The basic working principle of heating system: Low temperature heat medium is heated in the heat source, absorbs heat, and becomes high-temperature heat medium (high-temperature water or steam), which is sent to the indoor through the conveying pipeline and releases heat through the heat dissipation equipment, causing the indoor temperature to rise; After heat dissipation, the temperature decreases and becomes low-temperature heat medium (low-temperature water), which is then returned to the heat source through a recycling pipeline for recycling. In this continuous cycle, heat is continuously transferred from the heat source to the indoor area to supplement the heat loss and maintain a certain temperature.

Composition of Heating System Equipment

There are many equipment and facilities involved in the heating system, including:
Boiler Room
The boiler room is the heat source part of the heating system, which mainly consists of the following components:
Boiler body: including combustion equipment (gearbox, grate), various heating surfaces (various pipelines, drum, air preheater, economizer), furnace enclosure structure, etc.
Thermal system: including water treatment equipment, water separation and pressure control system, and circulation system.
Smoke and air system: including blower, induced draft fan, flue, air duct, oil remover, etc.
Coal ash removal system: including coal crushing, screening, conveying, lifting, ash removal, slag discharge equipment, etc.
Outdoor heating network
The laying methods of outdoor heating pipelines mainly include overhead laying and buried laying. Buried laying is more common, and buried laying can be divided into several types: ventilated trench, semi ventilated trench, non ventilated trench, and direct buried laying. The main equipment and facilities involved include supply and return water pipelines, various valves, expansion joints, brackets, flange pads, pipeline trenches, and roof expansion water tanks.
Indoor heating system
The indoor heating system mainly refers to the supply and return water pipes, exhaust valves, expansion joint valves, heat dissipation equipment, and indoor trenches on the pipes.

Classification of hot water heating systems

1. Classified by different types of cyclic power in the system
   According to the different circulating power of the system, hot water heating systems can be divided into natural circulation systems and mechanical circulation systems. A system that circulates based on the density difference of fluids is called a “natural circulation system”; A system that relies on external mechanical (water pump) force to circulate is called a “mechanical circulation system”.
2. Classification based on different supply and return water methods
   According to the different supply and return methods, hot water heating systems can be divided into single pipe systems and double pipe systems. In high-rise building hot water heating systems, a hybrid system of single and double pipes is commonly used.
3. Classification based on different pipeline laying methods
   According to different pipeline laying methods, hot water heating systems can be divided into vertical systems and horizontal systems.

Project Introduction

The hot water heating system mainly consists of a hot water boiler, a hot water circulation pump, a makeup water pump, a pipe network, and an indoor radiator. To meet the heating indicators and achieve the indoor design temperature for heating users, in addition to controlling and adjusting the boiler operating parameters and combustion conditions, the entire heating system should also be thermally regulated based on changes in heating season, heating time, and other factors.

According to the different requirements of boiler operation and heating users, the two most widely used heating regulation methods are as follows:

(l) Temperature regulation: Adjust by changing the supply water temperature of the heating network;

(2) Flow regulation: By changing the circulating water volume of the heating network, it is mainly achieved by changing the supply water temperature.

Temperature regulation

Temperature regulation is a method of adjusting the temperature of hot water supplied to the system by changing the temperature of the outdoor air while keeping the circulating water volume constant. By using temperature regulation, the circulating water volume in the system is constant, so there are no special variable requirements for the circulating water pump. Currently, most mechanical circulating hot water systems use temperature regulation.

Flow regulation

Flow regulation is to divide the heating period into three intervals according to the outdoor temperature: early winter, cold winter, and late winter. According to the concept that the latent heat of water is proportional to the flow rate, for each interval, the flow rate of hot water refers to maintaining a large flow rate in the cold winter interval with low outdoor temperature, using a large flow circulation pump; Maintain a small flow rate in the early and late winter period when the outdoor temperature is high, and use a circulation pump with a slightly lower flow rate. When adjusting the flow rate between zones, the circulating flow rate of each section of the pipeline network should remain unchanged. To reduce power consumption, two circulating pumps of different specifications and models can be installed in the heating system.