A method, system and computer program product for controlling an HVAC system
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Solution Overview
Problem
Existing HVAC systems face complexity and increased costs due to the need for multiple pressure sensors in each parallel zone to maintain differential pressure ranges, leading to inefficient pressure regulation across network sections.
Innovation Solution
A method that uses a single pressure sensor in the zone with the highest fluid resistance to regulate pressure across all zones, combined with a bypass flow regulating device to ensure minimum fluid flow and efficient operation, reducing the number of required sensors and simplifying maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple pressure sensors are installed in each parallel zone to maintain differential pressure ranges, then pressure regulation precision is improved, but device complexity and costs increase
Solution Approach 1:
The patent merges the pressure measurement function from multiple zones into a single measurement point. By installing one pressure sensor in the bypass line and using the known pressure drop characteristics of the bypass flow regulating device, the system infers the differential pressure across all parallel zones without requiring multiple sensors. This combining approach reduces the number of pressure sensors from multiple to just one, resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The bypass flow regulating device serves as an intermediary element that enables indirect pressure measurement. Instead of directly measuring pressure in each parallel zone, the system uses the bypass line as an intermediary path where pressure can be measured once and then used to calculate pressures in all zones based on the regulated flow characteristics. This intermediary approach maintains measurement capability while reducing sensor requirements.
2Reliability
If multiple pressure sensors are installed in each parallel zone, then pressure regulation reliability is improved, but ease of maintenance deteriorates
Solution Approach 1:
The patent combines multiple pressure sensing functions into a single pressure sensor located in the bypass line. This reduction from multiple sensors to one sensor directly improves ease of maintenance, as there is only one device to calibrate, troubleshoot, and replace. The reliability is maintained through the mathematical relationship between the bypass flow regulation and the parallel zone pressures, which provides redundant verification capability without requiring multiple physical sensors.
3Device complexity
If a single pressure sensor is used to regulate pressure across all zones, then device complexity is reduced, but measurement precision may deteriorate
Solution Approach 1:
The system implements a feedback mechanism where the single pressure sensor continuously measures the differential pressure in the bypass line, and this measurement is fed back to the control system. The controller uses this feedback signal to adjust the bypass flow regulating device, which in turn regulates the pressures in all parallel zones. This closed-loop feedback ensures that despite using only one sensor, the pressure regulation precision across all zones is maintained through continuous monitoring and adjustment.
Solution Approach 2:
The bypass line acts as an intermediary that provides a representative sample of the system's pressure conditions. By measuring pressure in this intermediary path and using the known relationship between bypass flow and parallel zone flows, the system achieves accurate pressure knowledge across all zones from a single measurement point, resolving the apparent contradiction between using one sensor and maintaining measurement precision.
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 approach allows for efficient operation of all parallel zones within specified differential pressure ranges while minimizing the number of pressure sensors, reducing complexity and costs, and ensuring stable fluid flow and pressure regulation.
Implementation Method 1
measuring a remote differential pressure in a first zone of the plurality of zones of the one or more network sections
Implementation Method 2
controlling the pressure regulating device to maintain the measured remote differential pressure within a specified differential pressure range
Implementation Method 3
A method that uses a single pressure sensor in the zone with the highest fluid resistance to regulate pressure across all zones, combined with a bypass flow regulating device to ensure minimum fluid flow and efficient operation
Data Source
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AI summary
A method of controlling an HVAC system 1 comprising a fluid transportation network (100) having network section(s) (F, Fa-z), each being connected to a fluid transportation circuit (C, Ca-z) through respective supply line(s) (LS, LSa-z) and return line(s) (LR, LRa-z), each network section (F, Fa-z) comprising a plurality of parallel zones (Z1-n, Za-z.1-n), the method comprising: arranging a pressure regulating device (PR, PRa-z) in the supply line(s) (LS, LSa-z) and/or respective return line(s) (LR, LRa-z) of the network section(s) (F, Fa-z); arranging flow regulating devices (PI1-n, PIa-z1-n) in the zones (Z1-n, Za-z.1-n) of the network sections (Fa-z); measuring a remote differential pressure dpRem, dpRem, a-z of the fluid in a first zone (ZmaxRes, ZmaxRes, a-z) of the plurality of zones (Z1-n, Za-z.1-n) of each of the network sections (F, Fa-z); and controlling, by a controller (20), the pressure regulating device(s) (PR, PRa-z) of each network section (F, Fa-z) to maintain the measured remote differential pressure dpRem, dpRem, a-z within a specified differential pressure range