Refrigeration Circuit Throttle Control Using Compressor Pressure Feedback
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Solution Overview
Problem
Refrigeration circuits face challenges in reducing energy consumption and protecting the compressor, as existing methods rely on temperature-based control of the throttle element, which may not accurately reflect the compression process, potentially leading to inefficient energy use and compressor damage from liquid refrigerant ingress.
Innovation Solution
The method involves continuously adjusting the setpoint for the throttle element using both the pressure at the inlet and outlet of the compressor, along with temperature sensors, to precisely control the compression process, thereby optimizing energy consumption and protecting the compressor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature-based control of the throttle element is used, then the control system is simple, but the compression process cannot be accurately reflected leading to inefficient energy use and potential compressor damage
Solution Approach 1:
The patent changes the control parameter from temperature-only to a combination of pressure and temperature measurements. Pressure sensors at the compressor inlet and outlet provide additional parameters that enable accurate determination of compression ratios and detection of liquid refrigerant conditions, resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The control system acts as an intermediary that processes multiple sensor inputs (pressure and temperature) and translates them into appropriate throttle element control signals. This intermediary function integrates the additional pressure measurements without requiring direct complex intervention in the compression process itself.
2Reliability
If pressure sensors are added to improve compression monitoring, then energy consumption can be reduced and compressor protected, but design complexity increases
Solution Approach 1:
The patent implements feedback control where pressure sensor readings from the compressor inlet and outlet are continuously fed back to the control system. This feedback enables real-time monitoring of compression conditions and automatic adjustment of the throttle element to prevent liquid refrigerant damage, improving reliability while managing complexity through automated control.
Solution Approach 2:
The patent replaces purely mechanical or temperature-based control mechanisms with an electronic control system that processes pressure and temperature data. This substitution enables more precise compressor protection through electronic sensing and control, trading mechanical simplicity for electronic intelligence that ultimately provides better protection.
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 allows for a more precise control of the refrigeration cycle, reducing energy consumption and preventing compressor damage by accurately managing the compression process, leading to improved system efficiency and reliability.
Implementation Method 1
the gaseous refrigerant is first compressed by a compressor
Implementation Method 2
In the subsequent heat exchanger, it condenses while releasing heat
Implementation Method 3
The liquid refrigerant is then expanded due to the pressure change via a throttling element
Implementation Method 4
In the downstream second heat exchanger (evaporator), the refrigerant evaporates while absorbing heat at a low temperature
Data Source
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AI summary
A method for operating a refrigeration circuit (K) with at least the following components in succession in the direction of flow of a refrigerant: - a heat-emitting heat exchanger (1), - a throttle element (2), - a heat-absorbing heat exchanger (3), - a compressor (4), whereby the degree of opening of the throttle element (2) is controlled using a set value for a temperature at the outlet of the heat-absorbing heat exchanger (3), is intended to be further improved on the one hand with regard to reducing energy consumption and on the other hand with regard to protecting the compressor during operation. To do this, the setpoint is continuously adjusted during operation based on the pressure at the compressor inlet (4) and based on the pressure at the compressor outlet (4).