Heating Pressure Control in Air Conditioners Using Supercritical Refrigerant
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Solution Overview
Problem
Air conditioners using supercritical refrigerants often fail to maintain the desired room temperature during heating operations, despite the refrigerant outlet temperature reaching the target value, leading to inadequate heating capacity.
Innovation Solution
An air conditioner with a controller that adjusts the high-pressure side pressure of the refrigeration cycle to match the necessary heating capacity by monitoring both the refrigerant outlet temperature and room temperature, increasing or decreasing pressure to eliminate deficiencies or excesses in heating capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the high-pressure side pressure is increased to improve heating capacity, then the heating capacity increases, but energy consumption increases due to excess capacity
Solution Approach 1:
The patent applies dynamics by making the high-pressure side pressure adjustable rather than fixed. The controller dynamically changes the pressure setpoint based on real-time feedback from room temperature sensors and refrigerant temperature sensors, allowing the system to adapt heating capacity to actual needs and eliminate both deficiencies and excesses in heating performance.
Solution Approach 2:
The patent implements feedback control by continuously monitoring room temperature and refrigerant outlet temperature, comparing these values against target values, and adjusting the high-pressure side pressure accordingly. This closed-loop control ensures the system maintains optimal heating capacity while avoiding energy waste from excessive pressure.
2Temperature
If the high-pressure side pressure is maintained at a fixed target value, then the refrigerant outlet temperature can be controlled, but the room temperature may not reach the setting temperature due to heating capacity deficiency
Solution Approach 1:
The system performs self-diagnosis by comparing actual room temperature and refrigerant temperature against target values to automatically detect heating capacity deficiency. When deficiency is detected, the controller autonomously increases the high-pressure side pressure setpoint to restore adequate heating capacity without external intervention.
Solution Approach 2:
The patent changes the pressure parameter dynamically by adjusting the high-pressure side pressure setpoint in response to detected heating capacity deficiency. This parameter change allows the system to transition from a fixed-pressure control mode to an adaptive pressure control mode that ensures reliable heating performance.
3Reliability
If the high-pressure side pressure is increased to eliminate heating capacity deficiency, then the room temperature reaches the setting temperature, but excess capacity is created when not needed
Solution Approach 1:
The system dynamically adjusts the high-pressure side pressure setpoint based on real-time heating capacity assessment. When heating capacity deficiency is eliminated and the room reaches the setting temperature, the controller reduces the pressure setpoint to avoid creating excess capacity, thereby preventing energy waste while maintaining reliable heating performance when needed.
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 ensures consistent heating comfort by eliminating deficiencies and excesses in heating capacity, thereby improving energy efficiency and maintaining the desired room temperature.
Implementation Method 1
The radiator causes heat radiation to be performed with respect to air from a supercritical refrigerant during heating operation
Implementation Method 2
an air conditioner that uses a refrigerant whose high-pressure side is operated at a supercritical pressure
Data Source
AI summary
An air conditioner includes an indoor heat exchanger (radiator) and a controller. The radiator causes heat radiation to be performed with respect to air from a supercritical refrigerant during heating operation. The controller controls a room temperature by causing a high-pressure side pressure and a refrigerant outlet temperature of the radiator to reach respective target values. Preferably, the controller detects a refrigerant outlet temperature of the radiator with an outlet temperature sensor and detects a room temperature with a room temperature sensor. The controller increases or decreases a target value of the high-pressure side pressure when the controller has judged that there is an excess or a deficiency of capacity in view of the room temperature inside a room that is to be heated even when the refrigerant outlet temperature of the radiator has reached a target value during heating.