Hydronic Heat Pump Mode Switching for Partial-Load Efficiency
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Solution Overview
Problem
Heat pumps in nearly Zero Energy Houses (nZEH) or Buildings (nZEB) operate inefficiently under partial load conditions, leading to frequent cycling, reduced efficiency, shortened system life, and increased electricity consumption.
Innovation Solution
A method and system that adjusts flow temperature and deadband settings in a hydronic heat pump system, allowing it to switch between operation modes based on load conditions, using a controller to set broader deadbands and higher flow temperatures during partial loads to maintain efficiency and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heat pump is sized to meet the worst-case heating demand, then the target indoor temperature can be maintained during coldest winter temperatures, but the heat pump operates at less than full capacity for the majority of the time, leading to frequent cycling and reduced efficiency
Solution Approach 1:
The patent applies dynamics by making the flow temperature adjustable rather than fixed. The system dynamically adapts the flow temperature setting based on outdoor temperature conditions and heating demand, allowing optimal operation across varying load conditions. This resolves the contradiction by enabling the heat pump to maintain reliable indoor temperatures while operating efficiently at partial load through continuous temperature adjustment.
Solution Approach 2:
The patent changes the operational parameters of the heat pump system by introducing variable flow temperature settings and adjustable deadband ranges. By modifying these parameters based on operating conditions, the system achieves both reliable temperature maintenance and improved efficiency during partial load operation, directly resolving the identified contradiction.
2Productivity
If the heat pump operates under partial load conditions for the majority of the time, then electricity consumption increases and system life shortens due to frequent cycling, but the heat demand is lower than full capacity
Solution Approach 1:
The patent applies periodic action through the use of a deadband range that prevents excessive cycling. By establishing a temperature band within which the heat pump remains off, the system reduces frequent on-off cycles during partial load conditions. This approach maintains heat demand matching while significantly reducing energy consumption associated with frequent starting and stopping.
Solution Approach 2:
The patent achieves continuity of useful action by maintaining the heat pump in a steady off-state within the deadband range, eliminating the disruptive cycling pattern. This continuous operation mode (either on or off) rather than frequent transitions reduces energy losses and extends system life while still meeting varying heat demands.
3Ease of operation
If a fixed flow temperature is used in the heating system, then the system operation is simple, but the heat pump efficiency deteriorates during partial load conditions
Solution Approach 1:
The patent transforms the fixed flow temperature system into a dynamic one where the flow temperature is continuously adjustable based on operating conditions. This dynamic adjustment capability allows the system to maintain high efficiency during partial load operation while preserving relative operational simplicity through automated control.
Solution Approach 2:
The patent changes the flow temperature parameter from a fixed value to a variable parameter that adapts to different operating conditions. This parameter change enables efficient partial load operation while maintaining ease of operation through automated parameter adjustment based on sensors and control logic.
4Measurement precision
If the deadband range is narrow to maintain precise temperature control, then thermal comfort is improved, but the heat pump cycles on and off more frequently during partial load conditions
Solution Approach 1:
The patent applies dynamics by making the deadband range adjustable rather than fixed. The deadband can be dynamically widened or narrowed based on operating conditions, allowing the system to maintain precise temperature control when needed while reducing cycling frequency during partial load conditions through adaptive deadband adjustment.
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
Enhances efficiency, prolongs heat pump life, and reduces electrical consumption by optimizing operation under partial load conditions without compromising thermal comfort.
Implementation Method 1
The heat pump may use a refrigerant such as R290, R32, CO2 or other type, and its principle of operation is known to persons skilled in the art
Implementation Method 2
The heat pump may use a refrigerant such as R290, R32, CO2 or other type
Data Source
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AI summary
A method for operating a heating system comprising a hydronic heat pump and a heating system comprising a hydronic heat pump are provided. The method comprises defining a first mode of the heating system by setting a first flow temperature and a first deadband, and comprises defining a second mode of the heating system by setting a second flow temperature and a second deadband. The method further comprises switching the heating system from the first mode to the second mode based on a signal received by the controller. In the method, the flow temperature in the second mode is set higher than the flow temperature in the first mode. Moreover, in the method, the second deadband is set broader than the first deadband by the controller. The heating system is configured accordingly. With the method and/or the heating system, an operation of the heating system with higher efficiency, especially during partial load conditions, is made possible.