Tasked with the quest to economically and efficiently extend civilization into the Northern regions, the construction industry has been hindered by the presence of perennially frozen ground. The thermosyphon is a device that facilitates the harmonious union of structure and ice. This paper will serve as a tutorial on thermosyphons, and present an exploration into the physical concepts that allow their operation.
The physical concepts and phenomenon that enable the operation of thermosyphons can at times be complex-but don’t be scared. This tutorial will start with the most rudimentary explanation of thermosyphons, and proceed from there to deliver more in depth examinations in a step by step process. Let’s get right down to business.
The steps in thermosyphon operation are: STEP 1-Heat flows into the thermosyphon, STEP 2-Heat flows through the thermosyphon tube, and STEP 3-Heat is released into the atmosphere.
Simply stated, a thermosyphon is a device which moves heat from one place to another. There are different types of thermosyphons which are used for different applications, but for the purposes of this primer we will concentrate on thermosyphons used by the construction industry to stabilize frozen ground. For example, consider a road built over permafrost.. In this situation it is desirable to keep the ground from thawing, otherwise the road embankment will be destroyed. A thermosyphon “collects heat” from the frozen ground. This collected heat is brought to the top of the thermosyphon and the cooling fins, where it is released into the atmosphere. In this way, the ground remains frozen.
Now, the thought of frozen soil warming the atmosphere may be hard to grasp. This brings us to an important point about the thermosyphon- they only work when the ambient air temperature is below the temperature of the soil (less than 31 degrees Farenheight). With this in mind, we can consider thermosyphons from a different perspective; a thermosyphon increases the exposure of sub-surface soil to freezing temperatures. Another thought, although not totally correct from a physical standpoint, is that the thermosyphon brings cold into the soil.
Let’s examine the thermodynamic process by which a thermosyphon operates. This process is outlined below in a step by step chronology.
Step 1-There is an accumulation of the working fluid in the bottom of the thermosyphon. The most important factor that governs the choice of a working fluid is that it must have an extremely low boiling point. Permafrost soil is typically at a temperature of 31F and consequently the fluid boiling point should be less than 31F.
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.
Firstly, when testing temperatures at 30°C and 40°C, the water was. sometimes heated more than needed, so I had to wait until it cooled. down to the required temperature. To avoid this happening, a. thermostatic water bath could have been used, because I could set it. to the required temperature.
The temperatures will be set up by using ice to cool tap water down to lower temperatures and boiling water to heat it up. The temperature will be measured to within 0.1°C on a mercury thermometer to ensure accuracy. The temperatures will range from 10°C to approximately 40 °C and it will be done at 5° C intervals.
First, a calorimeter was constructed with three standard styrofoam cups. One cup was stacked within the second for insulation, while the third cup was cut in half to be used as a lid. The lid was made to increase accuracy when recording the temperature. The temperature probe hooked up to Logger Pro software poked a hole in the top of the calorimeter by applied force with the end of the probe through the Styrofoam. Meanwhile, 40mL of deionized water were measured out in two clean 50 mL graduated cylinders, and poured into 100 mL beakers. The beakers and graduated cylinders were cleaned with deionized water to avoid contamination that may cause error. One of the beakers was placed onto a hot plate, which was used to heat the water in the beaker. The other beaker rested at room temperature. Once heated and at room temperature, the initial temperature was measured with the probe. Next, the two 40 mL of deionized water were poured into the calorimeter, quickly sealed with the lid, and the temperature probe emerged through the top of the calorimeter into the water to measure the temperature so the calorimeter constant would be determined. The equations used to determine the calorimeter constant were Δq = mCΔT and Δq =
Frost line is underground water in soil is expected to freeze. The depth is mostly depends on the location of the weather conditions in the area. When frost heave it can damage the building by moving location of the foundations. Foundations are expected to build under the frost depth. The building code requires for the northern five feet.
Refrigeration Refrigeration is defined as “The process of removing heat from an enclosed space, or from a substance, to lower its pressure.” (First website given in bibliography) In simpler terms, it is removing heat from states of matter in order to keep them cooler. The basic need for refrigeration is to cool food and beverages, as they often get spoilt if the temperature is high. Before actual refrigerators and other such mechanical systems were introduced, it was very common for people to cool their food with ice and snow.
Thermodynamics is defined as “the study of heat transfer and its relationship to doing work.” Specifically, it is a field of physics that has to do with “the transfer of energy from one place to another or from one form to another” (Drake P.1). Heat acts as a form of energy that equates to a total amount of work. Heat was recognized as a form of energy around the year 1798. Count Rumford (Sir Benjamin Thompson), a British military engineer, observed that “numerous amounts of heat could be generated in the boring of cannon barrels” (Drake P.1), which is where a cannon’s firing port is enlarged using a drill and immense amounts of heat to make the metal malleable. He also observed that “the work done in turning a blunt boring tool was proportional
For the generation of electricity, hot water, at temperatures ranging from about 700 degrees F, is brought from the underground reservoir to the surface through production wells, and is flashed to steam in special vessels by release of pressure. The steam is separated from the liquid and fed to a turbine engine, which turns a generator. In turn, the generator produces electricity. Spent geothermal fluid is injected back into peripheral parts of the reservoir to help maintain reservoir pressure. If the reservoir is to be used for direct-heat application, the geothermal water is usually fed to a heat exchanger before being injected back into the earth. Heated domestic water from the output side of the heat exchanger is used for home heating, greenhouse heating, vegetable drying and a wide variety of other uses.
... model for the thermodynamics and fluid mechanics calculations for this system need to be presented.
Next Dalton’s law of partial pressure is used. The mixture of gas in the graduated cylinder was filled with two things: water vapor and air. Using the Dalton’s law, it can be concluded that the total pressure is equal to the pressure of air and the pressure of water vapor added together. This is an endothermic reaction which means that it absorbs heat, and when a reaction gains heat, it is repres...
Finally, the liquid moves to the evaporator, where heat from the inside air is absorbed and changes it from a liquid to a gas. After that, it goes again to the compressor, where the entire cycle is repeated.
... temperature of 112 0C also and a pressure 2.5 bar. Cooling water is used to condense the vapor exiting column. Remaining methane and hydrogen are separated in reflux drum where the vapor stream is combined with other gases streams. The overhead of first and second separator are combined to form fuel gas. The liquid stream exiting in the bottoms of the reflux drum is pumped at pressure of 3.3 bar for discharging pressure. The pump stream is separated in two streams. One stream is to feed to tray one of the column and the other one stream is cooled down to 38 0C in heat exchanger. Then, the cooled product stream is sent to storage.
Then I placed a 100cm3 beaker underneath and filled that up with 25cm3. of the alkali. Then I read the temperature from the electric thermometer. Once I recorded the temperature and written it down I added 5cm3 of acid. into the beaker of alkali and then again I recorded and wrote down the temperature.
In order to understand the true nature of cryonics it is wise to give a simple example of what scientists are attempting to achieve.
In thermodynamics Refrigeration is the major application area, in which the heat is transferred from a lower temperature region to a higher temperature region. The devices which produce refrigeration are known as Refrigerators and the cycle on which it operates are called refrigeration cycles. Vapour compression refrigeration cycle is the most regularly used refrigeration cycle in which the refrigerant is alternately vaporized and condensed and in the vapor phase it is compressed. Gas refrigeration cycle is the well-known refrigeration cycle in which cycle refrigerant remains in the gaseous phase throughout the cycle. Cascade refrigeration are the other refrigeration cycles discussed in this chapter; absorption refrigeration is the one more refrigeration cycle which is used where the refrigerant is dissolved in liquid before it is compressed. One more refrigeration in which refrigeration is produced by passing the electric current through two dissimilar materials is called as the thermoelectric refrigeration.