Compressor Brake System Using Backflow for Rapid Mode Transition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing HVAC&R systems face challenges in quickly reducing the rotational speed of the impeller during transitions from active to inactive operating modes, leading to prolonged downtime and inefficiencies, as conventional methods are either time-consuming or costly when implementing additional braking components.
Innovation Solution
The implementation of a braking system that utilizes the flow of working fluid to rapidly reduce the impeller's rotational speed by enabling backflow through the compressor, followed by adjusting pre-rotation vanes and a variable geometry diffuser to block this flow, thereby quickly achieving an idle state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional methods are used to reduce impeller rotational speed during mode transition, then system reliability is maintained, but transition time is prolonged and productivity decreases
Solution Approach 1:
The patent converts the harmful backflow of working fluid through the compressor into a beneficial braking force. By allowing the working fluid to flow backward through the impeller during mode transition, the fluid's kinetic energy creates a counter-torque that rapidly decelerates the impeller from active to inactive mode, transforming what was previously a wasted energy loss into an effective braking mechanism that reduces transition time and improves productivity
Solution Approach 2:
The patent utilizes pneumatic principles by employing the working fluid itself as the braking medium. The controlled backflow of pressurized refrigerant through the compressor impeller creates hydraulic/pneumatic resistance that converts the fluid's momentum into a decelerating force, enabling rapid mode transition without mechanical contact or additional braking components
2Loss of time
If additional braking components are added to reduce transition time, then productivity improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent implements a self-service braking system where the working fluid automatically provides the braking function through its own backflow. The system uses the existing kinetic energy and pressure of the refrigerant to decelerate the impeller without requiring external power sources, control systems, or mechanical braking components. This eliminates additional complexity while achieving rapid mode transition
Solution Approach 2:
The patent makes the working fluid serve multiple functions: it acts as both the working medium for heat transfer and the braking medium for mode transition. The same refrigerant that circulates through the heat exchangers is also used to provide the decelerating force during transitions, eliminating the need for separate braking systems and reducing overall device complexity
3Loss of time
If additional braking components are added to reduce transition time, then productivity improves, but manufacturing cost increases
Solution Approach 1:
The braking function is achieved using the working fluid's own properties without requiring additional manufactured components. The system leverages the existing pressure and flow characteristics of the refrigerant to create the braking effect, eliminating the need for expensive mechanical brakes, electromagnetic motors, or complex control systems that would increase manufacturing costs
Solution Approach 2:
The patent extracts and utilizes the kinetic energy already present in the working fluid flow for the braking function. Instead of adding external braking mechanisms, the system redirects the fluid's own momentum against the impeller rotation, effectively taking out the braking capability from the working fluid itself rather than adding it as a separate system
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 enables the HVAC&R system to transition more quickly to an idle state, reducing downtime and allowing for faster re-initiation of the active operating mode, while avoiding the costs and structural impacts of additional braking components.
Implementation Method 1
A braking system for a compressor in an HVAC&R system may include a controller configured to control operation of the compressor. The compressor may include an impeller configured to rotate in a first rotational direction... During a transition period from the active operating mode to the inactive operating mode, a flow of working fluid through the compressor in a second flow direction may reduce a rotational speed of the impeller in the first rotational direction.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A heating, ventilation, and/or air conditioning (HVAC) system (10) includes a compressor (32) having an impeller (200) configured to rotate and drive a working fluid through a working fluid circuit (152) of the HVAC system (10) in an active operating mode. The HVAC system (10) further includes a controller (154) configured to, in response to receiving an input indicative of a transition to operate in an inactive operating mode, suspend the active operating mode by interrupting a supply of power to the compressor (32), adjust pre-rotation vanes (160) of the compressor (32), a variable geometry diffuser (162) of the compressor (32) to a first position, or both to enable a backflow (213) of the working fluid through the compressor (32) for a first interval of time, and, after the first interval of time has elapsed, adjust the pre-rotation vanes, the variable geometry diffuser (162), or both to a second position to block the backflow (213) of the working fluid through the compressor (32).