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Dear all,
I have carefully searched for more instructions on how to set up the control signals for the heat pump Type 525. However, I have not found any relevant information. If you have set up the control for this type of heat pump, could you please provide me with some guidance? Alternatively, if there is already a post about this, please let me know, as I was unable to find it.
In my case, I am trying to use the PV surplus instead of an electrical battery. I am using a heat pump to charge a PCM tank. Since Type 941 has a fixed-speed compressor, it will only run when the PV surplus is much higher than its rated power.
I have tried splitting my Type 941 heat pump into two units, and I was able to improve the results by operating a smaller-capacity unit when the PV surplus is lower. This made me think that using the variable-speed compressor Type 525 could be a better solution for maximizing heat storage based on the available PV surplus, as I could better adjust the heat pump's operation according to the available surplus.
The annual data I have consist of the building's heating and cooling loads in kW, and I am using Type 682 to simulate the building. Therefore, I am not using Type 56.
If there is any other information you need in order to help me, please feel free to ask.
Thank you.
Humberto
Humberto,
Type525 is intended to somewhat control itself. You give it an intended outlet liquid temperature and it will adjust the compressor speed internally to meet that temperature if it can. It does also have an on/off switch if you want it to be totally inactive at times.
I think the more challenging part of what you're doing is that Type525 (all the TRNSYS heat pumps I am aware of, in fact) are written in such a way that you tell them how much thermal energy you need and they tell you how much power it takes to produce that thermal energy. In your case you know how much extra power you have available and you want to know how much thermal energy you can add to or remove from the system as a result of using that power. What's more the heat pump models don't usually take load directly as an input; they take inlet condition and desired outlet condition.
One thing that I have begun doing is to use instances of the HVAC equipment in my system to determine the maximum amount of energy that the equipment can add/remove. I then compare that amount of energy to the amount that is truly needed and then run the actual equipment accordingly. The idea is to use one instance of the model as a kind of controller for the other. In your case perhaps there is a way to implement an instance of Type525 to determine how much electrical power would be needed at any given time to add energy to the PCM tank. You could then compare that amount of power to the surplus power from the PV and turn on a second instance of Type525 (the actual one as opposed to the virtual controller one) accordingly.
~david