Thermodynamics is basically concerned with heat transfer, energy transfer and conversion between heat and work and is also applied to describe phase change of a substance, such as condensation and evaporation.
1.1 Determination of steam quality
Saturated water is water in the condition in which any amount of energy put into the water or absorbed by the water can result in water-steam, two phase mixture, formed. In this case, latent heat, enthalpy of evaporation, is referred to as the energy required to change water into steam. Steam quality is referred to the percentage weight of the steam in a mixture of steam and water, that is, dry saturated steam contains no water. (Babcock & Wilcox Co., 2007).
Saturated steam, which is steam at equilibrium with water, can only exit at specific pressure and corresponding temperature. Provided any change of temperature and pressure is made, the condition of steam will be impacted. For example, if the temperature is decreased, or increasing the pressure, there will be amount of steam condensed and then wet steam formed. Otherwise, a large pressure drop can bring saturated steam into superheated steam. The relationship of water and steam can be found from temperature – entropy diagram.
It can be realised from the T-S diagram, that the condition of being steam-water mixture is at somewhere between that of saturated water and that of saturated steam. If any change of pressure or temperature of the water-steam mixture can lead the mixture to be saturated water or saturated steam.
Obviously, when there is amount of moisture present in steam, it will contribute to the energy consumed or heat utilised which rises the temperature of the moisture to that of the steam. (Babcock & Wilcox Co., ...
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...be moved by the difference in density of the air. In this case, the convection is called natural convection. The heat transfer rate of forced convection is basically higher than that of natural convection. It causes that the surface temperature in forced convection is lower than that in natural convection.
As previous mention, the heat transfer due to radiation is different from convection as well as conduction. The heat transfer due to radiation can be considered as a result of the changes in the electronic configurations of the atoms or molecules. (Cengel, 2007) owing to the fact that the heat transfer due to radiation does not require the presence of medium of passing or transferring heat, it is faster than the heat transfer due to convection. For example, in the experiment, the heat transfer due to radiation occurred in both of the part 1 and part 2.
Thermodynamics is essentially how heat energy transfers from one substance to another. In “Joe Science vs. the Water Heater,” the temperature of water in a water heater must be found without measuring the water directly from the water heater. This problem was translated to the lab by providing heated water, fish bowl thermometers, styrofoam cups, and all other instruments found in the lab. The thermometer only reaches 45 degrees celsius; therefore, thermodynamic equations need to be applied in order to find the original temperature of the hot water. We also had access to deionized water that was approximately room temperature.
At a constant temperature, a pure liquid has a vapor pressure that describes the pressure of escaped gaseous molecules that exist in equilibrium at the liquid’s surface. Adding energy to a pure liquid gives more molecules the kinetic energy to break the intermolecular forces maintaining the liquid and raises the overall temperature of the liquid. Eventually, adding energy boosts the liquid’s vapor pressure until it equals the surrounding atmospheric pressure. When this occurs, the pure liquid boils at a temperature called the boiling point.
The data which was collected in Procedure A was able to produce a relatively straight line. Even though this did have few straying points, there was a positive correlation. This lab was able to support Newton’s Law of Heating and Cooling.
Convection is a transfer of internal energy into or out of an object by the physical movement of a surrounding fluid that transfers the internal energy along with its mass. According to Oxford Dictionary, convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder or denser material to sink under gravity's influence, that results in transfer of heat. Two fluids are liquid and gas.The fluid above a hot surface expands, becomes less dense, and rises.This applies to objects such as steam from a hot cup of coffee turning cool, ice melting like heat moving to ice from the air, or frozen material becoming raw like how frozen food thaws more quickly under cold running water. When
on how long it takes to heat up. If we heat a large volume of water it
Water is heated in the first container (1) which produces steam. The steam carries heat, called latent heat. A pump on the wall of the first container (1) pumps the steam into the second container (2). The steam from the first container (1) heats the syrup and boils it, creating sugar crystals, in the second container (2), using up the latent heat in the steam from the first container (1). The evaporating syrup creates it's own steam, with latent heat as well. A pump on the opposite wall of the second container, (2), pumps the latent heat in the steam into the third container (3).
In this lab, I determined the amount of heat exchanged in four different chemical reactions only using two different compounds and water. The two compounds used were Magnesium Hydroxide and Citric Acid. Both compounds were in there solid states in powder form. Magnesium Hydroxide was mixed with water and the change in heat was measured using a thermometer. The next reaction combined citric acid and magnesium hydroxide in water. The change in heat was measured as well. For the third reaction citric acid was placed in water to measure the change in heat. In the last reaction, citric acid was combined with water. The heat exchanged was again measured. It is obvious we were studying the calorimetry of each reaction. We used a calorimeter
Theory: Steam distillation uses boiling point to separate organic liquid and water. The organic compound must be immiscible with water, have a high vapor pressure at 100˚C, and may decompose before boiling point is reached. Steam distillation increases the vapor pressure of water more than the vapor pressure of the organic compound as temperature rises to reach the boiling point of the mixture which is a little less than 100 ˚C (boiling point of water) but a lot less than 254 ˚C (boiling point of eugenol). Since the liquids are immiscible, the total vapor pressure only depends on the vapor pressure of each component added together and not the mole fraction leading to a higher vapor pressure which corresponds to the lower boiling point.
Also, when we put the insulation cans in warn water the water heated up the can. And lastly, in the insulated can experiments, both cooling and heating, when the cans temperature was changed it in turn changed the air temperature
Conduction is the process by which heat is transferred from on solid to another. When a solid is heated the molecules inside, which are normally almost static, start to vibrate. When another solid is brought into contact with the heated solid the energy from the vibrating molecules at the edge of the heated solid is transferred to the outer molecules of the other solid.
The rate of evaporation can increase if the gas pressure decreases around the liquid. Heat energy is used to break the bonds that hold water molecules together, that is why water easily evaporates at the boiling point but evaporates much slower at the freezing point. Net evaporation happens when the rate of evaporation surpasses the amount of condensation. Saturation occurs when these two process rates are equivalent when the humidity of the air is at one-hundred percent. On average, a fraction of the atoms in a glass of water has enough heat energy to escape from the liquid. Evaporation from the ocean is the primary device for supporting the surface-to-atmosphere part of the water cycle. Evaporation is the pathway where water moves from the liquid state back into the water cycle as atmospheric vapor. Studies have shown that the major bodies of water are nearly ninety percent of the moisture in the atmosphere from the evaporation of the water, the ten percent left is contributed from plant transpiration. Evaporation can only occur when water is available. It also requires the humidity of the surrounding atmosphere to be less than the evaporating surface. At one-hundred percent relative humidity, there is no more evaporation. The wind chill effect is one of the
Using steaming water to generate motorized movement has its history back from 2,000 years ago. The steam engine is a mechanism that executes motorized exertions by means of heat as its operating fluids. In common procedure, steam engines are the incorporated steam deposits like the transportable engines and railway steam engines, or could denote a mechanism single-handedly, as in stationary and beam steam engines [Benford, et. al, 2005]. Particular mechanisms like steam pile drivers and hammers are reliant on steams provided by disconnected boilers.
Radiate, by definition, means to send or spread out, and this is important to know when thinking about how exactly radiation occurs. We already discussed a child coming in from playing out in the snow, snuggling up to their father and getting warm through heat transfer by conduction- physical contact. Now, let’s say that the child comes inside from out in the cold, takes off their snow gear and places their hands over a hot fire instead. The child’s hands will warm up through the transfer of heat energy through radiation. Another example, which can be seen every day that you walk outside and the sun is shining bright- is the heat received on Earth by the sun, through the means of radiation. The Earth receives heat through the electromagnetic waves, and our bodies feel the warmth of the sun from these waves that are absorbed within our skin. Radiation is the only means by which heat energy can transfer through the empty space between Earth and the sun- neither conduction or convection have the ability to play a role in this area and therefore, we can see how truly important radiation is. Another interesting fact in regards to radiation is that “because more heat is radiated at higher temperatures, a temperature change is accompanied by a color change. For example, an electrical element on a stove glows from red to orange, while the
As air humidity is in an instance of increasing, its ability to absorb water vapor decreases and evaporation rate slows down. For evaporation to undergo there must be a difference in humidity (Tenalem Ayenew and Tamiru Alemayehu, 2001; Fetter C.W, 1994).
6. When water is distilled, it does not vaporize all at once when the boiling point is reached. When some water molecules evaporate, the kinetic energy of the remaining liquid goes down and the temperature drops slightly. As a result, the rest of the water needs to be heated again before more molecules of water evaporate. A constant source of heat is needed.