Recirculation Pump Control via ORP and Chlorine Sensors
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Solution Overview
Problem
Current pool and spa recirculation systems face challenges in efficiently managing chlorine levels and energy consumption, leading to suboptimal water quality and increased operational costs due to oversized pumps and simple on/off control modes.
Innovation Solution
A controller system that uses oxidation-reduction potential (ORP) and free chlorine sensors to calculate a quality factor, adjusting the recirculation rate and disinfectant levels continuously, employing a variable frequency drive for the recirculation pump to maintain optimal chlorine and ORP levels within predetermined thresholds, thereby optimizing energy use and chemical consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If simple on/off control modes are used with oversized pumps, then device complexity is reduced, but energy consumption increases and service life is shortened
Solution Approach 1:
The patent applies dynamics by transitioning from static on/off pump control to dynamic variable speed control. The recirculation pump's speed is continuously adjusted based on real-time water quality parameters (chlorine concentration, ORP, temperature, bather load) to match actual disinfection needs, thereby reducing energy consumption while extending pump service life through softer startup and operation at optimal points.
Solution Approach 2:
The control system implements feedback by continuously monitoring water quality parameters (free chlorine, ORP, temperature, combined chlorine) and using this information to adjust pump speed and chemical dosing. This closed-loop feedback enables the system to respond to changing conditions and optimize energy usage while maintaining water quality standards.
2Ease of operation
If fixed chlorine dosing is applied, then ease of operation is improved, but loss of substance increases due to oversupply
Solution Approach 1:
The system transitions from fixed static dosing to dynamic adjustable dosing. Chemical injection rates are continuously modified based on real-time measurements of chlorine demand, ORP, and water quality parameters, allowing the system to supply only the necessary amount of chemicals rather than fixed oversupply, thereby reducing chemical waste and loss.
Solution Approach 2:
The control system changes dosing parameters (chemical concentration, injection rate, timing) based on measured water quality conditions. By adjusting these parameters dynamically according to actual demand, the system avoids fixed oversupply and reduces chemical loss while maintaining effective disinfection.
3Reliability
If recirculation rate is constantly high, then water quality is maintained, but energy consumption increases
Solution Approach 1:
The recirculation pump operates dynamically with variable speed rather than constant high speed. The pump rate is adjusted in real-time based on water quality parameters, allowing the system to maintain adequate water quality while consuming less energy by reducing circulation when full recirculation is not necessary.
Solution Approach 2:
The system changes the recirculation flow rate parameter based on measured water quality conditions. By adjusting this parameter dynamically, the system optimizes the balance between maintaining water quality (through sufficient circulation) and reducing energy consumption (by lowering circulation rates when appropriate).
4Reliability
If maximum disinfectant levels are maintained, then reliability of disinfection is improved, but harmful factors increase due to combined chlorine formation
Solution Approach 1:
The control system uses feedback from multiple sensors (free chlorine, ORP, combined chlorine, temperature) to adjust disinfectant dosing in real-time. This prevents excessive chlorine accumulation that leads to combined chlorine formation, while maintaining sufficient free chlorine levels for effective disinfection, thereby reducing skin and eye irritation.
Solution Approach 2:
The system dynamically changes disinfectant dosing parameters based on water quality measurements and environmental conditions (temperature, bather load). By adjusting these parameters to match actual conditions, the system maintains effective disinfection while avoiding excessive chlorine levels that cause combined chlorine formation and associated irritation.
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 ensures consistent high water quality, reduces energy and chemical usage, extends the service life of the recirculation pump, and provides a cost-effective, flexible control system that adapts to changing water conditions.
Implementation Method 1
control the chlorine concentration based on an oxidation-reduction potential (ORP) set point to a certain defined range. Oxidizers cause the millivolt value to increase and therefore increase disinfection.
Implementation Method 2
receiving a plurality of measurement signals of at least one water property sensor, determining at least one characteristic value based on the measurement signals from at least one oxidation-reduction potential sensor and at least one free chlorine sensor
Implementation Method 3
employing a variable frequency drive for the recirculation pump to maintain optimal chlorine and ORP levels within predetermined thresholds, thereby optimizing energy use and chemical consumption
Implementation Method 4
A controller system that uses oxidation-reduction potential (ORP) and free chlorine sensors to calculate a quality factor, adjusting the recirculation rate and disinfectant levels continuously
Data Source
AI summary
The present invention relates to a method and system for controlling disinfection in recirculating water systems and a method for retrofitting a recirculation system.