the energy-saving modification for the HPHT Hydraulic Cubic Press is mainly achieved by not starting the oil pump (motor) during the pressure intensifier depressurization stage. This increases the non-working time of the oil pump motor, thereby reducing energy consumption.
Modification Rationale and Principles
Problem Statement: The HPHT Hydraulic Cubic Press operates continuously during the synthetic diamond production cycle, and its power source (oil pump motor) is in a continuous working state. With the trend towards larger equipment, motor power is typically 7.5kW, 11kW, or even higher, leading to alarming energy consumption, especially electricity. Therefore, reducing energy consumption, particularly electricity consumption, has become an urgent issue that needs to be addressed.
Solution Approach: The entry point for the modification is to increase the non-working time of the oil pump motor to reduce its loss. After analyzing the working principles, structure, and synthetic process of the press, the decision was made to focus on "not starting the oil pump (motor) during the pressure intensifier depressurization".
Problem with the Old System: Before the modification, to depressurize the pressure intensifier, an oil pump had to be started to generate pressurized oil. This pressurized oil would pass through check valve 14 and solenoid valve 48, eventually pushing open pilot-operated check valve 22, placing it in an open state. Only then could the high-pressure oil return to the oil tank via one-way throttle valve 21, pilot-operated check valve 22, and solenoid valve 10, completing the pressure intensifier depressurization. This process required starting the oil pump motor as the power source and took about 30-60 seconds.
Modification of the New System: The modified plan involves using the high-pressure oil retained in the pressure chamber after pressure-holding to replace the oil pump motor as the power source for depressurizing the pressure intensifier. The specific changes are as follows:
When the work program proceeds to the pressure intensifier depressurization, the solenoid YV14 is energized.
The high-pressure oil inside the intensifier cylinder is then used to open valve 21 through valve 19.
The hydraulic oil from the intensifier cylinder then returns to the oil tank through valve 21, valve 48, and filter 16, thereby achieving depressurization of the pressure intensifier.
Analysis of Benefits After Modification
Economic Benefits:
Modification Cost: The increase in cost for each modified hydraulic press is approximately 90 yuan.
Electricity Savings Calculation: Using a 15-minute synthesis process as an example, the pressure intensifier depressurization time is calculated as 40 seconds. A single 6x1300 ton HPHT Hydraulic Cubic Press working 340 days a year can save approximately 3989.33 kilowatt-hours of electricity annually.
Electricity Bill Savings: Based on an average electricity price of 0.60 yuan/kWh, the annual electricity cost savings for one modified press is about 2393.6 yuan. If a medium-sized factory with 50 large-tonnage HPHT Hydraulic Cubic Presses (assuming 11kW motor power) adopts this modification, the annual electricity savings alone could amount to 119,680 yuan. The economic benefits are undoubtedly considerable.
Environmental and Other Benefits:
Noise and Vibration: Before the modification, the workshop was filled with the roaring sound of the oil pump motor starting and stopping, and the vibration of oil pipes and the hydraulic station door panel caused by it. After the modification, the workshop is noticeably "quieter," significantly reducing the noise and vibration generated during the depressurization process.
Equipment Lifespan and Maintenance: The modification reduces the number of daily starts of the oil pump motor, which helps to extend its service life. It also greatly mitigates issues such as loose connections and oil leaks that can result from long-term pipe vibration, thereby reducing potential maintenance costs.
Working Environment: The equipment modification also significantly improved the working environment for the staff.
The modification to the HPHT Hydraulic Cubic Press, which enables depressurization without starting the oil pump (motor), is a technical upgrade that is low in investment, quick to show results, and highly effective. For manufacturers of the presses, this technology enhances the overall technical content and increases the added value of the product. For users of the presses, the greatest benefits are energy savings, reduced consumption, and an improved working environment.