1 SUMMARY 1.1 Statement of problem Within the experiment main aim is to observe on the effect of thermal insulation done on hot fluid carrying pipes and a cost analysis is done for observing the cost effective ness of the implementation. Here an infrared camera is used for observing the temperatures on the pipe surface and analysis is done for the insulated surface using the software. (Killington, VT Weather, n.d.) 1.2 Major results and conclusions From the generated experimental results, it can be observed that payback period for all flor cases is very low which is lower than 1.5 years and this can be considered as a cost effective implementation which will save a considerable amount of cost in long run. When the convective heat transfer coefficient is considered to be 21 W/m2K-1, it is observed a larger heat loss through the surface of the pipe and main reason for this is observed as when the convective heat transfer coefficient increases, amount of heat loss as convection increases and therefore a larger heat loss is observed. Here it was observed two sources of errors which are random intrinsic error and systematic intrinsic error. These were not significant and therefore generated results through the experiment is considered to be accurate and successful. 2 APPARTUS & PROCEDURE 2.1 Experimental setup and procedure For the conducted experiment it is selected a length of 200 m of the pipe with a diameter of 1.905 cm. here hot water is supplied through the boiler and using the infrared camera, temperatures on the surface of the pipe is obtained after system reaches the steady state condition of fluid flow. Average temperature of the surface of the pipe is selected for calculations. 2.2 Assumptions * Camera gives the accurate and precise images. * Boiler supplies a constant heat flux to the water without changes in the capacity. * Fluid flow rate through the pipe is constant. * There are no impurities on the pipe surface. * No forced convective sources are presented near the experimental apparatus. 4 RESULTS & DISCUSSION Summary From the generated experimental results, it can be observed that payback period for all flor cases is very low which is lower than 1.5 years and this can be considered as a cost effective implementation which will save a considerable amount of cost in long run. 4 UNCERTAINTY 4.1 Qualitative * There were wind flows and forced convective sources near apparatus which affected the measured temperature values on the surface of the pipe. This created a systematic intrinsic error through the results. * Boiler didn’t supplied a constant heat flux to the fluid and this affected the generated experimental results through generating a random intrinsic error through the results. * Thickness of the used pipe was not constant where there were impurities within the inner surface of the pipes that created a systematic intrinsic error through the results. 5 CONCLUSION 5.1 Major results From the generated experimental results, it can be observed that payback period for all flor cases is very low which is lower than 1.5 years and this can be considered as a cost effective implementation which will save a considerable amount of cost in long run. Here it was observed two sources of errors which are random intrinsic error and systematic intrinsic error. These were not significant and therefore generated results through the experiment is considered to be accurate and successful. When the convective heat transfer coefficient is considered to be 21 W/m2K-1, it is observed a larger heat loss through the surface of the pipe and main reason for this is observed as when the convective heat transfer coefficient increases, amount of heat loss as convection increases and therefore a larger heat loss is observed. 5.2 Recommendations to future If the software is used for analysis several thickness values of the insulation layer, then it can be obtained optimum insulation thickness which is the most cost effective. Experiment 3: Thermal Insulation 1. Objectives By completing this experiment, students will learn: - How to use infrared camera for thermal imaging and use the collected data accordingly. How to use 3ePlus software tool to evaluate potential energy and cost savings as the result of adding insulation on hot/cold surfaces 2. Theory/ Background Energy audit is a process in which a thorough assessment on the performance of one or multiple energy end users of a facility will be conducted to identify and evaluate the potential energy and cost saving opportunities. In an industrial plant, energy saving opportunities can be found in variety of systems: compressed air systems, motors, pumps and fans, process heat systems, steam systems, etc. Some of these energy saving opportunities can be rather easily identified and evaluated. One of these opportunities is thermal insulation of hot or cold surfaces. Consider an un-insulated chilled water pipe or steam pipe. Significant energy wastes through the exposed surface of the pipe to the ambient which translates into major cost. Addition of thermal insulation is often a rather inexpensive but very effective way to save energy. While there are different approaches for identifying and evaluating opportunities for addition of thermal insulation, one effective approach is to use thermal imaging and 3ePlus software tool. An infrared camera is a non-contact device that allows accurate detection and measurement of infrared energy as emitted from the objects. The optical system of the camera focuses infrared energy onto a sensor array that contains thousands of detector pixels arranged in a grid. These pixels produce an electronic signal. The camera processor takes the signal from each pixel and convert it into a color map. Each temperature value is assigned a different color. The resulting matrix of colors is sent to memory and to the camera’s display as a temperature picture (thermal image) of that object. Figure 1: schematic of an infrared camera (https://www.fluke.com/en-us/learn/best-practices/measurementbasics/thermography/how-infrared-cameras-work) One of the major applications of infrared imaging is in heat loss detection and evaluation of potential energy savings by adding insulation to the exposed hot/cold surfaces. Poor insulation of hot /cold pipes or fittings result in higher energy consumption by boiler/chiller which lead to thousands of dollars waste of money. Detection of hot/cold surfaces with poor insulation can always help energy and cost savings typically with a quick payback. 3. Procedure 3.1.Problem Statement and Apparatus Consider a pipe from the hot water heater tank in the machine shop. Use the infrared camera to take a few thermal images from the pipe when it is hot and reached to its maximum steady state temperature. Upload the thermal images to the computer and closely look at temperature variation. Find the average temperature for the surface of the pipe. Heat escapes from the surface of the pipe to the surrounding through convection and radiation: qloss = hA(Ts-Ta) + εσA(Ts4-Ta4) (1) where h is the convective heat transfer coefficient (W/m2K), A is the surface area (m2), Ts is the pipe surface temperature (K), Ta is the ambient/surrounding temperature (K), ε is the emissivity of the surface and σ is the Stefan-Boltzmann coefficient (5.67×10-8 W/m2K4). Let’s assume that this is a section of a pipe with a length of 200 m and diameter 1.905 cm. The hot water is produced using a boiler with an efficiency of 0.85. It is also considered the boiler uses Natural gas as the fuel. Consider weather data for a specific location in the United States. Your GSA will assign each group a certain location. Complete the table below using data provided in www.usa.com1. Table 1: weather data for location of the system Temperature (˚F) Wind Speed (mph) Hours Spring 2,190 Summer 2,190 Fall 2,190 Winter 2,190 3.2.Recommendation Insulate all exposed hot water piping to minimizes heat loss. Heat loss through the pipes requires a higher load on the boiler to provide required hot water. Minimizing this heat loss is recommended, as it reduces energy required by the boiler. 1 http://www.usa.com/ 3.3.Evaluate Energy and Cost Savings The 3EPlus program can be used to estimate the heat loss from uninsulated piping systems and surfaces. It can also calculate the reduction in heat loss for different insulation thicknesses. The base material is considered as steel. A mineral fiber thermal blanket with an all service jacket was selected as the type of insulation material to be used. A screenshot from the inputs the Energy module of the 3EPlus tool is shown in the figure below: Figure 2: 3EPlus: Energy module The resulting energy savings for the uninsulated pipe for each season is calculated as below: ES = L x (QUNI – QINS) /ƞboiler x H / (293297.22 Wh/ MMBtu) ES = energy savings for pipe section, MMBtu/yr L = length of uninsulated pipe section, 200 m Where, QUNI = heat lost per meter for un-insulated surface, W/m QINS = heat lost per meter with 25 mm of insulation, W/m H = number of operating hours ƞboiler = boiler efficiency, 0.85 Similar analysis must be performed for other seasons, using average temperature and wind speed for each season, and the results must be summarized in the table below: Table 2: heat loss and energy savings for steam pipe between boiler room and plant 1 area Heat Loss without Insulation (MMBtu/yr) Spring Summer Fall Winter Total Heat Loss with 3 inch Insulation (MMBtu/yr) Spring Summer Fall Winter Total Energy Savings (MMBtu/yr) The cost savings associated with adding insulation to the steam pipes is based on the average cost of natural gas per MMBtu and it is estimated as $4/MMBtu. CS = FS x UR CS = total cost savings, $/yr FS =fuel savings/ MMBtu/yr UR = calculated rate of wood waste sold, $4/MMBtu Where, 3.4.Carbon Dioxide Reduction Because of decrease in fueling input, the process will be responsible for lower emissions of carbon dioxide. These reductions are calculated below: CO2 = FS x CO2natural gas x K1 Where, CO2 = carbon dioxide emissions reduction, Tons CO2/yr CO2natural gas = amount of CO2 produced per MMBtu of gas consumed2, 117 lbs CO2/MMBtu K1 = conversion factor, 1 Ton / 2000 lbs 3.5.Implementation Cost This implementation cost includes the price of mineral fiberglass insulation with an all service jacket for the piping system and the installation costs. Item Cost ($) 25 mm thick, fiberglass insulation 1.905cm pipe – 200 m ($4.25/m) Labor-25 mm fiberglass insulation for 1.905cm pipe ($10/m) Total IC3 $ Simple Payback = IC / CS = years Table 3 calculated results Item Calculated result ES CS CO2 Simple Payback 4. - 2 3 Discussions Follow the given procedure and calculate the results for the assigned location. What did you find for the simple payback period? does it seem like a viable project? Is it a good idea to use a thicker insulation? Why? https://www.eia.gov/tools/faqs/faq.php?id=73&t=11 Costs obtained from RS Means Mechanical Cost Data, 2010.
Purchase answer to see full attachment