District Heating Heat Pump Circuits for Lower Network Temperatures
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Solution Overview
Problem
Heating networks, particularly local ones, face high heat losses and energy inefficiencies due to the need for maintaining high network-side flow temperatures, which are wasteful and require significant energy usage, especially in summer or when only a few consumers are active.
Innovation Solution
The method involves coupling heat from a heating network into multiple heating circuits using a heat pump circuit with evaporators and condensers, allowing for adjustable temperature regulation and reduced network losses by recycling the heat network medium and using optional network/heating circuit heat exchangers to optimize energy use based on load states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high network-side flow temperatures are maintained to supply heat to heating circuits, then heat supply reliability is improved, but heat losses in the distribution network increase and energy efficiency deteriorates
Solution Approach 1:
The system segments the heating network into multiple independent heating circuits, each with its own heat pump circuit. This allows each circuit to operate independently at optimized temperatures, so only the necessary temperature differential is maintained in each segment rather than the entire network requiring high temperatures.
Solution Approach 2:
The system changes the temperature parameter dynamically by using heat pump circuits to raise the temperature of heating medium locally at each heating circuit. The network can operate at lower temperatures while still delivering required temperatures to consumers through the heat pump temperature boosting function.
2Productivity
If high network-side flow temperatures are maintained to supply heat to heating circuits, then heat supply capability is improved, but energy expenditure for heat generation increases
Solution Approach 1:
Each heating circuit equips itself with a heat pump circuit that autonomously raises the temperature of the heating medium to the required level. The system serves itself by using the return water from each circuit as the evaporator feed, eliminating the need for centralized high-temperature generation for all circuits.
Solution Approach 2:
The temperature parameter is changed locally at each heating circuit through the heat pump, allowing the network to operate at lower temperatures while still achieving the required supply temperatures for each consumer.
3Reliability
If high network-side flow temperatures are maintained in summer for hot water preparation, then hot water supply reliability is improved, but heat losses increase since temperatures remain high regardless of consumer demand
Solution Approach 1:
The system segments hot water preparation into individual heating circuits, each with its own heat pump. This allows hot water to be prepared on-demand at each location rather than maintaining high temperatures throughout the entire network during summer months.
Solution Approach 2:
The heat pump circuits operate periodically or on-demand based on actual consumer needs rather than continuously maintaining high temperatures. The system activates heat pumps only when hot water is required at specific locations, reducing unnecessary heat losses during periods of low demand.
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 reduces energy expenditure and heat losses by allowing for precise temperature control, maintaining lower network temperatures and minimizing the need for high temperatures across the network, thereby enhancing operational reliability and efficiency.
Implementation Method 1
heat transfer from the heating network medium
Implementation Method 2
a working medium, preferably a refrigerant, of the heat pump circuit is evaporated by heat transfer from the heating network medium
Implementation Method 3
heating medium of the heating circuit, which has a first heating medium temperature and flows through the condenser, by heat transfer from the working medium to a second heating medium temperature
Data Source
AI summary
The method involves operating the district heating network in defined full load or high load operating modes, so that heating medium of heating circuit (3) is heated. The heating network in defined partial load or low-load operating conditions is operated with a local heating network flow temperature which is less than first local heating system flow temperature, and heating circuits associated with heat pump circuits (5) are switched, so that the heating circuit heat exchanger (2) is heated to a second heating medium temperature greater than the first heating medium temperature. An independent claim is included for device for providing heat from a district heating network into several heating circuits attached to heat load.