Refrigeration device
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Solution Overview
Problem
Conventional refrigeration apparatuses face challenges in reducing noise during the transition from defrost to heating operations while maintaining heating capacity.
Innovation Solution
The refrigeration apparatus employs a faster end-of-defrost frequency decrease rate, maintaining an operating frequency equal to or greater than a predetermined value without stopping the compressor, and maintaining a constant frequency before switching to heating, allowing for quicker pressure equalization and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the compressor is stopped before entering heating operation after defrost, then noise is reduced, but heating capacity cannot be ensured
Solution Approach 1:
The patent applies dynamics by making the compressor's operating frequency adjustable and time-dependent. Instead of a static on/off control, the system dynamically transitions the compressor through different frequency stages: rapidly decreasing during defrost, maintaining a predetermined minimum frequency during transition, and then increasing to normal operating frequency in heating mode. This dynamic frequency adjustment resolves the contradiction by preventing complete shutdown (which causes noise) while ensuring sufficient heating capacity through maintained operation.
Solution Approach 2:
The patent changes the operational parameters of the compressor by introducing a predetermined frequency threshold and time-based frequency adjustment. The control unit modifies the operating frequency parameter based on operational phase (defrost, transition, heating), maintaining frequency above a threshold during transition to prevent noise while ensuring heating capacity. This parameter change approach allows the system to optimize both noise reduction and heating performance.
2Object-affected harmful factors
If the compressor acceleration rate is reduced after defrost, then noise is reduced, but the time to reach necessary operating frequency is extended
Solution Approach 1:
The patent applies periodic action through staged frequency adjustment. Instead of a single continuous acceleration or deceleration phase, the system uses distinct time periods with different frequency adjustment rates: a rapid decrease rate during defrost operation, a maintenance phase at predetermined frequency during transition, and then a controlled increase rate during heating operation. This periodic, multi-stage approach reduces noise during critical transition periods while ensuring timely achievement of heating capacity.
3Reliability
If a normal frequency decrease rate is used during defrost operation, then compressor wear is reduced, but the time to reach pressure equalization frequency is extended
Solution Approach 1:
The patent applies dynamics by implementing a variable frequency decrease rate that adapts to the operational phase. During defrost operation, the system uses a first (faster) frequency decrease rate to quickly reach the pressure equalization frequency needed for switching. After switching to heating operation, it transitions to a second (slower) acceleration rate to reach normal operating frequency. This dynamic rate adjustment resolves the contradiction by prioritizing speed during the critical defrost-to-heating transition while maintaining reliability during normal operation.
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 approach effectively suppresses noise and enhances heating capacity by ensuring a rapid increase in compressor frequency during heating operations, improving low-temperature heating performance.
Implementation Method 1
a compressor 11 that compresses the refrigerant
Implementation Method 2
a vapor compression refrigeration cycle is performed
Implementation Method 3
uses an indoor heat exchanger to heat indoor air
Data Source
Figure 1
Figure 2
Figure 3
AI summary
To provide a refrigeration apparatus that suppresses noise that occurs when reverting to a heating operation and with which it is easy to ensure heating capacity. An air conditioner (1) that is a refrigeration apparatus has, in a refrigerant circuit (10), a compressor (11), an outdoor heat exchanger (13) that functions as an evaporator in a heating operation, an indoor heat exchanger (16) that functions as a condenser in the heating operation, and a four way valve (12). The refrigerant circuit (10) is configured in such a way that a high-pressure value of the refrigerant circuit (10) in a defrost operation is lower than a high-pressure value of the refrigerant circuit (10) in the heating operation. An end-of-defrost frequency decrease rate, which is a rate of decrease in the operating frequency of the compressor (11) in the defrost operation, is set faster than a normal frequency decrease rate, which is a rate of decrease in the operating frequency of the compressor (11) in the heating operation.