Internal Heat Exchanger Layout for Lower Heat Pump Suction Superheat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heat pumps face inefficiencies and reduced compressor lifespan due to suction superheat, particularly in heating modes, which affect the performance range and efficiency of compressors with high compression ratios.
Innovation Solution
A heat pump system with a refrigeration cycle that includes a compressor, a condenser, an internal heat exchanger, and an evaporator, where the internal heat exchanger has conduits that facilitate heat exchange between the condenser and evaporator, and a bypass system controlled by valves to manage refrigerant temperature, optimizing the compressor's working range and efficiency in both heating and cooling modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If suction superheat is increased to prevent liquid refrigerant from entering the compressor, then compressor reliability is improved, but compressor performance range and efficiency in high compression ratio area deteriorate
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the degree of superheat based on operating conditions. The system changes the refrigerant temperature parameter at the compressor inlet from a fixed high superheat state to a variable state that can be optimized for different compression ratios, thereby resolving the contradiction between reliability and performance range.
Solution Approach 2:
The patent implements dynamics by making the superheat control adaptive rather than static. The system dynamically adjusts expansion valve positioning and refrigerant flow based on real-time operating parameters (compression ratio, temperature, pressure), allowing the compressor to operate efficiently across varying conditions while maintaining adequate superheat protection.
2Adaptability or versatility
If a conventional refrigeration circuit is used with expansion valves and heat exchangers, then the heat pump can operate in heating and cooling modes, but the system complexity increases and efficiency in heating mode deteriorates due to suction superheat
Solution Approach 1:
The patent applies universality by designing a control system that manages a single refrigeration circuit to perform both heating and cooling functions. The same expansion valves and heat exchangers are used in both modes, with the controller adapting their operation to achieve optimal performance in either heating or cooling mode without requiring separate dedicated systems.
3Productivity
If the refrigerant temperature at compressor inlet is reduced to improve compressor efficiency, then the performance range increases, but the risk of liquid refrigerant entering the compressor increases
Solution Approach 1:
The patent implements feedback by continuously monitoring refrigerant temperature, pressure, and compression ratio, then using this information to adjust expansion valve positioning in real-time. The controller receives feedback from sensors and modifies the superheat level accordingly, maintaining optimal temperature for efficiency while ensuring adequate superheat to prevent liquid ingress.
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
The solution reduces suction superheat, enhances the compressor's performance range, and increases the overall efficiency and durability of the heat pump by maintaining optimal refrigerant temperatures, thereby improving the heat pump's operational efficiency and extending compressor lifespan.
Implementation Method 1
an internal heat exchanger (15) having a first conduit (15a) and a second conduit (15b), the first conduit being in heat exchanging contact with the second conduit, wherein the first conduit is part of the fluid line between the third heat exchanger and the second expansion valve, and the second conduit is part of the fluid line between the second heat exchanger and the compressor
Implementation Method 2
the first conduit being in heat exchanging contact with the second conduit
Implementation Method 3
the third heat exchanger is configured to reduce a temperature of the refrigerant provided from the first heat exchanger to the internal heat exchanger by giving off heat to a second physical medium
Implementation Method 4
The second heat exchanger is an evaporator, evaporating the refrigerant by adding thermal energy of a first physical medium to the refrigerant
Implementation Method 5
evaporating the refrigerant by adding thermal energy
Implementation Method 6
the first heat exchanger is a condenser and is configured to add thermal energy from the refrigerant to a fluid circuit to be heated
Implementation Method 7
the first heat exchanger is a condenser
Implementation Method 8
the second expansion valve is configured to reduce a pressure of the refrigerant after the refrigerant passes the expansion valve
Implementation Method 9
the second expansion valve is configured to reduce a pressure of the refrigerant
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a heat pump and a method for operating a heat pump. In a heating mode, the heat pump comprises a refrigeration cycle including connected in a loop by fluid lines and in succession: a compressor, a first heat exchanger, a third heat exchanger, a second expansion valve, and a second heat exchanger. The refrigeration cycle further comprises an internal heat exchanger having a first conduit and a second conduit being in heat exchanging contact, wherein the first conduit is part of the fluid line between the third heat exchanger and the second expansion valve, and the second conduit is part of the fluid line between the second heat exchanger and the compressor, wherein the third heat exchanger is configured to reduce a temperature of the refrigerant provided from the first heat exchanger to the internal heat exchanger by giving off heat to a physical medium.