Re: [TRNSYS-users] TRNSYS counter function

Thank you for your answer Angel,

I've already looked at this component but it does not seem to work as I would want.

I see that I was unclear with what I intented to do:

Basically, I want to wait about 45 minutes before triggering the Defrost signal to confirm the conditions for defrosting are met during this time lapse (Heating signal and temperature below about 6 °C).

However, if during those 45 minutes of waiting, the conditions change (No heating signal or temperature rises), I want to be able to reset the counter and start again when the conditions are met.

In Matlab or Python, I would do that with a "While" loop, for example.

With Type 93, I have to look at all the timesteps of those 45 minutes . I could however add en equation that would calculate the average signal during the 45 minutes and trigger the defrost signal. I will need to look into how to do this. I am running a 0.01h timestep, meaning 75 timesteps to evaluate.

I hope this clarifies what I intend to do.

Olivier Quevillon

Étudiant à la maîtrise en Génie Mécanique

École de Technologie Supérieure

De : Angel Carrera [angel.carrera@aiguasol.coop]
Envoyé : 14 novembre 2016 04:54
À : Quevillon, Olivier; TRNSYS users mailing list at OneBuilding.org
Objet : Re: [TRNSYS-users] TRNSYS counter function

Hi,

not sure if I understood right, but I think I use the input value recall for essentially the same problem: pass the condition (heat and ambient temperature under your limit) to type 93 as a 0/1, and sum the outcome of the number of time steps necessary to reach "a certain time". If the sum is equal to the required value, trigger the defrost condition. Hope it helps, regards

Angel

2016-11-13 4:17 GMT+01:00 via TRNSYS-users <trnsys-users@lists.onebuilding.org>:

Hello everyone,

I am trying to figure out a way to model a defrost timer on as air source heat pump. To do so, I would have to set up a counter that would activate a defrost cycle (force heat pump into cooling mode) after the heat pump has been working in heat mode and the outside temperature is below a certain limit for a certain amount of time.

I have tried using Type 1233, but this component does not wait before triggering the output, it rather starts right away when the conditions are met, then is stuck in OFF position for a certain amount of time.

Any help with this issue would be appreciated.

Thanks!

Olivier Quevillon

Étudiant à la maîtrise en Génie Mécanique

École de Technologie Supérieure

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Àngel Carrera Martín

Consultor sènior en Sistemes

Llicenciat en ciencies físiques

Sistemes Avançats d'Energia Solar Tèrmica - AIGUASOL

+(00) 34 663 276 680 Roger de Llúria 29, 3r 2a

angel.carrera@aiguasol.coop 08009 Barcelona

angel_aiguasol Tel: (+34) 933 424 755