Turbo Chiller Flow Control for Low-Load Temperature Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat source systems with turbo chillers face challenges in maintaining temperature control when the target heat load is low, as they struggle to adjust coolant temperatures effectively while minimizing the number of operational turbo chillers, which can lead to coolant freezing in heat transfer tubes.
Innovation Solution
A control system for turbo chillers that adjusts the coolant flow rate based on the target heat load and coolant temperatures, allowing for temperature control by setting a target coolant flow rate when the heat load is low, and includes mechanisms to stop the chiller when the flow rate falls below a predetermined threshold to prevent freezing, using evaporation pressure as a backup, and reducing feedback control sensitivity at low flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the target heat load is low and the coolant flow rate is reduced, then the number of operational turbo chillers can be minimized, but the coolant temperature cannot be controlled to the required value and freezing may occur
Solution Approach 1:
The patent implements dynamic control of coolant flow rate based on real-time monitoring of heat load and temperature parameters. The control system continuously adjusts the flow rate to maintain optimal temperature control while adapting to varying operational conditions, preventing freezing even when the number of operational chillers is reduced
Solution Approach 2:
The system changes operational parameters by dynamically adjusting coolant flow rate as a control variable. When heat load decreases, the control unit modifies the flow rate parameter to compensate for reduced cooling capacity, ensuring temperature remains within required ranges and preventing coolant freezing in heat transfer tubes
2Loss of energy
If the coolant flow rate is reduced to match low heat load, then energy consumption is reduced, but temperature control precision deteriorates
Solution Approach 1:
The control unit implements feedback control by continuously monitoring coolant inlet and outlet temperatures, heat load parameters, and flow rate. This feedback mechanism enables precise temperature control by adjusting flow rate based on actual system state, maintaining temperature precision while optimizing energy consumption during low-load operation
Solution Approach 2:
The system dynamically adjusts coolant flow rate based on real-time temperature measurements and heat load conditions. This dynamic control allows the system to maintain precise temperature control at varying flow rates, preventing both overheating and freezing while optimizing energy efficiency across different operational loads
3Productivity
If the number of turbo chillers is increased to handle higher heat load, then the heat load capacity is improved, but the system complexity increases
Solution Approach 1:
The patent implements dynamic control strategies that allow existing chillers to operate efficiently across a wide range of loads through real-time parameter adjustment. This dynamic operation reduces the need for additional chiller units, maintaining heat load capacity while avoiding the complexity of managing larger numbers of chillers and their associated control systems
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
Enables precise temperature adjustment and prevents coolant freezing by dynamically controlling the coolant flow rate and chiller operation, ensuring efficient operation even at low heat loads and protecting the system from freezing hazards.
Implementation Method 1
an evaporator that evaporates the expanded refrigerant and cools a coolant
Implementation Method 2
an evaporator that evaporates the expanded refrigerant and cools a coolant
Implementation Method 3
a condenser that condenses the compressed refrigerant
Data Source
AI summary
A turbo chiller that allows for temperature adjustment even when a target heat load is low is provided. A turbo chiller (11) is equipped with a chiller-side control unit that controls an operation so that a coolant outlet temperature is equal to a desired value. When a target heat load is lower than or equal to a predetermined value, the chiller-side control unit outputs a target coolant flow rate, which satisfies the target heat load, of the coolant on the basis of a current coolant inlet temperature, which is a current temperature of the coolant flowing into an evaporator, and a target coolant outlet temperature, which is a coolant outlet temperature to be targeted.