Two-stage compression centrifugal unit and middle air supplementing control method therefor, and heating and ventilation device
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Solution Overview
Problem
The control of gaseous refrigerant supplement amount in two-stage compression centrifugal units is not precise, leading to inefficiencies and risks of liquid carryover, especially under varying operating conditions, affecting energy efficiency and reliable operation.
Innovation Solution
A two-stage compression centrifugal unit with a gaseous refrigerant supplementing valve and a calculation module that adjusts the valve's opening degree based on real-time operating parameters to maintain the gaseous refrigerant supplement amount within an optimal range, using formulas to calculate actual and optimal amounts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If no valve is added to the gaseous refrigerant supplementing pipeline, then the device complexity is low, but the manufacturing precision of gaseous refrigerant supplement amount is poor
Solution Approach 1:
The patent applies parameter changes by introducing a gaseous refrigerant supplementing valve that dynamically adjusts the supplement amount based on operating conditions. The valve modifies the flow parameter of refrigerant from the economizer to the suction port, enabling precise control of the gaseous refrigerant supplement amount rather than relying on fixed pipeline dimensions.
2Reliability
If rough control is implemented to prevent liquid carryover, then the reliability is improved, but the manufacturing precision of gaseous refrigerant supplement amount is poor
Solution Approach 1:
The patent implements feedback control through a control module that receives operating parameters (evaporator temperature, condenser temperature, compressor speed) and adjusts the gaseous refrigerant supplementing valve accordingly. This closed-loop feedback system ensures both reliability by preventing liquid carryover and precision by optimizing the supplement amount based on real-time conditions.
Solution Approach 2:
The patent applies dynamics by making the gaseous refrigerant supplementing valve adjustable rather than fixed. The valve opening degree dynamically changes with operating conditions such as load variations, enabling the system to maintain optimal performance across different operating ranges rather than relying on rough static control.
3Device complexity
If the gaseous refrigerant supplement amount is not adjusted, then the device complexity is low, but the adaptability to varying operating conditions is poor
Solution Approach 1:
The patent makes the gaseous refrigerant supplement amount dynamic through the adjustable valve and control module. The system adapts to varying operating conditions including different loads, dual operating conditions (ice reserving and air conditioning, air conditioning and heat recovering), and changes in pressure ratio, water outflow temperature, and subcooling degree.
Solution Approach 2:
The control module changes the supplement amount parameter based on operating conditions. By calculating the optimal gaseous refrigerant supplement amount using evaporator temperature, condenser temperature, and compressor speed, the system adjusts the valve opening to maintain optimal performance across diverse operating scenarios.
4Manufacturing precision
If precise adjustment of gaseous refrigerant supplement amount is implemented, then the manufacturing precision is improved, but the device complexity increases
Solution Approach 1:
The patent introduces a gaseous refrigerant supplementing valve as an intermediary device between the economizer and the suction port. This intermediary component enables precise control of the refrigerant flow without fundamentally altering the main system architecture, achieving precision while managing complexity through a dedicated control element.
Data Source
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AI summary
A two-stage compression centrifugal unit. The two-stage compression centrifugal unit comprises: a two-stage centrifugal compressor; an evaporator and a condenser, a first-stage air suction port of the two-stage centrifugal compressor being connected to an air outlet of the evaporator, and a second-stage discharge port of the two-stage centrifugal compressor being connected to an air inlet of the condenser; an economizer and an air supplement valve, the economizer being connected between an air inlet of the evaporator and an air outlet of the condenser, and the economizer being connected to a first-stage discharge port and a second-stage air suction port of the two-stage centrifugal compressor by means of the air supplement valve; and a calculation module, the calculation module calculating, according to operation parameters of the two-stage compression centrifugal unit, an actual air supplement amount and an optimal air supplement amount so as to adjust an opening degree of the air supplement valve. The actual air supplement amount of the adjusted air supplement valve is within the optimal air supplement amount interval.