jfreissmann / heatpumps Goto Github PK

Desription of the task

Maintaining the offdesign_simulation method of each heat pump class, as well as extending it, is a huge hassle, as it has to be changed in all classes. Most of the code is pretty repetitive, so it could and should be generalized into a method of the HeatPumpBase parent class.

Necessary steps

A generalized version of the offdesign_simulation method has to be added to the HeatPumpBase parent class. The heat pump specific code has to be off loaded into respective functions, that each heat pump class implements individually. That containts the part load parametrization of the components and/or connections and the possible recalculation of intermediate pressure levels or temperatures.

Benefits

This task ensures easier maintainablility and reduces boilerplate code. Additionally, bugs in the code duplication, like the ones fixed in PR #10, can likely be avoided all together.

The model classes HeatPumpFlash and HeatPumpFlashTrans miss the desuperheating process step of the compressed gas exiting the first compressor stage. This issue stems from the fact, that the get_plotting_data method of the Drum component (used within these heat pumps as a flash tank) only return a line from the saturated liquid outlet to the saturated vapor outlet.

I created a Pull Request (see: oemof/tespy#521) to fix this issue by adding more process lines to be returned from the get_plotting_data method, so that the state diagrams can be fixed. Therefore the issue persists until the PR is merged and we bump the tespy version. This means we should prioritize issue #2 and get the tespy models up to date.

Hi,

I have been using the heat pump simulation with the web GUI and really enjoy trying out different design configurations. However, switching to Mac/Linux-based operating systems, I encountered the following problem.

Problem description

When running heatpumps under Mac/Linux, the usage of paths as follows is not feasible and causes the program to crash instantly (example):

cd example_directory/example_file.txt/../

whereas on Windows-based machines the directory would be changed to example_directory. This kind of formulation is used heavily in combination with various functions from the os module, e. g.

src_path = os.path.join(root_path, '..', 'src') or
os.mkdir(os.path.join(__file__, '..', 'stable'))

Necessary steps

Consider replacing the aforementioned combinations, maybe sth. like os.path.dirname(__file__) might ensure platform independent compatibility.

Best regards
Niklas

In all models when the the Sink temperature goes beyond particular temperature system fails to solve. For example, when the working fluid is NH3, if Temperature Rücklauf is greater than or equal to 100°C, solver fails to find the solution. Here, Teperature Vorlauf is not an issue. It can be any value less than T_crit.

Description of task

The model data base already has a lot of subcritical heat pump processes. The task in this issue is to create more transcritical versions of the existing heat pump models. This mainly concers changing the condenser to a normal heat exchanger and setting the heat output pressure.

Necessary steps

• Create copy of existing heat pump model class
• Change the setup to allow a transcritical process
• Create corresponding input parameter file
• Create topologie flow sheet as .svg file for light and dark mode
• Add the class to the hp_models dictionairy of variables.py

Description of task

The HeatPumpBase class implements the method perform_exergy_analysis for all child classes. This should work already to perform a component-wise exergy analysis. This task concerns the depiction of results gathered from the analysis. That includes key parameters, such as the exergetic efficiency, as well as meaningful plots (e.g. waterfall or Grashoff diagrams).

Necessary steps

The implemented analysis method already calculates the epsilon value. In addition, other key parameters have to be calculated and plots created. The corresponding methods have to be implemented -- ideally in the base class, if possible. Finally, the user should be able to set the ambient state (temperature and pressure), with default values analog to other parameters.

Additional information

Inspiration for key parameters and exergy analysis plots can be found in the Teaching Exergy using TESPy Jupyter Book and its corresponding GitHub Repository.

Description of the task

All heat pump model classes are using TESPy version 0.6.3. Since their creation, there has been a large refactoring of the TESPy back end, which should result in faster and maybe more stable solutions, which is an obvious enhancement for the dashboard. These changes also concern its API, so the model classes should be adapted to it.

Necessary steps

The adaption should use the most recent TESPy version (as of now that is 0.7.2.post2). An overview of the changes since version 0.6.3 can be found in the What's new section of the online documentation. It mostly concerns how the fluids are set within the network. In addition to what is said in the change log, trying out the new version showed that using the .res attribute of the Network class has been renamed to .residual.

Additional information

Since the update, TESPy should be better equipped to handle setting temperature and pressure pairs instead of enthalpy and pressure. This could mean that there would not be a need for initial simulations anymore. This would be a structural enhancement and could save a lot of time, as every design simulation would only need one run. As far as I know, there could remain a need for starting value simulations for setting states with Ref, which is used to set superheating temperature after an internal heat exchanger.

Description of task

The model data base already contains a lot of single cycle heat pump processes. The task in this issue is to create more true two cycle (that is "cascading") heat pump model classes. The variants of the single cycle heat pumps could be used as orientation.

Necessary steps

• Create child class of HeatPumpBase that implements all relevant methods
• Create corresponding input parameter file
• Create topologie flow sheet as .svg file for light and dark mode
• Add the class to the hp_models dictionairy of variables.py

The name of the python file is different from the Heat pump class code. So when we do simulation, it picks correct topology image but wrong heat pump class.
For example, python file name is HeatPumpEconIHX.py, but the Heat pump class code in it is for the HeatPumpIHXEcon.

Description of task

The simulation dashboard was not built for a wider audience from the start. That is reason a lot of text still is in german. On the other hand, the heap pump model classes are mostly using english, so we are not even consistent with german. The task for this issue is to implement a user selectable language, which is the dynamically applied to all text within the dashboard.

Necessary steps

• Existing german text has to be translated to english and vice versa
• Some kind of button or switch has to be added to the dashboard to toggle between languages
• Text has to be dynamically chosen based on language switch

Description of task

Since there are a lot of components in a heat pump, there are a lot of ways to arrange them. The gist of this task is to add more combinations of the exisiting component pool.

Necessary steps

• Conceive interesting heat pump topology setup
• Create child class of HeatPumpBase that implements said setup
• Implement all relevant methods in alignment with the existing classes
• Create corresponding input parameter file
• Create topologie flow sheet as .svg file for light and dark mode
• Add the class to the hp_models dictionairy of variables.py