As a result, we obtain four estimates of temperature for the choice of plated heat exchangers in the design.

It is these temperatures should be included in the specification that is passed to the manufacturer for selection of water to air heat exchangers.
Q: And what after all do in a situation where installed at the facility water to Air heat exchangers not provide hot water to the desired temperature?
The first step is to review, during which identify:
- Pollution degree plated heat exchangers deposits (as described above);
- Match input coolant temperature, and their costs calculated.
To increase the heat output plated heat exchangers can recommend the following actions:
1. Chemical cleaning (or mechanical treatment).
2. Raising the temperature and flow of heating fluid.
3. Replacement plated heat exchangers.
4. Reconstruction of the plated heat exchangers to transfer to the 2-way scheme, and an increase in the number of plates.
The last event we were tested on boiler number 1987 Ergach. At that, with respect to the project were equipped with two plated heat exchangers heating brands FPS-43-163-1E firm «FUNKE» the thermal capacity of 8.0 MW each. During the operation revealed that there is a rapid overgrowth of the heating surfaces plated heat exchangers deposits, resulting boiler was “locked up” – could not heat the water network above 65-70 ? C (for schedule 95/70 0 C).
The survey showed – with an estimated heat transfer coefficient plated heat exchangers 6600 W / (m2. 0C), its actual value was only 1736-2343 W / (m2. 0C), which corresponds to the relative nomu parameter (F/F0) = 0; 26-0,36. When disassembling the plated heat exchangers on the heating surface were detected scale-nye sediment thickness 0,2-0,3 mm with the following composition: 78% calcium, 22% iron oxides.
To normalize the heat from the boiler in the first place we have been made of the measure to increase spending (by about 30%) and the boiler water temperature to the maximum – from 110 to 115 ? C, as well as adjustments of reagent water chemistry. While all of these activities is limited, so the effect (failed to raise the temperature of network water for 5 .. 7 ? C), in conjunction with the regular-molecular =it possible to avoid disruption of heating a residential area.
Radically the problem was solved only in the summer of 2003. When, in collaboration with the well-known manufacturers of plate heat exchangers, “Reed, we performed a re-design of plated heat exchangers to transfer to the 2-way traffic scheme coolants and quantitative increase in plates with 163 to 250.
The reconstruction failed to fully normalize heat from the boiler room.
To the negative effects of reconstruction plated heat exchangers include the following:
- Hydraulic resistance of the water to air heat exchangers has increased from 2,0 to 6,8 m v.st., ie 3,4 times;
- Complicated by the operation of dismantling heat exchangers due to device ports and supply lines on both sides of the heat exchanger.