Steam Expansion via Split Flow Pressure Reducing Valve and Rotor Unit
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Solution Overview
Problem
Existing methods for expanding steam in industrial processes are inefficient as they only control pressure and result in superheated steam, leading to inefficient heat exchange and the need for expensive desuperheaters to reduce temperature.
Innovation Solution
A method involving a combination of a pressure reducing valve and a rotor-driven pressure reducing unit, where the steam is split into subflows to undergo isenthalpic and polytropic expansions, allowing for independent control of pressure and temperature adjustments without additional cooling, and conversion of expansion energy into mechanical energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pressure reducing valve is used to expand steam, then the pressure control is simple, but the temperature cannot be controlled and superheated steam is produced
Solution Approach 1:
The steam flow is divided into two separate subflows: one passing through a pressure reducing valve for isenthalpic expansion, and another passing through a pressure reducing unit with rotor for polytropic/isentropic expansion. This segmentation allows independent control of pressure and temperature by adjusting the ratio of subflows, resolving the contradiction between simple pressure control and temperature control capability.
2Stress or pressure
If isenthalpic expansion is used in pressure reducing valve, then pressure reduction is achieved, but expansion energy is not converted to useful work
Solution Approach 1:
A pressure reducing unit with rotor is introduced as an intermediary component between the steam source and the final output. This unit converts a portion of the steam flow through polytropic or isentropic expansion, transforming expansion energy into mechanical work on the rotor while still achieving pressure reduction. The mechanical energy can be utilized for useful work, eliminating the energy loss inherent in pure isenthalpic expansion.
3Stress or pressure
If superheated steam is produced, then pressure reduction is achieved, but heat exchange efficiency decreases
Solution Approach 1:
The invention changes the thermodynamic parameters of steam expansion by offering two pathways: isenthalpic expansion (maintaining enthalpy) and polytropic/isentropic expansion (changing enthalpy to mechanical work). By adjusting the proportion of steam taking each pathway, the final temperature and superheating level can be precisely controlled to match downstream process requirements, thereby optimizing heat exchange efficiency while maintaining pressure reduction.
4Temperature
If desuperheater is used to reduce steam temperature, then temperature control is achieved, but device complexity and cost increase
Solution Approach 1:
The system uses the inherent thermodynamic properties of steam expansion and the controllable mixing of two expansion pathways to achieve temperature control inherently, without requiring external desuperheating equipment. The dual-path expansion mechanism allows the steam to self-regulate its temperature based on the proportion of subflows, eliminating the need for additional complex temperature control devices.
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 approach enables efficient energy conversion and precise temperature control, reducing superheating and eliminating the need for desuperheaters, while allowing for the generation of mechanical energy.
Implementation Method 1
During expansion, the pressure and temperature of the steam change according to an isenthalpic law known in thermodynamics
Implementation Method 2
an expansion in a pressure reducing unit of the intended type proceeds according to a rather polytropic or approximately isentropic thermodynamic law
Implementation Method 3
an expansion in a pressure reducing unit of the intended type proceeds according to a rather polytropic or approximately isentropic thermodynamic law
Implementation Method 4
a pressure reducing unit with a rotor driven by the gas with an outgoing shaft for converting the energy contained in the gas into mechanical energy on this shaft
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Method for expanding a gas flow (Q) between an inlet (A) for the supply of the gas flow at certain inlet conditions of inlet pressure (pA) and inlet temperature (TA) and an outlet (B) for the delivery of expanded gas at certain desired outlet conditions of outlet pressure (pB) and outlet temperature (TB), whereby this method at least comprises the step of at least partly expanding the gas flow between the inlet (A) and the outlet (B) through a pressure reducing valve (5) and at least partly expanding it through a pressure reducing unit (10) with a rotor (11) driven by the gas for converting the energy contained in the gas into mechanical energy on this shaft (12).