CHP System Flow Temperature Control for Safe Mode Transition
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Solution Overview
Problem
Existing combined heat and power (CHP) systems face challenges in efficiently transitioning between domestic hot water temperature control and room temperature control modes, leading to risks of exceeding permissible flow temperatures and potential damage to heating and/or cooling circuits.
Innovation Solution
A method and system that adjusts the heat transfer fluid delivery unit based on temperature sensors and a control device to manage flow temperature during transitions, minimizing temperature differences and optimizing the operation of the CHP system to prevent overheating or underheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the system switches from domestic water tempering mode to room temperature control mode, then room temperature control is achieved, but flow temperature may exceed permissible values causing overheating or damage to heating/cooling circuits
Solution Approach 1:
The control device performs preliminary actions by detecting the end of domestic water tempering mode and proactively initiating a transition sequence before room temperature control begins. The heat transfer unit's delivery rate is gradually reduced and flow temperature is adjusted in advance to prevent exceeding permissible temperature values when switching to room temperature control mode.
Solution Approach 2:
The control device continuously monitors flow temperature and heat transfer medium temperature during the transition mode, using feedback signals to dynamically adjust the heat transfer unit's delivery rate and the combined heat and power engine's output. This closed-loop control ensures temperature remains within safe operating limits throughout the mode transition.
2Speed
If the system rapidly cools the heat transfer medium during cooling transition, then user comfort is improved, but the switching unit may switch too early causing instability
Solution Approach 1:
The control device dynamically adjusts the heat transfer unit's delivery rate based on real-time temperature measurements. During cooling transition, the delivery rate is reduced gradually rather than abruptly, allowing the system to adapt to changing thermal conditions. This dynamic control enables rapid cooling when needed while preventing premature switching that would cause instability.
Solution Approach 2:
The control device prepares for mode switching by monitoring temperature trends in advance. It initiates gradual delivery rate reduction before the actual mode transition point, ensuring that cooling occurs at an optimal rate that balances user comfort with system stability, preventing both premature and delayed switching.
3Productivity
If the heat transfer unit operates at high delivery rate during water tempering, then hot water production is efficient, but energy waste occurs when switching to room temperature control
Solution Approach 1:
The control device dynamically adjusts the heat transfer unit's delivery rate based on the operational mode. During domestic water tempering, the delivery rate is maintained at high levels for efficient hot water production. During the transition to room temperature control, the delivery rate is gradually reduced to match the lower thermal demands, eliminating energy waste while maintaining productivity during high-demand periods.
Solution Approach 2:
The system changes operational parameters (delivery rate, flow temperature) according to the operational mode. In water tempering mode, parameters are optimized for high productivity; during transition and room temperature control, parameters are adjusted to match actual thermal demands, reducing energy consumption without compromising system performance.
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 effectively manages temperature transitions, reducing the risk of circuit damage and maintaining user comfort by ensuring safe and efficient operation of the CHP system across different modes.
Implementation Method 1
The heat transfer unit is preferably provided to circulate a heat transfer medium, in particular water, in the heat transfer circuit
Implementation Method 2
In the domestic and/or drinking water tempering mode, the heat transfer medium is preferably heated by the combined heat and power engine to a flow temperature value of more than 60°C, in particular to kill germs
Implementation Method 3
In the room temperature control mode, the heating and/or cooling circuit is temperature-controlled, in particular heated or cooled, by means of the heat transfer medium directly or indirectly, for example via a hydraulic separator or a heat exchanger
Data Source
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AI summary
The invention relates to a method for operating a combined heat and power (CHP) system, comprising at least one domestic hot water (DHW) and/or drinking water temperature control mode (14a) for water treatment, at least one room temperature control mode for temperature control of a heating and/or cooling circuit (18a; 18b) connected to the CHP system, and a transition mode for adjusting the flow temperature of the CHP system when switching from the DHW and/or drinking water temperature control mode (14a) to the room temperature control mode. It is proposed that in the transition mode, at least one heat transfer fluid delivery unit (20a; 20b) of a heat distribution unit (22a; 22b) of the CHP system is adjusted depending on at least one temperature, in particular the flow temperature, of the heat distribution unit (22a; 22b).