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CHAPTER II THEORITICAL2.1 The Definition of Air ConditioningAir conditioner or AC is one of the cooling equipment (refrigeration). Other tools that work using the cooling system is like a refrigerator, a freezer and cold dispenser. The basic principle of the work of the cooling system can be defined as "relocate or move the heat". So the principle of work of an air conditioner in a cool room was by way of moving the hot air out of a room (in-door) into the air outside the room (out door).Figure 2.1 Air-conditioning (AC) [1] Principle or the workings of AC or refrigeration machine room ;1. Heat energy is absorbed refrigran in the Evaporator and where it comes out as the cold air.2. The heat absorbed by the evaporator is taken out by a steam pipe refrigran.3. Heat is carried by air to the air being dumped out of the condenser have circulated.4. Refrigran cool bersikulasi back the liquid pipe.5. And log back into the EvaporatorBecause indoor air temperature and the temperature of the outside air is actually no different, then to move heat in cooling AC needed energy. I.e. energy needed electricity to pump heat from indoors and throw it out of the room.Figure 2.2 The Scheme Of Work Of Cooling Machine (AC) [2] 2.1.1 Condenser The condenser is a tool for creating condensation cooling material gas from the compressor with high temperature and high pressure. For penempatanya, the condenser placed outside the room that is being cooled, so that the heat can throw out. The condenser is pipelines that serve as condensation. The dipompakan of the Refrigerant compressor will experience the emphasis so that it flows into the condenser pipe, then subjected to condensation. From here the refrigerant is condensed and liquid will flow to the evaporator pipe.

Figure 2.3 Condenser [3] The condenser is a heat exchanger machine type (heat exchanger), which serves to mengkondensasikan the working fluid2.1.1.1Types of Condenser In General, there are two types of the condenser:1. Surface Condenser The working principle of the surface condenser , as shown in Figure 2.4 sthe team goes into the condenser shell through the steam inlet connection on the top of the condenser. The Steam then intersect the spectral low condenser tube so that the temperature of the steam down and condensed, producing the condensate accumulated in the hotwell.

Figure 2.4 Surface Condensor [4] Low temperature on tube is maintained by means of mensirkulasikan water that absorbs heat from steam condensation on the process. The heat is here called latent heat evaporation and condensation heat also sometimes called (heat of condensation) within the scope of the discussion of the condenser. Hotwell condensate accumulated in later moved from the condenser by using the exhaust condensate condensate pump.When leaving the condenser, almost the entirety of the steam has been condensed from the saturated portion except the air that is in the system. There is air in the system generally occurs due to a leak at shaft seal, piping, valves-valve, and so on.It goes into the condenser together with steam. Dijenuhkan air by water vapor, and then water passes cooling section where a mix of steam and air cooled condenser for further disposed of by using water ejectors that serves to maintain a vacuum in the condenser. To eliminate the air dissolved in the air due to the condensate in the condenser, done de-aeration. De-aeration is done in the condenser with heat the condensate with steam to the air terlalut on condensate will evaporate. The air is then drawn into the air cooling section with a harness of low pressure that occurs in water cooling section. Air ejector would then move the air from the system.The following are the types of condenser type surface condenser.a.

Horizontal condenser Cooling water enters through the bottom of the konddensor, then enter into the cooling pipes and out at the top while the incoming heat flow through the central part of the condenser and out as condensate on the bottom of the condenser.b.

Vertical condenser Cooling water enters through the bottom of the konddensor, then enter into the cooling pipes and out at the top while the incoming flow of heat through the top of the condenser and out as condensate on the bottom of the condenser.2. Direct-Contact Condenser Direct-contact steam mengkondensasikan condenser mix it with cooling water. Direct-contact or open a condenser used in some special cases, such as:a.

Geothermal powerplantb. The powerplant that uses the temperature difference in sea water (OTEC)

Figure 2.5 Direct Contact Condenser-[5]An example of the condenser typeDirect-Contact spray condenser Condenser At steam, mixing with cooling water is carried out by way of spraying water into steam. So the steam coming out of the exhaust turbine at the bottom are mixed with water cooling in the Middle, producing condensate approaching phase saturated.Then dipompakan back into the cooling Tower. Some of the condensate back to the boiler as the feedwater. The rest refrigerated, usually in dry-(closed) cooling tower. The water is cooled in a Cooling tower is sprayed into the exhaust turbine and the process repeats.2.2 Definition of Heat Transfer Heat transfer is the transfer of energy due to differences temperature. There are three forms of heat transfer mechanisms are known, namely conduction, convection, and radiation.2.2.1Conduction Conduction is the transfer of heat from a place that has a high to low temperate in place in the medium that directly intersect. If on an object there is a gradient of temperature, then heat transfer may occur as well as energy from the high temperature to low temperature parts, so that it can be said that the energy will be moved by conduction, the rate of transfer of kalornya stated the following : [7]..................................................... (2.1)Where:

= Heat transfer Rate (W) = Cross-sectional area where heat flows (m2) = Temperature Gradient in the cross-section, or rate of change of temperature T against the distance in the direction of heat flow x

= Thermal conductivity of the material (W/moC)

Figure 2.6 Example of Heat Transfer by Conduction[6]2.2.2 Convection Convection is heat transfer between the solid surface and adjacent to a moving fluid or flow and it involves the effects of conduction and fluid flow[1] .

Figure 2.7 Examples of Heat Transfer from the Hot Plate[7]From the picture above, it can be seen that the speed of the fluid that flows in surface plate heat affects the temperature around the surface of the plate. The rate of heat transfer by convection can be expressed as[7 ] :.................................................... (2.2)Where:= Convection heat transfer Rate (W)= Heat transfer Coefficient of convection (W/m2 0C)= Cross-sectional area (m2)= Temperature difference or Change (0C; 0F)2.2.3 Radiation Radiation is the transfer of energy, because the emission of waves electromagnetic fields (or photons). The rate of heat transfer radiation has can be formulated with: [7].

.................................. (2.3)Where:

= Stefan-Boltzman Constant = 5,669 x 10-8 (w/m2 k4)

= Cross-sectional area (m2)

= Temperature ( C)

Figure 2.8 The Radiation Heat Transfer [6]2.3Types Of Water Flow The flow can be classified in various types such as: turbulent, laminar, real, ideal, and more. Fluid flow through the installation (pipes) there are two types of flow.2.3.1 Laminar Flow Laminar Flow, also known as viscous flow. These terms are descriptive of the laminar flow, because flow, a layer of water flows on top of each other with different speeds with virtually no mixing between the layers, the fluid particles move in definite paths and can be observed, and the flow was characteristic of the viscous fluid or is where one fluid viscosity plays a crucial part:

.........................(2.4)From the above equation note that flow is laminar, the magnitude of the friction factor is influenced by the amount of liquid to Reynolds, and not depending on the hardness of the pipe

Figure 2.9 Laminar Flow[8 ].2.3.2 Turbulent FlowTurbulent flow is a flow that is marked with the random movement of the fluid elements where each element of the fluid velocity has fluctuated. Happens on "high" the flow rate and is often utilized for better mixing. In the turbulent flow conditions that occur resulting in turbulent shear stress evenly throughout the liquid resulted in losses of flow.

Figure 2.10 Turbulent Flow[8 ].To determine the shape of the flow of laminar and turbulent flow there is in the image below:

Figure 2.11 Laminar Flow and Shape the Turbulent Flow [8 ].2.3.3 Incompressible FlowIn fluid mechanics or more generally continuum mechanics, compressible flow (isochoric flow) refers to the density of the material where the flow is constant in the package-a very small volume of fluid moving with water (fulid) speed. An example of a compressed fluid is: water, oil, various types such as emulsion, etc. Form the Bernoulli Equation for Incompressible flow is as follows: = constant ....... (2.5)

Information: = Water velocityg = Gravitational forceh = A relative highp = Pressure of fluid = Density of waterThe above equation is valid for incompressible flow with the following assumptions: steady state InviscidIn different forms, can be written as follows........ (2.6)

2.3.4 Compressible Flow Compressible flow describes the behavior of fluids that are experiencing significant variations in density. To flow where the density does not vary significantly, the flow behavior analysis can be simplified greatly by assuming a constant density. The Bernoulli equation for the compressed flow is as follows = constant ...... (2.7)Information: = Gravitational potential energy of mass unity: if gravity is constant then = gh W = Enthalpy of the fluid mass unity2.4 Thermoelectric ConceptThermoelectric technology works by converting heat energy into electricity directly (Thermoelectric generator), or otherwise, of electricity produces cold (refrigeration thermoelectric). To produce electricity, material Thermoelectric simply laid in such a way in the circuit that connects the hot and cold sources. The series will be produced from a number of electricity according to the type of materials used.2.4.1 Thermoelectric Generator (TAG) Thermoelectric (TAG) plant is a power plant based on the Seebeck effect, which was first discovered in 1821 by Thomas Johann Seebeck. He connected the copper and iron in a series. In between the two metal is then placed needle compass. When the metal is heated, the compass needle turns moves. This happens due to the flow of electricity that occurs at the metal gives rise to a magnetic field. The magnetic field that moves the needle of the compass. The phenomenon came to be known with Seebeck effect. Figure 2.12 shows the TAG structure, consisting of an arrangement of n-type element (a material with an excess of electrons) and p-type (material with an electron deficient). The heat goes on one side and the other side disposed of, resulting in a voltage drop that pass through sambuangan Thermoelectric. The magnitude of the voltage produced is proportional to the temperature gradient[3].Voltage (V0) can be expressed by the equation: V0 = X Y x (Th a T c) .................................. (2.8) Where:V0 = Output voltage (Volt)XY = Seebeck Coefficient of material between 2 X and Y (Volt/K)Th, Tc = Termokkopel hot and cold Temperature (K)

Figure 2.12 Structure Thermoelectric Generator (TAG) [9 ].Thermoelectric is a integrated circuit module in the form of a solid using the three principles of thermodynamics which is known as the Seebeck effect, Peltier and Thompson. Construction consists of a pair of p-type semiconductor material and n-type forming thermocouples which has the form of a sandwich between two wafer thin ceramic. This module can be used to generate heat and cold in each side if the electricity used is usually applied as a cooling system for example cooler vaccines or to produce electricity when used as a hot and cold temperature difference.Heatsink used to help increase the release of heat on cold side so as to improve the efficiency of the module. The potential power generation from a single berbedabeda Thermoelectric modules will depend on the size, construction and the difference in temperature. The greater the temperature difference between the hot side and the cold side of the module will generate a voltage and current. Thermoelectric modules can also be connected together either in series or in parallel like a battery to generate voltage or electric current. Each module is able to produce the average voltage 1-2V DC and even up to 5V DC depending on the variation, but generally the temperature delta one Thermoelectric module produces 1.5-2V DC[9 ].Currently, the application TAG has been widely applied in various fields, an American company (Hi-Z Technology, Inc.) has been successfully developed eight peltier module (model HZ-14) used on glycol generator and can generate power of 60 Watts with an ambient temperature of 15-30C and operating temperature range 175-200C. Large power generated due to the module used is a special TAGinstead of the TEC and the difference in the temperature reaches 170C. Thermoelectric technology development of Hi-Z experienced a rapid progress since the current Hi-Z technology is able to reach the value of ZT (figure of merit), although still produced on a small scale[9 ].2.4.2 Thermoelectric Cooling (TEC) Thermoelectric cooling (TEC) is a component of the Peltier Effect applied. Peltier is a component that includes the Thermoelectric component, which occurs when the temperature difference disntsrs two sides then these components transform it into electric voltage magnitudes, and vice versa, when an electrical voltage is given to this component, then it can turn it into two different temperatures[10].

Figure 2.13 Peltier Elements[10].In practice, the TEC uses several thermocouples laid out series that facilitate heat transfer. Generally the outside of this component is wrapped a thin ceramic containing stem-batangBismuth Telluride inside. The Material is a semiconductor which added an additional substance aims to provide excess free electron (N-type semiconductor) or give you a free electron deficient (P-type semiconductor) [10].

Figure 2.14 Peltier Element Work Illustrated[10].The electrons from the electron-deficient material (P-type material) material moves into excess electron (N-typematerial). In these circumstances it will absorb the enrgi connector. When the electron moves from the N-type to P-type, then the connector will release energy. The energy absorbed or released is given in the form of heat. Peltier element work illustration shown in Figure 2.14.2.5 Aluminum Aluminum is often found above the Earth in the form of chemical compounds, but not found in nature in a State of pure aluminum. The most important raw material for the manufacture of aluminum is bauxit, which is a crowd of minerals (land of alum, aluminum oksid) and affix oksid iron from acid siklat. Bauxit contains 55 65% ground alum, 2 24% iron, 12 30% water and 1 8% siklat acid. The color depends on bauxite affix. Figure 2.1 shows an example of aluminum ingots (ingots)[11].

Figure 2.15 Aluminum Ingots [11] .The main findings in Europe are France, Italy, the Balkan countries, Russia, and Hungary. But in Africa, the Americas, Asia, and Australia there are many sources of bauxit. How to obtain pure aluminum includes four stages: Preparation of bauxsit (pelumatan, purification, drying, penggerusan)Rarefaction bauxit become pure alumAbsorption of acidic substances (the reduction) of land into a raw aluminium alum through electrolysis melting with a solvent as kryolithSmelting of pure aluminum in Some properties of pure aluminum is kind of low weight, colour silver, shiny white, has a conductivity of heat and electricity well, endurance may be consumed. Aluminium envelop itself in the air with a layer of oksid (protector) that should not be tampered with. Aluminum is not sustainable against alkali and acid salts. Because violence is low, aluminum is less good for the modified form with appropriate for flakiness and knowest. This is required for the flakes are big, tall and sayat speed of a suitable lubricant.

Aluminum is really soft and easily stretched so easily modified form in a State of cold and heat. Aluminum can be welded and solder. This is required for pelumer materials and materials welding. Aluminum is not magnetic, no-toxic and a reflector (reflectors behind) are good for heat, light and electromagnetic waves. Through a suitable surface treatment can be diverse beautiful embodiment.As the power and violence is low, then the pure aluminum is not suitable for machine parts that are bearing the brunt. That specifies on its use besides does it weigh a light is preserved against corrosion. In elektroteknik, aluminum is used as an ingredient of carriage (special provisions) for capacitors, cables, cable sheath. Aluminum termurni meet the demands the highest chemical resistance will be increased in accordance with the degree of purity. The acid and soda is hard is able to dissolve membranes oksid and attacking aluminum. The most important exception: oxidized salpeter acid with strong and not dissolve or attacking the purest aluminum. Because it's the purest aluminum used in chemical manufacturing and installation assembly container for salpeter saturated acids [11].2.5.1 Aluminum Properties Aluminum is the most used metal after steel. Aluminum is amfoter and is easily oxidized. As for the basic properties of aluminum so it can be used in a machine or vehicle's frame: 1. Lightweight, with a specific weight of 2,7 g/cm3. Therefore, these metals are widely used in the form of metal as material exchanger with a high speed connection such as a piston at the bars.2. A good heat conductor, so used to additional material on the wire. If the thin steel core is added, then it would have greater power. 3. Aluminum has a very high thermal conductivity as a component of heat exchanger on the piston.4. Non-toxic, so it is widely used in chemical factories and in the food industry, for domestic purposes, for buildings, and equipment of the vessel, in addition in the form of aluminium foil used for packing and bottle caps.5. Have a great attraction to oxygen, which allows the metals used as pengoksidan in steel, as a mixture of iron oxide and Aluminum powder used to weld rail.To get a better strength and corrosion resistant aluminium is usually combined with other types of metal. Because of the light metal is a good conductor of heat, after copper. Can be forged, cast, done by machine, soldered, welded, stamped and hardened, withdrawn, and at ekstruksi. Can be made into a variety of forms for further processing or manufacturing process that is; sheets, plates, bars, pipes, and wires.Pure aluminum is soft and chewy, but when mixed with small amounts of other elements, her strength and violence will go up, some alloys have a strength equal to or more than the soft steel. To maintain the stability of aluminium corrosion does not occur in order for it to be painted or lacquered aluminium and so are not affected to the acid. Anodizing that is the formation of oxidation on surface of aluminum electrolysis, in which time the flow is passed through a metal and an electrolyte to the cathode, so the normal oxide layer will add a layer which is almost transparent and its thickness can be arranged. This layer is harder and less porous, allowing for permanent staining with basic ingredients in organic paint colors are very attractive. Surface-surface dianodise usually closed meetings and can be lacquered [11] .2.5.2 Aluminum Alloy Properties of aluminum materials will undergo repairs that blatant when he combined with other metals. Copper exalt violence, power, magnesium silisium. Other integrators metal is magnesium nickel zinc, resulting in a desired trait in a small percentage. Possibility of selection of the many aluminum manifold which opens an opportunity for area for aluminum spreaders. Mainly to increase the mechanical solidity of aluminium then try with the road design. In that case sought wherever possible to maintain or improve nature pure aluminum is good as a kind of low weight, durability may be consumed, electric and heat conductivity is good, its convenience for the trend to form and weld.Depending on the type of alloy, the weight of its kind located between 2.65 and 2.8 kg/dm3. Aluminum alloy have in standardization. Categorization is done into two main groups, namely processed aluminum alloy cast by pouring and alloy aluminum holding to squeeze on the structure of the cast, had been wading through a process of squeezing (unfolding, forging, milling).Based on an increase in power there are two groups of aluminum alloy that is not able to be hardened or naturally hard and that can be hardened.Aluminum alloy that can not be gained its power through the dituakeraskan change the shape at room temperature, for instance through grinding, forging, perentangan. But in that stretch is reduced and the material will become more fragile as the rise in the degree of change form. But reinforcing the cold can be restored to its original state with the soft candescance.Aluminum material properties will experience a change is good when combined with other metals. Copper will increase violence, magnesium will increase the strength. Selection of aluminum alloy which is a lot of exciting tours that open up opportunities to uses of aluminum are more numerous. Mainly to increase the mechanical robustness of aluminum, then tried with the road design. But the nature of pure aluminum are retained, such as the weight of its kind that is low, their rust resistance, heat conductivity is good, its convenience for modified shape with good[11] .2.5.3 Heat Treatment Of Aluminum Alloys Aluminum alloy gained its power through the change form at room temperature, for instance through grinding, forging, unfolding. However, in that it spans are reduced and materials will be more fragile in line with increasing degrees of change form. But reinforcing the cold can be restored to the original to do a candescance, then it can be done by warming the aluminum. Figure 2.16 shows the form of aluminum that has been melting.

Figure 2.16 Molten Aluminium Heated [11] .Through improved software pemijaran kesudian change the form of aluminum and aluminum alloys. Granules become more subtle. Thus these materials become soft and can be stretched Pack. It is only applied when the material has become too hard and brittle due to the reinforcing cold. Soft candescance takes place at temperatures between 300oC and 450oC[5] .2.6 Solidworks Software Solidworks is one type of software that can be used to create 2-dimensional modeling (2D) and 3-dimensional (3D) quickly and easily. And also to be able to make a calculation analysis such as stress analysis, flow simulation fluid, thermal, and other. This Software can create a model unit or with merangkainya. 2.6.1 Solidworks Simulation SolidWorks simulation is a special extra for doing simulations such as power, heat, pressure, and others. To run a simulation, then enter the required data used umtuk limits of put. SolidWorks flow simulation is one type of analysis in SolidWorks simulation that aims to quantify the phenomenon in the flow[12 ].5

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