RU2613337C2 - Thermal-mechanical converter with liquid working medium - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: thermal-mechanical converter with liquid working medium contains the heating and cooling areas, the shaft with an inclined flange installed in the bearings, heat-responsive elements, conjugated with them support flange, leaning through a bearing on the inclined shaft flange and also control valve connected to the shaft, controlling the flow of heating and cooling heat transfer fluids to heat-responsive elements. The working medium in it is a liquid, enclosed in the sealed shell with the ability to change its linear size under the internal pressure. The liquid has a contact with the heat transfer fluids through the wall inside its channel shell with developed heat conducting surface, made with ribbing.

EFFECT: converter is able to operate from a variety of thermal energy sources and is focused mainly on its renewable types and on the heat containing process products energy recycling and thermal discharges into the environment.

6 dwg

Description

The invention relates to the field of power engineering, in particular to non-traditional converters of thermal energy into mechanical work. It can be used in drives of electrical units, tubing and other equipment of industrial, agricultural and other purposes both in stationary and mobile facilities with the predominant use of renewable natural energy resources, as well as energy of heat-containing emissions into the environment.

A number of designs of non-traditional converters of thermal energy into mechanical work are known, presented, for example, in the inventions SU 478123, class. F03G 7/06, 1973; SU 709830, class F03G 7/06, 1978; SU 987162, class F03G 7/06, 1981; SU 1307084, class F03G 7/06, 1987; RU 2200252 C2, cl. F03G 7/06, 2001, which due to imperfections in the design have not found practical application.

The known design of the thermomechanical converter - according to the patent RU No. 2442906, 2012 - the most similar to the claimed device, it will be examined here in detail as an accepted prototype.

This thermomechanical converter, comprising a shaft mounted in bearings, heat-sensitive elements, as well as heating and cooling zones (temperature zones), has a support flange connected to the heat-sensitive elements, resting through the bearing on an inclined shaft flange rigidly connected to the spool, which controls the heating and cooling flows heat carriers (thermal agents).

The support flange allows you to convert a successive change in the lengths of the heat-sensitive elements associated with it under the influence of a changing temperature into a cyclical change in the direction of its inclination, affecting the shaft flange, which receives torque.

This analogue is distinguished by its simplicity of design, versatility in terms of the sources of converted thermal energy used, and the ability to work in the mode of automatically maintaining a stable speed under changing load conditions. Its main drawback is its low efficiency due to the limited elastic limit of the working heat-sensitive elements (TEC) with their low coefficient of thermal expansion and high total heat capacity.

The indicated drawback is practically irrelevant when using this converter in integrated power supply schemes of facilities, when the heat discharged by it is used to heat these facilities. In purely power plants, this performance indicator may be unacceptable.

The task in the development of the inventive converter is to increase its efficiency by no less than an order of magnitude, reducing weight and overall dimensions.

The problem is solved in that the inventive thermomechanical converter containing heating and cooling zones, a shaft installed in the bearings, heat-sensitive elements, a supporting flange connected to them, supported through the bearing on an inclined shaft flange, and also a spool connected to the shaft, controlling the heating and cooling flows heat transfer agents to heat-sensitive elements, characterized - according to the invention - in that the working fluid in it is a liquid enclosed in an airtight shell, having w ability to change its linear dimension under internal pressure, the liquid inside the shell is connected with the coolant channel of the heat-conducting wall with heat-developed surface (fins).

The use of a fluid enclosed in an airtight strong shell with a small specific heat capacity and an increased coefficient of thermal volume expansion with a reduced mass of the working fluid and, therefore, its total heat capacity will increase the efficiency of the device - at least by an order of magnitude, since if the prototype transducer, the pressure on the inclined flange was limited by a relatively low elastic limit of the TCE material (i.e., a thin-walled pipe under tension), then in the inventive device this pressure is limited only by the degree of compressibility of the working fluid.

The fins of the coolant channel provide a good heat exchange with the working fluid, which will increase the rate of change of its temperature, increase the frequency of rotation of the shaft and, therefore, the resulting power.

In FIG. 1 shows a general view of a thermomechanical transducer with a liquid working fluid; FIG. 2 - section "AA" at the junction of the tube sheet with a spool.

The inventive thermomechanical converter comprises a housing 1, on one end of which there is a flange with an angular contact bearing 2 of the shaft 3 with an inclined flange 4 (in Fig. 1 for clarity, it is shown rotated 90 °), coupled through an axial bearing 5 with elastic axial direction - links 6 of the shell 7 located around the shaft 3.

The ends 8 and 9 of the coolant located inside the shells 7 enter into the tube sheet 10 with a central hole for the shaft 3. The outer channel 8 has ring-shaped outside and longitudinal ribs inside. The internal (outlet) channel 9 is covered, like the shell 7, with a heat-insulating layer.

The movable part of the spool 11 with a channel system for supplying and removing heating and cooling agents from the heat exchanger groups is connected with a shaft 3 in the simplest version by a key, and in more advanced devices it is connected by a known design that allows controlling the advance angle in the supply of coolants. On the end surface of the spool 11 made arcuate grooves 12 and 13. Its cylindrical surface with annular grooves 14 is adjacent to the wall of the sleeve of the housing 1 with pipes for connection with external pipelines. The elastic links 6 in the area of greatest inclination of the flange 4 in their direction are compressed as much as possible.

The operation of the inventive converter is not fundamentally different from the work of its prototype. Only the efforts exerted on the inclined flange 4 are created not by extended HSE, but by compressed links 6 under the action of overpressure in the shells 7 located around the shaft 3. As in the prototype converter, in the inventive device in any of its state on the flange 4, the forces of prestressed HCEs act, which are transmitted through the bearing 5 to the inclined flange 4 of the shaft 3 installed in the bearing units. In this case, the total torque is created on the shaft 3:

M _∑ = ∑ (F _k ⋅tgϕ _k ) ⋅R _fl ,

where: F _k - the force applied to the flange 4 from the compressed link of 6 branches of the k-th HSE;

ϕ _k is the angle (taking into account the sign) of the slope of the thrust bearing groove at the point of application of this force;

R _fl - the radius of the circle along the bottom of the specified grooves.

If the temperature is equal for all HSEs, the total moment M _∑ = 0, and shaft 3 is at rest. With the supply from the external network through the annular grooves 14 and the internal channels of the spool 11 of the heating and cooling fluids, the temperature and, consequently, the liquid pressure inside the shells 7 in each of the two groups of electrical elements, the ends of the channels 8 and 9 of which are connected through the tube sheet 10 to the corresponding arcuate grooves 12 and 13, does not change the same, the balance of oppositely directed torques is disturbed, and the shaft 3 begins to rotate. The spool 11 connected to it connects adjacent HFEs to the heating and cooling flows, which is why the point of application of their resultant force on the support flange 4 is displaced, bypassing the axis of the shaft 3 and preserving its torque at the latter.

Since the channel 8 is made of light and high-strength material with a large coefficient of thermal expansion, its finned structure can not only withstand the external pressure of the working fluid, but also provide an additional positive effect in the operation of the transducer, since the pressure inside the shells 7 will depend on a combination of coinciding signs changes in volumetric parameters of both the working fluid and the heat exchange channel 8. At the same time, the size of their outer shell 7 (not counting the elastic link 6), heat insulators constant of the fluid (e.g., known coatings "Armor" series), remains practically unchanged.

The inventive converter is capable of operating from a wide variety of sources of thermal energy (with or without heat exchangers) and is mainly focused on its renewable types, as well as on the utilization of energy from heat-containing technological products and thermal discharges into the environment.

At a sufficiently high temperature of the heating agent, cascade switching of such converters is possible, which will increase their overall efficiency.

The last remark is borrowed from the description of the thermomechanical converter according to patent RU 2442906 C1. The proposal contained in it: “The most economical flow rate of the coolant can be achieved by the optimal distribution of its flows within the HSE groups using a well-executed shape of the spool channels” is also directly related to the claimed device, since in it this will also increase the converter efficiency several times.

Therefore, the essence of this technical solution should be described in more detail.

The simplified scheme for supplying heating and cooling fluids presented in the description shows their supply to the same groups in terms of the number of TFEs. This is done for ease of explanation. With this scheme, all the heat needed to heat the HSE group is taken from its source. Then, in the cooling circuit, almost all of this heat is taken from these solid fuel cells and removed, at best, partially utilized. And only a small part of it is converted into mechanical work.

In the most advanced scheme, the bulk of the non-converted heat energy is used to pre-heat the above mentioned group of heat-generating elements, and the heat from the heating source is spent only on the final pre-heating of one heat-generating element, which is at the last heating position. And being in the next position, he himself, but already in the composition of another group, heats up the flow of cooling coolant that goes further into the preheated group.

This becomes real if all TECs are connected in series by channels, equipping the latter with controlled gates and leaving for each TEC the possibility of contacting with spool grooves. At the same time, the grooves have a different design, which allows heat transfer from the heat source to only one TEC pre-heated by the heat carrier passing through the cooled TEC and then, bypassing the mentioned “preheated”, through all other TEC. And only then, having given them the bulk of its heat and the already cooled stream through the corresponding groove of the spool, does the converter leave. Switching gates when turning the valve is carried out by special known design cams, rigidly connected with the valve.

The operation of the coolant flow distribution system according to such an economical principle is illustrated by the attached drawings: in FIG. 3 shows a new version of the spool; FIG. 4 is a general view of a converter in an embodiment with a serial connection of a HFC; in FIG. 5 and 6, respectively, sections B-B and B-V along the axes of the HSE and their connecting channels equipped with gates.

The cooling fluid through one of the grooves 12 of the spool 11 passes into the channel 8 of the nearest TEC (see Fig. 5). In this case, the connecting channel with the adjacent HSE is blocked by the gate. Therefore, the coolant flow has an outlet only through channels 8 and 9 of the first of the mentioned HSE and open connecting channels in the entire group of cooled HSE located on its other side. Having passed the latter — already in the heated state — this flow (in front of the closed gate) is fed through the bypass channel in the spool 11 to the heated HSE group, and from it through the second groove 12 is removed from the converter.

At the same time, which has been isolated from this stream and preheated by it, the HSE receives additional heating through the grooves 13 from the external heat source — in a closed loop.

When the shaft 3 is rotated, the spool 11 connected to it sequentially connects to its grooves the next TFEs with optimal automatically adjustable lead.

In this design, the inventive converter, comparable in its efficiency to internal combustion engines, will find wide application in power plants using - mainly - renewable energy sources.

Claims (1)

A thermomechanical converter with a liquid working fluid containing heating and cooling zones, a shaft with an inclined flange mounted in bearings, heat-sensitive elements, a supporting flange coupled to them, supported through an bearing on an inclined shaft flange, and also a spool connected to the shaft, controlling the heating and cooling flows coolants to heat-sensitive elements, characterized in that the working fluid in it is a liquid enclosed in an airtight shell with the ability to change a linear dimension under internal pressure, wherein the liquid is in contact with the coolant through the wall inside the shell of its channel with the developed heat conducting surface provided with fins.

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