Methods and systems for using mean kinetic temperature to control a transport climate control system
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Solution Overview
Problem
Existing transport climate control systems face challenges in maintaining stable and safe temperatures for cargo products, such as pharmaceuticals and fruits, due to temperature fluctuations and limited battery capacity in electrified systems, which can lead to inefficient energy use and compromised product quality.
Innovation Solution
The implementation of a transport climate control system that uses a mean kinetic temperature (MKT) setpoint to control the compressor and fans, allowing for optimized energy use by adjusting the cooling and heating capacity based on the difference between the MKT setpoint and the actual MKT in the climate-controlled space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermostatic control based on temperature setpoint is used, then the system is simple to operate, but the cumulative thermal stress on cargo products cannot be effectively controlled
Solution Approach 1:
The patent changes the control parameter from simple temperature to mean kinetic temperature (MKT), which is calculated based on temperature measurements over time. This parameter transformation allows the system to account for cumulative thermal stress while maintaining a relatively simple control architecture. The MKT calculation integrates temperature data chronologically, providing a more comprehensive quality metric without requiring complex control logic.
Solution Approach 2:
The patent introduces MKT as an intermediary parameter between raw temperature measurements and control decisions. Instead of directly controlling temperature or quality, the system uses MKT as a mediator that captures the cumulative effect of temperature fluctuations on cargo quality. This intermediary enables more informed control decisions while keeping the overall system structure manageable.
2Reliability
If cooling capacity is continuously increased to maintain temperature stability, then cargo product quality is improved, but energy consumption increases
Solution Approach 1:
The patent applies partial action by using MKT to determine when and how much cooling is needed. Instead of continuously applying maximum cooling capacity, the system adjusts cooling intensity based on the calculated MKT and its rate of change. This allows the system to apply just enough cooling to maintain quality standards, avoiding excessive energy consumption while still protecting cargo quality.
Solution Approach 2:
The patent implements dynamic control by continuously calculating MKT from time-series temperature data and adjusting cooling capacity accordingly. The control system responds to the rate of change of MKT, increasing cooling when MKT rises too quickly and reducing cooling when MKT is stable. This dynamic adjustment optimizes the balance between maintaining cargo quality and minimizing energy consumption.
3Use of energy by stationary object
If battery capacity is increased to ensure sufficient power for climate control, then energy availability is improved, but system cost and weight increase
Solution Approach 1:
The patent applies preliminary action by using MKT to predict future energy requirements. By continuously monitoring MKT and its trajectory, the system can anticipate when energy will be needed and prepare accordingly. This allows for more efficient battery utilization, ensuring sufficient power availability for climate control without requiring excessive battery capacity, thereby reducing weight and cost.
4Stability of the object's composition
If temperature fluctuations are reduced to maintain cargo quality, then product stability is improved, but system complexity and energy use increase
Solution Approach 1:
The patent implements feedback control by continuously calculating MKT from temperature measurements and using this information to adjust cooling capacity. The MKT serves as a feedback parameter that reflects the cumulative effect of temperature fluctuations on cargo quality. By feedbacking on MKT rather than instantaneous temperature, the system achieves better product stability with a relatively simple control structure that integrates temperature history into its decision-making process.
Data Source
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AI summary
Methods and systems for operating a transport climate control system (100) providing climate control within a climate controlled space (106) of a transport unit (105), the method including setting a mean kinetic temperature setpoint to control a compressor (210) and/or fans in the transport climate control system (100) and determining a mean kinetic temperature in the climate controlled space (106). The method further includes regulating the mean kinetic temperature in the climate controlled space (106) while optimizing the energy spent by adjusting the cooling and/or heating capacity of the system (100).