270 likes | 463 Views
Course Exam . Next Thursday (April 15) 7 pm Same classroom (ECJ 7.208) 2.5-hour exam Open book open notes All problem types of questions (short but comprehensive). Objectives. Finish the pumps and plumbing systems Discuss the final project . Pumps and Plumbing .
E N D
Course Exam • Next Thursday (April 15) 7 pm • Same classroom (ECJ 7.208) • 2.5-hour exam • Open book open notes • All problem types of questions • (short but comprehensive)
Objectives • Finish the pumps and plumbing systems • Discuss the final project
Pumps and Plumbing • Very similar to fans and ducts • Same principles based on fluid dynamics • With some specifics
Hydronic Terms • Head loss • Open-loop vs. closed loop • 2-pipe vs. 4-pipe
Table 19.1 • Pipe dimensions for standard pipe
Pumps • Driving force to move air water in buildings • Raise pressure and produce flow • One main type • Centrifugal
Pump curves • NPSHR = Net Positive Suction Head Required
Finding Volumetric Flow • Same procedure as for air • Intersection of pump curve and system curve • How can you control flow?
Example 19.7 • Similar to equal friction method • Calculate head loss for common pieces of system • Size pipes to have equal head loss between points 2 and 3
Review for the Exam • Should be able to do all calculations associated with lectures as well as HW1 • Questions/problems may deal with context • i.e. Explain how thermal conductivity influences fin efficiency? Holding all other parameters equal, how important is increasing the thermal conductivity
Psychrometrics and Processes (7 & 8) • Know all parameters and their location/orientation on a psychrometric chart • Be able to look up conversions of parameters on a psychrometric chart and with calculations • Use protractor to calculate SHR and ΔW/Δh • Plot processes on a chart for real buildings • List what is held constant for different processes
Direct Contact (10) • Describe how a cooling tower works • Describe analysis procedure for direct contact devices
Cycles (3), Refrigerants (4) • Describe Carnot cycle and components • Understand constant variables for each component • List, describe, and calculate inefficiencies • Use figures, refrigerant tables and equations for different substances • Contrast different refrigerants • List important parameters for refrigerant selection/differentiation
Heat Exchangers (11) • Differentiate types • Calculate NTU, ε, cr, R, P, F, m, UA, etc. • Complete broad analysis • Which m is larger, which Δt is larger? • Within and between heat exchangers
Heat Exchangers (11) • Calculate and compare different thermal resistances • Describe influence of key factors • Integrate different parameters/resistances • Manipulate UA equation • Describe differences/parameters of relevance for wet heat exchangers
Diffusers, Duct Components (18) • Select diffusers • Define all terms on manufacturer data sheets • Calculate pressure drop of: • Straight duct • Duct fittings • Components (coils, VAV boxes, dampers, etc.) • Differentiate fans and describe fan curves • Use fan laws
Duct layout/design (18) • Describe static regain method • Compare to equal friction method • Supply or return systems • Balance the system
Project • Design problem • For example: Given cooling and heating load design HVAC for the building • Research problem • Analysis based problem. For example: • Find the optimum solution for…. • Developed control strategy for… • Life cycle cost analysis for … • ……….