Reciprocating-piston compressor
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Solution Overview
Problem
Reciprocating compressors in refrigerant circuits experience excessive lubricant accumulation in the crankcase, leading to insufficient lubricant availability for downstream components, which can result in operational issues.
Innovation Solution
A lubricant suction channel is introduced to draw lubricant from the crankcase and integrate it into the suction gas stream, with the inlet opening positioned to control the lubricant level, and optionally using a nozzle or throttle device to create a pressure gradient for efficient lubricant extraction, ensuring adequate lubricant supply while preventing excessive accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a pressure equalization line is provided between the crankcase and suction gas system, then pressure balance is maintained, but excessive lubricant accumulates in the crankcase
Solution Approach 1:
The patent extracts lubricant from the crankcase through a dedicated lubricant suction channel that draws lubricant from the collection chamber and introduces it into the suction gas flow, thereby removing the harmful accumulation while maintaining pressure balance
Solution Approach 2:
The suction gas flow acts as an intermediary carrier that transports lubricant from the crankcase collection chamber through the compressor to the discharge side, enabling lubricant redistribution without disrupting pressure equilibrium
2Quantity of substance
If lubricant is extracted from the collection chamber, then lubricant accumulation is prevented, but the lubricant level may drop below the inlet opening
Solution Approach 1:
The inlet opening position in the collection chamber provides a passive feedback mechanism where the lubricant level naturally regulates extraction - when lubricant is drawn out, the level drops and eventually stops flow at the inlet opening, preventing complete depletion
Solution Approach 2:
The suction gas flow automatically draws lubricant from the collection chamber through the lubricant suction channel without requiring external control, and the system self-regulates when the lubricant level reaches the inlet opening
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 solution effectively manages lubricant levels, preventing excessive accumulation and ensuring sufficient lubrication for the compressor and downstream components, while minimizing disruptions to the compressor's operation.
Implementation Method 1
the static pressure in the suction gas flow area is lower than the static pressure in the crankcase, no lubricant is drawn in
Implementation Method 2
a pressure gradient between the static pressure in the crankcase, especially in the collection chamber, and the static pressure in the constriction of the nozzle, resulting in the suction of lubricant from the collection chamber
Implementation Method 3
the area with the outlet opening of the lubricant suction channel is located in a constriction of a nozzle. This creates a static pressure in the constriction of the suction gas flowing through the nozzle, which is lower than the rest of the pressure in the suction gas
Implementation Method 4
the area of the suction gas guide containing the outlet opening of the lubricant suction channel lies behind a throttling device in the suction gas guide in the direction of flow of the suction gas stream. Such a throttling device allows, for example, the static pressure behind the throttling point to be reduced
Data Source
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AI summary
To improve a reciprocating-piston compressor for a refrigerant circuit, comprising a crankcase in which is arranged a collecting chamber for lubricant, a cylinder housing in which at least one reciprocating piston is movable in an oscillating fashion, a valve plate which closes off the cylinder housing and in which at least one inlet valve and one outlet valve are arranged, and a cylinder head in which are provided a suction gas conduit which runs to the inlet valve and a compressed gas conduit which leads away from the outlet valve, in such a way as to prevent excessive accumulations of lubricant, it is proposed that a lubricant suction duct is provided which has an inlet opening assigned to the collecting chamber and an outlet opening assigned to the suction gas conduit, and that the outlet opening (56) is situated in a region of the suction gas conduit in which, at least intermittently, a static pressure prevails which is lower than a static pressure in the collecting chamber for lubricant.