Assembly for heat generation
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Solution Overview
Problem
CO2 heat pumps are uneconomical for heating applications with small temperature differences, as the return temperature in heating systems is too high to be suitable as an inlet temperature, making them inefficient for room or building heating.
Innovation Solution
A fluid/fluid heat pump is integrated into the fluid circuit between the heat exchanger and the CO2 heat pump to segregate the fluid stream into a cold and a warm stream, allowing the cold stream to be used as the inlet for the CO2 heat pump and the warm stream to be reused, while the fluid reservoir acts as a buffer to manage fluid flow and temperature differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a CO2 heat pump is used directly in a heating system with small temperature difference, then the system structure is simple, but the return temperature is too high to be suitable as inlet temperature to the CO2 heat pump, making operation uneconomical
Solution Approach 1:
The patent divides the heating system into two separate circuits: a primary circuit with the CO2 heat pump operating at large temperature difference (5-10°C), and a secondary circuit with a conventional heat exchanger handling the building heating load at small temperature difference. This segmentation allows each component to operate in its optimal temperature range, resolving the contradiction between simple structure and energy efficiency.
Solution Approach 2:
The patent introduces an intermediary heat exchanger that couples the primary CO2 heat pump circuit and the secondary building heating circuit. This intermediary transfers heat from the CO2 refrigerant (operating at large ΔT) to the building heating system (requiring small ΔT), enabling the CO2 heat pump to operate efficiently without directly serving the low-temperature heating load.
2Ease of operation
If a CO2 heat pump is used directly in a heating system with small temperature difference, then the installation is straightforward, but the temperature spread is too small, making operation uneconomical
Solution Approach 1:
The system is segmented into an efficient CO2 heat pump unit (primary circuit) and a conventional distribution system (secondary circuit). The CO2 heat pump handles only the refrigeration/cooling load with optimal large temperature spread, while the secondary circuit distributes heat to buildings, maintaining installation simplicity while maximizing operational efficiency.
Solution Approach 2:
The CO2 heat pump system serves multiple functions: it provides both cooling (refrigeration) and heating (through the intermediary heat exchanger). This multi-functionality allows the system to operate efficiently in both modes, resolving the contradiction between ease of operation and productivity by making the system adaptable to different operational requirements.
3Device complexity
If the fluid flow from the heat exchanger is directly introduced into the CO2 heat pump, then the system is simple, but the temperature is too high to be suitable for CO2 heat pump inlet
Solution Approach 1:
The patent introduces an intermediary heat exchanger that acts as a temperature mediator between the building heating system and the CO2 heat pump. This intermediary extracts heat from the CO2 refrigerant at high temperature and transfers it to the building heating system, allowing the CO2 heat pump to receive fluid at its optimal inlet temperature while still meeting the heating demand.
Solution Approach 2:
Different parts of the system are designed with different temperature characteristics: the CO2 heat pump operates at high temperature with large temperature spread, the intermediary heat exchanger provides temperature transition, and the building heating system operates at lower temperature with small spread. This local quality differentiation resolves the temperature incompatibility while maintaining overall system simplicity.
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 configuration enables economical operation of CO2 heat pumps with small temperature spreads by adjusting the fluid temperature to match the CO2 heat pump's inlet requirements and utilizing the extracted heat efficiently, allowing for effective heat recovery and reuse.
Implementation Method 1
a fluid-to-fluid heat pump (4), which is configured to extract heat from a first fluid flow (14) and transfer the extracted heat to a second fluid flow (15)
Implementation Method 2
CO2 heat pumps are characterized by the high environmental compatibility of the refrigerant CO2 (also known as R744) used, as well as by their high efficiency
Data Source
Figure 1
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AI summary
In a heat generation arrangement comprising a CO2 heat pump having a fluid inlet and a fluid outlet and for which a maximum fluid inlet temperature is specified, a heat exchanger having a fluid inlet and a fluid outlet and whose fluid outlet temperature is higher than the maximum fluid inlet temperature of the CO2 heat pump, and a fluid/fluid heat pump having a first and a second fluid inlet as well as a cold fluid outlet and a hot fluid outlet, wherein the fluid/fluid heat pump is configured to direct a first fluid flow entering through the first fluid inlet to the cold fluid outlet and a second fluid flow entering through the second fluid inlet to the hot fluid outlet, thereby extracting heat from the first fluid flow and transferring it to the second fluid flow, the CO2 heat pump,The heat exchanger and the fluid/fluid heat pump can be connected in series in this order in a fluid circuit through which a fluid flows; the fluid outlet of the heat exchanger is in flow communication with the first fluid inlet of the fluid/fluid heat pump; the fluid/fluid heat pump is configured to cool the first fluid flow to a temperature that is at most equal to the maximum fluid inlet temperature specified for the CO2 heat pump; and the cold fluid outlet of the fluid/fluid heat pump is in flow communication with the fluid inlet of the CO2 heat pump.