Lab Report Guidelines

In this document, your team will discuss the laboratory experiment on heat pump cycles and present results. The report should present all appropriate information, including error analysis and discussion, and should be written clearly so that anyone with an engineering/science background can understand the motivation behind the study, the underlying physics of the experiment and its results, and any conclusions your team makes based on the results. An effective lab report can be divided into 5 sections: abstract, introduction, procedure/methodology, results/discussion, and a conclusion. Some of the necessary elements of each of these sections are described below.

The body of lab report (minus the Discussion and Conclusion section) will be submitted by a single member of each group. This part of the lab report has a maximum page limit of 5 pages. All p-h and T-s diagrams not included in the main text should be provided in an appendix, which will not count towards the page limit. Please upload the lab report through Gradescope before the start of your next lab.

Each team member will be responsible for writing their own Discussion and Conclusion sections. Each individual submission has a maximum page limit of 2 pages. Each student should upload their individual submission through Gradescope before the start of your next lab.

Abstract (10 points)

Abstract should be no longer than a paragraph.

1. Aim of the lab (5 points). Try to summarize the motivation and the goal of the experiments in a few sentences.

2. Succinct summary of main results/conclusions (3 points)

3. Succinct summary of measurement methods (2 points)

Introduction (20 points)

1. Explanation of the motivation for experiments (5 points). Convince your audience why it is worth reading your lab report. Try to connect your experiment to a bigger problem that can be solved and is more easily understood by a wider audience. For example, a study on testing different types of battery materials could be used to help with creating faster-charging electric vehicles.
2. Explicitly mention the heat pump performance metrics that were measured (5 points), and discuss their relevance.
3. Scientific background (10 points). Discuss the underlying scientific concepts that are relevant for both heat pumps and the performance metrics used in this lab. You should include a discussion of the basic physics behind the refrigeration cycle in this section. You should cite at least 3 different external sources.

Procedure/Methodology (15 points)

1. Explanation of general setup (3 points). Walk your audience through how your experiments were conducted and using what types of equipment. This is where figures can be useful.
2. Limitations of the setup (2 points). Your setup won't be perfect so try to discuss why. This discussion can also get your team thinking about sources of error in your experiment.
3. Measurement procedure (5 points). How did you actually take measurements and what was measured? For example, to measure electrical power you would need a current and voltage. How did you measure each?
4. Useful figures for understanding setup (5 points). Figures are a great way for your audience to follow along with your experiment. However, be careful with how many figures you use as the maximum page limit is only 5 pages.

Results (25 points)

Present your results in a clear and concise manner. Tables and plots may be appropriate here to better convey results, but you do not need to include every plot created during the lab experiment. Any unused p-h and T-s diagrams should be included in an Appendix section. This section should include the following:

1. Temperature, pressure, and power measurements for three different mass flow rates (5 points). You should note the uncertainty in all of these measurements.
2. p-h and T-s diagrams (5 points). Please present these diagrams for at least one mass flow rate and discuss their significance.
3. Calculation of coefficients of performance (10 points). Calculate COPs for both refrigeration and heat pump cycles at each mass flow rate.
4. Calculation of power use (5 points). Calculate the power used by the compressor based on your pressure and temperature measurements for each mass flow rate. Compare this result to the wattage measured at the wall socket, and perform an error analysis.

Discussion (15 points)

This section will be done by each team member individually and submitted separately.

1. Explanation of results (5 points). In this section, your team should try to make a connection between your observed results and the scientific concepts that were discussed in the Introduction section. Can you use some scientific concepts to explain the trends that you observe? For example, can you explain the observed relationship between mass flow rate and COP?
2. Comparison of performance metrics with other results (5 points). How do your results compare with those in literature? Does this refrigeration cycle have a better or worse coefficient of performance than commercially available models? Explain the differences.
3. Discussion of experimental error (5 points). In the Introduction section, you have mentioned limitations of your setup. Can you think of any ways that those limitations may have contributed to large errors in your experiments? Attempt to quantify any large sources of error.

Conclusion (15 points)

This section will be done by each team member individually and submitted separately.

1. Summary of the experiments (3 points)
2. Statement on the main results (7 points). Try to summarize the main points of your results and discussion. You could also discuss the real-world consequences of your results.
3. Explain how the experiments could be improved (3 points). Throughout the lab report, your team has acknowledged the shortcomings and large sources of error of your experiments, so here is your chance to explain how you think they can be improved.
4. Future directions/recommendations for new experiments (2 points). What other information might we want to know about this or other heat pump cycles, and how might we obtain it?