In the case of an electroplating factory, there are 4 phosphating production lines in the factory. The degreasing tank, phosphating tank and saponification tank in each production line need to be heated and insulated at a temperature of 80-85°C. The electroplating factory previously used gas boilers to burn natural gas to generate high-temperature steam at about 160°C, and supplied the steam to the water tanks that needed to be heated in each production line through steam pipes, and achieved the insulation effect by heat exchange in the water tanks. At present, the use of insulation steam is about 0.3t/h per production line. It takes about 80 cubic meters of natural gas to supply 1 ton of steam using a gas boiler. From January to August, the average monthly gas bill for the four phosphating production lines is 142,000 yuan, and the annual cost is about 1.7 million yuan. Due to the factory’s energy-saving and carbon-reduction transformation and upgrading needs, it is necessary to transform the heating end of the energy consumption system.
Requirements of the electroplating factory:
Under the condition of not affecting the original production process, realize the demand for heat automation of the phosphating production line, cancel the annual inspection process of gas boilers and the qualification certification of boiler workers, reduce the production line energy consumption and energy cost, and reduce the carbon emissions of the factory.
The specific technical requirements are as follows:
The air-energy high-temperature steam heat pump equipment we provide can meet the supply of high-temperature hot water above 95℃ in the phosphating production line heat energy replacement project under the condition that the ambient temperature is not less than 5℃ throughout the year. When the equipment supplies 95℃ high-temperature hot water under the condition that the ambient temperature is not less than 20℃, the energy efficiency is not less than 2.2, and the ratio of heat supply and power consumption of the air-energy high-temperature steam heat pump equipment is not less than 2.2.
When the production line is running, the equipment we provide can meet the production of 70-80℃ chemical degreasing tank temperature in the four phosphating production lines A, B, C, and D; the production of 80-85℃ phosphating tank insulation temperature, and the saponification tank insulation requirements of 65-70℃. And through intelligent control and early start of the equipment, the degreasing tank is heated to 80℃, the phosphating tank is heated to 85℃, and the saponifying tank is heated to 70℃ within 0.5h of the phosphating production line. When there are two phosphating tanks (each with a capacity of 1100L) in the phosphating production line for liquid replacement, the water temperature in the two phosphating tanks is heated from normal temperature (based on the average winter ambient temperature of 5℃) to the required maximum insulation state and to 85℃ within 1.5h.
System solution:
According to the calculation, the required insulation heating power of the system is 452kW. Four air source heat pump steam engines are designed to meet the system insulation requirements. At the same time, the system is equipped with a 1m³ hot water tank, a 3m³ insulation water tank, a 1t/h water purifier, and auxiliary supporting water pumps, valves, control systems and other equipment.
In the actual heating process, the circulating water in the hot water tank is sent to the heat pump for heating through the heat pump side circulating pump. After being heated to the set temperature, it enters the hot water tank. The temperature of the circulating water in the hot water tank will continue to rise. When it reaches the workshop heating temperature, it is sent to the workshop through the workshop side circulating pump to heat the production liquid in the phosphating production line tank. The cooled circulating water flows back to the hot water tank and is sent to the heat pump through the heat pump side circulating pump for heating, forming a cycle. At the supply end, the same pipe resistance is ensured through the same pipeline design, so that water vapor and hot water can be effectively sent to the heat exchanger of each thermostatic tank, and finally flow back to the hot water tank, realizing the replacement of the gas boiler heating system.
The system can realize the heating of high-temperature hot water or steam in the range of 95-120℃. The actual supply situation can be determined according to the on-site needs. Appropriately reducing the supply temperature can reduce energy consumption and shorten the equipment recovery cycle.
Actual use effect
Energy saving and emission reduction
The main component of natural gas is methane. One cubic meter of natural gas emits about 1.96 kg of carbon dioxide. The factory used to use 108 cubic meters of natural gas per hour for combustion. According to 11 hours a day, 25 days a month, and 12 months a year, 698,544 kg of carbon dioxide are emitted throughout the year. According to electricity emissions, if clean energy is used for power generation, the carbon emissions are 0.
The use effect of this project
Based on the project’s active promotion of the application of relevant technologies and equipment, traditional coal-fired boilers, gas boilers and electric boilers are used to replace heating, and energy-saving transformation and upgrading of heating are promoted. The original heat energy of the electroplating factory production line was replaced, and the air source high-temperature heat pump steam engine was used to supply 120°C high-temperature hot water. After testing, the air source high-temperature heat pump steam engine has been able to stably supply 120°C high-temperature hot water since it was put into operation, which is used for heating the phosphating production line to meet the production needs of the production line. The comprehensive COP of the system during operation reached 1.8, and the annual operating cost was reduced by nearly US$130,000, or about RMB 900,000, compared with the original gas boiler.
Post time: Jul-03-2024