Chilled Water Air Handling Control for Partial-Load Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air conditioners face challenges in maintaining optimal chilled water temperature and air temperature control, leading to inefficient operation and inadequate response to varying indoor cooling loads, which can result in super-cooling and over-drying of indoor spaces.
Innovation Solution
An air conditioner system comprising an air handling unit with a fan and heat exchanger, and a chiller with a compressor, condenser, and evaporator, where temperature sensors monitor indoor and supply air temperatures to adjust the chilled water set temperature and compressor capacity, and fan velocity to maintain optimal conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the compressor operates continuously to maintain cooling, then the cooling capacity is sufficient, but the energy consumption increases and the system cannot respond efficiently to partial load conditions
Solution Approach 1:
The patent implements variable frequency drive (VFD) control on the compressor motor, allowing the compressor speed and capacity to dynamically adjust according to actual cooling load requirements. This enables the system to operate efficiently across varying load conditions rather than running at fixed capacity, resolving the contradiction between maintaining sufficient cooling and reducing energy consumption.
Solution Approach 2:
The system changes the operating parameters of the compressor by adjusting its rotation speed through frequency control. By varying the compressor speed parameter, the system can match the cooling output to the actual load requirements, preventing energy waste during partial load operation while ensuring adequate cooling capacity when needed.
2Reliability
If the chilled water temperature is lowered to increase cooling capacity, then the cooling effect improves, but the risk of super-cooling and over-drying the indoor space increases
Solution Approach 1:
The patent employs temperature sensors to monitor both the chilled water temperature and the indoor air temperature, creating a feedback control system. The controller adjusts the chilled water temperature based on real-time indoor conditions, preventing the system from over-cooling or over-drying the space while maintaining adequate cooling effect. This closed-loop control resolves the contradiction between cooling capacity and harmful effects.
Solution Approach 2:
The system dynamically adjusts the chilled water temperature parameter based on actual indoor cooling needs and humidity conditions. By changing this parameter adaptively rather than maintaining a fixed low temperature, the system achieves effective cooling without causing super-cooling or excessive dehumidification.
3Ease of operation
If the air conditioner operates with fixed chilled water temperature, then the system operation is simple, but the system cannot effectively respond to varying indoor cooling loads
Solution Approach 1:
The patent transforms the fixed chilled water temperature system into a dynamic one by implementing variable frequency control on the compressor and pump motors. This allows the system to automatically adapt its cooling capacity to match varying indoor load conditions while maintaining relatively simple operation through automated control, resolving the contradiction between operational simplicity and load adaptability.
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 prevents super-cooling and excessive dehumidification, ensuring efficient cooling and dehumidification with minimal electric consumption by dynamically adjusting chilled water and air temperatures according to indoor conditions.
Implementation Method 1
an evaporator and supplies the chilled water from the evaporator to the heat exchanger
Implementation Method 2
a refrigeration cycle of a refrigerant comprising a compressor, a condenser, an expansion device and an evaporator
Implementation Method 3
a heat exchanger for exchanging the mixed air blowing by the fan with the chilled water
Data Source
AI summary
An air conditioner intakes indoor air and outdoor air, blows it through a heat exchanger, then supplies the conditioned air to an indoor space. In the heat exchanger, water cools the air. A remote refrigeration circuit, also known as a chiller, cools the water. A controller controls the chilled water to stay within a temperature range. When the chilled water exceeds the temperature range, the air conditioning fan is decelerated, thus reducing the amount of heat that the water absorbs from the air. When the desired indoor temperature is less than the actual indoor temperature, then the fan is returned to its maximum velocity.