Cogenerative Organic Rankine Cycle System High-Temperature Steam
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Solution Overview
Problem
Existing organic Rankine cycle (ORC) systems are inefficient for high-temperature cogeneration, particularly in producing steam above 190°C, due to limitations in thermal energy recovery and electrical efficiency, and are not suitable for industries with high thermal demands.
Innovation Solution
A cogenerative ORC system using high-temperature resistant working fluids like Therminol VP-1 and other organic fluids, with a heat recovery system and condensation temperatures ranging from 150°C to 250°C, to achieve high thermal power production and improved electrical efficiency, including a direct exchange configuration to avoid thermo-chemical degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional ORC systems use condenser heat for low-temperature applications, then electrical efficiency is maintained, but high-temperature steam production capability is lost
Solution Approach 1:
The system divides the thermal energy recovery process into two separate ORC cycles: a high-temperature ORC cycle for electricity generation and a low-temperature ORC cycle for thermal energy recovery. This segmentation allows each cycle to operate optimally at its respective temperature range, resolving the contradiction between maintaining electrical efficiency and enabling high-temperature steam production.
Solution Approach 2:
The patent changes the operating parameters of the ORC system by introducing a dual-cycle configuration with different condensation temperatures. The high-temperature cycle operates with condensation temperatures between 80-150°C while the low-temperature cycle operates with condensation temperatures below 80°C, enabling simultaneous electricity generation and high-temperature steam production.
2Temperature
If ORC systems operate at high temperatures above 190°C, then high-temperature steam production is achieved, but thermal energy recovery efficiency decreases
Solution Approach 1:
The patent segments the thermal energy recovery into two distinct cycles operating at different temperature levels. The high-temperature ORC cycle captures energy at temperatures above 190°C for electricity generation, while the low-temperature ORC cycle recovers additional thermal energy at lower temperatures, thereby maintaining overall thermal power production efficiency while enabling high-temperature operation.
3Reliability
If direct exchange configuration is used to avoid thermo-chemical degradation, then system reliability improves, but device complexity increases
Solution Approach 1:
The patent introduces an intermediate heat exchanger system that facilitates direct exchange between the exhaust gas stream and the ORC working fluid without direct contact. This intermediary approach prevents thermo-chemical degradation of the organic working fluid by avoiding direct exposure to combustion products, while maintaining system reliability through efficient heat transfer.
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
The system achieves a high first principle yield of 5.5 thermal units to 1 electrical unit for saturated steam at 190°C, enhancing electrical efficiency and meeting high thermal demands while maintaining low maintenance and installation costs.
Implementation Method 1
an organic working fluid, characterised by a ratio between the critical temperature Tc and the evaporation temperature Tv (both expressed in Kelvin), comprised between about 0,7 and 0,95
Implementation Method 2
one or more heat exchangers to perform preheating, vaporization and possibly overheating
Implementation Method 3
a turbine or volumetric expander for the fluid expansion, which is mechanically connected to an electric generator or a working machine
Implementation Method 4
a condenser carrying the organic liquid back to the liquid state
Implementation Method 5
one or more pumps for supplying the organic working fluid
Implementation Method 6
with a heat recovery system and condensation temperatures ranging from 150°C to 250°C
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An organic Rankine cycle system (10,100, 110, 120) which uses an organic working fluid utilizing an organic working fluid and provided with a feed pump (1) of the organic working fluid in a liquid phase, a heat exchanger (2), which exchanges heat between a hot source and the organic working fluid exiting from the working exchanger in the vapor phase, an expansion turbine (3), which expands the vapor of the organic working fluid, a condenser (5), the condensation heat of which is used for cogeneration purposes for temperatures higher than 120°C. The organic working fluid comprises, in combination or alternatively, toluene, diphenyl, diphenyl oxide, terphenyl, quadriphenyl, linear hydrocarbons, siloxanes, alkylated aromatic hydrocarbons, phenilcycloexane, bicyclohexyl and perfluoropolyethers.