Parallel Heat Exchanger Valve Control for Stable Refrigerant Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing refrigeration apparatuses face challenges in rapidly regulating valve openings to maintain optimal refrigerant temperature and flow rates across heat exchangers, leading to fluctuations and inefficiencies in heat energy utilization.
Innovation Solution
A heat source unit with a compressor, multiple heat exchangers, motor-operated valves, and temperature sensors that adjust valve openings based on discharge temperature and refrigerant pressure to maintain stable refrigerant flow and achieve saturation, optimizing heat exchange performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the valve opening is regulated based on the temperature difference of refrigerant at heat exchanger outlets, then the temperature uniformity of outlet refrigerant is improved, but the response speed of valve regulation is insufficient due to considerable temperature fluctuations
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors the temperature difference between refrigerant outlets of parallel heat exchangers and dynamically adjusts the opening degrees of expansion valves accordingly. When the temperature difference exceeds a predetermined threshold, the controller increases the opening of the expansion valve associated with the lower-temperature heat exchanger and decreases the opening of the expansion valve associated with the higher-temperature heat exchanger, creating a closed-loop feedback system that maintains temperature uniformity while enabling rapid response to temperature fluctuations
Solution Approach 2:
The patent employs dynamic adjustment of expansion valve openings based on real-time temperature differential measurements. The controller continuously modifies the opening degrees of expansion valves in response to changing operating conditions, allowing the system to adapt quickly to temperature fluctuations and maintain optimal performance under varying load conditions
2Power
If multiple heat exchangers are connected in parallel with flow-rate-regulating valves, then the heat exchange capacity is improved, but the complexity of valve control system increases
Solution Approach 1:
The patent employs a single controller that performs multiple functions: it monitors temperature differences between heat exchanger outlets, calculates appropriate opening degrees for multiple expansion valves, and executes the control adjustments. This multi-functional controller simplifies the overall system architecture by consolidating control logic into one device rather than requiring separate control mechanisms for each heat exchanger, thereby managing system complexity while maintaining enhanced heat exchange capacity
Solution Approach 2:
The patent combines the control functions for multiple expansion valves into a unified control system. The controller integrates temperature sensing, calculation, and actuation control for all parallel heat exchangers, merging what could have been separate independent control systems into a single coordinated mechanism that manages multiple valves through centralized logic
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 configuration allows for stable regulation of valve openings, ensuring efficient refrigerant flow and heat exchange, reducing temperature fluctuations, and enhancing the performance of both heat exchangers by maintaining refrigerant in a stable gas-liquid two-phase state.
Implementation Method 1
heat energy is consumed in order to cause the liquid refrigerant to be evaporated as latent heat of vaporization
Implementation Method 2
a plurality of heat exchangers mutually connected in parallel
Implementation Method 3
a first temperature sensor configured to measure the temperature of refrigerant flowing to a first outdoor heat exchanger; a second temperature sensor configured to measure the temperature of refrigerant flowing to a second outdoor heat exchanger
Implementation Method 4
a compressor, a first heat exchanger, a second heat exchanger
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a heat source unit capable of demonstrating sufficient capability by stable regulation of the valve opening of motor-operated valves provided in corresponding fashion to each of a plurality of heat exchangers mutually connected in parallel. A first heat exchanger (24) and a second heat exchanger (25) are mutually connected in parallel, and a first heat-source-side flow-rate-regulating valve (26) and a second heat-source-side flow-rate-regulating valve (27) for regulating flow rate are provided on an upstream side when each function as an evaporator. A heat-source-side controller (20) specifies a total valve opening of the first heat-source-side flow-rate-regulating valve (26) and the second heat-source-side flow-rate-regulating valve (27) on the basis of the discharge refrigerant temperature of the compressor (21), and a relationship between the valve opening of the first heat-source-side flow-rate-regulating valve (26) and the valve opening of the second heat-source-side flow-rate-regulating valve (27) is regulated on the basis of the temperature of refrigerant flowing from the first heat-source-side flow-rate-regulating valve (26) toward the first heat exchanger (24), and the temperature of refrigerant flowing from the second heat-source-side flow-rate-regulating valve (27) toward the second heat exchanger (25).