There is no need to talk much about the value of the heat point in the general heat supply system. Thermal circuits of thermal nodes are involved both in the network and in the internal consumption system.
The concept of a heat point
Efficiency of use and the level of heat supply to the consumer directly depends on the correct functioning of the equipment.
In fact, a heat point is a legal border, which in itself involves equipping it with a set of test equipment. Thanks to this internal filling, the definition of mutual responsibility of the parties becomes more accessible. But before you figure it out, you need to understand how the thermal circuits of thermal nodes function and why read them.
How to determine the thermal node circuit
When determining the scheme and equipment of a heat point, they rely on the technical characteristics of the local heat consumption system, the external network branch, the operating mode of the systems and their sources.
In this section, you will familiarize yourself with the flow diagrams of the coolant - the thermal diagram of the thermal unit.
A detailed review will allow you to understand how the connection to the common collector is made, the pressure inside the network and relative to the coolant, the indicators of which directly depend on the heat consumption.
Important! If the heat unit is connected not to the collector, but to the heat network, the flow rate of one coolant inevitably affects the flow rate of the other.
Analysis of the thermal node circuit in detail
The figure shows two types of connections: a - in the case of connecting consumers directly to the collector; b - when connected to a branch of a heat network.
The drawing reflects graphical changes in coolant flow rate when such circumstances occur:
A - when connecting heating and water supply (hot) to the collectors of the heat source separately.
B - when inserting the same systems to an external heating network. Interestingly, the connection in this case is characterized by high rates of pressure loss in the system.
Considering the first option, it should be noted that the indicators of the total coolant flow rate increase synchronously with the flow rate for supplying hot water (in modes I, II, III), while in the second, although an increase in the flow rate of the heating unit takes place, along with it heating rates are automatically reduced.
Based on the described features of the thermal circuit of the thermal unit, we can conclude that as a result of the total flow rate of the coolant, considered in the first embodiment, when applied in practice, it is about 80% of the flow rate when using the second prototype circuit.
The place of the circuit in the design
When designing a diagram of a heating heating unit in a residential microdistrict, provided that the heat supply system is closed, pay special attention to the choice of a scheme for connecting hot water heaters to the network. The selected project will determine the estimated flow rates of the coolants, the functions and modes of regulation, etc.
The choice of the circuit of the heating heating unit is primarily determined by the established thermal regime of the network. If the network operates according to the heating schedule, then the selection of the drawing is based on a feasibility study. In this case, the parallel and mixed circuits of thermal heating units are compared.
Features of the equipment of the heating station
In order for the heat supply network of the house to function properly, the following additional items are installed on the heating points:
- gate valves and gates;
- special filters that trap dirt particles;
- control and statistical instruments: thermostats, manometers, flow meters;
- auxiliary or standby pumps.
Symbols of schemes and how to read them
The figure above shows a schematic diagram of a thermal unit with a detailed description of all the constituent elements.
Item number | Symbol |
1 | Three way valve |
2 | Gate valve |
3 | Cork plug |
4.12 | Sump |
5 | Check Valve |
6 | Throttle washer |
7 | V-shaped connection for the thermometer |
8 | Thermometer |
9 | Pressure gauge |
10 | Elevator |
eleven | Heat meter |
thirteen | Water meter |
14 | Water flow regulator |
fifteen | Subpair Regulator |
16 | Gates in the system |
17 | Stroke line |
The designations on the diagrams of thermal units help to understand the functioning of the unit by studying the circuit.
Engineers, guided by the drawings, can assume where the network breakdown occurs with the observed problems, and quickly fix it. Schemes of heating units will be useful even if you are designing a new house. Such calculations are necessarily included in the package of project documentation, because without them it is not possible to perform system installation and wiring throughout the house.
Information about what a drawing of a thermal system is and how to take it in practice is useful to anyone who has at least once in their life encountered heating or water heating appliances.
We hope that the material presented in the article will help to understand the basic concepts, understand how to determine the basic nodes and designation points of the fundamental elements in the diagram.