CHP Working-Medium Bypass for Peak Heating Without Extra Boiler
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Solution Overview
Problem
Combined Heat and Power (CHP) plants face challenges in providing sufficient heating power during low outside temperatures without the need for a peak load boiler, leading to higher investment costs and complex construction due to the requirement for additional heating capacity beyond standard design.
Innovation Solution
The CHP plant operates in multiple modes, including a conventional mode and a heating operation mode, where a portion of the working medium is bypassed past the expansion machine to directly provide heat, and a heat pump mode, where the expansion machine compresses the working medium, allowing for increased heating power without a peak load boiler. This is achieved through a method involving a heating boiler, vaporizer, expansion machine, and condenser, with control valves managing the flow to optimize heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the CHP plant is designed for standard design temperature with fraction of maximum heating power, then investment costs are reduced, but heating power is insufficient during low outside temperatures
Solution Approach 1:
The expansion machine operates dynamically in two modes: power generation mode (expanding working medium) and heating mode (compressing working medium). The system transitions between modes based on heating demand, eliminating the need for a separate peak load boiler while providing sufficient heating power during low outside temperatures
Solution Approach 2:
The expansion machine serves multiple functions: it acts as a turbine for power generation during normal operation and as a compressor for heating during peak demand. This multi-functionality allows the CHP plant to meet both power and heating requirements without additional peak load equipment
2Reliability
If a peak load boiler is added to provide maximum heating power, then heating power is sufficient during cold weather, but investment costs and construction complexity increase
Solution Approach 1:
The system dynamically switches between expansion modes based on heating demand. During peak heating demand, the expansion machine operates in compression mode to provide additional heating power, ensuring reliability without requiring a separate peak load boiler and its associated complex construction
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 allows for a reliable increase in heating power by up to 30% compared to normal operation, eliminating the need for a peak load boiler and reducing overall costs, while maintaining efficient energy utilization throughout the year.
Implementation Method 1
a vaporizer (2) designed to evaporate a working medium
Implementation Method 2
transferring heat of the expanded working medium supplied to the condenser to a medium of a heating circuit
Implementation Method 3
a condenser (6) designed to condense the expanded working medium
Implementation Method 4
transferring heat of the expanded working medium supplied to the condenser to a medium of a heating circuit
Implementation Method 5
an expansion machine (4) designed to expand the evaporated working medium
Implementation Method 6
a heating boiler (1) designed to burn fuel
Data Source
AI summary
The present invention provides a method for operating a combined heat and power (CHP) plant comprising a heating boiler, a vaporizer, an expansion machine, and a condenser, achieved according to claim 1. The method comprises steps a), when a first condition is met: supplying a working medium to the vaporizer to obtain an at least partially evaporated working medium, feeding the (total) evaporated working medium to the expansion machine, and operating the expansion machine such that the working medium is expanded, supplying the working medium expanded by the expansion machine to the condenser, and transferring heat of the expanded working medium supplied to the condenser to a medium of a heating circuit designed to heat an object; and b) when a second condition is met which is different from the first condition: i) supplying at least a portion of the working medium to the condenser of the CHP plant without the portion of the working medium having been supplied to the expansion machine, and transferring heat of the working medium supplied to the condenser to a medium of a heating circuit designed to heat an object, and/or supplying a medium supplied from the heating boiler to the vaporizer to a heat transfer device in which heat is transferred from this medium to a medium of a heating circuit designed to heat an object.