Heat pump and control method therefor
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Solution Overview
Problem
Existing heat pumps face challenges in accurately determining the flow rate of the second refrigerant, particularly when there is no flow sensor, leading to difficulties in distinguishing between refrigerant shortages in the first and second refrigerant cycles.
Innovation Solution
The heat pump incorporates a pressure sensor in the first refrigerant pipe to measure surging pressures, allowing the controller to determine the flow rate of the second refrigerant without a separate flow sensor. When surging is detected a preset number of times within a preset time, the controller supplies the second refrigerant to maintain system efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a flow sensor is installed in the first refrigerant cycle to detect refrigerant flow rate, then the flow rate of the first refrigerant can be determined, but it becomes difficult to distinguish whether the detected error is due to insufficient first refrigerant or insufficient second refrigerant
Solution Approach 1:
The patent divides the refrigerant monitoring function into two separate detection systems: a flow sensor in the first refrigerant cycle for detecting first refrigerant flow, and a pressure sensor in the second refrigerant cycle for detecting second refrigerant flow issues. This segmentation allows independent monitoring of each refrigerant cycle, resolving the ambiguity of identifying which refrigerant is insufficient.
2Device complexity
If no flow sensor is installed in the second refrigerant cycle, then the system structure remains simple, but the flow rate of the second refrigerant cannot be determined
Solution Approach 1:
The patent uses the first refrigerant as an intermediary to indirectly measure the second refrigerant flow rate. By monitoring the pressure changes and surging of the first refrigerant in the heat exchanger, the system can infer the flow rate of the second refrigerant without directly installing a flow sensor in the second refrigerant cycle, thus maintaining system simplicity while achieving accurate measurement.
3Productivity
If the second refrigerant is continuously monitored and supplied, then the heating and cooling capacity is maintained, but the system requires additional sensors and control complexity
Solution Approach 1:
The patent implements a self-service mechanism where the system automatically detects second refrigerant insufficiency through pressure sensor monitoring of the first refrigerant, automatically determines the need for supplementation, and automatically controls the supplementation process. This eliminates the need for complex manual intervention systems while maintaining continuous heating and cooling capacity.
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 solution enables the heat pump to accurately determine the flow rate of the second refrigerant and supply it as needed, thereby maintaining heating and cooling capacity without the need for additional sensors.
Implementation Method 1
determine a flow rate of the second refrigerant based on surging occurred in a pressure of the first refrigerant measured by the pressure sensor
Implementation Method 2
a first outdoor heat exchanger for exchanging heat between the first refrigerant and outdoor air, a second outdoor heat exchanger for exchanging heat between the first refrigerant and a second refrigerant
Data Source
AI summary
A heat pump and a control method thereof are provided. The heat pump includes an outdoor unit includes a compressor that compresses a first refrigerant, a first outdoor heat exchanger that exchanges heat between the first refrigerant and outdoor air, an expansion mechanism that expands the first refrigerant, and a second outdoor heat exchanger that exchanges heat between the first refrigerant and a second refrigerant; a first refrigerant pipe that connects the compressor, the first outdoor heat exchanger, and the expansion mechanism, and through which the first refrigerant flows; a pressure sensor disposed in the first refrigerant pipe; a second refrigerant pipe connected to the second outdoor heat exchanger, and through which the second refrigerant flows; an indoor heat exchanger that is disposed in the second refrigerant pipe, and exchanges heat between indoor air and the second refrigerant; and a controller that determines a supply of the second refrigerant by determining a flow rate of the second refrigerant based on surging occurring in a pressure of the first refrigerant measured by the pressure sensor, so that the flow rate of the second refrigerant flowing through the second refrigerant pipe is determined only by the pressure value of the first refrigerant measured by the pressure sensor disposed in the first pipe, thereby determining the flow rate of the second refrigerant without a separate flow sensor.