Intermediate-Pressure Heat Pump Circuit for Heat Balance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional heat pumps with auxiliary heat exchangers waste energy as the auxiliary heat exchanger does not directly contribute to heating or cooling loads, leading to decreased efficiency due to unnecessary power usage for refrigerant supply.
Innovation Solution
A heat pump design with a refrigerant circuit featuring two-stage compression and expansion, where the auxiliary heat exchanger is positioned at an intermediate-pressure line, allowing it to function as both an evaporator and condenser based on load conditions, and controlled by a compression mechanism to optimize operational capacity and flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an auxiliary heat exchanger is added to maintain heat balance in the refrigerant circuit, then heat balance control is improved, but compression power increases and efficiency decreases
Solution Approach 1:
The auxiliary heat exchanger is designed to perform multiple functions: it can serve as an evaporator to absorb heat when heating load exceeds cooling load, and as a condenser to dissipate heat when cooling load exceeds heating load. This multi-functionality allows the system to maintain heat balance without requiring separate dedicated components for each function, thereby reducing the overall compression power required.
Solution Approach 2:
The system dynamically switches the operational mode of the auxiliary heat exchanger based on real-time load conditions. When heating load > cooling load, the auxiliary heat exchanger operates as an evaporator; when cooling load > heating load, it operates as a condenser. This dynamic adaptation optimizes the refrigerant circulation path and minimizes unnecessary compression work.
2Reliability
If the auxiliary heat exchanger is positioned on high-pressure line or low-pressure line, then heat exchange function is achieved, but compression power is wastefully used
Solution Approach 1:
The auxiliary heat exchanger is positioned on the intermediate-pressure line, which acts as a mediator between the high-pressure and low-pressure sides of the refrigerant circuit. This intermediate position allows the auxiliary heat exchanger to exchange heat with refrigerant at moderate pressure levels, avoiding the high compression power requirements that would be needed if it were positioned on the high-pressure line, while also avoiding the low efficiency associated with the low-pressure line.
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 reduces compression power, enables efficient operation by adjusting the auxiliary heat exchanger's function according to load conditions, and maintains heat balance, thereby enhancing the overall efficiency of the heat pump.
Implementation Method 1
a refrigerant dissipates heat into a high-temperature fluid in the high-temperature heat exchanger (13)
Implementation Method 2
the refrigerant absorbs heat from a low-temperature fluid and evaporates in the low-temperature heat exchanger (16)
Implementation Method 3
an auxiliary heat exchanger (1) which exchanges heat between the refrigerant of the refrigerant circuit (10) and a heat-source fluid
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention is intended to prevent a reduction in efficiency of a heat pump even if an auxiliary heat exchanger is used to control heat balance of a refrigerant circuit. A refrigerant circuit (10) is provided with an auxiliary heat exchanger (1) which exchanges heat between the refrigerant in the refrigerant circuit (10) and outdoor air. The auxiliary heat exchanger (1) is connected so as to communicate between a connection path (4) between a low-stage compressor (11) and a high-stage compressor (12) and a connection path (7) between a low-stage expansion valve (15) and a high-stage expansion valve (14).