Heat transfer engine

Abstract

The invention provides a method for a thermally activated closed loop heat transfer system, and requires no other external power source other than the heat which it is transferring. The system is based on a two-phase (liquid / vapor) working fluid, with heat input through an evaporator and heat rejected through a condenser. All of the mechanical power produced by an engine, driven by the high vapor quality fluid leaving the evaporator, is consumed by the pump. The pump drives the low vapor quality fluid leaving the condenser back to the evaporator. Nearly isothermal heat transport can be achieved when using a pure or azeotropic working fluid, since the operation only requires the evaporator pressure to be marginally higher than the condensers pressure.

Description

PRIORITY STATEMENT UNDER 35 U.S.C. §119[0001]The present U.S. Patent Application claims priority pursuant to 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61 / 890,656, filed Oct. 14, 2013, in the name of Jeremy Rice, entitled “A TWO-PHASE (LIQUID / VAPOR), CLOSED LOOP HEAT TRANSFER SYSTEM WITH A PASSIVE VAPOR DRIVEN PUMP (VDP),” the disclosure of which is hereby incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]There are several existing closed loop heat transfer technologies, including both passive and active methods. The passive methods are generally limited by heat load, transport distance or orientation, while the active methods require an external power source.[0003]Heat pipes are a passive device relying on two-phase heat transfer (evaporation / condensation). The liquid is pumped by capillarity through a continuous wick, from the condenser, to the evaporator. This device is reversible (i.e., the condenser and evaporator can be switched). The h...

AI Technical Summary

Benefits of technology

The present invention is a heat transfer system that uses a circulating fluid and an engine to transfer heat without the need for an external power source. The system automatically adjusts the fluid flow proportional to the amount of heat being transferred, resulting in highly efficient heat transport. The system can accommodate different heat transport distances and can work against gravity or other body forces, making it flexible for various applications. This invention eliminates the need for a separate power source and reduces the associated external power overhead.

Problems solved by technology

The passive methods are generally limited by heat load, transport distance or orientation, while the active methods require an external power source.

The heat load and distance is most frequently limited by the capillarity of the wick, but can also be limited by the sonic limit, nucleation limit, and entrainment limit.

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