Modular thermal management system for thermal recovery and demand-oriented energy supply

Abstract

Modular thermal management system for thermal recuperation and demand-oriented energy supply, comprising a storage tank (2.0) containing a phase change material (PCM) for latent heat storage, and a heat exchanger for thermal coupling to a heat source of a vehicle, characterized in that • the heat exchanger is designed as a high-temperature heat exchanger for direct placement on an exhaust system, in particular an exhaust manifold, • and that an electric heater (1.5) is integrated into the fluid circuit of the system, which is configured to thermally condition a heat transfer fluid to increase efficiency and ensure flowability.

Description

Technical field

[0001] The invention relates to a device for generating, storing, and providing thermal energy on demand, particularly for use in motor vehicles with internal combustion engines and for stationary heat supply. The system utilizes the thermal energy of the exhaust system to charge a latent heat storage unit. State of the art

[0002] Most existing heat recovery systems in vehicles use the engine coolant as a heat source. This has the disadvantage of a limited temperature range (approximately 90°C), which limits the energy density in the storage system. Other systems that directly interact with the exhaust stream require structural modifications (cutting the exhaust pipe), which can void the vehicle warranty and type approval. Furthermore, the high viscosity of heat transfer fluids at low ambient temperatures makes system startup difficult and reduces efficiency during the start-up phase. Object of the invention

[0003] The invention is based on the objective of providing a heat recovery system that utilizes a high temperature level without compromising the structural integrity and warranty conditions of the vehicle, while simultaneously ensuring high operational reliability and flowability of the heat medium under extreme climatic conditions. Solution to the task

[0004] Solution to the problem: The problem is solved by a system with the features of the main claim. The device comprises a heat exchanger unit (1.4) which is applied externally to a heat source (e.g., exhaust manifold). Thermal energy is transferred to a circulating heat transfer fluid by means of contact heat.

[0005] The core of the invention is the design of the storage tank (2.0) as a multi-circuit system. A separate, integrated intermediate tank is located within the main tank, in which the phase change material (PCM) is stored in a stationary manner. This PCM serves as a thermal buffer, maintaining the temperature of the heat transfer fluid surrounding the intermediate tank at a constant level over a long period by releasing the stored latent heat to the fluid as needed.

[0006] The energy transfer to the external consumer (e.g., a heating system) is materially separate from the PCM: A pump transports only the thermally conditioned (heated) heat transfer fluid from the main tank to the external system. After heat transfer, the cooled fluid is returned to the main tank, where it is thermally recharged through contact with the PCM intermediate tank. This closed-loop heat transfer fluid system ensures that the PCM remains in place and functions solely as a high-density energy storage medium, while the fluid serves as the transport medium.

[0007] To ensure the fluid's flowability at low starting temperatures, an electric heater (1.5) is integrated into the circuit, which reduces the fluid's viscosity before the pumping process.

[0008] Advantages of the invention: The invention offers the following advantages: 1. Warranty preservation: The external mounting of the heat exchanger unit (1.4) allows retrofitting without intervention in the vehicle's hardware. 2. Thermal stability: Due to the separation of PCM (intermediate tank) and heat transfer fluid, the temperature level of the fluid remains stable over long periods of time, as the PCM acts as a buffer. 3. Low maintenance: Since only the heat transfer fluid and not the PCM itself is pumped, wear and blockages in the piping system are avoided. 4. Optimized start-up phase: The integrated electric heater (1.5) ensures the immediate circulation of the fluid even at extremely low temperatures. 5. Systemic flexibility: The cooled fluid from external systems can be efficiently and with minimal loss recharged in the main tank via the PCM in a closed circuit. Reference list Figure 1 1.0 The mobile system 1.1 Gear pump 1.2 Control electronics 1.3 Vehicle battery 1.4 Heat exchanger unit 1.5 Electric heating 2.0 Storage tank 2.1 Connections 2.2 Tank Insulation 3.0 Vehicle heating 4.0 Thermal hose 5.0 The stationary system 5.1 Stationary heating system 5.2 Buffer storage 5.3 Quick coupling 5.4 Safety valves

Claims

[1] Modular thermal management system for thermal recuperation and demand-oriented energy supply, comprising a storage tank (2.0) containing a phase change material (PCM) for latent heat storage, and a heat exchanger for thermal coupling to a vehicle heat source, characterized by , that • the heat exchanger is designed as a high-temperature heat exchanger for direct placement on an exhaust system, in particular an exhaust manifold, • and that an electric heater (1.5) is integrated into the fluid circuit of the system, which is configured to thermally condition a heat transfer fluid to increase efficiency and ensure flowability. [2] System according to claim 1, characterized by, that the electric heater (1.5) is controlled in such a way that it heats the heat transfer fluid to a defined minimum temperature before or during a start-up phase in order to reduce the flow resistance within the system. [3] System according to one of claims 1 or 2, characterized by , that the system has an external quick coupling (5.3) which is designed as a thermal coupling point to a stationary heating system (5.1) in order to release the heat stored in the storage tank (2.0) to a vehicle-external heating network at a later time. [4] System according to any one of the preceding claims, characterized by that the storage tank (2.0) has vacuum insulation or insulation based on, for example, aerogel, which is designed to keep the phase change material charged by exhaust heat above its phase change temperature for a period of at least 24 hours. [5] System according to any one of the preceding claims, characterized by, that a control unit is provided which activates the electric heating depending on a measured outside temperature and / or fluid viscosity in order to prevent solidification of the heat transfer fluid in the area of ​​the heat exchanger surfaces. [6] System according to any one of the preceding claims, characterized by , that the high-temperature heat exchanger is designed as a heat exchanger sleeve, which is configured to be applied externally to an existing exhaust manifold or exhaust system in order to extract thermal energy purely invasively through the wall of the exhaust component without opening or structurally altering the exhaust system. [7] System according to any one of the preceding claims, characterized by, that the heat exchanger sleeve is designed as a non-destructively removable retrofit component, which is fixed by means of temperature-resistant clamping devices, so that the original manufacturer's warranty conditions of the vehicle remain unaffected. [8] System according to one of the preceding claims characterized in that a flexible, metallic heat-conducting medium or a high-temperature thermal paste is arranged between the heat exchanger sleeve and the surface of the exhaust stream to compensate for irregularities in the geometry of the manifold and to minimize the heat transfer resistance. [9] System according to any one of the preceding claims, characterized by , that the electric heating unit is designed as a PTC heating element, which is arranged in the fluid circuit between the storage tank (2.0) and the heat exchanger sleeve in order to selectively reduce the viscosity of the heat transfer fluid before it enters the sleeve. [10] System according to any one of the preceding claims, characterized by , that the storage tank (2.0) has a housing with high-performance insulation designed to buffer the thermal energy obtained through the heat exchanger sleeve with minimal loss for a period of at least 24 hours. [11] System according to any one of the preceding claims, characterized by , that the external quick coupling (5.3) is designed as a leak-free quick coupling which enables media transfer to a stationary heating system (5.1), the system being configured such that the exhaust heat recuperated during driving is released for building heating in the stationary state. [12] System according to any one of the preceding claims, characterized by, that an electrical control electronics (1.2) is provided which, among other things, regulates the electrical heating unit depending on the waste heat available via the heat exchanger sleeve in order to ensure a constant operating temperature of the PCM storage medium. [13] System according to any one of the preceding claims, characterized by , that the heat exchanger sleeve has radiation protection insulation on its side facing away from the exhaust system in order to prevent uncontrolled heat radiation into the engine compartment and to maximize the thermal efficiency of the recuperation. [14] System according to any one of the preceding claims, characterized by that the system includes an integrated bypass mechanism that interrupts or throttles the fluid flow through the heat exchanger sleeve once the phase change material in the storage tank (2.0) has reached its maximum saturation temperature. [15] System according to any one of the preceding claims, characterized by , that the storage tank (2.0) is fluidically connected to an expansion vessel which is configured to accommodate the temperature-related volume change of the heat transfer fluid within the closed circuit in a pressure-compensating manner. [16] System according to any one of the preceding claims, characterized by , that the expansion vessel is located within the thermal insulation of the storage tank (2.0) to prevent premature cooling of the fluid in the expansion vessel and to minimize the thermal inertia of the overall system. [17] System according to claim 15 or 16, characterized by that the expansion vessel includes a pressure-monitored safety valve which allows controlled pressure release when a defined limit pressure is exceeded. [18] System according to any one of the preceding claims, characterized by, that the storage tank (2.0) additionally has an internal compensation space for the phase change material (PCM) in order to accommodate the specific volume expansion of the PCM during the phase transition from solid to liquid without mechanical stress. [19] System according to any one of the preceding claims, characterized by , that the electric heater (1.5) is positioned in relation to the expansion vessel in such a way that circulation of the heated fluid by thermosiphon effect (gravity circulation) is enabled even before activation of a mechanical pump. [20] System according to any one of the preceding claims, characterized by that the system includes a level sensor in the expansion vessel, which is coupled to the control unit to detect leaks in the area of ​​the heat exchanger sleeve or the quick couplings at an early stage and, if necessary, to put the system into a safe state. [21] System according to any one of the preceding claims, characterized by , that the storage tank (2.0) is designed as a multi-circuit system, comprising a main tank for receiving the heat transfer fluid and a materially separated, sealed intermediate tank located inside the main tank, in which the phase change material (PCM) is stored in a stationary manner. [22] System according to claim 21, characterized by , that the intermediate tank is surrounded by the heat transfer fluid in the main tank in such a way that the phase change material (PCM) acts as a thermal buffer, which keeps the temperature of the surrounding fluid at an approximately constant level for a period of at least 12 hours through passive heat transfer. [23] System according to claim 21 or 22, characterized by, that the system is configured so that for external energy supply by means of a pump only the thermally conditioned heat transfer fluid is pumped out of the main tank, while the phase change material (PCM) remains stationary in the intermediate tank. [24] System according to any one of claims 21 to 23, characterized by , that the fluid circuit is designed to return the cooled heat transfer fluid to the main tank after external heat dissipation, with thermal recharging of the fluid occurring through physical contact with the wall of the PCM intermediate tank. [25] System according to any one of the preceding claims, characterized by that the phase change material (PCM) within the intermediate tank is embedded in a matrix of thermally conductive material, in particular in a metal framework or graphite matrix, to increase the thermal conductivity within the storage system and to reduce charging and discharging times.

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