Cooling towers devices that are mainly designed to aid in the removal of the waste fluid from the existing fluid and then transferring it to the atmosphere through the air stream. The major principle on which the cooling towers in based on the heat transfer. Heat is normally transferred from the high water temperature to the lower water temperature that exists within the air stream temperature. Cooling towers are very significant and essential in entire aspects of life. The principle of the cooling towers is normally applied in diverse fields ranging from heavy engineering industries to the existing smaller domestic cooling systems within our homes. Within the petroleum engineering studies, the fundamental understanding of the diverse applications of the cooling towers is very significant. Cooling towers are utilized in the cooling of the circulation of water within the power and petroleum production, oil refineries accompanied by the chemical and gas processing industries. Moreover, cooling towers are also utilized I the cooling of the waste fluid within the petroleum factories prior to depositing them to the surrounding water bodies such as rivers and seas.
There are four tests that are normally utilized in the examination of diverse association associated to the divergence of the existing theories that are mainly concerned with air. The associated air test include the inlet and the outlet test, dried up and wet bulbs hotness, water inlet and outlet hotness and lastly pressure that involves utilizing the principle of the cooling tower. The major aim of the existing four tests is to focus on the detailed study that is entailing the material accompanied by the heat transfer mechanism as pertaining to the cooling tower design and its operation dependant. Moreover, this study will intend in the examination of the impact of fluctuating the cooling load accompanied by the fluid mass flow rate as pertaining to existing air. The fluid that is considered is normally air the inlet and the outlet test, dried up and wet bulbs hotness, both the prevailing pressure that exist at the orifice differential. This examination is also entailing the packing across accompanied by the quantity of the water make up. This study is also geared towards the analysis of the impact of the unstable the cooling load accompanied by the fluid mass flow rate as pertaining to the flow rate of the dehydrated air via the orifice. Both the experimental and the theoretical make up rates accompanied by the alteration of the balance based of the air and water circulation. The study is also aimed at the determination of the entire alteration of the enthalpy balance of the existing system as pertaining to heat loss.
The prevailing four tests were done through variety of the prevailing equipments during the diverse levels of the experiment. The equipments that were utilized entail an instrumentation panel that includes various apparatus. These apparatus includes main switch, 0.5 KW switch, manometer, temperature selector 1 KW switch, temperature indicator, mass flow rate regulator, a pump for water transmission and thermostat. A make up that depicted water tank placed on a water heater accompanied by a thermometer utilized in the measuring of the required temperature of the design make up water reservoir. A packed column equipped with an orifice, water distribution system accompanied by packing that enlarges the existing surface area of the design waterfalls. The base that entails a damper accompanied by a fan that gusts chilly air up the prevailing waterfall within the packed column. A stop watch in collaboration with a digital ruler is utilized to measure time and the resultant latitude of the water drop respectively. The Figures 1 below shows the equipments, which were utilized in the entire four, test while Figure 2 exemplifies a schematic diagram that elaborates the mechanism of the cooling tower.
Figure 1: The equipments which were utilized in the experiment
Figure 2: A schematic diagram elaborating the mechanism of the cooling tower
The first test that is at the beginning of the experimental process, the model water reservoir was filled with water to certain stage. The mass flow rate regulator was set to mass flow rate of 20 g/s accompanied by the cooling load of zero kilowatts. The chief switch within the instrumentation panel was subsequently switched on which was then utilized in the measurement of the resultant air inlet dry bulb hotness (t1) and the air inlet wet bulb hotness (tAw) = (t2). The parameters that were subsequently measured were the air outlet dry bulb hotness (t3), the air outlet wet bulb hotness (t4), the water inlet hotness (tC) = (t5), the water outlet hotness (tD) = (t6), the hotness of the model tank (t7), the pressure depicted at the prevailing orifice differential marked as (x) and then eventually the pressure difference across the packing marked as (?p). After duration of five minutes the latitude realized on the water drop within the model tank was determined and then measured. Eventually, a duration of a specified time was granted amidst every experiment so that to allow stabilization of the temperatures.
All the preceding experiments tests followed the above process exactly only that some of the arrangement of the instrumentation panel were altered accordingly. In the second test, the mass flow rate regulator was placed at 20 g/s and the existing cooling load was at 0.5 kilowatts. In the third test the mass flow rate regulator was placed at 20 g/s while the cooling load was at 1.0 kilowatts. Lastly, in the fourth test the prevailing mass flow rate regulator was placed 20 g/s while cooling load was at 1 kilowatt.
The data that was obtained in the four tests were tabulated in form of numerical figures
The set conditions for the four tests were as shown below:
Test1: 0.5 (low flow rate) 20g/s
Test2: 0.5 (high flow rate) 20g/s
Test 3: 1.0 (low flow rate) 20g/s
Test4: 1.0 (high flow rate) 20g/s
Time (min) Power (Kw) T1 C T2 C T3 C T4 C T5 C T6 C T7 C H/mm Pressure/mmH2o Exit pressure/mmH2o 25 0.5 24.6 14.8 21.8 18.8 27.8 21.3 21.5 108.47 10.1 13.3
Time (min) Power (Kw) T1 C T2 C T3 C T4 C T5 C T6 C T7 C H/mm Pressure/mmH2o Exit pressure/mmH2o 20 0.5 24.5 14.9 21.5 18.5 27.3 21 21.5 74.21 10.3 14.1
Time (min) Power (Kw) T1 C T2 C T3 C T4 C T5 C T6 C T7 C H/mm Pressure/mmH2o Exit pressure/mmH2o 30 1 24.3 15.7 28.7 24.2 44.2 26.8 21.5 188.79 10.1 13.2
Time (min) Power (Kw) T1 C T2 C T3 C T4 C T5 C T6 C T7 C H/mm Pressure/mmH2o Exit pressure/mmH2o 20 1 25 15.2 27.2 22.9 43.2 25 22.5 145.4 10.2 14.2
The computation of mE is done in the following manner
mE = d× V
But V = ? × r2 × L
mE = represent model quantity measured in kilograms (kg)
d = Represent the density of water = 1000 kg/m3
V = Represent the alteration in volume of the water model in m3
r = Radius of the existing water model tank = 0.03406 m
L = Represent the prevailing latitude water drop within the model tank in metres
mE for test 1 = 1000 × ? × (0.03406)2 × 0.02427
= 0.088 kg
mE for test 2 = 1000 × ? × (0.03406)2 × 0.02830
= 0.103 kg
mE for test 3 = 1000 × ? × (0.03406)2 × 0.03932
= 0.143 kg
mE for test 4 = 1000 × ? × (0.03406)2 × 0.03949
= 0.144 kg
?Ee = mE / y
?Ee= Represent the experimental model rate presented in (kg/s)
y= Represent the time interval presented in (s)
Make up rate for test 1
?Ee = 0.088 / (25×60)
= 0.00005867 kg/s
Make up rate for test 2
?Ee = 0.103 / (20×60)
= 0.000085833 kg/s
Make up rate for test 3
?Ee = 0.143 / (30×60)
= 0.00007944 kg/s
Make up rate for test 4
?Ee = 0.144 / (20×60)
= 0.00012 kg/s
Computation of the total cooling load
?T = ? + P
?T= Represent the total cooling load presented in (KW)
? = Represent the cooling load presented in (KW)
P= Represent the pump input power
Total cooling load for test 1
?T = 0 + 0.5 = 0.5 KW
Total cooling load for test 2
?T = 0 + 0.5 = 0.5 KW
Total cooling load for test 3
?T = 0 + 1.0 = 1.0 KW
Total cooling load for test 4
?T = 0 + 1.0 = 1.0 KW
The data recorded within the table depicts that the air outlet dry bulb hotness (t3) and the air outlet wet bulb hotness (t4) gradually increases with increase in the cooling load. This is majorly because as the cooling load increases the quantity of the heat transferred to the water within the model tank increases. This heat is then transferred to the air that collides within the tower through the process of convention hence resulting to rise in the temperature of the air within the outlet dry accompanied by the wet bulb temperatures. Moreover, it is noticed that the both the existing temperature (t3) of the air outlet dry device together with the air outlet wet bulb temperature (t4) also rapidly increases as the water mass flow rate decline. This is resulted the decline in the fluid mass flow rate that is resulted by the corresponding decrease in the velocity of the prevailing water in the tank.
It is also depicted within all the tables that the entire water inlet heat (t5) and the water outlet heat (t6) increases with increase in the cooling load. This is because increase in the water inlet hotness (t5) is directly proportional to the cooling load in that the quantity of heat transferred to the existing water increases as the water inlet temperature increases. The increase in the temperature of the water outlet (t6) is taken to be having steady flow rate that is the quantity of cooling water within the prevailing tower is constant. Hence, the temperature of outlet water increases at a constant rate concerning the cooling load. The test in table 3 and table 4 were carried out by power of 1KW of the existing cooling load depicts that the temperature of the inlet water (t5) is inversely proportional to the flow rate that is it decreases as the flow rate increases and vice versa. This is due to the fact that water mass flow rate decline as the velocity decline. Consequently, the duration of contact amidst water and the existing heater increases through the process of convection. This then makes the temperature of the inlet water to increase. Nevertheless, the temperature of the water outlet (t6) normally decreases with the decreases in the mass flow rate of the prevailing water. This is because as the mass flow rate of the fluid decreases the corresponding velocity of the fluid entering the tank decreases thereby resulting into the interaction duration amidst the water particles that is present within the tower through the process of convention current. This eventually in the end lead to the general decline in the temperature of the outlet water
The most common sources of error that might have affected the result of the experiment error due to humankind that might have arise during the measurement of the latitude within the water drop and thus resulting to inaccurate results.
The main outcome of the four test while utilizing the cooling tower as pertaining to the determination of the diverse effect of water mass flow rate made the easier arrival to the following conclusions. The cooling load is directly proportional to booth inlet and outlet air bulb temperatures but inversely proportional to the fluid mass flow rate. The cooling load is also directly proportional to the both inlet and outlet temperatures but on the other hand water mass movement rate is inversely associated to the existing inlet and outlet temperatures. The cooling load is considered inversely associated to the water mass movement rate but directly proportional to the mass movement rate of the dry air that is moving within the orifice. It was also deduced that the cooling rate was directly proportional to the cooling load but inversely correlated to the prevailing water mass movement rate. Humankind and the associated equipments were found to be greatest cause of errors on the data.
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