THERMO Lesson P= C, T = C, V = C Flashcards
_______ are substances that have UNIFORM and CONSISTENT chemical composition and retain their distinct properties regardless of the conditions or phases it may undergo.
Pure Substances
Pure substances can exist in different phases, such as solid, liquid, or gas, depending on the ______ and _______ conditions.
Temperature and Pressure
____________ is the state at which solid, liquid and gas coexist
Triple point
The 3D P-V-T surface model provides a visual representation of how pressure, volume, and
temperature influence the behavior of a substance. It is also known as the ________.
Phase Diagram.
Phase Space Diagram
__________ is where the saturated liquid and saturated vapor lines meet
Critical Point
For Water, the triple point is at t = _______ and P = __________
t = 0.01degree C and P = 0.611657 kPa
For water, the Critical Point is at t = ________ and P = _________
t = 374.13 degreeC and P = 22,090 kPa
The __________________ is given by the Pressure – Specific Volume, PV projection
The Ice-Water-Water Vapor System
The _______________ is given by the Pressure – Temperature, PT projection
Phase Diagram
The _____________ is shown in Temperature-Specific Volume, TV projection:
Lines of Constant Pressure
The change of phase of water illustrated in ___________ diagram
Temperature – Specific Volume Diagram
are tables widely used by engineers and scientists in the design and operation of equipment where steam is used as a working substance in thermodynamic processes and cycles.
Steam tables
Steam tables gives an idea about the phase of steam at various ______ and ______.
Temperature and Pressure
_______ is the proportion by mass of vapor in a liquid-vapor mixture.
Steam quality
A quality of zero (0) indicates 100% _________ while a quality of one (1) indicates 100% _________
Quality of 0 = 100% WATER
Quality of 1 = 100% STEAM
It is one of the thermodynamic cycle that converts heat into work. Water is usually the working fluid of the cycle and heat is supplied externally in a closed system. WHAT IS THE CYCLE CALLED????????????????!!??!?!?
Rankine Cycle
4 process of Rankine Cycle
Process 1-2: High pressure liquid enters the boiler and heat is added at a constant pressure until the working fluid becomes superheated vapor.
Process 2-3: The superheated vapor then goes to the turbine and expands isentropically. This process decreases the pressure and temperature, and condensation may occur.
Process 3-4: The wet vapor enters the condenser, where it is condensed at a constant pressure until it becomes saturated liquid.
Process 4-1: The saturated liquid is pumped from low to high pressure. At this stage, the pump requires low power input since the working fluid is liquid.
___________ is the equation of state of an ideal gas. It is a good approximation of the behavior of gases in relation to its pressure, volume and temperature.
General Gas Law
WHAT LAW??
If the temperature remains constant within a closed system, the volume of the gas varies ________ (inversely or directly) with the pressure during the change of state.
Boyle’s Law
INVERSELY
WHAT LAW??
If the pressure remains constant within a closed system, the volume of the gas varies ________ (inversely or directly) with the temperature during the change of state.
Charles’s Law
DIRECTLY
WHAT LAW??
The pressure of an ideal gas if held at a constant volume is _________ (inversely or directly) proportional to its temperature at any change of state.
Gay-Lussac’s Law
DIRECTLY
What Principle states 1 mole of any ideal gas alyways occupies the same volume at a constant pressure and temperature
Avogadro’s Law
One mole of ideal gas occupies how much volume? (english and SI units)
22.4 m^3
359 ft^3
_______ is given by the Universal Gas Constant over the Molar Mass.
Ideal Gas Constant
________ is a thermal property that measures the heat required to increase the temperature of one unit of thermodynamic substance by one degree.
Specific Heat
Constant Volume Specific heat is equivalent to the change in _______
Internal Energy
Constant Pressure Specific heat is equivalent to the change in _______
Enthalpy
Specific heat of a gas at constant pressure (C_P) is greater than the specific heat at constant volume (C_V) because????
Unlike C_V , C_P is allowed to EXPAND at constant pressure, doing external work against expansion
C_P > C_V
________ the ratio of specific heat at constant pressure and constant volume.
Isentropic Expansion
or
Specific heat ratio
Problem 1: yes, may problem solving
An ideal gas with a mass of 2 kgs is contained in a 3.2 m3 rigid container. The initial temperature is 303 K and a pressure of 150 kPa. Determine the ideal gas constant.
(Ans. 0.7921 kJ/kg-K)
Problem 2: yes, may problem solving
A rigid tank initially contains hydrogen initially at 100 kPa and 20oC. One and a half kilograms of hydrogen is added so that the final temperature and pressure of the tank is 30oC and 250 kPa, respectively. Determine the volume of the tank, in m3 and the final mass of the hydrogen inside the tank, in kgs. (RH2 = 4.125 kJ/kg-K)
(Ans. 12.79 m3, 2.56 kgs)
Problem 3: yes, may problem solving
A pressurized vessel contains air at a gage pressure of 275 kPag and temperature of 28oC. If the bursting gage pressure of the vessel is found to be 1800 kPag, determine the temperature where the vessel will burst, in oC.
(Ans. 1697.18oC)
Problem 4: yes, may problem solving
A 2-m3 rigid vessel contains helium initially at a gage pressure and temperature of 320 kPa and 315 K, respectively. Because of the leaks in the fittings of the vessel, the gage pressure dropped to 280 kPa and the temperature decreased to 300 K, determine the mass of the helium that leaked out and also the mass of nitrogen that remained in the vessel. (RHe = 2.077 kJ/kg-K)
(Ans. 0.06399 kg, 1.2240 kg)
_____ occurs at a constant temperature. An example of this is a system immersed
in cooling water maintained at a constant temperature.
Isothermal Process
n = 0 ; __ = C
P ; Isobaric Process
n = Infinite ; __ = C
V; Isochoric Process
n = 1 ; __ = C
T ; Isothermal Process
Constant Pressure. What Process
Isobaric Process
_____ are equipment where heat transfer between two different or similar fluids takes place. Heat transers occurs in an ____________ process
Heat Exchangers
Isobaric Process ; P = C