CN112923596B

CN112923596B - Heat engine power circulation method of single heat source

Info

Publication number: CN112923596B
Application number: CN202110069359.4A
Authority: CN
Inventors: 张学文
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-11-04
Filing date: 2021-01-19
Publication date: 2023-01-13
Anticipated expiration: 2041-01-19
Also published as: CN112923596A

Abstract

The invention provides a heat engine power cycle method of a single heat source, which at least comprises two working media which are respectively used as an expanding agent and an absorbent, wherein the two working media have different boiling points, the working media with low boiling points and easy vaporization are used as the expanding agent and participate in expansion to apply work to the outside, so that heat energy is converted into mechanical energy, and the other working media with higher boiling points are used as the absorbent and can dissolve and absorb the expanding agent and steam molecules thereof. The invention realizes the expansion of the working medium in an isothermal environment, fully utilizes the internal force of the working medium and realizes the power cycle process of the heat engine under the condition of a single heat source.

Description

Heat engine power circulation method of single heat source

Technical Field

The invention relates to the field of thermodynamics, in particular to a circulation method for converting heat energy into mechanical energy under a single heat source.

Background

The equipment for converting thermal energy into mechanical energy is called a thermodynamic prime mover, called a heat engine for short, and the working cycle of the heat engine is called a power cycle. According to the prior art and theory, the conversion of thermal energy to mechanical energy needs two heat sources with relative temperature difference, that is, after the thermal energy absorbed from the high-temperature heat source is partially converted into mechanical energy, the residual thermal energy is discharged to the low-temperature heat source, that is, the heat engine in the prior art needs at least two heat sources for cooperation. It can be said that the existing conversion technology from heat energy to mechanical energy is based on temperature difference, circulation cannot be realized without temperature difference, and a large amount of heat energy is discharged to a low-temperature heat source, which results in energy waste. In addition, the hard requirement for the number of heat sources also causes the limitation of the working environment of the heat engine, and it must be considered that the environment with temperature difference is created to provide the environmental basis for the work of the heat engine, so the power cycle of the heat engine in the prior art has certain limitations.

Disclosure of Invention

The invention aims to solve the technical problem in the background technology and provides a heat engine power circulation method with a single heat source, which realizes the expansion of a working medium in an isothermal environment, fully utilizes the internal force of the working medium and realizes the power circulation process of a heat engine under the condition of the single heat source.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the heat engine power circulation method of the single heat source, the said heat engine power circulation method includes two kinds of working mediums at least, as swelling agent and absorbent separately, the boiling point of two kinds of working mediums is different, the working medium that the boiling point is lower and apt to vaporize is regarded as the swelling agent, participate in the swelling and do work to the outside, make the heat energy turn into the mechanical energy, another working medium with higher boiling point is regarded as the absorbent, can dissolve and absorb swelling agent and its steam molecule, the said heat engine power circulation method includes the following steps:

(1) Expanding the expanded agent steam a subjected to heat absorption vaporization through an expander to form steam b, and outputting mechanical energy w in the expansion process;

(2) The expanded steam b is absorbed and liquefied by a solution 4 in an absorber to form a solution 1;

(3) The solution 1 after absorption in the absorber enters a constraint separation device, and the expansion agent liquid d and the solution 2 are separated by the constraint separation device;

(4) The expansion agent liquid d separated by the constraint separation device enters a vaporization heat exchanger to absorb heat discharged by an absorber and heat absorbed from a single heat source to be vaporized into steam a;

(5) The solution 2 separated by the constraint separation device is depressurized by a throttle valve (or an energy recovery device) to form a solution 3, the solution enters an absorber to continue the step (2) to form a circulation, and the solution 1 is continuously formed;

(6) And (3) continuing the step (1) to form a cycle, and continuously outputting the mechanical energy w outwards.

Further, the relative temperature between the absorber and the vaporization heat exchanger is adjusted through a heat exchange pump.

Further, the solution 1 is at a certain pressure P ₁ A solution 4 having a higher concentration than said solution 1.

Further, the concentration of the solution 2 is higher than that of the solution 1, and the concentration of the solution 4 is lower than that of the solution 3, wherein the concentration refers to that of the absorbent.

Further, the vaporization heat exchanger can provide heat required for separation for the constraint separation device through a heat exchange pump.

In the present invention, the constrained separation device plays an important role in the feasibility of the whole cycle, and therefore, in order to facilitate a better understanding of the technical solution of the present invention, the constrained separation device will be described and illustrated below.

In the invention, the constraint separation device is arranged under a centrifugal force field, a progressive constraint separation structure capable of constraining molecules of the swelling agent step by step is arranged in the constraint separation device, and in the constraint separation device, a solution formed by the swelling agent and the absorbent can be subjected to progressive constraint separation along the direction of the centrifugal force generated by a centrifugal force field, so that the swelling agent and the absorbent are further separated from the absorbed solution for the next circulation.

Further, the absorbent molecules are larger and the swelling agent molecules are smaller, so that in the constraint separation device, the absorbent molecules can be excluded, the swelling agent molecules can enter the constraint separation device and are constrained from inside to outside step by step along the centrifugal force field, the number of the swelling agent molecules constrained by the outer step is more than that of the inner step, and the constrained swelling agent molecules migrate in the progressive constraint separation structure along the centrifugal force direction under the action of the centrifugal force field until being discharged out of the progressive constraint separation structure in a higher-purity form.

Further, the progressive confinement separation structure includes a material capable of being fixed in the progressive confinement separation structure and capable of adsorbing or fixing the molecules of the swelling agent, such as a strongly water-absorbent resin or a similarly acting substance or structure, to achieve stepwise confinement of the molecules of the swelling agent.

Further, the progressive confinement separation structure comprises a flexible porous material in which other materials capable of adsorbing or immobilizing the swollener molecules may be immobilized.

Further, the starting end of the progressive separation constraint structure is provided with a semi-permeable membrane structure with a rigid support, which can block the absorbent molecules in the solution but can allow the swelling agent molecules to pass through.

The invention has the beneficial effects that:

(1) Theoretically, the invention breaks through the traditional concept that the thermal engine power cycle must have temperature difference, utilizes the absorption effect of the solution and the constraint cycle separation method, combines the absorption and separation of the solution in the cycle process, outputs mechanical energy through the expansion of the solution in a saturated state, directly releases heat to a heat source through the absorption effect of the solution after the expansion, separates the absorbed solution through a constraint separation device, does not need to additionally increase a heating source in the constraint separation process, and can put the separated working medium into the next cycle, thereby realizing the thermal engine power cycle through one heat source, receiving and releasing heat without a low-temperature heat source and avoiding the waste of residual heat energy of the expanded working medium.

(2) Practically speaking, the heat source of the heat engine power cycle can be obtained from the surrounding environment, such as air, seawater and the like, the existing environmental heat energy can be converted into mechanical energy/electric energy by the method, the dependence on fossil energy is greatly reduced, and the method has great significance for inhibiting climate warming; moreover, the invention has no restriction of region, day and night, season and the like common renewable energy sources, and can be used anytime and anywhere, for example, household electricity can be obtained from balcony air; the automobile and the steamship do not need to be oiled, and can continue to sail indefinitely under the drive of electric power; the aircraft may be infinitely airborne, etc. The invention expands the applicability of the heat engine power cycle, and can better utilize environmental energy and save resources.

Drawings

Fig. 1 is a typical schematic diagram of conventional absorption refrigeration.

FIG. 2 is a micro-mechanical diagram of the prior art for separating water vapor from a solution by using high temperature heat energy.

FIG. 3 is a micro-mechanistic diagram of a constrained separation process to achieve separation of water vapor and solution.

Fig. 4 is a simplified schematic diagram of conventional absorption refrigeration after a constrained separation process.

FIG. 5 is an indicator diagram of the "entropy-reducing non-exothermic cycle".

FIG. 6 is a heat map of an "entropy-reduced non-exothermic cycle".

Fig. 7 is a schematic diagram of molecular separation of solute molecules and water molecules in an ideal state simulated by a magnetic field.

Fig. 8 is a schematic diagram of molecular separation of an ideal absorption refrigeration generator simulated by a magnetic field.

FIG. 9 is a schematic diagram of the molecular separation of the reverse osmosis process under ideal conditions simulated by a magnetic field.

FIG. 10 is a schematic view of the molecular separation of the present invention under ideal conditions of magnetic field simulation.

FIG. 11 is a schematic representation of the separation of a semi-permeable membrane under a centrifugal force field.

FIG. 12 is a schematic view showing the separation of water molecules in a porous structure.

FIG. 13 is a progressive constraint separation diagram.

Fig. 14 is a schematic view of a rigid support.

FIG. 15 is a schematic enthalpy-concentration diagram of a solution during a progressive separation process.

Fig. 16 is a schematic diagram of a rankine cycle in the prior art.

FIG. 17 is an lgp-h diagram of a Rankine cycle.

FIG. 18 is a lgh-h plot of a solvent (expansion agent) vapor cycle of the present invention.

FIG. 19 is a schematic of the absorption Rankine cycle of the present invention.

FIG. 20 is a schematic view showing the change of state of the solution of the present invention during circulation.

Fig. 21 is an overall flow chart of the present invention.

Detailed Description

In order that those skilled in the art will better understand the concept of the present invention, a clear and complete description of some embodiments of the present invention will be provided below with reference to the accompanying drawings and examples of the present invention.

Since there are some theoretical or theoretical ideas or references in the present invention, in order to make the ideas or references embodied and operated in the technical scheme of the present invention better understood and implemented, the ideas or references are first described and explained, and it should be noted that the descriptions and explanations are for the convenience of understanding, and should not be regarded as limitations to the present invention or regarded as an aspect or part of the present invention, nor should they be regarded as limitations to the present invention.

For ease of understanding and explanation, this embodiment is illustrated with a lithium bromide solution, and indeed the principles and structures of the present invention may be applied to other solution circulations.

It is known that the conversion of thermal energy into mechanical energy according to the prior art and theory requires two heat sources with a relative temperature difference, i.e. the residual thermal energy is discharged to the low temperature heat source after the absorbed thermal energy from the high temperature heat source is partly converted into mechanical energy. It is obvious that the existing basic theory is violated to realize the purpose of converting the heat energy of a single heat source into the mechanical energy. For this reason, there is a need to dissect and innovate existing theories.

1. Discussion of the second law of thermodynamics

The second law of thermodynamics and the principle of entropy increase of isolated systems have never been questioned since the world for over a hundred years. The physicist maxwell has also set up a "door-watching demon" in an attempt to find a mechanism of entropy reduction, the well-known maxwell demon. The problem is now not examined in terms of cosmic thermal silence from the principle of entropy increase.

The principle of entropy increase of isolated systems has been considered to be applicable to the whole universe, that is, the whole universe will eventually lose all potential differences of working capacity to form thermal equilibrium thermal silence. In other words, all potential differences in the universe with the capability of doing work are finally heat energy, and even if the temperature difference is not enough, the universe is silent. Then one does not imagine a scene after thermal silence, where all celestial bodies (large or small, or in particle state) are uniformly distributed in the universe without any difference in temperature and velocity. However, the gravitational force always exists, and at this time, the celestial bodies can be reunited into a plurality of blocks or larger celestial bodies due to the gravitational force, and then the speed difference, the temperature difference and the like are formed again, and the process is entropy reduction. From this analysis, it is certainly problematic to apply the principle of entropy increase of isolated system to the entire universe, and then we can question the second law of thermodynamics and the principle of entropy increase of isolated system as well as those of predecessors.

The second law of inverse thermodynamics and the principle of entropy increase of isolated systems can be found to be based on both the carnot cycle and carnot theorem. The detailed Carnot cycle can find that the Carnot cycle has a preset condition, namely that the compression of the working medium can only be completed by external force, or the working medium cannot be compressed by internal force of the working medium. This impossibility is fixed by a number of theories which are derived from a cycle which assumes the premise of a certain impossibility. As the foregoing analysis shows, after the cosmic heat is silent, self-polymerization can be realized by the internal force of the gravitational force, and further, it can be expected that the gaseous working medium can be self-compressed by the internal force of the working medium.

The intermolecular actions commonly utilized in engineering practice are absorption, adsorption, etc., and the absorption refrigeration is taken as an example to analyze the relevant processes. For ease of understanding and data acquisition, binary working medium pair (and optionally multiple) lithium bromide solutions are used herein as examples. Analyzing the lithium bromide absorption refrigeration system, the low temperature water vapor from the evaporator is absorbed by the solution in the absorber and releases heat to the relatively high temperature cooling water, obviously the process completes the heat release from low temperature to high temperature. It is clearly not correct to refer to the process of separating the solution from the solvent in the generator as a process of compensating for the evolution of heat at low to high temperatures. In other words, the mechanism of entropy reduction, which violates the second law of thermodynamics, already exists, and the energy consumption in the separation of the solution from the solvent to achieve the cycle must not be limited by the carnot's theorem. For this purpose, the absorption/desorption process of the solution needs to be analyzed.

Because the attraction of solute molecules or ions to solvent molecules is greater than that between solvent simple substance molecules, the method is a basic principle of the absorption effect of the lithium bromide solution, belongs to a mature theory, and does not need excessive analysis. The key process is the separation of the solution from the solvent. To complete one cycle, the separated solvent (water) needs to be in liquid state. The absorber and the condenser have the same cooling environment, that is, the temperature of the solution before separation and the temperature of the separated simple substance are the same, and the saturation pressure of the simple substance is higher than the saturation pressure of the solution at the same temperature, so that the solution needs to be separated after being pressurized, the separated water can be liquefied, and further the saturation temperature of the solution is increased due to the action of the pressurization, which is the reason that the absorption refrigeration system needs a high-temperature heat source to heat and separate the solution, as shown in fig. 1, which is a typical mode of the conventional lithium bromide absorption refrigeration.

As mentioned above, the lithium bromide absorption refrigeration system utilizes high temperature heat energy to separate the solution from water, the separated water vapor is in a superheated state, and the micro-mechanism of this process can be described by referring to fig. 2, and the forces applied to the water molecules on the surface of the solution include the attraction force of solute ions, the vapor pressure (vapor molecular impact) and the repulsive force of the thermal vibration of the water molecules themselves to the solute ions. When the solution is in a saturated state, the repulsive force F can just counter the resultant force F of the ion attraction and the vapor phase pressure, and at the moment, if the water molecules are impacted by other molecules a, the water molecules are ejected into the vapor phase, and the molecules a get energy supplement from a high-temperature heat source. Obviously, the energy provided by the high-temperature heat source can be divided into two parts, wherein the first part is used for heating the solution to be in a saturated state, and the second part is used for providing kinetic energy for water molecules to enter a vapor phase. It will be appreciated that the second portion of energy acts to separate water molecules from the solution. When the solution is in a saturated state, the repulsive force F of the water molecules can counterbalance the resultant force F, and if a 'manipulator' is supposed to grasp the water molecules to move, the constraint range of the 'manipulator' on the water molecules does not influence the repulsive force effect of the thermal vibration of the water molecules, namely the 'manipulator' does not influence the original stress balance of the water molecules when moving, the 'manipulator' obviously moves the water molecules to achieve the separation effect without the energy consumption of the second part. It should be noted that the solution at position 1 in FIG. 1 is the solution after absorption is completed, i.e. it is saturated, and if the "robot" is used to separate water molecules at position 1, the aforementioned first part of the energy consumption may not be needed, or it is understood that the energy consumption may be provided by the environment. The mechanical hand sends the separated water molecules into the water under the pressure of P ₂ Ensures that it is in liquid state, as shown in FIG. 3, and the process "robot" moves water molecules from P ₁ Pressure feeding P ₂ The energy required by the pressure vessel is flow work, i.e. it is recovered as it flows out of the vessel, and the method of separating water molecules by "manipulators" can be called as a constraint separation method, so that the separated water molecules are directly in liquid state. After the constraint separation method, the loop of fig. 1 can be simplified as shown in fig. 4.

Through the analysis, the working medium can realize self-compression through the attraction among the internal particles, and the refrigeration cycle is completed without compensation. Thermodynamics tells us that in an ideal gas constant-temperature compression process, all work of external force on gas is converted into heat energy to be released outwards, while in the existing working medium internal force self-compression process, external work is not obtained, and the constant-temperature entropy reduction process is realized without releasing heat to the outside, so that the thermodynamic cycle of working medium internal force self-compression can be temporarily called as 'entropy reduction non-heat release cycle'. It should be noted that the heat release during absorption of absorption refrigeration is understood to be phase change heat release, and does not conflict with the "entropy reduction non-heat release" herein, and the heat energy conversion nature of the "entropy reduction non-heat release cycle" can be represented by an indicator diagram such as fig. 5 and an indicator diagram such as fig. 6. Is arranged at a heat source T ₁ The working medium is expanded from a state a to a state b in an isothermal way, absorbs heat q from a heat source and outputs expansion work w outwards ₀ And the process from b to a is an internal force self-compression process, does not need external work and releases heat to the outside, so q and w ₀ The net value obtained by the circulation shows that the circulation is composed of 2 processes, and the positive circulation and the reverse circulation can be distinguished without the Carnot circulation, and the heat source T ₁ As to the refrigeration cycle; for the outside world, the net work w is obtained ₀ The heat engine cycle of (1); if necessary to direct heat to a higher temperature heat source T ₂ Exothermic, then mechanical energy w ₀ Conversion to q is carried out, so as to heat source T ₂ In other words, a heating cycle.

In summary, the second law of thermodynamics can be redefined: thermal and mechanical energy can be equally converted, or micro-mechanical energy and macro-mechanical energy can be unified. The redefinition of the second law of thermodynamics does not negate the carnot cycle, which differs from the "entropy-reducing non-exothermic cycle" in the way in which thermal energy is used, whereas the principle of entropy increase of an isolated system is only applicable to carnot cycle systems.

2. With respect to constrained separation processes applicable to practical recycling

In the above-described constrained separation method for separating a solution, the "robot" is assumed for the convenience of explanation of the problem, and it is not easy to realize a mechanical gripper on a molecular layer in practical use, so that it is necessary to design a solution constrained separation method that can be applied to practical circulation.

The purpose of restricting the separated water molecules is to limit the moving space of the water molecules, so that the water molecules cannot obtain unnecessary excessive heat energy for circulation, and to illustrate the problem more pictorially, a model as shown in fig. 7 can be designed, the mutual attraction action of ions and water molecules in the solution can be indicated by the attraction of magnetism to iron, if common magnets are attracted together, the separation of the common magnets certainly needs an external force f to act for a certain distance s and then is separated from the action of a magnetic block, the external force consumes f × s, the amplitude of the molecules which are represented by the iron balls and vibrate due to heat is increased along with the increase of the temperature, the amplitude also reaches a balance distance when the saturation temperature is reached, the repulsive force generated due to vibration can counterbalance the attraction force (resultant force) borne by the water molecules, namely, the water molecules can be moved without consuming energy to separate from the control of the ions. If the separated water molecules are constrained in space and only do thermal vibration at the saturation temperature, the separated water molecules cannot continuously absorb heat energy to form a vapor phase. The energy consumption required by the conventional absorption refrigeration can be in the manner shown in fig. 8, the first part of the energy consumption is heat energy q, and the second part of the energy consumption is also heat energy q. The reverse osmosis method for seawater desalination can use the mode as shown in fig. 9, and because the energy consumption is separated in a supercooled state, the seawater desalination requires external force to do work as shown in fig. 7, namely, the first part of energy consumption is f × s, and water molecules are directly constrained into a liquid state after being separated, so that the second part of energy consumption is avoided. The constraint separation method is to perform constraint separation in a saturation state, so that the energy consumption only needs to be the first part energy consumption q for raising the temperature to the saturation temperature, as shown in fig. 10, it should be noted that the saturation temperature in fig. 10 is different from that in fig. 8, and the saturation temperature in fig. 10 is the heat source temperature in a single heat source cycle, that is, it can be understood as the ambient temperature, so that the first part energy consumption can be provided by the environment, or it can be understood that the first part energy consumption is also not needed.

The purpose and the energy consumption of the constraint are analyzed, the key to realizing the constraint separation method is the constraint on the separated molecules or ions, the mechanical arm constraint is difficult to realize, and the constraint can be considered from an external force field, such as a gravity field, a centrifugal force field, an electric field, a magnetic field and the like, and obviously, the centrifugal force field can be selected preferentially from the aspects of realizability and universality.

Also taking lithium bromide solution as an example to design a constraint separation method, the basic idea of saturated solution separation is to cover the liquid surface with a porous structure with selective sieving function, such as a semi-permeable membrane, and then to perform circular motion to separate molecules by centrifugal force, as shown in FIG. 11, the saturated pressure P of the solution ₁ And the saturated pressure P of pure water at the same temperature ₂ Is obviously greater than P ₁ If the separated water molecules are directly pressed into P by centrifugal force ₂ The container is constrained and difficult to implement in practical terms, as shown in fig. 12. For this purpose, a porous structure having a selective sieving function can be designed, and molecules or ions having a water absorbing function of a solute (or other water absorbing substance) are fixed on the spatial structure, like an electrodialysis membrane, a Super Absorbent Polymer (SAP), etc., as shown in fig. 13.

The structure of fig. 13 is wholly at a temperature T ₁ In the environment of (2), the rotation is performed at an angular velocity ω with the left side O as the center of the circle and the left side T ₁ Saturated solution at temperature, pressure P ₁ . The right side is pure water side, and the pressure of the right side reaches T under the action of centrifugal force ₁ Pure water saturation pressure P at temperature ₂ . The pressure increases with increasing radius in the middle part due to the centrifugal force, and when the angular velocity ω is stabilized, there is a corresponding pressure in each position. Due to solute ions(or other water-absorbing ions) are immobilized on the substrate, and water molecules are free to move therein, so that each site is at the same temperature T ₁ The saturation concentration will be different due to different pressures, i.e. as shown, each ion attracts a different number of water molecules, and each ion is in saturation. At the moment, water molecules separated from the solution on the left side pass through the semi-permeable substrate under the migration of centrifugal force, firstly push away and replace water molecules (1), then push away and replace water molecules (2) after the water molecules (1) are separated out, and then the water molecules move in sequence until the water molecules reach the pure water side. The water molecules are supplied with energy input from the outside for migration, and the energy can be recovered when pure water leaves the separation device after the water molecules are separated. The energy change before and after separation, e.g. the spacing between pure water molecules increases in solution, and is determined by T ₁ Thermal energy provided by the environment is realized (i.e. a single heat source).

It can be seen that the energy consumption required by the solution separation method designed above is T ₁ The thermal energy provided by the environment is constrained in a progressive manner by the fixed ions, and therefore can be called as: the thermal driving solution separation method of progressive restraint under the centrifugal force field is called as a restraint solution separation method for short.

If this separation is graphically represented, the enthalpy-concentration diagram of the lithium bromide solution can be used, as shown in FIG. 15. Starting from the starting point O of the solution separation, the separated water molecules follow the isotherm T ₁ And the concentration of lithium bromide is increased until the concentration of lithium bromide is 0, namely the pure water state. The remaining solution follows the isotherm T ₁ Down to the desired concentration.

According to the principle described above, when in actual practice the solution is at the saturation pressure P ₁ On entering the rotary mechanism, the solution side pressure in fig. 13 will be greater than P, since the solution has a certain thickness in the radial direction ₁ For this purpose, a rigid support is required on the side of the porous material close to the solution, so that a pressure difference is generated on the two sides of the semi-permeable substrate, and the pressure on the right side is reduced to P ₁ As in fig. 14.

3. Thermodynamic cycle with single heat source

The existing heat-work conversion technology is based on temperature difference, circulation can not be realized without temperature difference, and a large amount of heat energy is discharged to a low-temperature heat source, so that heat energy waste is caused. Now, according to the conclusions drawn before: the heat energy and the mechanical energy can be converted equivalently, so that the heat energy absorbed from the high-temperature heat source can be converted into the mechanical energy, the low-temperature heat source is not required to receive heat release, and the heat engine power cycle of a single heat source can be designed for engineering practice. It is clear that what needs to be applied here are solution absorption and constrained solution separation.

The steam (water vapor is taken as an example here) power cycle in the prior art adopts a Rankine cycle, the working principle of which is shown in FIG. 16, and the cycle process is 1-2-3-4-5-1. For the convenience of comparative analysis, the process is indicated by an lgp-h diagram of a common working medium, as shown in FIG. 17, rankine cycle outputs mechanical energy by utilizing steam expansion, the process is 1-2, and the expanded steam is condensed to release heat and is discharged into the atmosphere, and the process is 2-3. If the water vapor after the expansion is finished directly releases heat to a high-temperature heat source through the absorption effect of the solution, obviously, the purpose of circulation can be realized by one heat source, and the solution after the absorption is finished is separated by a constraint separation method. According to the basic idea, the condensation heat release process 2-3 of the Rankine cycle is completed by using the absorption type solution working medium pair, so the method can be called as the absorption Rankine cycle.

A proper absorption solution working medium pair can be found according to different heat source temperatures, a working medium which is low in boiling point and easy to vaporize participates in expansion to do work externally, the working medium is called an expanding agent, in addition, the working medium plays an absorption role and is an absorbent, in order to facilitate understanding and data acquisition, a lithium bromide solution is used as a reference working medium pair, lithium bromide is used as the absorbent, and water is used as the expanding agent.

The lgp-h diagram of the solvent (swelling agent) vapor cycle is shown in FIG. 18, and the process is a-b-c-d-a. The high-pressure steam with the state point a enters an expander to be adiabatically expanded to output mechanical energy, and the pressure is P ₂ Reducing the pressure to P ₁ The low-pressure steam forming the point b enters an absorber to be absorbed by the solution, the liquid region on the lgp-h graph shows the circulation process by a dotted line because the absorbed expanding agent is not pure, and the point c is only shown in the figure. And the steam in the state b is absorbed and liquefied to a point c, then is subjected to constrained separation, the separated expanding agent is in a state d of P2 pressure, and then is subjected to heat absorption and vaporization to a state a to complete a cycle. In order to fully utilize the saturation pressure difference, the position of the whole circulation in the figure needs to be comprehensively considered by combining the dry-wet working condition performance, the heat exchange area and other factors of the expansion machine, and the uppermost position should consider that the vaporization line does not exceed the heat source temperature T ₁ The lowest position of the line, such as the cycle of a ' -b ' -c ' -d ' -a ' in the figure, is preferably considered, and the position of the isenthalpic point e corresponding to the point b on the vaporization line is in the two-phase region and does not enter the superheat region.

The "absorption rankine cycle" works on the principle of fig. 19. The vapor a after heat absorption and vaporization enters an expander to output mechanical energy w outwards, the vapor b after expansion enters an absorber to be absorbed and liquefied by solution, the heat released in the absorption process is discharged to a vaporization heat exchanger and a constraint separation device by a heat exchange pump, the solution after absorption enters the constraint separation device, the separated expansion agent liquid d enters the vaporization heat exchanger to absorb the heat discharged by the absorber and the heat source T ₁ The absorbed heat is vaporized into a steam, the pressure of the separated solution can be increased due to the process requirement in the separation process of the constraint separation device, so that the solution 2 is decompressed to 3 through a certain throttling before entering the absorber, and the solution in the state 3 enters the absorber to absorb the steam b from the expander.

The change of state of the solution in the circulation process can be shown on the enthalpy-concentration diagram of the lithium bromide solution, as shown in fig. 20, and the solution 1 which completes the absorption process in the absorber is the pressure P ₁ The saturated state of the solution B is subjected to the constraint separation, the concentration is increased to 2 points, the solution is reduced to 3 points through the throttle valve, the 2 points and the 3 points are overlapped due to throttling in the supercooled state, the solution in the state 3 enters the absorber, the temperature of the solution 3 is rapidly increased after the solution absorbs a little of steam because the liquefaction latent heat of the steam b is much larger than the specific heat of the solution 3, the solution 4 is increased to the saturated state 4 from the supercooled state, the solution 4 continuously absorbs the steam b, meanwhile, heat is released outwards, the concentration is reduced, and finally the solution reaches the state 1 point.

In combination with the above theories, the heat engine power cycle method of the present invention may employ the steps shown in FIG. 21:

s1, establishing a heat engine power cycle system. The structure and the principle of the heat engine power cycle of the invention are shown in figure 19, and the heat engine power cycle system comprising a vaporization heat exchanger, an expander, an absorber, a constraint separation device, a throttle valve and a heat exchange pump is constructed in the invention.

S2, passing through an external single external heat source T ₁ And providing heat energy q to the vaporization heat exchanger to vaporize the expanding agent.

S3, the expanding agent enters an expander in the form of high-pressure steam a to participate in expansion work, and heat energy is converted into mechanical energy w, and the pressure of the high-pressure steam a for expansion work is P ₂ Down to P ₁ (P ₂ ＞P ₁ ) And low-pressure steam b is formed.

S4, the low-pressure steam b enters the absorber and is absorbed by the original solution 4 in the absorber to form solution 1, and the pressure is reduced to P ₁ The solution 1 is at a certain pressure P ₁ Saturated solution of (b).

And S5, the solution 1 enters a constraint type separation device, and the swelling agent liquid d and the solution 2 are separated through the constraint type separation device.

The constraint type separation device can be made of flexible porous materials, the size of the pores of the flexible porous materials is enough to allow the molecules of the swelling agent to pass through but not to allow the molecules of the absorbent in the solution 1 to pass through, therefore, when the solution 1 passes through, only the molecules of the swelling agent can enter the flexible porous materials, in the constraint type separation device, due to the effect of centrifugal force, each part of the solution 1 has certain pressure, the solution 1 is in a saturated state at each part of the constraint type separation device, and at the moment, the molecules of the swelling agent are in an unbound state, therefore, when the saturated solution passes through, the flexible porous materials can allow the molecules of the unbound swelling agent to enter, but block the molecules of the solute, and primary separation is realized.

The flexible porous material can be provided with a material or a structure capable of adsorbing or fixing swelling agent molecules, such as a high water-absorption resin material, appropriate hydrophilic groups are crosslinked in the resin, and the hydrophilic groups and the swelling agent molecules form an equivalent adsorption state, so that the swelling agent molecules are restrained, the swelling agent molecules in an unbound state are restrained, the swelling agent molecules are prevented from being gasified, the swelling agent molecules are prevented from being converted from a liquid state to a gaseous state, the swelling agent molecules are directly separated in a saturated state, and the energy consumption in gasification is avoided. And moreover, a plurality of levels of constraint structures are arranged in the flexible porous material along the direction of the centrifugal force, the molecules of the expanding agent are respectively constrained (adsorbed) at different radius positions (namely under different pressures) along the direction of the centrifugal force, and in the optimal state, the next level of constraint structure can constrain the molecules of the expanding agent which cannot be constrained in the previous level, so that progressive constraint on the molecules of the expanding agent is formed until the molecules of the expanding agent are aggregated to form pure expanding agent liquid d which is discharged. Accordingly, another portion separated is the solution 2 with an increased absorbent concentration due to the reduction of the swelling agent.

S6, the expansion agent liquid d separated by the constraint separation device enters a vaporization heat exchanger, absorbs the heat discharged by the absorber and the heat absorbed from a single heat source, and is vaporized into steam a (circulation of the steam a).

And S7, depressurizing the solution 2 separated by the constraint separation device through a throttle valve and returning the solution to the absorber.

And S8, continuing the circulation formed by the steam a in the step S3, and continuously outputting the mechanical energy w outwards.

In the process, the heat required by the constraint separation device can be obtained by heat exchange between the heat exchange pump and the absorber, and the heat released by the absorber in the absorption process can also be transferred to the vaporization heat exchanger or the constraint separation device through the heat exchange pump.

If the circulating heat source T1 is a certain target space, it is obvious that the apparatus can double as a refrigeration apparatus.

Claims

1. The heat engine power circulation method with single heat source is characterized in that,

the power circulation method adopts two working media with different boiling points as an expanding agent and an absorbing agent respectively, and comprises the following steps:

(5) The solution 2 separated by the constraint type separation device is depressurized by a throttle valve to form a solution 3, the solution enters an absorber to continue the step (2) to form a circulation, and the solution 1 is continuously formed;

(6) Continuing the steam a in the step (1) to form a cycle, and continuously outputting mechanical energy w outwards;

the constraint type separation device is arranged under a centrifugal force field and can constrain the molecules of the expanding agent step by step along the direction of the centrifugal force generated by the centrifugal force field;

the constrained expanding agent molecules gradually migrate along the centrifugal force direction under the action of the centrifugal force field until being discharged out of the constrained separation device in a form of higher purity;

the constraint separation device is internally provided with a progressive constraint separation structure for gradually constraining the molecules of the expanding agent;

the constrained separation device comprises a material capable of being immobilized in the progressive constrained separation structure and capable of adsorbing or immobilizing a swelling agent molecule;

the constrained separation device comprises a flexible porous material, wherein a material capable of adsorbing or fixing swelling agent molecules can be fixed in the flexible porous material;

the starting end of the constrained separation device is provided with a semi-permeable membrane structure with a rigid support, which can block the absorbent molecules in the solution and can allow the swelling agent molecules to pass through.

2. A method of operating a heat engine according to claim 1, wherein,

and the relative temperature between the absorber and the vaporization heat exchanger is regulated by a heat exchange pump.

3. A method of operating a heat engine according to claim 1, wherein,

the solution 1 is a saturated solution under a certain pressure P1, and the concentration of the solution 4 is higher than that of the solution 1.

4. A method of operating a heat engine according to claim 1 or claim 3, wherein,

the concentration of solution 2 is higher than that of solution 1 and the concentration of solution 4 is lower than that of solution 3.

5. A method of operating a heat engine according to claim 1, wherein,

the vaporization heat exchanger can provide heat required for separation for the constraint separation device through a heat exchange pump.