Scroll Compressor Back Pressure Control via Flow Valve
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Scroll compressors face efficiency issues due to varying back pressure conditions during changes in operating loads, leading to inadequate axial sealing and potential overload or underload situations, as existing designs struggle to maintain consistent back pressure across different load conditions.
Innovation Solution
A scroll compressor design that includes a flow control valve in the oil feed passage to regulate the amount of oil supplied to the back pressure chamber based on suction pressure, discharge pressure, and drive motor rotational frequency, ensuring a constant back pressure is maintained across varying load conditions by adjusting the oil flow through the oil feed passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the scroll compressor is designed so that back pressure capable of axial sealing is generated at a maximum load condition, then axial sealing is achieved at maximum load, but at a low load condition the back pressure is lowered so that axial sealing is not properly performed
Solution Approach 1:
The back pressure chamber is designed with a variable volume configuration that changes dynamically with the operational load. At maximum load, the chamber volume is smaller to generate higher back pressure for axial sealing. At low load, the chamber volume expands to maintain the necessary back pressure level, ensuring continuous effective axial sealing across all operating conditions.
Solution Approach 2:
The system changes the physical parameter of back pressure chamber volume to adapt to different load conditions. By varying the chamber volume parameter dynamically, the back pressure is maintained within the optimal range for axial sealing regardless of whether the compressor operates at maximum or low load.
2Reliability
If the scroll compressor is designed so that a back pressure capable of axial sealing is generated at a minimum load condition, then axial sealing is achieved at minimum load, but at the maximum load condition more back pressure than necessary is generated so that the scroll compressor is overloaded
Solution Approach 1:
The back pressure chamber volume is dynamically adjusted based on the operational load. At minimum load, the chamber volume is larger to generate sufficient back pressure for axial sealing. At maximum load, the chamber volume reduces automatically, preventing excessive back pressure and avoiding compressor overload, while still maintaining adequate axial sealing.
Solution Approach 2:
The system dynamically changes the back pressure chamber volume parameter to match the operational requirements. This parameter adjustment ensures that back pressure remains within the optimal range for axial sealing without causing overload at maximum load conditions.
3Use of energy by moving object
If the scroll compressor operates at variable load conditions to save energy, then energy efficiency is improved, but the back pressure varies leading to efficiency loss
Solution Approach 1:
The system incorporates a feedback mechanism where the back pressure chamber volume is automatically adjusted in response to changing operational loads. This feedback control ensures that back pressure is maintained at the optimal level for axial sealing and compressor efficiency, even when the compressor operates at variable load conditions to save energy.
Solution Approach 2:
The back pressure chamber is designed with dynamic volume adjustment capability that responds to load variations. This dynamic adaptation allows the compressor to operate efficiently at variable loads while maintaining constant back pressure conditions optimal for axial sealing and overall compressor performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively maintains constant back pressure, enhancing the sealing of the compression chamber and preventing refrigerant leakage, thereby improving the operational efficiency of the scroll compressor across different load conditions.
Implementation Method 1
a flow control valve disposed in the oil feed passage, the flow control valve configured to control an amount of oil to be supplied to the back pressure chamber via the oil feed passage
Implementation Method 2
an orbiting scroll to be rotated by the drive motor, a fixed scroll engaged with the orbiting scroll, a compression chamber formed by the orbiting scroll and the fixed scroll
Implementation Method 3
a drive motor accommodated in the casing, an orbiting scroll to be rotated by the drive motor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A scroll compressor includes a casing, a drive motor, an orbiting scroll, a fixed scroll engaged with the orbiting scroll, a back pressure chamber proximate to the orbiting scroll, an inlet pipe for supplying refrigerant to a compression chamber formed by the orbiting scroll and the fixed scroll, and a discharge pipe for discharging the refrigerant discharged from the compression chamber. The scroll compressor includes an oil feed passage configured to connect the back pressure chamber and an oil storage tank provided in the casing so that oil of the oil storage tank is supplied to the back pressure chamber; and a flow control valve disposed in the oil feed passage and configured to control an amount of oil to be supplied to the back pressure chamber via the oil feed passage according to a suction pressure, a discharge pressure, and a rotational velocity.