Design of thermal solutions for gas boiler
We have completed the development of working documentation for the MEP built-in gas boiler for an administrative two-story building. We have developed sections of the design documentation.
THERMOMECHANICAL SOLUTIONS BOILER DESIGN
The heating system is supplied with heat from the built-in boiler house on two Vaillant atmoTEC plus VU 280 / 5-5 brand boilers with a total capacity of 62.2 kW, and an efficiency of 91%.
The boilers are equipped with pumps, 10-liter expansion tanks, waste valves, automation kit.
The boilers have an open combustion chamber.
Design temperatures for equipment selection are taken according to the schedule of the heat source operation:
- in the supply heating T1 = 85 degrees.
- in reverse heating T2 = 65 degrees C
The boiler circuit to the hydraulic separator T1 = 85 degrees. C T2 = 70 degrees. With
Pipelines within the boiler house shall be provided from steel pipes in accordance with the requirements of SNiP 2.04.07-86, 2.04.01-85.
The boilers are equipped with automatic safety and regulation systems. Control and protection devices are located on the front control panel.
Heat supply for heating needs from the boiler house is carried out according to a closed scheme. The boilers are connected to heat supply systems through a hydraulic separator (hydraulic needle), which performs the additional functions of the air vent and sludge removal.
The circulation of coolant in the heating system is forced, for which an electric pump is installed in the boiler room in the mixing module. Standby pump stored in stock.
For the circulation of water in the boiler circuit pumps are used that are built into the boiler. The circulation of the coolant after the hydraulic needle in the heating system is carried out by a pump installed in the Geffen module, Russia.
PROJECT DOCUMENTATION OF HEAT MECHANICS
Maintaining the return water temperature at the boiler inlet is maintained automatically by the boiler automatics. Installation of bypass pumps is not required.
Make-up and the initial filling of the heating system is provided from the household drinking water with water corresponding to GOST 2874-82 “Drinking water”. Water consumption for recharge will be 0.02 m3 / h. For treatment of make-up water, an automatic water treatment unit of WSC-0.5 of periodic action, operating according to the method of Na-cationation, is provided.
The project provides for automatic regulation of the temperature of the direct network water supplied to the heating system, depending on the outdoor temperature by passing part of the return network water into it. Three-way valve in position K2.
All pumping equipment operates on a three-step scheme, which allows you to adjust its performance.
To compensate for the volume expansion of the water, a 25 l membrane expansion tank with a capacity of 25 liters is provided; additional expansion tanks are built into the boilers.
Install automatic air vent valves in the upper points of pipelines, in the lower ones - fittings for water drainage. Removal of drainage in emergency situations and in the case of repair is provided to the sewage system with dilution of wastewater, see section VK. There are no permanent drains in the boiler room.
Removal of combustion products from the boilers is provided through a chimney D 130 mm H = 7.2 m separated from each floor of the boiler room, separated for each boiler. Chimneys are made of double-walled stainless steel pipes with a heat-insulating gasket of basalt non-combustible fiber. Factory production.
Pipelines, chimneys and chimneys having a surface temperature above 45 ° C must be protected by thermal insulation.
Calculation of the expansion tank heating.
The volume of the expansion tank V = (VL x E) / D, where
VL - capacity of the expansion system (capacity of the boiler, all pipes and heat accumulators, if any)
E - the coefficient of expansion of the liquid,%
D - the efficiency of the membrane expansion tank