Self-cleaning filters in the heating system of a carbon plant

2022-09-26

Background of the project

In September 2020, China put forward the new target of "striving to achieve carbon peaking by 2030 and carbon neutrality by 2060" to combat climate change.

Energy conservation and environmental protection have become China's basic national policy, and we are vigorously promoting centralized heating and waste heat utilization, continuously promoting the transformation of clean heating, expanding the scope of centralized heating, and implementing clean heating methods such as gas-to-coal, electricity-to-coal, heat-to-coal and centralized biomass according to local conditions, in order to promote the sustainable development of urban centralized heating.

Project Overview

This project is to recover the waste heat from the carbon plant for central heating of the town.

The return water of the heating network is first heated by the condenser, then by the plant's peak heater, and then by the municipal heating network for external heating, but the urban heating and heat pipeline system is huge and the pipelines are complex, and the quality of the heating return water drops significantly, and even mud and sand and other debris appear, causing damage to the heating equipment and blockage of the heat exchanger, which seriously affects the safety of heating, so filters are added to the main pipeline and each branch pipeline to purify the heating water quality.

Water quality requirements of the pipe network

According to the Code for the Design of Urban Heating Pipeline Networks (CJJ34-2010), the water quality of the pipeline network recharge shall meet the following requirements.

【Oil】：≤2mg/L

【Turbidity】：≤5mg/L

【Hardness】：≤0.6mmoL/L

【Dissolved oxygen】: ≤0.1mgL

【CL-content】：<25ppm

【Equipment PH (25℃)】：7-11

To ensure that the water quality of the network meets the standards and the normal operation of other equipment, self-cleaning filters are provided in the first station and the booster station.

Self-cleaning filter decontamination principle

The self-cleaning filter has the function of filtering the raw water and automatically cleaning and discharging the filter element, and the system has uninterrupted water supply when cleaning and discharging.

The filtering time is set on the timer, and when the filtering time is up, the discharge is started, while the control system compares the differential pressure of the system with the differential pressure set by the user in real time, and when the differential pressure of the system reaches the set differential pressure, the filter is also cleaned and discharged.

When the drainage time is up, the cleaning stops and the system returns to its initial state, ready for the next filtration process, ensuring that impurities in the water in the pipe network are regularly removed.

The role of self-cleaning filter in the heating pipeline

The self-cleaning filter has PLC remote control program, real-time feedback on equipment operation, automatic monitoring in linkage with the pipe network and automatic flushing and discharging, which greatly improves work efficiency, reduces labour costs and improves the reliability and safety of the pipe network and equipment operation.