DE10042546A1 - Method to convert heat energy/differential into mechanical energy utilizes variations in volume of fluids in the Carnot cycle with hydraulic appliances for energy conversion - Google Patents

Abstract

A fluid system contains hydraulic appliances for pressure separation between hot and cold areas. The variations in volume of the fluid medium are converted into mechanical energy by hydraulic appliances. The fluid is pumped by pumps in a circuit into hot/cold areas, e.g. tank, heat exchanger, and the areas are separated immediately after pumping by hydraulic valves. Volume variations are converted into mechanical energy, and after the fluid has generated a set volume of energy, the cycle begins again. The fluid is constantly pumped between two hydraulic cylinders with piston rods, which are mechanically coupled directly or via levers.

Description

It is known that substances change their volume when the temperature changes. It is also known that with hydraulic devices (pump, cylinder, hydraulic motor, valves ...) mechanical Work can be controlled and carried out, whereby here the power supply usually also mechanical (internal combustion engine, electric motor, hand pump...) he follows.

It is also known that motors / devices have also been invented, which are also included in the work on the thermodynamic effect (e.g. Stirling engine), but so far none favorable power factor could be demonstrated.

The invention is based on a thermodynamic cycle (Carnot process), wherein a liquid is used as the medium, the volume change of which is caused by high Differences in pressure are converted into mechanical energy. In experiments with different liquids worked (e.g. motor oil, petroleum, vegetable oils).

Due to the features / inventions listed in claims 1 to 12 in connection with the above known technology it is possible with the invention to use the energy of any Heat source with existing temperature difference effectively in mechanical energy implement.

Through consistent pressure separation between hot and cold areas by hydraulic Devices is achieved that the steadily increasing / decreasing volume in the warm / Cold areas are mandatory due to the drive unit provided (hydraulic motor, Pump, hydraulic cylinder) is directed, and there performed mechanical work. at Appropriate dimensioning, the pressure-separating device can simultaneously perform submit (e.g. claim 4).

In order to increase the efficiency of the system, the vacuum in the Cold area a liquid (e.g. water) can be evaporated in addition to cooling contribute. The favorable pressure range is several thousand bars, but the prices are still very high for suitable devices. Commercial hydraulic devices work in a pressure range up to approx. 350 bar.

To claim 3 ( Fig. 1) ingredients

1

Heat exchanger with high pressure line for medium (hot area)

2

Heat exchanger with for medium (cooling area)

3

Pump (cold area → warm area)

4

Pump (warm area → cold area)

5

Hydraulic motor (for driving the pumps and for output)

6

mech. Gearbox (for speed adjustment hydraulic motor ↔ pumps)

7

Volume control tank

8th

liquid medium (...)

9

Hydraulic motor in the intake line (option)

conditions

Temperature warm area 60 ° C
Temperature cold area 20 ° C
Expansion factor medium 0.001 / ° C
Mediumvol. Warm area 1000 cc
Mediumvol. Cold area 1000 cc

construction

Both pumps ( 3 + 4 ) are connected so that the pressure side faces the warm area ( 1 ) and the suction side faces the cold area ( 2 ). The pumps are mechanically coupled in such a way that when they are actuated, the same volume of medium is exchanged between the two pressure ranges. The hydraulic motor / working cylinder ( 5 ) is connected between the hot area and the expansion tank. Only one suction line or a second hydraulic motor ( 9 ) can be connected between the expansion tank and the cold area. If a spring or bladder accumulator is used, the pressureless expansion tank ( 7 ) and the second hydraulic motor ( 9 ) can be dispensed with, since this can then take over the function of temperature-dependent total volume compensation.

function

By heating the warm area ( 1 ), the liquid medium ( 8 ) in it expands and pressure builds up. The mechanically coupled pumps ( 3 + 4 ) prevent more medium from flowing from the warm area ( 1 ) into the cold area ( 2 ) than vice versa. The now excess medium can only flow off via the hydraulic motor ( 5 ) and does work by driving it. The hydraulic motor ( 5 ) in turn operates the coupled pumps ( 3 + 4 ), so that cold medium is constantly pumped into the warm area and the same amount of warm medium (which has already done work) is pumped out of this area. The result is a constant volume increase of the medium in the warm area.

Exactly the opposite of the processes described above runs simultaneously in the cold area from.

The operation of the mechanically coupled pumps is quasi depressurized Pumping into the other pressure range, since the forces on the Remove the coupled shafts of the pumps. One of the two pumps works in the "Reverse operation" and must be suitable for this (e.g. gear pump, Hydraulic motor,. , .). It is also important that components with as little as possible Losses (friction, leakage current) are used, on the other hand for possible high pressure / negative pressure are suitable.

The volumes of the warm and cold areas must be large enough to be able to heat / cool the medium long enough during pumping. This in turn depends on how much contact surface to the heat source is available per ccm medium (in tests approx. 3 to 9 / cm (cm ² / cm ³ ) metal surface). This is usually achieved by using the appropriate pipe diameter and length in the heat exchanger ( 1 + 2 ), whereby several spirals can also be connected in parallel to reduce the flow resistance.

The efficiency of the system is decisively influenced by the pressure with where the hot high pressure part (or negative pressure in the cold part) is loaded. This Pressure is proportional to a load attached to the hydraulic motor (Working cylinder).

It is important to place a volume expansion tank (e.g. Spring accumulator or unpressurized expansion tank) to connect, since that Total volume of the liquid medium with the average temperature of the Overall system changes.

Power calculation (warm area)

V1 = pumped volume per second
V2 = volume expansion / second
DT = differential temperature
P = pressure in the warm area (assumption: cold area without pressure)
F1 = expansion factor of the medium per ° C
Pout = output power
Ppump = required pumping power (friction, leakage) (assumption: 50 watts)
Peff = effective system output

(a) V2 = V1. DT. F1

(b) Pout (watts) = 9.8 N. P (bar). V2

(c) Pout (watts) = 9.8 N. P (bar). V1 (ccm / sec). DT (° C). F1

(d) Peff (Watt) = Pout (Watt) - Ppump

example

12 liters of medium are pumped per minute, (200 ccm / sec) results in a volume expansion of (a) 8 ccm / sec (200 ccm / sec. 40. 0.001) at a temperature difference of approx. 40 ° C between warm and cold areas. If a pressure of approx. 300 bar (ideally much more would be expected), mechanical power of (imagine a hydraulic cylinder with A = 1 cm ² , stroke = 8 cm / sec):

(b) Pout = 9.8 N. 300 (bar). 0.08 m / sec = 240 Nm / sec (watt)

(d) Peff = 240 watts - 50 watts = 190 watts

If a second hydraulic motor / working cylinder ( 9 ) is switched into the suction line, the output increases according to the load (negative pressure) in the cold area. It should then be noted that the pumps ( 3 + 4 ) must be designed for the entire pressure difference between the hot and cold areas.

To claim 4 ( Fig. 2)

Claim 4 is largely identical to claim 3 with the following differences: The hydraulic motors / working cylinders ( 5 + 9 ) are omitted, a (adjustable 1: 1.04 +/-) mech. Gearbox / transmission ( 6 ) is placed between the two pumps ( 3 + 4 ).

If the ratio is set correctly, the medium volume increased in the warm area is delivered via the reverse running pump / hydraulic motor, which then drives the other pump. The output power can be taken from one of the pump shafts. At least one volume expansion tank ( 7 ) is required.

To claim 5 ( Fig. 3) Design example

The liquid medium is between a heated and a cooled piston cylinder pumped back and forth, the piston rods being mechanically coupled to pass through lifting forces to separate the two pressure areas from each other. The enlarging Volume in the heating cylinder is forced into a hydraulic motor by the valve system (M1) passed. The negative pressure created in the cooling cylinder by volume reduction sucks in medium through the other hydraulic motor (M2), which means that mechanical Work is done. The pump lever is mechanically coupled from one of the Motors operated.

General, advantages, innovations

The advantage over known systems (internal combustion engines, solar cells ...) is in that on the one hand no combustion of fuels is required (no exhaust gases), on the other hand, any existing heat (e.g. sun, residual heat of all kinds, heat from Internal combustion engines, geothermal energy, combustion heat (e.g. gas)) in mechanical energy can be implemented. The mechanical energy can then either be used directly be (e.g. lifting loads, drives, operating pumps ...) or again in other forms of energy are transformed (e.g. electricity.).

The advantage over thermodynamically working systems with gaseous medium consists in that, on the one hand, a significantly higher pressure difference with liquid medium can be generated, on the other hand, even with relatively small temperature differences (e.g. 40 ° C) can already be worked effectively.

Claims (12)

1. A method for converting thermal energy / heat difference into mechanical energy by thermodynamic cycle (Carnot process), characterized in that hydraulic devices for pressure separation are used in a liquid system between hot and cold areas, the volume change of the liquid medium by hydraulic Equipment is converted into mechanical work. 2. Device and method according to claim 1, characterized in that the Liquid with pump (s) in the circuit in the opposite (hot / cold) preheated area (tank, heat exchanger) are pumped, the areas be separated from each other immediately after pumping by hydraulic valves. The volume change is done by hydraulic devices in mechanical work implemented. After the liquid has done a certain job, it begins Cycle again (etc.). 3. Device and method according to claim 1, characterized in that the Liquid by two suitable pumps, each of which is based on the hot / cold / Cold / hot transition points of a liquid circuit are constantly in the circuit through two different temperature ranges (one heated, one cooled) is pumped, the pumps being mechanically (directly or via gear / Translation) that they function on the one hand as valves have to separate the high pressure and low pressure areas, on the other hand, the quasi-depressurized circulation pumps each in the other pressure range enable. The power output can be via hydraulic motor or working cylinder done, these can simultaneously operate the coupled (circulation) pumps and deliver additional power. 4. The device and method according to claim 3, characterized in that, in contrast to claim 3, the power output is not achieved by a separate working cylinder / hydraulic motor, but in that the two pumps work with different delivery rates per unit of time. This can be achieved in different ways e.g. B .:

• a) The two pumps have different delivery rates due to their design.
• b) the two pumps can have the same delivery rates, but are not mechanically rigid, but connected to one another via an (adjustable) gearbox / transmission.
• c) combinations of (a) and (b).

Note on 3, 4. , , .: one of the two circulation pumps works in reverse, so to speak, and can also be designed as a hydraulic motor. 5. The device and method according to claim 1-4, characterized in that the liquid is constantly pumped back and forth between two hydraulic cylinders, the piston rods of which are mechanically coupled (directly or via levers). The pumping around of the liquid can be carried out by moving the coupled piston rods or by one or more intermediate pumps in the medium circuit. One of the cylinders is heated, the other cooled. One or both chambers (flow / return) of the cylinders can be used. The mechanical performance can be extracted in various ways, e.g. B .:

• a) by the oscillating movement of the cylinders or piston rods, relative to each other
• b) A hydraulic motor or working cylinder is operated via two check valves per fluid system.
• c) with intermediate, suitable pumps on their drive shaft.

6. The method according to claim 1, characterized in that at least two pressurized hydraulic devices are mechanically coupled such that the forces cancel each other for the purpose that liquid medium between different pressure ranges with as little line supply as possible can be. 7. The method according to claim 1, characterized in that at least two pressurized hydraulic devices are mechanically coupled such that the forces do not cancel each other out for the purpose that liquid medium between different pressure ranges can be replaced without external line supply can. 8. The method according to claim 6-7, characterized in that the two devices, if it is a rotating shaft, using a differential gear be coupled, for the purpose that on the central shaft of this transmission Output power can be taken off during the pumping process turn on one of the side shafts of the gearbox, each with a pump is connected, operated. 9. The method according to claim 1-8, characterized in that the Volume change of the liquid medium by hydraulic devices (e.g. pumps, Hydraulic motors) is implemented in rotating motion. 10. The method according to claim 1-9, characterized in that heat exchanger can be used that have several parallel channels, for the purpose that at lower flow resistance a larger contact surface for heat / Cold source exists. 11. The method according to claim 1-10, characterized in that by a system, consisting of four check valves, a pulsating change in volume into one co-flowing hydraulic flow is diverted (example see claim 5). 12. The method according to claim 1-11, characterized in that with the help of Vacuum in the cold area, a liquid is evaporated, thereby cooling to contribute to this area.