[Solved] Heating with electricity, electrode boiler 15 kW galan & # 8211; opinion and

The buffer is too small if it would be enough between the low tariff hours.
The temperature, if the boiler is working all the time, is better lower, because it has lower losses.
If there is a buffer, it is heated to the maximum in a cheaper tariff, and the temperature is lowered by a mixing valve.

Lodek wrote:

A mechanical mixing valve would probably do the trick. But I don't like the idea of heating the water to high temperature just to be mixed right away.
I wanted to avoid heaters. Apparently the electrode furnace is more efficient. But it is difficult to verify this information. Could use a comparative test. But I haven't found any

I was wondering about the Kospel stove, perhaps it would be a better option. Can you write something about electricity consumption? I am curious to compare

Forgive me, but you are simply wrong. The electrode furnace, induction furnace and furnaces with (resistance) heaters or the heaters themselves installed in the buffer have almost the same efficiency / efficiency close to 100%. Simply put, all of these furnaces convert almost 100% of the electricity into heat.
From this whole group, the electrode furnace is the worst, because not only does it require appropriate water parameters, but it also causes many problems that induction and resistance boilers are devoid of.

Not only do you need to ensure proper water conductivity, but in the case of electrode boilers, oxygen and hydrogen gas are released on the electrodes, which greatly accelerate the corrosion of the entire installation. In addition, the water in such an installation must be changed frequently, and the fresh water has oxygen and air in it, which also corrode the installation.

Regardless of whether you will have an electrode boiler, induction boiler, resistance boiler or installed heaters in the buffer, your bills will be the same.
However, the cheapest and the best of all these solutions is a buffer with electric heaters, because it allows you to use the cheaper night energy tariff.
Besides, it is the cheapest to install and operate. Heating the water in such a buffer to higher temperatures enables the accumulation of more energy from the cheaper, night-time tariff and the use of this energy in a more expensive tariff.
A Kospel resistance boiler is also a good solution.

The truth is that the installed photovoltaic will not provide you with electricity production to cover the entire energy demand for heating and, after using your own electricity, you will have to buy it from the energy sector.

In sum:
The electrode boiler is a great way to get the money out of the suckers.

As I wrote, I have a Kospel electric house stove of 130m2 and the maximum consumption of this stove every day is 55kW and the temperature at home is 22.5 degrees Celsius.
The furnace at the output is 44 ° C at 0 outside temperature.
Plain Polish Kospel heater.

Leon444 wrote:

As I wrote, I have a Kospel electric house stove of 130m2 and the maximum consumption of this stove every day is 55kW and the temperature at home is 22.5 degrees Celsius.
The furnace at the output is 44 ° C at 0 outside temperature.
Plain Polish Kospel heater.

If it is 55kWh (kilowatt hours), it is a unit (amount) of energy. The unit kW (kilowatt) is a unit of power.

Yes, my mistake, I lost the "h" at the end, 55kWh but I wrote the daily consumption, not instantaneous

Hi

more than a year has passed and I am completing some information. The first is that I didn't change the water and didn't clean the stove. So it works for me without topping up, adjusting etc. so the idea with a closed system and distilled water works well. I noticed that the installation has to be vented quite often (someone wrote about it).

In an electrode boiler, the power consumption depends on the conductivity of the water and the temperature. I set the conductivity for over a year ago, but let me give you how my consumption changes depending on the temperature.
20 degrees - about 5kwh
30 st - 6 kwh
40 st - 7.5 kwh
50 st - 9 kwh
55 st - 10 kwh
65 st - 11 kwh
70 st - 12 kwh
80 st - 15 kwh
the effect is that it takes off relatively slowly and then runs at "full" power. the concept of full power is a bit conventional in my opinion, because when I had a different conductivity, I reached 25 kWh. But I was afraid to test it further.

on electricity consumption in the long term: winter 2019-2020 (it was warm)
11-2019 - 500 kWh
12-2019 - 680 kWh
01-2020 - 704 kwh
02-2020 - 685 kWh
03-2020 - 571 kwh
04-2020 - 180 kWh
I did not turn on the gas stove, I only used the fireplace. I had enough electricity

09-2020 - 73 kwh (I did not use the fireplace)
10-2020 - 368 kWh (I did not use the fireplace)
11-2020 - 789 kwh (I did not use the fireplace)
12-2020 - 911 kwh
01-2021 - 552 kWh
02-2021 - 378 kwh
in the settlement for the second half of 2020, I ran out of electricity, so now I use more of the fireplace

Finally, I will have some questions for you ... I got the (original) stove controller, the stove works non-stop on one of the phases. The controller only controls the other 2 phases. I have to replace it - probably on GH07EB http://www.geco.pl/prod.php?id=182&lang=pl, but I don't know how to connect it to 3 phases. Anyone have any idea?

and wants to additionally secure the installations - can anyone advise me on what protection to apply? I don't know much about electrical installations and I am looking for advice. And I'm thinking about thermal protection. Yesterday, when I turned off the installation with a damaged switch, this phase 1 was still working (which I did not know) and there were only strange sounds from the stove. When I turned it on it was 110 degrees. A security feature would be useful to disable in a similar situation

This equipment had no warranty?

As for me, your interests are so senseless. Make such a large investment to heat the fireplace.
Take into account that a 6.6kW PV installation basically covers the electricity consumption for lighting, washing, cooking and DHW heating only suddenly.
From 6.6kW PV you can get a maximum of about 6MWh of energy per year, but you can only recover from it 4.8 MWh. For domestic needs, apart from heating, an average family needs 2-4 MWh for lighting and the operation of all household appliances + 2-4 MWh for DHW heating. That is, in total 4-8 MWh are needed for needs other than heating. Assuming that you are very economical, you can still see that the energy you have produced will be scarce anyway for heating purposes.

This 3.3 MWh of energy for heating a home is suspiciously low. Either the house is very small and very well insulated, and you only need to heat it, or you just heat it with a fireplace and only heat it with electricity.
Having a gas boiler and heating up these 3.3 MWh, you would spend less than PLN 750 for gas (gas from the network) and a little over PLN 1000 for LPG (you did not write what gas you use).

Now count yourself what costs you incurred to heat with an electric boiler. For the money you put into this boiler, you would set up a large heat buffer with built-in electric heaters. Thanks to this, you could use the cheaper 2nd energy tariff. If you buy electricity in the 2nd tariff, you would pay less than PLN 1,000 for these 3.3 MWh.

What controls, the controller must control a decent contactor, and this switch turns on / off the heating circuit.
But 15kW is no longer blowing on the stick and to turn on such power, you need really good contactors so that their contacts do not burn out. Especially that when heating the central heating system without a buffer, the boiler must clock a lot and the number of starts and stops during the day is large, and each switching on and off of the circuit causes the contactor contacts to burn out, because it is accompanied by sparks on the contacts.
When controlling such power, the best solution would be SSR solid-state relays, because they switch the circuits on and off without sparking.
If I were to control such a boiler, I would use a PLC that would control 3 SSR relays + a 3-phase contactor. Depending on the needs, the PLC would switch 1, 2 or 3 phases depending on the power demand. In this way, 3 levels of heating power can be obtained. In addition, it would switch on and off a mechanical contactor without loading its contacts with current. The contactor is needed as a protection to turn off the heating system in the event of damage to the SSR. In addition, the PLC could also control the condition of the contactor contacts and damage to the SSRs and control the individual phases sequentially so that the consumption of electrodes in the boiler was the same at all phases.
Besides, when using SSRs, you can be tempted to smoothly regulate the power.

But the most important information is whether the boiler has a power supply of 3x230V or 3x400V, because it depends on whether the phases can be controlled independently. The point is whether the electrodes are connected in a triangle or a whistle pattern.
In the case of a delta connection, you can turn on only one heater or all 3
Only in the star configuration, 1, 2 or 3 heaters can be switched on.
But if you write that the boiler is currently not disconnecting one phase, the electrodes are probably star connected.

First of all - thanks for the answer !!!

The annual electricity consumption is about 2700-2800 kWh. I have hot water heating from the sun (100% for half a year) + gas. My long-term goal is to give up LPG gas (no possibility from the network). But I have a contract and I have to deal with them for almost 3 years (high cancellation costs before that date). The heating current was supposed to be only a supplement for the time being.

Ultimately, it wants to add more panels to the roof and close everything with electricity. A buffer would be a nice solution, but I don't have space for it, and I won't put it in the living room )) ... only the option of the tank outside would be considered, but the costs of the tank and its insulation would certainly be high, and having photovoltaics, it makes no difference to me if it heats with a stove in the 1st or 2nd zone. So I am left with an electric stove or a heat pump. The stove + all costs are PLN 3800, the pump would cost much more.... So I prefer to furnace + more photovoltaics.

In practice, the power of the stove is 5-7 kW. With a cold installation, eg in the morning, the contactor does not turn on for a long time and works perfectly. But as the installation and the floor (underfloor heating) absorb less heat, the contactor trips every few minutes. And this may be the reason for my failure - the number of starts and stops was quite large. The buffer would help here, but I have nowhere to fit it, unless it is 100-150l - but does it make sense?

Smooth power control would definitely help ))... I like your description, but I must admit that I don't understand much of it yet. I don't know much about electricity.... And if you could write me more precisely, I would be grateful.

If he's well versed, it's 3x230v. the boiler has 3 electrodes and each is connected to 1 phase conductor + N conductor, and to earth. Theoretically, 1, 2 or electrodes can be turned on, but you need to control it somehow. Ideally, it would be possible to smoothly control the power, if necessary, reduce the power to keep the output temperature constant, but I am not sure how to do it. At the same time, I would like to be able to control the DHW supply (to the tank through a coil with a working temperature of e.g. 80 degrees Celsius) and CO. But I do not know how to do it. I found the GH07EB driver on the website http://www.geco.pl/prod.php?id=182&lang=pl, I thought to work with it. But maybe there will be the same problem with the contactor ...... I don't know anymore; (((

Ps. The warranty was there, but it was over.

For me, your electricity consumption in January at 552kWh is not realistic.
In January, my entire house used only 1500kWh from the 1500kWh network and I have an ordinary 6kW Kospel electric stove and everything on electricity. And you used up 1/3 of that with a stove twice as big? It's probably your house is 45m2, I will agree.

Lodek wrote:

Smooth power control would definitely help ))... I like your description, but I must admit that I do not understand much of it yet. I don't know much about electricity.... And if you could write me more precisely, I would be grateful.

When it comes to PLCs, you would have to have a bit of a clue about their programming. generally speaking, these are devices with a certain number of inputs and outputs and the ability to create various logical structures and dependencies in the form of a program inside.

Inputs and outputs can be digital (i.e. on / off) or analog (voltage 0-5V, 0-10V), current (0-20mA, 4-20mA) and dedicated inputs, e.g. resistance for resistance sensors and thermocouples.
Programs can be created in the form of diagrams, diagrams or text.
If you have never had contact with a PLC, it is unlikely to be for you as it requires specific knowledge of electrical, electronic, logic and programming.
The advantage of PLC are very large possibilities of creating many very complex structures and dependencies. But they require a lot of knowledge.

But there is a simpler solution. The use of ready-made regulatory elements, assembling them like Lego blocks to achieve a PLC-like effect.

You have 3 heat sources, radiators and underfloor heating, it begs you to cover the whole thing with some smart automation. The Tech i3 Plus controller can be such automation.
It can control all pumps and mixing valves for underfloor heating. It supports 3 heating circuits (radiators or floor heating), controls 2 heat sources using On / Off contacts, controls the heating of the DHW tank, the DHW circulation pump, but most importantly, it has 2 control outputs, analog 0-10V. It can also control solar panels.
These analog outputs can control the heating power of the boiler. This control takes place by setting the control voltage in the range from 0 to 10V, corresponding to the boiler power from 0 to 100%.
In order to be able to control the power of an electric boiler, it is enough to use a 3-phase SSR solid-state relay with smooth power control with an input signal of 0-10V.

Download the manual for this driver and see the example diagram on page 40
https://www.techsterźniki.pl/!uploads/products/pl_-i-3-plus_ot_28.01.2021.pdf

Thanks, I can see that this control room has a lot of possibilities. I have to read it carefully and analyze it, and PLC probably isn't for me; (
Ps. I have large radiators in the rooms (2 in each) and they work at the same temperature as the floor heating (32-35 degrees). I don't have mixing valves (I used to, but I gave up). I have automation for solar panels, which works well, so I will not change it, so I will be able to use only some of the capabilities of this driver. But I will read anyway. Thanks