the exergy is wasted, it can neve...

29 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 722 | Lượt tải: 0

Entropy and the Clausius Inequality The second law of thermodynamics leads to the definition of a new property called entropy, a quantitative measure of microscopic disorder for a system. Entropy is a measure of energy that is no longer available to perform useful work within the current environment. To obtain the working definition of entropy an...

52 trang | Chia sẻ: nguyenlinh90 | Ngày: 25/07/2019 | Lượt xem: 923 | Lượt tải: 0