Any heating network includes a heat source - a boiler room, a heating plant, primary or secondary pipelines for transferring a heat carrier, and a consumer - a house, apartment, enterprise. The indicators of hot water in the line differ significantly from the temperature of the liquid that is supplied to the batteries. A heat point is a complex in which the coolant is prepared for supply to the consumer.
Types and features of the substation
The heating unit includes equipment for connecting power plants to heating networks, fluid supply systems, measuring and control devices. Typically, the heating unit is located in a separate room or building.
The purpose of any type of TP is to regulate the supply of the coolant. All elements of the system - highways, pipelines serving apartments, radiators - are designed to work with a coolant of a certain temperature, purity, and gas content. Violation of these indicators leads to clogging and system failure.
TP controls the indicators of incoming and outgoing water. The consumer receives a liquid of the optimal temperature under the pressure for which the heating, ventilation, and water supply systems are designed. If any indicators change by an unacceptable value, the control system turns off the water supply.
Here, the transformation of the heat carrier takes place, for example, steam condensation and transformation into superheated water.
TP can serve a different number of consumers, include different heat consumption systems. Methods of mounting and installation of equipment are also different.
Central heating station
The peculiarity of the heating unit is the large number of connected consumers. The central heating station serves several houses, an enterprise or even an entire microdistrict. Usually it is placed in a separate building, but installation in a basement is allowed if its size allows it.
This option is not very convenient for an ordinary consumer - an apartment dweller. The central heating station sets the same temperature of the heat carrier, not taking into account that the length of the pipelines is not the same. Nearby buildings, as a rule, overheat, distant ones receive very cool water. During preventive and repair work, the whole microdistrict remains without heat at once.
Individual heating point
ITP is an individual heating station. It performs the same functions as the central heating station, but in a smaller volume. It supplies the heating medium to 1 building or even to one part of it. Since its dimensions are much smaller, the heating unit is placed in the basement or in another technical room.
The plus of an individual heating point is the supply of water to consumers of the same temperature. The length of the pipeline, even in a high-rise building, is not so long as to affect the temperature. This option is more economical, since less heating is required to maintain optimal conditions in apartments.
Modular heating station
A block or modular heating unit is a finished factory product. The blocks are compact, assembled and work according to the same scheme. You can place them on the smallest area.The blocks are assembled very quickly: you only need to connect external wires. By the number of consumers, a modular point can be either individual or central.
Advantages and disadvantages
Each type of TP has its own advantages and disadvantages. Pros of TSC:
- coolant parameters - temperature, pressure, are maintained and controlled automatically;
- the point serves a large number of consumers.
There are many more disadvantages of this solution:
- Each consumer receives a strictly metered amount of heat. However, these shares are equal only at the TSC level. Due to the different length of the pipeline, the residents of the buildings receive water at different temperatures.
- The longer the piping, the greater the heat loss. Because of this, it is necessary to increase the temperature at the central heating station, which leads to an increase in the cost of heating and hot water.
- During the renovation, a large number of residents remain without heat.
- Hot water circulation is uneven. In houses located far from the central heating station, it takes a long time to drain cold water before getting heated. The meter counts this entire volume as hot flow.
ITP is much more profitable:
- Less heat loss during heat transfer. Installing an ITP in a building saves 15 to 30% of costs.
- All apartments receive the same amount of heat, taking into account the area.
- From the tap, the water comes really hot and immediately.
- Since the heating unit operates without a high load, the likelihood of breakdowns is lower. Installation and repair of equipment takes less time.
- If the TP fails, fewer tenants suffer.
The disadvantages of an individual complex are associated only with its limited capabilities. TP serve 1 house, sometimes even a part of it. It will take a lot of money to modify an entire neighborhood.
The advantages and disadvantages of the MTP are determined by its purpose. However, such a system has its advantages:
- The finished module takes up a minimum of space. Even if it is a central heating station, it can be installed in the basement.
- Installation is extremely simple - you just need to connect it to the heating main and the power grid.
The higher the degree of automation of the heating unit, the lower the cost of its maintenance and service.
Principle of operation
The principle of operation of a modern substation is simple. The liquid from the mainline gives up its heat through the heat exchanger to the hot water supply and heating system. Then the coolant is transferred through the return pipeline to the boiler room or power plant, where it heats up again. The heated liquid from the TP is distributed among the users.
The substation supplies users with heating media and hot water. The systems work differently.
Tap water enters the TP. Part of the cold water is supplied to consumers, the other part is heated in the 1st stage heater. The heated liquid enters the circulation circuit. The pump provides a constant flow of hot water along the circuit from the heating unit to the users and vice versa. As needed, the inhabitants of the house take away hot water.
Since the liquid gradually cools, it is periodically reheated in the 2nd stage heater. Since the volume of water in the circuit decreases, it is necessary to constantly take cold water, heat it up and make up for its deficiency.
The scheme of operation of a heating unit for heating in an apartment building is somewhat different. It is simpler: water, having given off heat to pipes and radiators, returns in almost the same volume in which it was supplied. Leaks are possible, but small. The make-up system, operating on the basis of the primary heating network, compensates for the losses.
Key components of the substation
The thermal complex includes several main elements:
- The heat exchanger is an analogue of a heat boiler in a boiler room. Here the heat from the liquid in the main heating system is transferred to the heat carrier TP. This is an element of a modern complex.
- Pumps - circulation, feed, mixing, booster.
- Mud filters - mounted at the inlet and outlet of the pipeline.
- Regulators of pressure and temperature.
- Shut-off valves - acts in case of leaks, emergency changes in parameters.
- Heat metering unit.
- Distribution comb - distributes the coolant to consumers.
Larger transformer substations include other equipment.
Selection of systems
Water preparation for transfer to users is carried out using a regulating unit. By the type of this element, several schemes of the heating unit work are distinguished.
Elevator - was installed on the old-style TP. The unit mixes liquid from the main network and cooled water from the return pipeline to obtain a heat carrier with a temperature suitable for secondary networks. The temperature is maintained at a certain level regardless of the outdoor or indoor air temperature. When overheating, the only way to remove excess heat is to open a window. If it is too low, you have to connect electric heaters.
The heating unit circuit with a controller is much more efficient. The heat exchanger and control equipment allows you to regulate the water temperature in the heating circuit according to real air readings. There are 2 systems of this kind:
- Dependent scheme - increases or decreases the temperature of the supplied liquid by stirring the cooled coolant from the return pipeline. The controller monitors temperature changes and automatically turns on pumps and valves. The installation of pressure regulators is mandatory, since this indicator differs in the primary and secondary networks.
- Independent - the water used to heat the house circulates in a closed loop, heat from the coolant from the main is transferred only through the heat exchanger. Pressure regulators are not needed here, temperature control is more accurate and faster. The cost of a transformer substation with an independent circuit is higher, but it is more economical to use: the water does not get polluted, does not overheat, and does not lead to corrosion of pipes and radiators.
Hot water supply is also implemented according to 2 schemes:
- One-stage - water from the water supply is supplied to the heater. Heated by the network heat carrier, which came from the source. The cooled mains supply is transmitted to the source, and the heated water supply is supplied to the consumer.
- Two-stage - water is heated in 2 stages. First, due to the coolant from the return pipeline - up to + 5– + 30 С, then it heats up thanks to the use of the supply heat pipe - up to +60 С. In this case, waste energy of the return pipeline is used - it is cheaper.
The more efficiently the TP reduces the cost of the heat supply service, the more expensive is its installation.
System balancing
The calculations for any hydraulic circuit are very complex. During installation, features and deviations appear that cannot be taken into account in calculations: blockages, dross, narrowing. In practice, hydraulics are linked at the design stage and then adjusted using balancing valves. This device is an adjustable washer. With its help, the throughput of the valve is changed, that is, the hydraulic resistance. Thus, the work of all the contours is connected.
Balancing valves are installed on all units and TP systems: heat exchanger, pumps, water supply, ventilation, heating circuits. Additional devices are required to coordinate the operation of the circuits and compensate for the operation of the pumps.
Installation efficiency
An individual heating unit in an apartment building reduces the cost of heating and hot water supply:
- The heat meter itself does not affect its consumption, but it correctly takes into account. Heating companies often raise the cost of services without supplying enough heat.With accurate accounting, it turns out that before the installation of the TP, residents were overpaying.
- Automation reduces maintenance costs. More precise temperature control also reduces costs.
- A closed heat supply system is more profitable: there is no need to constantly purify water, repair pipes and radiators. Heat loss in a closed system is less.
- ITP works according to the schedule: it lowers the temperature at night, stops the pumps, and increases it in the morning.
The heat supply unit saves from 1.5 to 8 million rubles in 5 years.
Applications
TP are necessary for the correct distribution of heat between consumers. These include:
- Hot water supply. Part of the heat, since hot water is supplied through pipes, goes to heating the bathroom and kitchen.
- Heating systems - maintain a comfortable temperature in residential and public areas.
- Ventilation system - the air is heated before entering the building.
- Cold water supply - refers not to consumers, but to the elements of supply. Cold water serves as a regulator.
Install TP for heating, water supply, air conditioning, both old and new buildings.
