Refrigeration apparatus
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Solution Overview
Problem
Conventional refrigeration apparatuses face challenges in maintaining heating capacity while reducing noise when reverting from defrost to heating operations, as they often require stopping or slowing the compressor, which affects the efficiency of the heating process.
Innovation Solution
The refrigeration apparatus employs a compressor with adjustable frequency, a faster end-of-defrost frequency decrease rate, and maintains an operating frequency equal to or greater than a predetermined value during the transition from defrost to heating operations, ensuring quick pressure equalization and efficient heating capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the compressor stops or slows down when reverting from defrost to heating operation, then noise is reduced, but heating capacity is compromised
Solution Approach 1:
The patent applies dynamics by making the compressor's operating frequency adjustable and variable. The control unit dynamically changes the compressor's frequency based on operational phase: during defrost operation, it reduces frequency to lower pressure; when reverting to heating, it quickly increases frequency to restore heating capacity. This dynamic frequency adjustment allows the system to adapt to different operational requirements, resolving the contradiction between noise reduction and heating capacity maintenance.
Solution Approach 2:
The patent employs parameter changes by modifying the compressor's operating frequency as a key parameter. During defrost operation, the frequency is reduced to decrease refrigerant pressure and enable safe switching. When transitioning back to heating mode, the frequency is rapidly increased to restore heating performance. This parameter adjustment strategy allows the system to temporarily accept lower performance during defrost while ensuring quick recovery of full heating capacity, effectively managing the noise-capacity trade-off.
2Productivity
If the compressor maintains high operating frequency during defrost operation, then heating capacity is ensured, but noise increases when reverting to heating operation
Solution Approach 1:
The patent applies preliminary action by proactively reducing the compressor's operating frequency during defrost operation before the transition back to heating mode. This preliminary frequency reduction lowers the refrigerant pressure in the circuit during defrost, preparing the system for a smooth transition. When reverting to heating operation, the compressor can quickly increase frequency without causing excessive noise or pressure shocks, as the system has already been conditioned during the defrost phase.
3Object-affected harmful factors
If the compressor stops before entering heating operation after defrost, then noise is reduced, but the time to restore heating capacity increases
Solution Approach 1:
The patent resolves this contradiction through dynamic frequency control rather than complete stopping. The compressor maintains continuous operation but dynamically adjusts its frequency: during defrost, frequency is reduced; during transition, frequency is quickly increased; and during heating operation, frequency is optimized for maximum heating capacity. This continuous dynamic adjustment eliminates the time loss associated with stopping and restarting, while still achieving noise reduction during the critical transition phase.
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 allowing the compressor to maintain necessary operating frequencies without stopping, thereby shortening defrost times and improving low-temperature heating performance.
Implementation Method 1
a compressor that is provided in the refrigerant circuit and whose operating frequency is capable of being changed
Implementation Method 2
an evaporator that is provided in the refrigerant circuit and is for performing heat exchange by causing refrigerant circulated by the compressor to evaporate in a heating operation
Implementation Method 3
a condenser that is provided in the refrigerant circuit and is for performing heat exchange by causing the refrigerant circulated by the compressor to condense in the heating operation
Implementation Method 4
uses an indoor heat exchanger to heat indoor air
Data Source
AI summary
An air conditioner that is a refrigeration apparatus has, in a refrigerant circuit, a compressor, an outdoor heat exchanger that functions as an evaporator in a heating operation, an indoor heat exchanger that functions as a condenser in the heating operation, and a four way valve. The refrigerant circuit is configured in such a way that a high-pressure value of the refrigerant circuit in a defrost operation is lower than a high-pressure value of the refrigerant circuit in the heating operation. An end-of-defrost frequency decrease rate, which is a rate of decrease in the operating frequency of the compressor 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 in the heating operation.