WHAT systems with forced circulation?
most important element of the system is a forced circulation pump, which makes moving (circulating) coolant.
These pumps are called - circulation.Pump power must be sufficient to overcome the resistance (friction) in the pipe.
thicker than the pipe, the less resistance and less pump capacity is needed.But thick pipes are inconvenient, ugly in the rooms and much more.
As a result, generally maintain a reasonable balance between the diameter of pipes and power pump.
most comfortable for humans temperature heating -37 degrees Celsius.
that converts the pump in heating systems with forced circulation?
pump encourages moving water (coolant) in the heating system, overcoming the resistance of the tube.He does not lift water.How much hot water in the heating system had risen as much as the cold sank.
Let's try an example.If you turn the bike and spin the wheel well, it can be twisted for a long time, if it is set on a good bearing.It will stop only frictio
water in a closed heating system like this wheel.The pump only overcomes the friction and the water moves in a circle.That is why the circulation pumps for private homes (ie for domestic heating systems) have a small capacity and hence low power consumption - about 100 watts, like a light bulb.
If the pump is shut down, the water after some time as the rotating wheel, stop, and if you do not turn off, the water will be moving constantly.
based on it the ability to control the supply of heat from the boiler to the radiators at home.The pump can be switched on at full power, or to be turned off, or work half-heartedly.
If the house is hot, and the pump is running at full capacity, it is possible to reduce the capacity of the pump, the flow of coolant in the system drops below the temperature decreases on a radiator.
can connect the pump to the power line through the sensor.The pump will then be automatically switched on only when the temperature in the house drops below desired.This sensor is also called a thermostat.
what the system with natural circulation?
In a system with natural circulation pump no.The role of the pump it performs force generated by the difference in density (weight) in the coolant supply and return pipes.
coolant (such as water) in the boiler is heated.The density of the hot water smaller;it is lighter than cold, and moving up one thick tube (feeding riser).Then the hot water flows in several downstream pipes (return risers), penetrating the building, to the radiators from the top down and cooled, giving heat.The density of cold water increases, the water becomes heavier and returns to the boiler at the return line.
circulation in such a system arises from the difference in the weight of the hot coolant feed riser and cold - after cooling in devices and return pipe.The larger the diameter of the vertical risers, the greater the motive power of natural circulation.
What distinguishes Double-pipe WIRING FROM SINGLE PIPE?
the room temperature is more easily controlled when applied to so-called two-pipe arrangement.With this type of wiring every heater announced two pipes - forward and reverse.The temperature of the coolant entering the unit, all devices will be the same.
For comfortable heating system - two-pipe arrangement.
-pipe radiator layout is similar to the parallel connection of electrical appliances when each unit from a common source summed up "plus" and "minus".
For comfortable heating system - two-pipe arrangement.
When one pipe layout coolant passes successively from one radiator to another.In this last radiator in the "chain" can be considerably colder first, since the coolant cools in each radiator.Control system with one pipe wiring difficult.It is impossible without special techniques to block access of coolant to only one radiator, since this overlaps and access to all other.To organize
bypass coolant through the radiator is blocked by apply the so-called "bypass" (or jumpers).
But even if you use this trick in store, there are still two drawbacks:
1. Appearance - "not very".
2. riser pipe and bypass will be hot, even when the radiators are closed, that is, again, remains unregulated portion of the heating system.
all known heating in apartment buildings - an example of one pipe routing.
What is "sandwiched" system?
Sometimes when installing the heating system there is a desire to save money and use thinner pipe.It seems that enough to put a more powerful pump - and the coolant will move.
Savings on purchase of the pipe will be "eaten" the need to buy more expensive and more powerful pump.And it may even be that any power of the pump will not be enough to overcome the resistance in the pipe - system of "squeezed".
heating medium in the pipe must move at a certain speed, so that every second a sufficient amount of hot coolant to enter the radiator and reaches the desired heat.This amount is called the flow of coolant.The higher the coolant flow rate, the greater the expense.
However, with increasing speed and increases the resistance (friction) in the pipe.That is, with the increase in coolant flow rate is increased and the system resistance.If you use a thicker pipe, the resistance decreases, thinner - rise.
is too thin tubes, no matter how much increased pumping capacity, the water flow in the system remains small, and the resistance in the pipe (pressure, pressure) increases.The coolant in such a system does not move or moves too slowly, often overheated boiler and radiators remain cold as hot coolant does not flow into them in the right amount.Such a system is called the "sandwiched".
"Who can build a house?"№9-2006