In detail: do-it-yourself repair of the ctm from a real master for the site my.housecope.com.
The experience of operating the boiler, it is not too great, a little more than a year, but already enough to acquaint the reader with this wonderful unit, let's touch on its device a little (more details here), a 3-section boiler, a firebox with an internal size of 320 by 210 mm, which allows you to send firewood there maximum length up to 30 cm. According to the boiler passport, its capacity on dry wood is 17 kW. I only use them to drown, unfortunately I was not able to test other types of fuel, since they are not common in our rich woodland. On the topic of experience, I would like to dwell separately on the draft regulator, the device is extremely necessary, it has proven itself from the best side within a year, but after a year of operation, the internal device did not react so “vividly” to the set temperature, the boiler is already in full swing at 80, but the damper does not hides behind. Analysis of the situation suggested that the cylindrical part moving the spring began to work out its stroke more slowly, since if the spring was to blame (its pressure was weakened), then the regulator would simply cover the damper on the air supply, overcame the problem simply, change the angle of inclination of the thrust and it sank lower to the floor , the move decreased, but T began to hold more clearly.
... those. the lever was not so big on pressing the damper, respectively, the pressure on the regulator from the damper decreased and everything worked more or less well.
Let's go back to the fuel, fired with different wood, damp, dry, birch, pine, it's no secret that the best thing is, of course, birch, the heat is good, it burns for a long time.
In terms of firewood consumption, with my moderately insulated house, with a total area of about 145 m2 (with a chicken coop, of course, we heat it in winter), about 100 kg goes into a frost of minus 25-30 degrees, the temperature in the boiler is about 80 degrees. At an outside air temperature of minus 5-15, the flow rate decreases to 50 kg, the temperature in the boiler is 60 degrees (this is an advantage of cast iron boilers, the ability to keep the return T below 60-65 degrees, since steel boilers with such a return T quickly rot). A simple calculation of the fuel consumed also gives us an approximate picture of the heat loss of my house, dry firewood 1 kg = 12 mJ, if translated into more familiar kilowatts = 3 kW of energy / 1 kg, accordingly, when burning 100 kg of firewood, we release about 300 kW of energy, if we take into account that the efficiency of the boiler is not more than 60%, then 180 kW per day is consumed in the heat loss of the house, but we also prepare hot water in the boiler, which probably takes at least 10% of the consumed heat, so the house loses about 160 per day kW of heat, or 6 kW per hour, is not so much!
Video (click to play).
On the burning of firewood, observations of the combustion of fuel gave the following information, at first the firewood (any) burns with a not very hot flame, which causes the release of moisture and volatile compounds from them, white smoke flies from the chimney at this time, sometimes it turns a little black, then combustion passes in the phase when transparent smoke comes out of the chimney, and a lot of heat is released, at this time I try to press the damper at the outlet of the boiler into the chimney so that the heat does not go into the chimney and the efficiency increases.
On the furnaces, since the boiler furnace is small and you cannot put a lot of firewood there, you have to heat continuously throughout the day, i.e. tossing 1-4 logs, depending on T in the boiler, at 60 degrees I throw a piece of wood every half an hour, at 80 degrees the number of logs increases, at night at minus 30 we heat as follows: when going to bed, throw a full firebox, it burns for about 2 hours until the formation of embers at the bottom, which makes it easy to melt it again, i.e.2-4-6-8 o'clock in the morning we throw in the logs, the one who gets up and throws the logs. In warmer months at night (above minus 15) we do not drown at all, i.e. fire up again in the morning, and the boiler does not work for about 8-10 hours.
For soot and condensate, condensate in my chimney is simply absent as a class, although a fitting was made at the bottom of the chimney to drain it, but it was not needed, of course this does not speak in favor of the boiler, but only says that the T of flue gases is such that it does not form , which, in general, indicates a low boiler efficiency, i.e. heat loss through smoke, but this is the essence of solid fuel. For soot, I wrote about cleaning the boiler here. There have not been any comments on this, the only thing is that I began to clean the boiler a little less often, since after cleaning there is no tangible saving of firewood.
In the bottom line, the KChM-5 Combi boiler is a wonderful apparatus, it eats almost any firewood, is unpretentious, with small dimensions it has high power indicators - 17 kW, is easy to maintain, does not require any special care, together with a draft regulator, it greatly facilitates the work of supervision behind the combustion of the boiler, of the minuses - the firebox is too small, which does not allow you to throw more firewood there and ensure combustion for at least 4-5 hours. Mostly satisfied with the boiler.
When fuel (coal, wood) for solid fuel boilers was available at an affordable price, few people thought about increasing the efficiency of these heating devices. But we now live in a time when energy resources for the population are becoming more expensive every year, so the issue of modernizing KChM boilers, which are still preserved in many villages and urban settlements, is far from idle, but most likely vital.
The website visitors are offered the simplest and most affordable options for increasing the efficiency of solid fuel boilers of the KChM series:
Inserting a partition sheet inside the boiler.
Air supply from above to the boiler.
Air supply from below to the boiler.
The essence of the revision is to maximize the use of hot air, which heats the sections inside the boiler. Imagine that you are boiling tea in a kettle not on a gas burner, but by placing the kettle next to it. It is clear that in this case the water in the kettle will boil for a very long time and, if at all, it will boil. A similar situation occurs inside the boiler, where the air is first heated, and then this hot air heats up the sections where the water circulates. In addition, part of the heat is actually used to heat the water, but a considerable part also comes out through the chimney without any benefit.
Installation diagram of partition plates in KChM
This injustice can be avoided by inserting a metal sheet with a thickness of 3 to 5 mm inside the boiler over the flame, which will retain heat and direct it to the walls of the water sections. But an even greater effect can be achieved if you build a labyrinth inside from inserted sheets. How it will look, you can find out by looking at the attached picture.
A completely fair question may arise: how to accomplish all this in practice? There is already room for creativity of each owner of a private house. But as an option, you can weld corners or strips of metal to the walls of the boiler, and attach partition sheets to them. Or you can weld the sheets directly to the walls. But in any case, the idea is important, and who and how will bring it to life is a personal matter, because there are many smart people.
P air supply to the KChM from above through the chimney
We all had to kindle a fire more than once to warm up, bake potatoes, barbecue, etc. And every time in order to better kindle the firewood, we had to fan the fire with a flat object in the form of a spatula. Why is this done? And this is done in order to increase the supply of oxygen in the air, which promotes the activation of a chemical reaction called combustion.Naturally, the more oxygen is supplied to the combustion products, the more actively they will burn and generate more heat.
Baffle plate V KChM
In a similar way, it is possible to improve the combustion of solid fuel in the furnace of the KChM boiler. Structurally, this can be done by welding a piece of pipe Ǿ 50 mm with an adapter Ǿ 40 mm into the chimney using electric welding. Through this pipe, by means of a compressor or a simple vacuum cleaner, air is pumped into the furnace, thus activating the process of burning wood. The attached photos show where the pipe is welded and how the air enters the furnace. Another picture shows the partition sheet, which conserves heat and directs the flame along the walls of the sections.
By analogy with the upper air supply, the oxygen supply under the grates has been modernized. For this, smart owners also came up with a device that contributes to better combustion of solid fuel in the firebox. It would be possible to describe in detail this simple structure, which, by the way, is not difficult to make yourself, but the attached video will more clearly introduce you to the course.
I would also like to offer one video from YouTube, in which the inventor shares a device that saves gas in KChM boilers, which is a coolant.
