The energy consumption of a single column straightening machine is mainly concentrated in the hydraulic system (accounting for 60% -70% of the total energy consumption), motor drive system (20% -25%), and auxiliary systems (such as heating and lighting, 5% -10%). Controlling energy consumption requires two aspects: technological transformation and management optimization. On the premise of ensuring straightening accuracy and production efficiency, the energy consumption per unit workpiece can be reduced by 15% -25%.

1、 Energy saving technology transformation of hydraulic system

The hydraulic system is a major energy consumer. In the traditional quantitative pump hydraulic system, during the straightening process of workpieces, regardless of the load size, the oil pump outputs at the rated flow rate. Excess oil overflows through the overflow valve, causing a large amount of energy waste (overflow loss accounts for 30% -40% of the energy consumption of the hydraulic system). The following solutions can be adopted for energy-saving renovation:

Variable displacement pump energy-saving system: Replace the quantitative pump with a variable displacement piston pump (such as an axial piston variable displacement pump). The variable displacement pump can automatically adjust the output flow rate according to the actual needs of the system (such as the flow rate requirements for different stages of head rise, fall, and holding). When the head is holding pressure (at this time, the flow rate requirement is only 10% -15% of the working flow rate), the output flow rate of the variable displacement pump is significantly reduced to avoid overflow losses. After the renovation, the energy consumption of the hydraulic system can be reduced by 25% -35%. Taking a single column straightener with a rated power of 15kW as an example, working 8 hours a day can save about 12000 to 15000 yuan in electricity bills per year.

Hydraulic oil energy-saving management: Select low viscosity and high anti-wear hydraulic oil (such as 46 # anti-wear hydraulic oil) to reduce the resistance of hydraulic oil along the pipeline and minimize energy loss; At the same time, regularly clean the hydraulic oil tank and pipelines to remove impurities and ensure the cleanliness of the hydraulic oil (NAS level 8 or below), avoiding oil pollution that may cause wear and tear on the oil pump and valve components, and increasing energy consumption. In addition, an oil temperature control device is installed in the hydraulic oil tank. When the oil temperature is below 15 ℃, the electric heater (with a power of 2-3kW) is started to preheat the oil, avoiding an increase in energy consumption caused by an increase in oil viscosity at low temperatures; When the oil temperature is above 60 ℃, start the cooling fan (power 0.5-1kW) or cooler to prevent the viscosity of the oil from decreasing and increasing leakage, ensuring that the hydraulic system operates at the optimal oil temperature (40-50 ℃), which can reduce energy consumption by 5% -8%.

2、 Energy saving optimization of motor drive system

The motors of single column straightening machines (such as hydraulic pump motors and conveyor line motors) are mostly asynchronous motors. The traditional direct starting method not only has a large starting current (5-7 times the rated current), causing grid impact, but also significantly reduces motor efficiency during low load operation (such as workpiece clamping stage, motor load rate is only 30% -40%) (the optimal efficiency range for asynchronous motors is load rate 70% -90%). Energy saving optimization measures include:

Variable frequency speed regulation technology: Install a frequency converter (such as a vector frequency converter) at the motor power supply end to adjust the motor speed according to the operating conditions of the equipment. For example, when the pressure head rises without load, the motor speed can be increased to 120% of the rated speed, shortening the idle time; When the pressure head is maintained, the motor speed decreases to 30% -40% of the rated speed, reducing the motor output power. Taking the 15kW hydraulic pump motor as an example, after installing a frequency converter, the average operating power can be reduced from 12kW to 8kW. Working for 8 hours a day can save about 8000-10000 yuan in electricity bills per year. At the same time, the soft start function of the frequency converter can control the starting current within 1.5 times the rated current, protect the motor and power grid, and extend the service life of the motor (the motor life can be extended by 2-3 years).

Motor selection optimization: Select the appropriate power motor based on the actual load requirements of the equipment to avoid the phenomenon of "big horse pulling small car". For example, if the actual maximum load power of a single column straightener is 10kW, and a traditional 15kW motor is used with a load rate of only 67%, it can be replaced with an 11kW high-efficiency motor (energy efficiency level 2 or above), which can increase the motor efficiency from 85% to over 90% and save energy consumption by 3% -5% annually. In addition, for auxiliary motors that operate at low loads for a long time (such as cooling fan motors), permanent magnet synchronous motors can be used, which have an efficiency 5% -10% higher than asynchronous motors and a power factor of over 0.95, reducing reactive power losses.

3、 Energy saving measures for auxiliary systems

Energy saving heating system: For workpieces that need to be heated and straightened (such as high-temperature alloys), the traditional resistance heating method has a thermal efficiency of only 50% -60%. Induction heating method (such as medium frequency induction heating furnace) can be used instead, which can increase the thermal efficiency to over 85%, shorten the heating time by 30% -40%, and reduce heat loss. In addition, installing insulation covers (using aluminum silicate insulation material) in the heating area can reduce the impact of ambient temperature on heating efficiency and further save energy consumption by 10% -15%.

Energy saving lighting and air conditioning system: LED energy-saving lamps are used for workshop lighting, replacing traditional fluorescent lamps. The lighting power can be reduced by more than 50%, and the service life can be extended by 5-8 times; The air conditioning system adopts frequency conversion control, which automatically adjusts the operating frequency according to the workshop temperature, avoiding long-term full load operation and saving 20% -25% of air conditioning energy consumption.