CN103470399A - Volumetric heat engine - Google Patents

Abstract

The invention relates to a volumetric heat engine which has the advantages of high efficiency, simple structure, miniaturization and the like. According to the volumetric heat engine, the method for improving the efficiency of heat engines is theoretically discovered, and a specific embodiment is provided; the embodiment is that the structure of a volumetric compressor is used for completing the expansion compressing procedure of a heat engine and outputting power outwardly; the volumetric heat engine disclosed by the invention is widely used, and can be used in the important fields such as vehicles and solar energy.

Description

The positive displacement heat engine

Technical field

The present invention relates to a kind of heat engine.

Background technique

In current prior art, what approach Carnot Engine most has been exactly Stirling engine, and its structure is reciprocating piston type.Main feature is to use the various energy, no matter be liquid, gaseous state or solid-state fuel, when adopting heat-carrying system (as heat pipe) indirect heating, almost can use any high temperature heat source, and motor itself (except heater) does not need to do any change.Heat engine actual cycle efficiency is higher, has approached diesel engine, and in exhaust, harmful components are less, and noise is lower.Because fuel is continuous burning under the more excess air, heat engine is without valve mechanism, and without knocking fuel, the vibration that operates steadily is little.But also exist the higher gas seal technology of manufacture cost more difficult, reliability and the life-span of Sealing also have problems, and the power adjustments control system is more complicated, the shortcomings such as machine is comparatively heavy, thereby do not obtain extensive use, and particularly be difficult to miniaturization, placed restrictions on its application area.Widely used steam turbine also is difficult to miniaturization because of various reasons.

Summary of the invention

Purpose of the present invention is exactly the heat engine that a kind of high efficiency simple in structure and energy miniaturization will be provided.

As everyone knows, Carnot's cycle has pointed out to improve the reliable approach of efficiency of heat engine in theory, and the basis of having established thus the second law of thermodynamics.The efficiency of Carnot's cycle is:

$\mathrm{\η}=1-\frac{T_2}{T_1}$

Carnot's cycle is simultaneously pointed out: the efficiency of Carnot's cycle is only relevant with the temperature of high and low temperature thermal source, and irrelevant with gas property.The approach of raising the efficiency is the temperature that improves the temperature of high temperature heat source or reduce low-temperature heat source.And usually, a kind of way is uneconomic.This is the classical formulation of textbook, and being in fact has economic method to reduce the temperature of low-temperature heat source, and that allows gas fully expand exactly, and method is to increase the adiabatic expansion volume, thereby the temperature that has so both reduced low-temperature heat source has also improved the efficiency of heat engine.Prove as follows:

The Kano direct circulation is comprised of gas isothermal expansion, gas adiabatic expansion, gas isothermal compression, gas adiabatic compression four processes.

The gas adiabatic expansion, volume is from V ₂expand into V ₃, do to external world positive work, temperature is from T ₁be down to T ₂:

$T_1{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="201310440062X1000031.png,HSA0000095506110000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_2^{\mathrm{\&gamma;}-1}=T_2{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="201310440062X1000031.png,HSA0000095506110000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_3^{\mathrm{\&gamma;}-1}$

$\frac{T_2}{T_1}=\frac{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="201310440062X1000031.png,HSA0000095506110000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_2^{\mathrm{\&gamma;}-1}}{{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="201310440062X1000031.png,HSA0000095506110000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_3^{\mathrm{\&gamma;}-1}}{\left(\frac{V_2}{V_3}\right)}^{\mathrm{\&gamma;}-1}$

Will $\frac{T_2}{T_1}={\left(\frac{V_2}{V_3}\right)}^{\mathrm{\&gamma;}-1}$ The substitution formula $\mathrm{\&eta;}=1-\frac{T_2}{T_1}$ Can obtain:

$\mathrm{\&eta;}=1-{\left(\frac{V_2}{V_2}\right)}^{\mathrm{\&gamma;}-1}$

If the volume V after the gas adiabatic expansion ³the volume V after isothermal expansion ₃n be doubly V ₃=nV ₃, efficiency is exactly:

$\mathrm{\&eta;}=1-{\left(\frac{1}{n}\right)}^{\mathrm{\&gamma;}-1}$

N gets a series of different values just can calculate corresponding efficiency, the theoretical value of perfect gas for γ here, and following table is some result of calculations:

Efficiency in table means with percentage, and the n value is more greatly that the larger efficiency of the volume of adiabatic expansion is just higher, and n equals 8 o'clock its efficiency and substantially surpassed all existing power plant.Certainly be not that the volume of adiabatic expansion is larger just better, but will consider the factors such as maximum pressure, temperature and device fabrication difficulty that thermal source size gas can reach, make optimal selection.The abundant expansion that also shows gas is the key point that improves efficiency of heat engine simultaneously.

This adequately expanded heat engine of gas that can make is easy to Design and manufacture, because the Carnot Engine circulation is to consist of two expansions and two compressions, show that the requirement to equipment will have the sealed cavity of variable volume to carry out this cyclic process exactly, when becoming, the sealed cavity volume can realize the expansion of gas greatly, when diminishing, the sealed cavity volume can be compressed gas, the structure of general positive displacement compressor just in time can meet this requirement, volume-diminished when during its air inlet, volume becomes large its compression.Therefore simply with a positive displacement compressor mechanism or two positive displacement compressor mechanisms series windings, just can form a heat engine of the present invention, for narrating conveniently back, positive displacement compressor mechanism referred to as positive displacement machine.Because positive displacement compressor has various structures, thereby the machine also can have the as many structure of co-content formula compressor.And be named the positive displacement heat engine, this volume type heating function easier realizes, and has the simple efficient little advantage of volume.The concrete practice is referring to embodiments of the invention.

The accompanying drawing explanation

Below in conjunction with accompanying drawing and specific embodiments, be described in further detail.

Fig. 1 is the structural representation of the machine (reciprocating piston type), Fig. 2 is for introducing the schematic diagram of the machine (reciprocating piston type) working principle, Fig. 3 is the p-V figure of the machine (reciprocating piston type), Fig. 4 is the machine (reciprocating piston type) twin-tub series connection schematic diagram, Fig. 5 is the structural representation of the machine (rolling rotor-type), Fig. 6 is the fundamental diagram of the machine (rolling rotor-type), and Fig. 7 is the machine (rolling rotor-type) twin-tub series connection schematic diagram.

Embodiment

As shown in Figure 1, the machine (single cylinder reciprocating piston type) body is comprised of cylinder block 7 and crankcase 9 and cylinder cap 4, piston 6 is housed in cylinder block, bent axle 11 is housed in crankcase, by connecting rod 8, crankshaft and piston is coupled together, suction tude 2 afterbodys are equipped with suction valve 10, and one-way valve 5 is equipped with in muffler 3 ends, cylinder is connected with gas tank 1 by the advancing of its top, muffler, and thermal source 12 can carry out continuous heating to the gas in gas tank.When gas is heated to the temperature, pressure of setting, unlatching suction valve gas enters cylinder promotion piston and moves downward, transmission by connecting rod, bent axle, piston is done upper and lower to-and-fro motion in cylinder, and under the cooperation of suction valve and one-way valve, the inflate compression process that continuously completes gas is simultaneously by the external outputting power of bent axle, supposes large many of the volume ratio volume of cylinder of gas tank here, thereby can ignore the impact of the variation of volume of cylinder on gas pressure in system.

The working principle of the machine is described below in conjunction with Fig. 2, and the work cycle of the machine can be divided into Four processes as shown in Figure 2:

1. gas isothermal expansion

When piston during in position, the top 1-1 (top dead center), open suction valve, enter cylinder from gas tank and the gas that is heated to certain temperature and pressure from suction tude, gas expands and promotes piston and move downward in cylinder, and gas is to the piston acting and absorb heat from thermal source, when piston runs to 2-2, suction valve cuts out, gas pressure during cylinder drops to 2-2 from 1-1 slightly descends, and temperature remains unchanged, and this process is called to isothermal expansion.

2. gas adiabatic expansion

After suction valve cuts out, the gas be closed in cylinder continues to expand, and piston is done work, promote descent of piston to 3-3 (lower dead center), gas temperature descends, due to gas and isolation and piston descending fast, the process that cylinder drops to 3-3 from 2-2 is called adiabatic expansion.

3. gas isothermal compression

After piston arrives 3-3 (lower dead center), under the effect of inertia of piston crankshaft connecting rod mechanism, piston moves up to 4-4, piston compression gas to air work, and gas pressure raises and externally heat release, and this process is called the gas isothermal compression.

4. the isobaric compression of gas

When piston movement arrives the 4-4 position, now gas pressure is a little more than the pressure of gas in muffler, one-way valve is opened, gas is pressed into muffler, this process gas pressure is substantially constant, piston is to air work, and when piston is got back to the 1-1 position, a circulation finishes, and piston rises to 1-1 position process from the 4-4 position is called the isobaric compression of gas.

After completing above-mentioned Four processes, piston is got back to top dead center, and INO starts again the next round work cycle, thereby can continuously convert the heat energy of thermal source to mechanical energy.

Want to obtain higher efficiency according to the calculating of front, the ratio of the volume of the volume after adiabatic expansion after to isothermal expansion is the bigger the better, and in the machine, namely piston total kilometres and piston are from the ratio of 1-1 to 2-2 stroke, and this ratio at least will be more than 2.

Fig. 3 is the p-V figure of gas circulation in the machine cylinder, along 1-1 → 2-2 → 3-3 → 4-4 → 1-1, within such one week, completes a circulation.The positive work that gas is externally done in whole circulation equals the area that 2-2,3-3,4-4 surround.The p-V figure that can find out this figure and Carnot's cycle has any different, and this is because actual heat engine can not be in strict conformity with Carnot's cycle, as long as substantially meet.

The machine of single cylinder has limitation in actual applications, and the machine also can be made the twin-tub cascaded structure.Fig. 4 is the schematic diagram of the machine twin-tub, actual arrangement is twin-tub common crankshaft and crankcase, two crank phases differ 180 ° with guarantee one, piston in two cylinders top dead center another just in lower dead center, varying in size of two cylinders, the volume of vat is at least more than 2 times of little cylinder volume, connect two cylinders with a transfer pipeline 14, connecting tube one end is equipped with valve 13.

The machine twin-tub is work like this: little cylinder piston moves to from top dead center the isothermal expansion that lower dead center completes gas; And when little cylinder piston moves upward from lower dead center Open valve 13, the vat piston moves downward from top dead center simultaneously, gas flows to vat by transfer pipeline 14, this process gas volume is expanding, therefore work as the vat piston and move to from top dead center the adiabatic expansion that lower dead center has just completed gas, gas is also just transferred to vat from little cylinder fully, and now throttle down 13; And work as the vat piston, from lower dead center, move upward again, gas is compressed, when cylinder pressure slightly surpasses the pressure of gas in muffler, one-way valve is opened, gas is pressed into muffler, until vat piston arrives top dead center, this process has been equivalent to isothermal compression and the isobaric compression process of gas.

If the twin-tub acc power can not meet the demands, a plurality of twin-tub machine combinations can be used.

Fig. 5 is the machine (rolling rotor-type) main structure schematic diagram, and the machine mainly is comprised of cylinder 21, rolling rotor 22, bent axle 23, slide plate 24, spring 25 and both sides end cap, also comprises gas tank, suction tude, suction valve, muffler, one-way valve.Rolling rotor is contained on bent axle, and rotor rolls along cylinder inner wall, and forms a meniscate active chamber between cylinder, and its two ends by the cylinder cap seal, forms the active chamber of the machine.Slide plate makes its end and rotor close contact by the active force of spring, and meniscate active chamber is divided into to two-part, and the part linked with suction tude is called expansion chamber, and opposite side is called compression chamber.Slide plate is reciprocating along vane slot with the rolling of rotor.The machine is work like this, when the rolling rotor inhour turns over the suction tude mouth, the pressurized gas that the unlatching suction valve has been heated by thermal source enter expansion chamber, the rotation of drive rotor inhour, forward certain position to, closes suction valve, this process is exactly isothermal expansion, suppose that the volume that now gas is full of is a, and the maximum volume of cylinder is b, b is at least than a large 2 times.After suction valve cuts out, the gas that enters cylinder continues to expand, and drive rotor rotates, and this process is called adiabatic expansion, until gas expansion, to the maximum volume of cylinder, expands and finishes.Rotor is rotated further under the effect of inertia, and the gas in cylinder is compressed, when compressed gas pressure a little more than muffler in during gas pressure, one-way valve is opened, gas is pressed into muffler, is rotated further until gas all is pressed into muffler, and this process is exactly isothermal compression and isobaric compression.This Four processes of the machine successively carries out, thereby can to continue thermal power transfer be mechanical energy.

Fig. 6 has chosen five diverse locations of the machine (rolling rotor-type) rotor its fundamental diagram has been described.

The machine (rolling rotor-type) also can be as reciprocating piston type the work that is together in series of two cylinders, Fig. 7 is the schematic diagram of the machine (rolling rotor-type) twin-tub, actual arrangement is that twin-tub shares a bent axle, two rotor phases are identical, two cylinders must small one and large one, the left cylinder of Fig. 7 is little cylinder, right cylinder is vat, the vat maximum volume is more than 2 times of little cylinder maximum volume, suction tude connects the expansion chamber of little cylinder, muffler connects the compression chamber of vat, between the compression chamber of little cylinder and the expansion chamber of vat, with a transfer pipeline, connects.

The machine (rolling rotor-type) twin-tub is work like this: little cylinder expansion chamber completes the gas isothermal expansion, little cylinder compression chamber and vat expansion chamber complete the adiabatic expansion of gas jointly, gas flows to vat from little cylinder through transfer pipeline, and the compression chamber of vat completes isothermal compression and the isobaric compression of gas.

Can sum up the working principle of all positive displacement heat engines by top two embodiments, the heat engine of remaining positive displacement machine can be done specific embodiments according to this principle.

The machine (single volume formula mechanism) working principle: the overall process that the machine enclosed volume increases is used for carrying out isothermal expansion and the adiabatic expansion of gas, volume after requiring adiabatic expansion to complete is more than 2 times of volume after isothermal expansion completes, and the process that the machine enclosed volume diminishes has been used for isothermal compression and the isobaric compression of gas.

The machine (dual-volume storage formula mechanism) working principle: the machine is in series by one little one large two identical positive displacement machines of structure, the volume of large positive displacement machine is more than 2 times of little positive displacement machine volume, the process that little positive displacement machine enclosed volume increases is used for carrying out the isothermal expansion of gas, the process that the process that little positive displacement machine enclosed volume diminishes and large positive displacement machine enclosed volume increase completes the adiabatic expansion of gas jointly, gas is transferred to large positive displacement machine by transfer pipeline from little positive displacement machine, the process that large positive displacement machine enclosed volume diminishes has been used for isothermal compression and the isobaric compression of gas.

The machine (screw type) embodiment slightly.

The machine (eddy type) embodiment slightly.

The machine (sliding vane) embodiment slightly.

The machine (rotary vane type) embodiment slightly.

The machine (swing-rotor type) embodiment slightly.

When the machine gas is used water vapor, because water vapor is not suitable for compression, after having carried out isothermal expansion and adiabatic expansion, just it is not being compressed, directly it is discharged to the condensation recycling use, similar to the processing of exhaust steam with thermoelectricity plant.

The machine does not have specific (special) requirements to thermal source, and various thermals source can utilize.

Claims (9)

1. the present invention relates to a kind of positive displacement heat engine, comprise gas tank, suction tude, muffler, valve, one or two positive displacement machines; It is characterized in that: the gas that is heated to uniform temperature and pressure can complete isothermal expansion, adiabatic expansion, isothermal compression, the isobaric compression process of gas continuously in positive displacement machine, sustainable thermal power transfer is become to mechanical energy, the volume after the gas adiabatic expansion is more than 2 times of volume after the gas isothermal expansion.

2. positive displacement heat engine as claimed in claim 1, it is characterized in that: gases used is water vapor, after the isothermal expansion that completes water vapor and adiabatic expansion, no longer to its compression, by its direct discharge.

3. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is reciprocating piston type.

4. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is rolling rotor-type.

5. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is screw type.

6. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is sliding vane.

7. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is rotary vane type.

8. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is eddy type.

9. positive displacement heat engine as claimed in claim 1, it is characterized in that: positive displacement machine is swing-rotor type.

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