Reciprocating Compressor Capacity Control With Digital Bypass Valve
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reciprocating compressors in refrigeration and air conditioning systems face challenges with 100% on-off switching, leading to transient operation and high peak loads, which limits control precision and efficiency, especially in applications requiring variable cooling capacity.
Innovation Solution
A reciprocating compressor with an infinitely variable control system using a digitally controllable control valve to regulate delivery capacity from 100% to approximately 10%, allowing for stepless adjustment of refrigerant delivery, integrating suction and high-pressure volumes with a shut-off device to ensure energy-efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If 100% on-off switching is used to control compressor capacity, then the control is simple, but the control precision deteriorates and transient operation occurs
Solution Approach 1:
The invention applies dynamics by making the compressor capacity continuously adjustable rather than fixed at 100% or 0%. The control device enables stepless variation of delivery capacity from 100% down to approximately 10%, allowing the system to adapt dynamically to varying cooling demands and avoid transient operation while maintaining simple control through digital signals.
Solution Approach 2:
The invention changes the parameter of compressor delivery capacity from a binary state (on/off) to a continuously variable parameter. By digitally controlling the degree of opening of the high-pressure volume connection, the system achieves precise control of refrigerant delivery across a wide range, transforming the control mechanism from simple switching to precise parameter adjustment.
2Device complexity
If 100% on-off switching is used, then the device complexity is low, but peak loads increase during switching
Solution Approach 1:
The system uses dynamic capacity adjustment to gradually change compressor output rather than abrupt on-off switching. This dynamic control eliminates peak loads during capacity changes while maintaining relatively simple device complexity through digital control signals and a controllable valve mechanism.
Solution Approach 2:
The invention introduces an intermediary control mechanism (controllable valve regulating high-pressure volume connection) between the binary on-off states. This intermediary enables gradual transition and smooth capacity adjustment, preventing peak loads while keeping the overall control system relatively simple through digital actuation.
3Productivity
If stroke-controlled axial piston compressors are used to compensate for speed variations, then delivery capacity can be regulated, but the design is limited to passenger cars with limited service life
Solution Approach 1:
The invention creates a universal compressor control system that can be applied across multiple vehicle types and applications. By using a digitally controlled valve mechanism rather than stroke control limited to axial piston compressors, the system achieves delivery capacity regulation applicable to reciprocating compressors in commercial vehicles, passenger cars, and various refrigeration applications, significantly expanding adaptability.
Solution Approach 2:
The invention replaces the mechanical stroke control mechanism (limited to axial piston compressors) with a digitally controlled valve system. This substitution enables delivery capacity regulation in reciprocating compressors with higher service life requirements, allowing the technology to be universally applied in commercial vehicles and stationary refrigeration systems beyond the limited passenger car application.
4Productivity
If cylinder banks are shut off to regulate capacity in 50% steps, then some control is achieved, but control quality remains insufficient
Solution Approach 1:
The invention transitions from static 50% capacity steps (cylinder bank on/off) to dynamic continuous capacity adjustment. The controllable valve enables smooth, stepless variation of delivery capacity from 100% to approximately 10%, achieving high control quality while maintaining simple digital control implementation.
Solution Approach 2:
The invention changes the control parameter from discrete 50% capacity steps to continuous variable capacity control. By digitally controlling the degree of opening of the high-pressure volume connection, the system achieves precise capacity regulation in any intermediate value between 10% and 100%, dramatically improving control quality over binary cylinder bank switching.
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 provides enhanced control quality and energy efficiency by enabling precise regulation of refrigerant delivery, reducing peak loads and allowing for finer control of cooling capacity, suitable for various applications including bus air conditioning and transport refrigeration.
Implementation Method 1
a connection (26) being formed between the at least one suction gas volume (22) and the at least one high-pressure volume (24) of the refrigeration system, with the digitally controllable control valve (16) being arranged in the connection (26)
Implementation Method 2
The reciprocating compressor (10) has a shut-off device (28), in particular a non-return valve, which, viewed in a flow direction of the refrigerant during normal operation of the compressor, is arranged downstream of the one/one associated high-pressure volume (24)
Implementation Method 3
a reciprocating piston compressor (10), in particular a V-compressor with two cylinder banks (40), arranged in a V-design
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a reciprocating-piston compressor (10), comprising a control device (12), which control device is designed to control a flow rate of the reciprocating-piston compressor (10), in particular in a continuously variable manner, and which control device has an input (18) for feeding input information, in particular suction pressure or high pressure of a corresponding compressor (10), and has at least one output (20) for controlling a control element (16), wherein the control device (12) is designed to generate a digital output signal, wherein the control element has a digitally controllable control valve (16), wherein the reciprocating-piston compressor (10) has at least one suction-gas volume (22) and at least one high-pressure volume (24), wherein a connection (26) is formed between the at least one suction-gas volume (22) and the at least one high-pressure volume (24) of the reciprocating-piston compressor (10), wherein the digitally controllable control valve (16) is arranged in the connection (26), wherein the reciprocating-piston compressor (10) has a shut-off device, in particular a valve, further in particular a check valve (28), which is arranged downstream of the high-pressure volume (24), as regarded in a flow direction of the refrigerant during normal operation of the reciprocating-piston compressor (10), wherein the at least one suction-gas volume and the at least one high-pressure volume and the control valve (16) are integrated into the reciprocating-piston compressor (10). The invention further relates to a refrigerating or air-conditioning installation or heat pump having a corresponding compressor (10), and to a corresponding control method.