System for regulating a temperature of a thermal energy carrying fluid in a sector of a fluid distribution network
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Solution Overview
Problem
The challenge is to control the flow in a bypass line for mixing return fluid into the feed line in a heating distribution network, despite uncontrolled disturbances or fluctuations in the pressure difference between the feed line and the return line, while efficiently regulating the temperature in a sector of the fluid distribution network to a stable desired target temperature.
Innovation Solution
A system comprising a bypass line connecting the return line to the feed line, a bypass pump, a control unit that controls the speed of the bypass pump using a combination of closed-loop and feed-forward control, temperature sensors to determine the feed line temperature, and pressure sensors to determine the uncontrolled pressure difference between the feed line and the return line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a pump is used in the bypass line to mix return line fluid into the feed line, then the temperature control is improved, but the system becomes sensitive to uncontrolled pressure fluctuations causing large flow changes
Solution Approach 1:
The patent implements a feedback control mechanism where a pressure sensor measures the pressure difference between feed line and return line, and a control unit adjusts the bypass pump speed accordingly. This closed-loop feedback system compensates for uncontrolled pressure fluctuations, maintaining stable flow through the bypass line despite variations in network pressure conditions.
Solution Approach 2:
The control unit proactively adjusts the bypass pump speed based on measured pressure differences before large temperature deviations occur. By continuously monitoring pressure and pre-adjusting pump speed in response to pressure changes, the system prevents rather than merely reacts to temperature instability.
2Temperature
If a pressure reducing valve is installed in the feed line or return line to control pressure fluctuations, then the temperature stability is improved, but hydraulic losses increase and efficiency decreases
Solution Approach 1:
The patent replaces the mechanical pressure reducing valve with an electrically controlled bypass pump system. Instead of using a valve to mechanically restrict flow and reduce pressure, the system uses an electric motor-driven pump with variable speed control to actively manage pressure differences, eliminating the continuous hydraulic losses associated with valve-based pressure reduction.
Solution Approach 2:
The system dynamically changes the operational parameters of the bypass pump (speed, flow rate) based on real-time pressure measurements. By adjusting pump speed as a variable parameter rather than using a fixed mechanical restriction, the system maintains pressure control while minimizing energy losses and maximizing thermal efficiency.
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
The system effectively stabilizes the feed line temperature by compensating for uncontrolled pressure and temperature fluctuations, ensuring efficient thermal energy distribution while minimizing hydraulic losses and maintaining system efficiency.
Implementation Method 1
a pump is needed in the bypass line or shunt line, because the pressure in the feed line is higher than in the return line
Implementation Method 2
mixing return line fluid back into a feed line supplying the sector with thermal energy carrying fluid
Implementation Method 3
a control unit that controls the speed of the bypass pump based on a combination of a closed-loop control and a feed-forward control
Implementation Method 4
a control unit that controls the speed of the bypass pump based on a combination of a closed-loop control and a feed-forward control
Data Source
AI summary
A system (15) regulates a temperature of fluid in a sector of a fluid distribution network, including a feed line (11) transporting fluid from a thermal energy source (3) to a thermal energy consumer (7) within the sector and a return line (13) transporting fluid back. A bypass line (17) connects the return line to the feed line, mixing fluid from the return line into the feed line. A pump is at the bypass line. A temperature sensor determines a temperature of fluid in the feed line downstream of the bypass line. A pressure sensor determines an uncontrolled pressure difference between the feed line and the return line, or an uncontrolled pressure difference correlated therewith. A control unit controls the speed of the pump with a closed-loop control for achieving a target feed line temperature based on the determined temperature, and a feed-forward control compensating fluctuations of the pressure difference.