Refrigerated Truck Chamber Heating via Fan-Speed Temperature Control
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Solution Overview
Problem
Existing heating systems for maintaining positive temperatures in refrigerated enclosures face limitations in autonomy and maximum power, particularly when dealing with extreme temperature differences between the interior and exterior, especially in harsh cold conditions, where battery-powered electrical resistors are insufficient due to high current demands and limited capacity.
Innovation Solution
The proposed solution involves regulating the heating system by controlling the hot air circulation fans and fluid circulation in the heat exchanger, adjusting based on temperature differences and using solenoid valves to manage power input effectively, allowing for efficient heating management in both extreme and temperate cold conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If battery-powered electrical resistors are used for heating, then the system can provide heating power, but the autonomy is limited due to high current demands and limited battery capacity
Solution Approach 1:
The patent replaces the electrical heating system (electrical resistors powered by batteries) with a mechanical heating system using a diesel engine-driven boiler. This substitution eliminates the limitation of battery capacity, providing sustained heating power without being constrained by electrical energy storage, thereby resolving the contradiction between heating power and operational autonomy.
Solution Approach 2:
The patent changes the energy source parameter from electrical (batteries) to mechanical/chemical (diesel engine). This parameter change allows the system to operate continuously as long as fuel is available, dramatically extending operational autonomy while maintaining sufficient heating power through the boiler system.
2Power
If boiler-type heating with fluid circulation is used, then heating power is sufficient, but the system complexity increases due to multiple components (boiler, heat exchanger, circulation system)
Solution Approach 1:
The diesel engine serves multiple functions: it drives the boiler for heating and can also power the circulation fans through the same mechanical power source. This multi-functionality reduces the need for separate power sources and simplifies the overall system architecture, offsetting the complexity introduced by the boiler-heater components.
Solution Approach 2:
The patent merges the heating function (boiler) with the air circulation function (fans) by using a single diesel engine to power both systems. This consolidation reduces the number of independent power sources and control systems needed, thereby managing system complexity while providing sufficient heating power.
3Temperature
If high power heating is applied to maintain temperature in extreme cold, then the setpoint temperature is maintained, but energy consumption increases
Solution Approach 1:
The patent implements dynamic control of the heating system by adjusting fan speeds based on the temperature difference between the cargo hold and outside environment. In moderate cold conditions, lower fan speeds reduce energy consumption while still maintaining the setpoint temperature. In extreme cold, the system can increase power output when needed, optimizing the balance between temperature maintenance and energy consumption.
Solution Approach 2:
The system uses periodic modulation of heating intensity rather than continuous maximum power output. By cycling the heating intensity according to actual temperature needs and using feedback control, the system maintains the setpoint temperature while avoiding unnecessary energy consumption during periods when less heating is required.
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 enhances the autonomy and power regulation of the heating system, ensuring precise temperature control by optimizing fan speed and fluid circulation, thereby extending operational time and reducing energy consumption in maintaining setpoint temperatures.
Implementation Method 1
the burning of fuels, in particular diesel, fuel oil, in a boiler which will heat a fluid
Implementation Method 2
This coolant will then give up its heat through the exchanger which is placed inside the enclosure of the truck which will see its temperature increase
Implementation Method 3
the means carrying out an indirect heat exchange by heat transfer fluid... the cooling circuit of the heat engine of the vehicle... can be recovered and used in a heat exchanger here again placed inside the enclosure
Implementation Method 4
With regard to conduction heating, there is essentially the use of electrical resistors, in various forms
Data Source
Figure 1~2
Figure 3~4
AI summary
A method for transporting heat-sensitive products in a refrigerated truck, where the truck is provided with at least one chamber (1) for storing the products, the truck further comprising a heating system capable of heating the internal air to at least one rooms, heating system which is an air heater type system, where the air to be heated, coming from outside and/or inside the room, is blown, using a fan ( 3) hot air circulation, through a heating heat exchanger (2) located inside the chamber, characterized in that the heating is regulated by acting on the fans for circulating hot air, by ordering, on the basis of the consideration of one or more events, a feedback of stopping the ventilation, or of decreasing the ventilation speed, or of increasing the fan speed, the fan(s) concerned.