Team Vision for Detailed Design Phase
SummaryOur team intended on finalizing designs for our test stand, system plumbing, and electrical system. We also intended to begin initial testing of our pump and valve systems to ensure we could meter our flow down to the 0.5GPM required for our collector.
What We AccomplishedDuring this phase we were able to complete all of the things above we set out to do.
The progress report live document can be accessed here.
Drawings, Schematics, Flow Charts, Simulations
Stand UpdatesThe stand we plan to build for our system has been updated slightly since the Preliminary Design Review. Most notably, the uprights have been changed from 2x4 beams to 4x4 beams. Also, the single sheet of plywood on the base pieces has been changed from one large sheet to 2 smaller sheets per base. These changes can be seen below
The complete detailed design review drawing package for our stand can be seen here.
Pump Wiring Diagram
Above is a wiring diagram used to run the pump. The system is powered using a 12V lawn mower battery. A 5A inline fuse is used to protect the pump and there is a toggle switch to turn the system on and off.
Above is the plumbing diagram used to test our pump and flow meter. This diagram has all components minus the solar collector.
Above is the full plumbing diagram for our system including the solar collector.
Prototyping/Beta TestingDuring this phase our team made a mock up of our plumbing in order to ensure we could meter our flow down from the pump output of 3GPM down to the solar collector maximum flow rate of 5GPM. During our initial testing we found that meter the flow down below ~.6GPM caused too much back pressure on the pump. Therefore we added a Y-valve to our system in order to bleed off extra flow. By doing this we were able to achieve our required flow rates. The video below shows our flow meter being adjusted throughout our flow range.
Bill of Material (BOM)
The whole Bill of Materials with links to where they were/will be purchased can be accessed here.
Test PlansIt is essential for the team to test and verify all aspects of the physical system. The test plans below have been derived in order to ensure that all manufacturing specifications are being met by purchased products, as well as to ensure that components such as the pump and power source are both safe for use and effective.
The team will be testing to ensure that:
- Car battery is effective source of power for pump
- Car battery can provide energy for sufficient
- Ensure that plate testing can be done using just 1 car battery (12V)
- Pump flow can be dampened to the specifications of the flat plate collector
- Test temperature regulation to avoid pump’s exposure to temperatures outside of safe operating range (130°F)
- Test maximum achievable temperature by plate
- Test time for plate to heat qty X of water to varying temperatures A,B,C,...
Car Battery as Effective Source of Power
This test will simply involve hooking the pump to the source and allowing it to run. Once we ensure that the pump can move water while hooked to the battery, we can conclude that the power source is sufficient. Subsequent tests will ensure the battery has a long enough life span and other necessary characteristics
Car battery can provide energy for sufficient time frames
This testing will require us to run the pump for a time frame around 3 hours. We will hook the pump to the battery and run it until the battery dies. Charge and repeat multiple times to arrive at some confidence level for pump run time. If necessary, additional batteries can be purchased in the event that the single battery does not provide ample pumping time.
Pump flow can be dampened to the specifications of the flat plate collector
This test will involve running the pump without the flat plate collector and use a flow valve to adjust it to the specification of the flat plate collector. The maximum flow rate the flat plate can reach according to specifications is .5 gallons per minute (gpm). Using the flow valve as well as a lower voltage battery the team should be able to meet the suggested specifications of .2-.5 gpm.
Test temperature regulation to avoid pump’s exposure to temperatures outside of safe operating range (130°F)
Using the mixing valve that is included on our BOM, we will ensure that we can sufficiently control the water temperature to avoid pump malfunction. This is not something that will be tested outright because we risk catastrophic failure at higher temperatures. This testing will be ongoing and will require constant attention for the user. We can test the mixing valve capabilities but running hot and cold water through it from sources that do not require our pump as the medium to move water (hook to faucet), but we plan to minimize the risk of getting the internal pump mechanisms too hot.
Test maximum achievable temperature by plate
Run system outside in ideal weather conditions (clear skies, above average ambient temperature). We plan to run this test via a circulating water model (the inlet and deposit water locations are the same tank). We will measure the temperature and graph the increase and look for the stagnation point where the water temperature begins to stay constant rather than rising.
- We may run encounter the case where the graph of the water temperature is still on the rise when T approaches 130°F. In this event, we will stop the test and make note that the full plate potential is higher than 130°F but we are limited by our pump and are therefore unable to test to its fullest capacity. We are not privy as to whether or not this is a relevant problem and will not know until testing begins.
Test time for plate to heat some constant qty X of water to varying temperatures A,B,C,...
Running the system outside during a sunny day will be an ideal situation for this test, because in order to heat the water there must be sufficient enough solar radiation to do so. Using a stopwatch and thermometer the team will time how long it will take for water of a specific quantity to heat from average temperature of water (50°F) to varying temperatures. This process will take time, because the water may have to run through the collector several times in order to reach the desired temperatures.
Test the Overall Efficiency of the Flat Plate
There will be some difference in the amount of usable energy that arrives at the solar plate and the amount of usable energy that the plate is able to transfer into heat energy and use to heat water. We will measure/tabulate the total usable energy that arrives at the flat plate via the use of solar sensors and tabulated online data. We will then measure (via thermometer) the temperature that the plate was able to hear the water to. Mathematically we can then derive the amount of energy required to create that temperature increase. We can then compare the energy needed to the theoretical value of energy available and then compute efficiency.
The test plans document can be accessed here.
Test Plans & Engineering Requirements
The test plans and engineering requirements document can be accessed here.
Flat Plate Collector Information
- 29 ft2 Flat Plate Collector - V2
- ALDH Series Connector (1 Pc Coupling) 22mm x 22mm
- ALDH Series End Cap
- ALDH29 Flush Mounting Kit
The new risks are listed above, and the whole risk assessment can be accessed here.
Issues and Concerns
- Pump starts to “choke” 0.6 GPM
- Added a bypass valve assembly to reduce flow to collector while also running the pump with decreased back pressure
- Plate and cart may be difficult to move around due to length/height/weight and elevator limitations
Design Review Materials
The presentation live document can be accessed here.
Notes From Presentation
- Document advantage of running the system with a high temperature pump
- Temperature limit of PVC
- Model is manual, how much would it cost to automate it?
- Area discussion
- Find prices for "n/a" on Bill of Materials for potential future projects
Plans for next phase
MSD II Team Goals
The Gantt chart for MSD II is listed above, and the whole gantt chart can be accessed here.
MSD II Overarching Plans
- Plate testing will happen on weather dependent basis
- When a nice day arises, we will aim to do testing ASAP
- Will derive times where each member is free to
sit with plate and test
- This may be on days when MSDII class does not meet
- Each member will be responsible for the collected and
analysis of one of the outlined testing plans
- Ensures each member has experience running the plate
- Plate operating procedures will be derived in the first week of MSDII
- Efficiency testing will happen in different climates
- Important to understand the delta between summer and winter performance
- Figure out how to flush the plate to eliminate bacteria growth
- Plans for plate after MSDII is over
- Continuation Project?
- Tom Kirk?
The MSD I Self-Critique can be accessed here.
Preliminary MSD II Plan
Deliverables for Early in MSDII
- Understand the difference between manual temperature control and an automated system
- Decide where the model will be stored once it is
- Brinkman Lab
- What will happen to the plate after the project is
- MSD want it?
- Follow up project?
- FMS want it?
- Tom Kirk want it?
- Further understand the area derivations for plate sizing
- Rich is leaving RIT...find new FMS contact for project