Variable-Speed Scroll Compressor Oil Injection Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable-speed scroll-type refrigeration compressors face challenges in accurately controlling oil injection into the compression volume, leading to inefficient performance at low speeds and potential damage from excessive oil at high speeds, with complex calibration and maintenance issues, as well as increased greenhouse gas emissions due to external pipe arrangements.
Innovation Solution
A variable-speed scroll-type refrigeration compressor with a solenoid valve attached to the enclosure wall, controlled by magnetic field, allowing precise oil injection based on compressor speed and refrigerant gas delivery temperature, reducing external pipe exposure and enhancing maintenance accessibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a compression spring is used to control the oil injection valve, then oil injection can be enabled at low speeds, but the valve control becomes inaccurate and complex calibration is required
Solution Approach 1:
The patent replaces the mechanical compression spring system with an electromagnetic solenoid valve system. The solenoid valve uses electromagnetic actuation instead of mechanical spring pressure to control oil injection, enabling precise electronic control through control means that respond to compressor speed and refrigerant gas delivery temperature, thereby improving control accuracy while reducing mechanical complexity and calibration requirements.
2Reliability
If oil is injected into the compression volume at high speeds, then lubrication is improved, but excessive oil enters the refrigerant gas causing heat exchanger inefficiency
Solution Approach 1:
The patent implements dynamic control of the solenoid valve based on real-time compressor operating conditions. The control means adjusts the valve state according to compressor speed and refrigerant gas delivery temperature, enabling the system to inject oil when needed at low speeds while preventing excessive oil injection at high speeds, thus dynamically optimizing both lubrication and heat exchange efficiency.
Solution Approach 2:
The control system uses feedback from sensors monitoring compressor speed and refrigerant gas delivery temperature to automatically adjust the solenoid valve operation. This closed-loop control ensures oil injection is precisely regulated according to actual operating conditions, preventing the heat exchanger inefficiency caused by excessive oil while maintaining adequate lubrication.
3Ease of manufacture
If supply and injection pipes are arranged externally, then installation is simplified, but greenhouse gas emissions increase and protection against external impacts is reduced
Solution Approach 1:
The patent nests the oil supply and injection pipes within the sealed enclosure structure rather than arranging them externally. The solenoid valve is integrated into the enclosure wall, and the injection pipe is positioned to deliver oil directly into the compression volume through the sealed barrier, thereby eliminating external pipe exposure that would compromise the sealed enclosure integrity and reduce greenhouse gas emissions while maintaining manufacturing feasibility.
4Object-affected harmful factors
If the solenoid valve is integrated into the enclosure wall, then protection and emission reduction are improved, but maintenance accessibility may be affected
Solution Approach 1:
The patent segments the solenoid valve into a removable module that can be detached from the enclosure wall for maintenance purposes. This modular design allows the solenoid valve to be integrated into the enclosure structure for protection and emission reduction during operation, while enabling easy removal and replacement when maintenance is required, thus resolving the contradiction between integration benefits and maintenance accessibility.
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 ensures easy maintenance, precise oil control, reduced greenhouse gas emissions, and improved protection against external impacts, while maintaining efficient performance across varying speeds without increasing energy use or oil pump pressure.
Implementation Method 1
a solenoid valve (25) having a core (34) which can be made to move by a magnetic field, between a first position allowing oil to be injected into the compression volume and a second position preventing or limiting the injection of oil into the compression volume
Data Source
AI summary
The compressor includes a sealed housing defining a suction volume and a compression volume respectively provided on either side of a body contained in the housing, an oil injection circuit supplied with oil from an oil contained in a casing and adapted for injecting oil into the compression volume, the oil injection circuit comprising an electrovalve including a body attached to the wall of the sealed housing and a core movable under the action of a magnetic fluid between a closing position for injecting oil into the compression volume and an opening position preventing or limiting the injection of oil into the compression volume. The compressor includes a control system for moving the core of the electrovalve between the opening and closing positions based on the compressor speed and/or on the cooling gas discharge temperature.