Interlaced Heat Pump Defrosting for Continuous Heating
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Solution Overview
Problem
Conventional heat pump systems face inefficiencies in defrosting modes, leading to frequent interruptions in heating and unnecessary energy loss, as they typically defrost all pipelines simultaneously, which is not targeted and results in heat loss during the process.
Innovation Solution
A heat pump system with an interlaced outdoor heat exchanger and a control method that allows for local defrosting by selectively conducting specific refrigerant flow paths, maintaining the heating mode and reducing heat loss through targeted defrosting, utilizing four-way valves and throttling elements to manage refrigerant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional defrosting mode is used to defrost all pipelines of the condenser, then complete defrosting is achieved, but heating mode is interrupted and energy loss occurs
Solution Approach 1:
The outdoor heat exchanger is divided into multiple independent flow paths (first refrigerant flow path and second refrigerant flow path), allowing selective defrosting of specific paths rather than the entire condenser. This segmentation enables targeted defrosting while maintaining heating in other paths, thus avoiding complete interruption of heating mode.
Solution Approach 2:
The patent implements local defrosting by directing high-temperature refrigerant to specific flow paths that require defrosting based on their individual frosting conditions. Different flow paths can be in different operational states (heating or defrosting) simultaneously, optimizing both defrosting effectiveness and heating continuity.
2Reliability
If conventional defrosting mode is used to defrost all pipelines of the condenser, then complete defrosting is achieved, but unnecessary energy loss occurs
Solution Approach 1:
By segmenting the heat exchanger into multiple flow paths with independent control, the system defrosts only the necessary portions rather than the entire condenser. This reduces the amount of heat energy required for defrosting and minimizes heat loss to the surrounding environment.
Solution Approach 2:
The patent applies partial defrosting action by selectively defrosting only the flow paths that require it, rather than applying full defrosting to all paths. This partial action approach reduces energy consumption while still achieving effective defrosting where needed.
3Adaptability or versatility
If multiple flow paths are used in the outdoor heat exchanger, then local defrosting is enabled, but device complexity increases
Solution Approach 1:
The outdoor heat exchanger is segmented into multiple flow paths with independent refrigerant circulation. Each flow path has its own throttling element and can be controlled independently, providing defrosting flexibility while using a relatively simple segmented structure rather than a completely complex system.
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 system achieves targeted defrosting, reducing energy loss and maintaining the heating mode, thereby improving user experience and efficiency by selectively defrosting specific areas of the outdoor unit while minimizing heat transfer losses.
Implementation Method 1
heat exchangers in the outdoor unit that are already in low temperature environment are still used to absorb heat to evaporate refrigerant in the pipelines
Implementation Method 2
high-temperature gas-phase refrigerant discharged from the compressor flows directly into the outdoor heat exchangers and defrosts through heat dissipation of the high-temperature refrigerant
Data Source
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AI summary
The present application provides a heat pump system and a control method thereof. The heat pump system (200) comprises: a compressor (210); an indoor heat exchanger (220); an outdoor heat exchanger (230) configured as an interlaced heat exchanger having at least two refrigerant flow paths (230a, 230b); a plurality of throttling elements (241, 242); and a first type four-way valve (251) and a second type four-way valve (252), with ports thereof respectively connected to the air inlet (210a) and the air outlet (210b) of the compressor (210), the indoor heat exchanger (220), and one of the at least two refrigerant flow paths (230a, 230b) of the outdoor heat exchanger (230); wherein, in a local defrosting mode, refrigerant from the air outlet (210b) of the compressor (210) flows respectively through the indoor heat exchanger (220) and at least one of the at least two refrigerant flow paths (230a) of the outdoor heat exchanger (230), and then sequentially through the throttling elements (241, 242), at least the other of the at least two refrigerant flow paths (230b) of the outdoor heat exchanger (230), and the air inlet (210a) of the compressor (210). According to the heat pump system and the control method thereof of the present application, targeted defrosting operations can be performed on some heat exchangers with more severe frosting in outdoor units.