Reverse cycle machine provided with a turbine
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Solution Overview
Problem
Existing refrigeration systems and heat pumps face challenges in efficiently recovering pressure energy due to erosion of turbine blades, presence of lubricating oil, and scale effects, leading to reduced efficiency and reliability, especially in reverse cycles with two-phase working fluids.
Innovation Solution
A boundary layer turbine, also known as a friction or Tesla type turbine, is used to process single-phase or multiphase fluids without rotor blades, minimizing erosion and optimizing performance by utilizing viscosity and adhesion properties, and incorporating discharge drains to manage liquid fractions and prevent flooding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a traditional turbine with rotor blades is used to recover pressure energy, then energy recovery efficiency is improved, but turbine blade erosion occurs due to contact with two-phase working fluid and lubricating oil
Solution Approach 1:
The patent replaces the traditional mechanical blade system with a boundary layer turbine that has no rotor blades. Instead of using mechanical blades to extract energy from the fluid flow, the invention utilizes the boundary layer effect where the fluid's viscosity and adhesion properties create friction forces on the turbine's surface, converting kinetic energy to mechanical work without blade contact erosion
Solution Approach 2:
The patent introduces discharge drains as an intermediary mechanism to manage the liquid fraction and lubricating oil separately from the main turbine flow path. These drains prevent liquid accumulation and flooding in the turbine, allowing the turbine to operate efficiently with primarily vapor-phase fluid while maintaining reliability
2Volume of moving object
If turbine dimensions are reduced for small-scale applications, then device size is reduced, but scale effects reduce turbine efficiency
Solution Approach 1:
The boundary layer turbine design changes the fundamental operating parameters by relying on viscous friction forces rather than blade aerodynamics. This allows the turbine to maintain efficient energy conversion across a wider range of scales, as the boundary layer effects remain significant even in small-dimensional applications where traditional blade turbines would suffer from excessive scale effects
3Loss of energy
If a turbine is introduced to replace the throttling valve, then COP increases by up to 20%, but the system becomes more complex
Solution Approach 1:
The patent extracts only the essential energy recovery function from the complex blade turbine system, implementing a simplified boundary layer turbine without blades, shafts, or complex mechanical components. This extraction of the core function maintains the COP improvement benefit while significantly reducing system complexity
Solution Approach 2:
The boundary layer turbine design serves multiple functions simultaneously: it recovers pressure energy, handles two-phase flow, manages liquid separation through integrated drains, and operates across various scales. This multi-functionality reduces the need for additional separate components, thereby reducing overall system complexity despite the COP improvement
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 reduces energy consumption, increases the coefficient of performance (COP) by up to 20%, minimizes turbine erosion, and enhances refrigerating capacity, while maintaining efficiency even at small dimensions.
Implementation Method 1
utilizing viscosity and adhesion properties
Implementation Method 2
utilizing viscosity and adhesion properties
Implementation Method 3
which utilize the phase transition, both evaporation and condensation, of a working fluid
Implementation Method 4
phase transition, both evaporation and condensation
Implementation Method 5
the condenser operates at a higher pressure than the evaporator: therefore, the working fluid is transferred from the condenser, in the liquid phase
Data Source
Figure 1~2b
Figure 3
Figure 4
AI summary
A reverse compression cycle machine (M) comprising an evaporator (9), a compressor (1) and a condenser (3) arranged in series along a path of a working fluid in the machine (M), further comprising a boundary layer turbine (7) placed between the condenser (3) and the evaporator (9), said turbine (7) comprising: a set of power disks (30) mounted on a shaft (33) which rotates inside a volume of a rotor casing (53), an inlet opening (70) for introducing a working fluid in a stator volume (51), a stator nozzle (52), which accelerates the flow in a direction that is tangential to the power disks (30), a discharge (73) of a working fluid, the rotor casing (53) comprising a drain (71, 72) of a liquid fraction of said working fluid from the peripheral part of the power disks in order to avoid its concentration in the peripheral part of the volume of said rotor casing.