Heat Pump with Jet Pump Integration to Reduce Compressor Drive Energy
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Solution Overview
Problem
The thermal efficiency of existing heat pump cycles, such as the compression cold vapor cycle, is limited by high drive energy consumption due to the compressor's output, which results in increased fuel consumption and CO2 emissions in vehicles.
Innovation Solution
Incorporating a jet pump downstream of the condenser in the heat pump circuit, where the compressed working medium is used as a motive fluid to suck in and compress a gaseous working medium from the evaporator, forming a two-phase mixture, and using an intermediate heat exchanger to reduce exergy losses, while operating with carbon dioxide as the working medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional compression-refrigerant cycle is used for heating vehicle interiors, then the heat pump can provide heating function, but the drive energy consumption is high and thermal efficiency is limited
Solution Approach 1:
An intermediate heat exchanger is introduced between the condenser and the evaporator to recover waste heat from the high-pressure liquid refrigerant. This intermediate heat exchanger acts as a mediator that transfers heat from the condenser outlet to the evaporator inlet, reducing the compression work required and lowering drive energy consumption while improving thermal efficiency.
Solution Approach 2:
The invention recovers waste heat that would otherwise be discarded in the conventional cycle. By extracting heat from the high-pressure liquid refrigerant after condensation and using it to preheat the refrigerant before evaporation, the system recovers energy that would be lost, thereby reducing the compressor's energy consumption and improving overall thermal efficiency.
2Power
If the compressor power is increased to improve heating capacity, then the thermal efficiency decreases due to higher drive energy consumption
Solution Approach 1:
The intermediate heat exchanger performs preliminary heating of the refrigerant before it enters the evaporator by recovering heat from the condenser outlet. This preliminary action reduces the temperature difference that the compressor must overcome, allowing the system to achieve the required heating capacity with lower compressor power consumption.
Solution Approach 2:
The invention changes the temperature and pressure parameters of the refrigerant by introducing the intermediate heat exchanger. The refrigerant is heated at a intermediate stage, changing its thermal state before evaporation, which optimizes the cycle parameters and reduces the work required by the compressor while maintaining heating capacity.
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 the compression work of the compressor, enhancing thermal efficiency, lowering drive energy consumption, and reducing fuel and CO2 emissions, while utilizing an environmentally friendly and cost-effective refrigerant.
Implementation Method 1
The term 'jet pump' here is used as an example for any device in which the pumping action is generated by a fluid jet ('motive fluid') that, through momentum exchange, draws in, accelerates, and compresses/conveys another medium ('suction medium')
Implementation Method 2
The working fluid (refrigerant), a superheated fluid, is compressed in the compressor and fed to the condenser, which releases latent and sensible heat directly into a vehicle interior
Implementation Method 3
The working fluid (refrigerant), a superheated fluid, is compressed in the compressor and fed to the condenser, which releases latent and sensible heat directly into a vehicle interior
Implementation Method 4
the working fluid is throttled in the subsequent throttle valve under isenthalpic conditions, reaching wet steam parameters at the end of the throttling process
Implementation Method 5
In the subsequent evaporator, the phase transition from liquid to gaseous takes place, for which heat is supplied to the evaporator from the surroundings
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a heat pump, in particular for heating a vehicle interior, and a method for operating a heat pump with a compressor (V) arranged in a heat pump circuit of a working medium, a condenser (KON), a throttle valve (DV) and an evaporator (VER). According to the invention, gaseous working medium is compressed in the heat pump circuit in the compressor (V). The compressor output is connected to the input of the condenser (KON), in which the working medium condenses while releasing heat, the heat being supplied directly or indirectly to a consumer, in particular a passenger compartment, as useful heat. Furthermore, the condenser (KON) is followed by a jet pump, which on the one hand is supplied with the liquid working medium coming from the condenser (KON) as a motive medium and on the other hand with the gaseous working medium flowing out of the evaporator (VER) as a suction medium, such that the motive medium and suction medium in the Jet pump are compressed as a two-phase mixture. The jet pump outlet is connected to the inlet of a separator (SEP), to which the two-phase mixture is fed and in which the gaseous working medium is separated from the liquid working medium. The gas outlet of the separator (SEP) is connected to the compressor inlet and the liquid outlet of the separator (SEP) is connected to the inlet of the throttle valve (DV), whereby the liquid working medium is throttled in the throttle valve (DV) and the outlet of the throttle valve is connected to the inlet of the Is connected to the evaporator (VER), in which the phase change to gaseous working medium takes place with the supply of heat, which is fed as a suction medium to the suction medium inlet (6) of the jet pump.