Eurotherm ES /EST domestic gas boilers use air of the room in which they are established for firing (have the open combustion chamber). The combustion products withdrawal is conducted into a chimney. The air flow and combustion gases removal are performed naturally — at the expense of density difference. Household gas coppers are supplied with draft stabilizers and have the monitoring system of combustion products withdrawal. According to “Technical rules for installation of the gas equipment DVGW – TRGI 1986/1996” classification devices belong to the B11BS type.
The EST domestic gas boilersuse air of the room in which they are established for burning (have the open combustion chamber). Devices are supplied with draft stabilizers and have the combustion products withdrawal monitoring system. Combustion products withdrawal can be conducted into isolated flue, general flue or directly through the protecting building construction (a wall, a roof). Combustion gases removal is performed compulsorily — due to functional operation of smoke exhauster established after draft stabilizer. The air intake evacuation is provided on burning from the room where the device is established due to artificially created in furnace chamber.
Description and operation of the device
The air intake and combustion products withdrawal diagram is provided on figure 1.
The combustion products withdrawal diagram for EST devices to isolated flue is produced on figure 2. Such diagram is applied to intermediate gas duct (between copper and flue) with a high aerodynamic resistance (small diameter, difficult design) and significantly facilitates designing conditions into existing buildings.
The combustion products withdrawal diagrams for several EST devices into general flue are provided in figure 3. The general flue, at the same time, in case of all operating modes in every weather condition range (for GVS providing – that and during non-heating season), must provide steady evacuation in gas flues of devices connection points.
The combustion products withdrawal diagrams for EST devices through the protecting designs are provided in figure 4. The combustion products withdrawal through a wall (in the figure to the left) is possible for process buildings, roof boiler houses and cases provided by existing standard rates. The chimney flue negative grade must be organized towards an exit through wall. The combustion products withdrawal through a roof (in the figure to the left) is possible for device installation case on upper floors or in one-storey building. The gas flue length limit no more than 6 m must be maintained, however. Moreover, each withdrawal on 900 reduces this length to 0,75 m. The observance of this term is caused by need to guarantee smoke exhauster’s functional operation in output target values range. The gas flue horizontal bend’s negative grade must be organized towards the device. The combustion products withdrawal through eaves (in the middle of figure) is possible in case of upper floors, or one-storey building device installation. The gas flue limiting length conditions and its horizontal bends negative grade is the same, as in the previous case.
The case forbidden for devices installation application on residential and public buildings’ lower floors has been illustrated in figure 5 – the EST device installation with combustion gases bend through the wall. The EST device installation with combustion gases bend through the wall on industrial buildings’ lower floors can be admissible if the deaf facade is located above and there are no occupied places. For this case, generally speaking, it is necessary to provide a gas flue exit through wall onto not lower than 2,2 m over pass level mark.
Copper’s work and device
The ES 50 and EST 50 devices are structurally executed on the sole heat recovery system’s basis – 46 kW. The ES 100 and EST 100 devices are structurally executed on the basis of two 46 kW heat recovery systems in the sole case each. Further into device’s description and functional operation of ES 100 and EST 100 devices in descring heat recovery system, gas fuel unit, safety and management automatic equipment, a turboadd-on units etc. One must keep in mind that the question is about one of device’s two components – the left or right section.
The running mode copper heat recovery system, the premixing gas atmospheric water-cooled burner, combined gas charging valves, the circulation pulser, automatic air-purge valves, safety relief valve, combustion chamber, a flue, system of pipelines with shut-off valves and a set of sensors are parts of the device. Each device has the control panel, a set of the sensors and devices providing automatic ignition of gas, safe operation features automatic control,the device’s functional operation automatic protection and control. The device’s functional operation is completely automated which allows to operate the heating installation consisting of devices’ cascade without permanent stay in service personnel boiler room’s area.
The device’s decoratory case consists of the frame, two side, forward and top plates. The front plate of the control panel with buttons of management and liquid crystal display are fixed on the forward plate.
The branch pipes are removed in order to connect the device to external heating lines from corresponding elements of the device. The combustion products formed in the combustion chamber pass through the copper heat recovery system.
The combustion chamber is located over the burner and represents the rectangular box formed from four sides by metal walls with internal thermal insulation. The combustion chamber creates space between burner and heat recovery system where fuel burning occurs. The inspection window for burning process observation is located in the combustion chamber’s front wall.
The irregular shape chimney flue, serving for cooled combustion products’ intake and bend in a chimney, arriving from the combustion chamber via heat recovery system, is attached to the combustion chamber over it. The special aperture for lowering of influence on the evacuation changing external weather conditions combustion chamber is located in the upper part of a flue. The draft controll attermperator which reacts to draft disappearance into chimney flue and giving the controling signal on gas-feeding block signalling is located in close proximity to an aperture.
The set of sensors consists of:
- an ionization electrode of flame control (located over burner);
- the draft control attemporator (located in the upper part of draft interrupter);
- emergency attemporators (are located on heat recovery systems on special branch pipes);
- the channel relay sensor (it is located on the lifting pipeline between the pump and the heat exchanger);
- temperature sensor (it is located on the lowering pipeline).
On ionization electrode (in case of burner flame loss), the draft control attemporator (in case of draft’s disappearance in chimney flue), the emergency attemporator (in case of excess of heating water temperature’s admissible value), the channel sensor (in case of heating water insufficient circulation) signals there is an emergency blocking of gas supply to the burner.