In the north, boiler heating is related to the daily work and life of thousands of households. Especially in the large-scale central heating system, the constant pressure constant temperature control and reliability requirements are high. SINCR c500-z medium voltage inverter series (power range: 45kW~800kW) can meet the needs of boiler high-power fan and water pump, mature technology and stable production process to ensure product reliability and stability.

The picture below shows the application scene of the SINCR 400kw inverter in a city heating project in Shandong:

China is a developing country with rapid development. The unique state of the country requires that the rate of urbanization in our country be maintained at a relatively high level. At the same time, the rate of urbanization in the faster implementation will remain at a relatively high level. At the same time, in the rapid implementation of urbanization, environmental pollution can not be caused, and energy-saving technologies are vigorously promoted in cities. Under such a background, the technology of central heating in northern China is strongly promoted.

Centralized heating usually refers to the heat source plant (power plant or large boiler room) sending hot water to various residential quarters through urban high-temperature heat pipes, heat exchange stations in enterprises, hot water supply in high-temperature pipes in heat exchange stations The hot water pipes of the hot user's indoor radiator exchange heat through the heat exchanger. After the heat exchange, the hot water in the secondary network flows into the heat users.

Boiler drums, induced draft fans, make-up pumps, and circulating water pumps in heat source and heat exchange stations are often large energy consumers. If direct start or ordinary soft starter is used, it is often necessary to use a valve for throttling control because it cannot be operated at a variable speed. , causing energy waste. If the frequency conversion speed regulation method is adopted, although the initial procurement cost is higher, due to the energy-saving characteristics of the frequency conversion speed regulation, the frequency converter has a good promotion value under the current situation of energy shortage in the world.

1, the selection method of the inverter

When selecting a frequency converter, you must fully understand the load characteristics driven by the inverter. Production machinery is divided into 3 types: constant torque load, constant power load, fan pump load. Most of the load in the central heating industry belongs to the fan pump load, such as boiler feed, induced draft fan, circulating water pump, circulating water pump of heat exchange station. In various fans, pumps, and oil pumps, as the impeller rotates, the resistance generated by air or liquid in a certain speed range of the medium is roughly proportional to the square of the speed. As the speed of rotation decreases, the torque decreases by the square of the speed. The power required for this load is proportional to the cube of the speed.

When the required air volume and flow rate change, the frequency converter and the flow rate can be adjusted by the frequency converter through the speed regulation mode, which can greatly save the electric energy. Since the power required at high speed increases with the speed, it is proportional to the cube of the speed. Therefore, the fan and pump load should not be operated at the power frequency.

When the motor is dragging such a load, the actual motor current value should be used as the basis for the inverter selection. The rated power of the motor can only be used as a reference. In addition, it should be fully considered that the output of the inverter is rich in high-order harmonics, which will deteriorate the power factor and efficiency of the motor. Therefore, compared with the power frequency grid power supply by the inverter, the current of the motor will increase by 10% and the temperature rise will increase by about 20%. Therefore, when selecting the motor and the inverter, this situation should be taken into consideration, and a margin should be left to prevent the temperature rise from being too high and affect the service life of the motor.

2, the debugging of the inverter

In the inverter application of the fan pump, the general function is not too complicated, so the debugging is also simple. Now there are more inverter manufacturers and more brands, but the debugging steps are similar, but the name is not the same. In general, debugging a new drive should include several steps.

First of all, after getting the inverter, you should first perform the factory reset operation, reset the parameters to the factory default settings, and have a bottom in mind, in case someone has moved the parameters to avoid unnecessary mistakes.

Secondly, in order to adapt the inverter parameters to the corresponding motor, the motor should be parameterized and motor identified according to the steps in the product manual. The parameter setting is to input the motor nameplate data into the inverter; the motor identification needs to start the inverter, and the inverter performs the parameter calculation and measurement of the motor. If vector control is used, automatic optimization of the regulator is required. It should be noted that the identification needs to disconnect the motor from the load such as the fan and the water pump.

After doing the above work, you need to set the function, such as start and stop control, speed control and feedback signal settings. By doing the above work one by one, you can put it into operation.

3. Precautions for use and maintenance of the inverter

The characteristics of the central heating industry are very obvious, and the annual downtime is usually longer. In order to ensure safe and stable operation and ensure reliable heating, more attention should be paid to the use and maintenance of the inverter.

First of all, the installation position of the inverter should be kept away from the possibility of water leakage. For example, do not install the inverter under the water pipe because condensation may form on the surface of the water pipe. Do not install the inverter in a place where the humidity is too high and condensation may occur.

4, about the energy saving of the inverter

At present, the heating period in northern China has changed to five months. In the warmer months, there is actually room for energy conservation.

The load characteristics of fans and pumps are square torque type, and the change of performance parameters follows the law of proportionality: the flow rate is proportional to the square of the rotational speed; the indenter (head) is proportional to the square of the rotational speed; the axial power and the rotational speed are three times. Fang Cheng is proportional.

When the flow rate is adjusted by reducing the motor speed, the motor output power can be greatly reduced to achieve energy saving.

5. Market requirements when using inverters

In recent years, China's urban construction has developed rapidly. The uncertainties in the partial demolition and construction of the city have increased. The low-rise buildings and the high-rise buildings coexist. They have different requirements for the heating medium-hot water parameters, especially the return water. The pressure of pressure and hydration will cause certain social contradictions if they do not meet the requirements of their respective users. At the same time, some developers have a large development area, but the heating area is increasing every year, especially the first year of heating area. The proportion of the total development area is very low. For this reason, the heating equipment should have strong adjustability. The DC speed control equipment does not have the use conditions in the thermal engineering for various reasons, and only the frequency converter can meet the actual demand.

6, the use of frequency converters is a requirement for technological progress

Due to the technological progress in China, all walks of life have tried to save manpower, and the original manual work is intelligent. Traditional equipment cannot accept the analog automatic signal, and the generation of the inverter solves this problem.

In recent years, national and local regulations have also improved with technological advancement. All newly built residential buildings require household measurement, but old residential houses cannot measure households. Imagine that in a certain area, during the same period of time, new residential tenants will close or reduce their own heating valves. Old residential households cannot adjust their own hot water flow, then the entire heating network will be out of control. The country is increasingly commodifying heating services and providing high-quality services at low cost. Only the system can be used in large quantities. Traditional equipment cannot be matched and can only be eliminated.