Multi-Unit Air Conditioner Load-Based Temperature Control
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Solution Overview
Problem
In multi-type air-conditioning systems, controlling evaporating and condensing temperatures to reduce power consumption is inefficient due to high fan power consumption relative to compressor power, and existing methods do not effectively manage temperature control across multiple indoor units.
Innovation Solution
The air-conditioning apparatus controls both evaporating and condensing temperatures by using a refrigerant circuit configuration with a heat source side unit, refrigerant control unit, and multiple load side units, where the compressor frequency and fan rotation speed are adjusted to match target temperatures, and the fan's power consumption is minimized by optimizing the outdoor heat exchanger's capacity based on load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the evaporating temperature and condensing temperature are controlled to constant values in multi-type air-conditioning systems, then the system can operate multiple indoor units simultaneously, but the power consumption increases and energy-saving effect is reduced
Solution Approach 1:
The patent segments the temperature control for each indoor unit independently. Each indoor unit's evaporating temperature is controlled separately based on its individual load conditions, rather than using a single constant evaporating temperature for all units. This allows the system to adapt to varying loads across different indoor units while optimizing power consumption for each segment.
Solution Approach 2:
The patent implements dynamic temperature control where the evaporating temperature for each indoor unit is adjusted in real-time based on its current load conditions. The control system dynamically determines the evaporating temperature according to the specific operational state of each indoor unit, enabling the system to respond to changing conditions and minimize power consumption while maintaining cooling/heating effectiveness.
2Measurement precision
If the fan rotation speed is increased to control condensing and evaporating temperatures, then the temperature control precision improves, but the fan power consumption increases significantly
Solution Approach 1:
The patent changes the control parameter from fan rotation speed to evaporating temperature设定值. Instead of adjusting fan speed to control temperature, the system sets the evaporating temperature according to load conditions and adjusts the expansion valve opening degree accordingly. This parameter change allows temperature control while avoiding the high power consumption associated with high fan speeds.
Solution Approach 2:
The patent replaces the mechanical fan speed control system with a thermal parameter control system. Rather than using mechanical means (fan speed) to control heat exchange, the system uses thermal parameters (evaporating temperature设定值 and expansion valve opening) to achieve the same temperature control objective with significantly lower energy consumption.
3Use of energy by moving object
If the compressor frequency is decreased to reduce power consumption, then the energy-saving effect improves, but the cooling/heating capacity becomes insufficient to meet load demands
Solution Approach 1:
The patent changes the control parameter from compressor frequency to evaporating temperature设定值. By controlling the evaporating temperature according to load conditions rather than adjusting compressor frequency, the system achieves better matching between cooling/heating capacity and actual load demands. This allows the compressor to operate at optimal frequency while the evaporating temperature adjustment provides fine-tuned capacity control.
Solution Approach 2:
The patent implements feedback control where the evaporating temperature设定值 is continuously adjusted based on the difference between the actual evaporating temperature and the target value. The control system monitors the load conditions and feedback from temperature sensors, then adjusts the expansion valve opening degree to maintain the optimal evaporating temperature, ensuring adequate cooling/heating capacity while minimizing power consumption.
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 significantly reduces power consumption by optimizing the operating frequencies of the compressor and fan, thereby enhancing the energy-saving effect across cooling and heating operations.
Implementation Method 1
a compressor (101) which compresses the refrigerant
Implementation Method 2
an outdoor heat exchanger (103) which heats or cools the refrigerant
Implementation Method 3
an indoor heat exchanger (312) which heats or cools indoor air
Implementation Method 4
the outdoor heat exchanger (103) which heats or cools the refrigerant
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A target condensing temperature and a target evaporating temperature are changed in accordance with a load of each load side unit 300 obtained by using load detection means 315, and an operating frequency of a compressor 101 and a rotation speed of a fan 106 are controlled such that a condensing temperature obtained by using temperature detection means coincides with the target condensing temperature and an evaporating temperature obtained by using the temperature detection means coincides with the target evaporating temperature.