System for highly efficient waste heat recovery, thermal storage and demand-based energy supply in internal combustion engines
The spiral heat exchanger system with a heatable liquid storage medium and electric heating unit addresses the inefficiency of waste heat storage in combustion engines, ensuring efficient thermal energy storage and utilization in external systems.
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2026-01-20
- Publication Date
- 2026-04-09
AI Technical Summary
Conventional combustion engines release a significant portion of primary energy as waste heat, which is not efficiently stored for later use, leading to substantial energy losses.
A spiral heat exchanger system positioned at the exhaust manifold extracts thermal energy from exhaust gases, using a heatable liquid storage medium with a variable-speed pump for temperature control, and an integrated electric heating unit for viscosity maintenance and backup energy, enabling efficient storage and use in external systems.
The system effectively stores thermal energy for later use in domestic or industrial heating systems, maintaining operational readiness and efficiency independent of driving conditions.
Smart Images
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Abstract
Description
[0001] Conventional combustion engines (diesel and gasoline engines) have the inherent disadvantage that a significant portion of the primary energy used is released unused into the environment as thermal energy (waste heat) via the exhaust system. Efficient intermediate storage of this energy for later use in external systems has not yet been consistently implemented, resulting in massive energy losses.
[0002] The invention solves this problem with a highly efficient heat exchanger system, preferably positioned at the exhaust manifold. Thermal energy is extracted from the exhaust gas stream by means of a spiral heat exchanger unit (for example, made of copper or highly thermally conductive alloys). This energy is transferred to a highly heatable, liquid storage medium. The medium circulates continuously in a closed loop between the extraction unit and an insulated, pressure-resistant storage tank.
[0003] Thanks to optimized heat absorption, the storage medium reaches temperatures of up to 300 degrees Celsius in a very short operating time. Precise temperature control is achieved via a variable-speed pump (preferably a gear pump). Modulating the flow rate ensures that the medium's temperature is always kept within the optimal operating range, preventing thermal spikes and undercooling.
[0004] According to the invention, the system has an integrated electric heating unit (E-heater). This fulfills a dual protective and support function: • It ensures the necessary viscosity (flowability) of the storage medium, especially during cold winter periods, even before or immediately at system start-up. • It serves as a redundant energy source for short trips or idling when the engine's accumulated waste heat is insufficient to maintain the target temperature level in the storage tank. This ensures the system's operational readiness completely independent of the vehicle's driving profile.
[0005] The high-temperature energy stored in the storage medium can then be used with high efficiency to support domestic or industrial heating systems. For this purpose, the medium is transferred to an external buffer storage tank and fed into the heating circuit in a controlled manner. After the thermal release, the cooled fluid is returned to the vehicle's system for reheating. Reference symbol list 1 Exhaust gas-carrying component 1.1 Center muffler 1.2 Pre-silencer 2. Supply from the tank 2.2 Gear pump 2.3 electric heating unit 3 Return to tank 4 heat exchanger unit 5 air cushions 6 Storage medium 7 storage tank 8 buffer storage (external system) 9 Building heating (external system) 10 Flow to the buffer storage tank 11 Return to vehicle tank