Control apparatus for cooling system
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Solution Overview
Problem
Existing cooling systems for air-conditioning equipment face inefficiencies due to the need for expensive dry and wet-bulb temperature measurement sensors, leading to wasteful power consumption when outside air conditions limit cooling water temperature reduction, especially under low outside air temperatures and high humidity.
Innovation Solution
A control apparatus that uses only a cooling water temperature measurement sensor, incorporating a wet-bulb temperature estimation control unit to reduce the output frequency of the inverter apparatus when it reaches an upper limit, storing an optimal frequency at which the cooling water temperature does not rise, allowing for efficient control of the cooling fan or pump without the need for additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If uniform inlet temperature control or uniform outlet temperature control is implemented using expensive dry and wet-bulb temperature sensors, then the cooling water temperature can be precisely controlled, but the system cost increases and power consumption becomes wasteful when outside air conditions limit cooling effectiveness
Solution Approach 1:
The patent uses a simple cooling water temperature sensor to copy or estimate the effect of expensive dry and wet-bulb temperature sensors. By monitoring cooling water temperature at the inlet or outlet of the cooling tower and using this data to control the cooling fan speed, the system achieves effective temperature control without requiring expensive humidity sensors, thus reducing both cost and unnecessary power consumption.
Solution Approach 2:
The patent replaces expensive, complex dry and wet-bulb temperature sensors with a simple, inexpensive cooling water temperature sensor. This substitution uses a cheaper sensing element that, while simpler, provides sufficient control capability when used with the proposed control method, eliminating the need for costly sensor infrastructure.
2Temperature
If the cooling fan operates at high speed to reduce cooling water temperature, then the cooling effect improves, but power consumption increases significantly when outside air temperature is low or humidity is high
Solution Approach 1:
The patent implements feedback control by continuously monitoring the cooling water temperature (at inlet or outlet) and using this information to adjust the cooling fan speed. The controller compares the actual temperature with the target temperature and adjusts fan operation accordingly, ensuring the fan runs at high speed only when necessary to achieve the desired cooling effect, thereby avoiding wasteful power consumption during conditions where cooling is less effective.
Solution Approach 2:
The patent makes the cooling fan speed dynamic rather than fixed. The fan speed is continuously adjusted based on real-time cooling water temperature measurements and outside air conditions. This dynamic control allows the system to operate at high speed when cooling demand is high and reduce speed or stop when cooling effectiveness is limited by environmental conditions, optimizing energy usage.
3Ease of operation
If the cooling system operates without considering outside air conditions, then the control logic remains simple, but the system cannot adapt to conditions where cooling effectiveness is limited
Solution Approach 1:
The patent enables the cooling system to self-adjust based on cooling water temperature feedback without requiring complex external sensor inputs. The system uses its own operational parameters (cooling water temperature at inlet or outlet) to determine appropriate fan speed adjustments, making the control logic remain relatively simple while improving adaptability to varying outside air conditions through intelligent interpretation of temperature data.
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 achieves optimization control equivalent to using dry and wet-bulb temperature sensors, reducing energy consumption by adjusting the cooling system's operation based on cooling water temperature or differential, even in conditions where a significant cooling effect cannot be achieved, thereby minimizing power wastage.
Implementation Method 1
the cooling tower is commonly an open cooling tower which utilizes the heat of evaporation (latent heat) of water
Implementation Method 2
utilizes the heat of evaporation (latent heat) of water
Data Source
AI summary
A cooling system includes a cooling tower, a refrigeration device, a cooling fan provided in the cooling tower, a cooling water pump which circulates cooling water between the cooling tower and the refrigeration device, an inlet temperature sensor which detects the cooling water temperature at an inlet of the cooling tower, an outlet temperature sensor which detects the cooling water temperature at an outlet of the cooling tower, and an inverter apparatus which variably controls the speed of the cooling fan or the cooling water pump. The output frequency of the inverter apparatus is reduced after the output frequency reaches an upper limit frequency. The inverter apparatus controls the cooling device based on a temperature differential between a temperature of the cooling water at the inlet and a temperature of the cooling water at the outlet.