Container for a waste heat utilization circuit

Abstract

A container for a waste heat utilization circuit may include a housing that defines a housing interior such that the housing interior can be flowed through by a working medium. A sheath may be arranged in the housing interior for accommodating an auxiliary medium. The sheath may be fluid-tight and heat-conductive at least in certain areas. The sheath may define a sheath interior of variable volume.

Claims

1. A container for a waste heat utilization circuit, comprising: a housing delimiting a housing interior such that the housing interior can be flowed through by a working medium; a sheath arranged in the housing interior for accommodating an auxiliary medium, wherein the sheath is fluid-tight and is heat-conductive at least in certain areas, and the sheath delimits a sheath interior of variable volume; and wherein the housing interior is at least one of at least partially filled with the working medium and flowed through by the working medium, and the sheath interior is filled with the auxiliary medium in at least one of a gaseous state and a liquid state, and wherein a boiling temperature of the auxiliary medium has a lower value than a boiling temperature of the working medium.

2. The container according to claim 1, wherein the sheath includes a heat-conductive material at least in certain areas for temperature equalization between the working medium and the auxiliary medium.

3. The container according to claim 1, wherein the sheath includes a fluid-tight and resilient membrane.

4. The container according to claim 1, wherein the sheath is arranged freely movable in the working medium disposed in the housing.

5. The container according to claim 1, wherein the sheath is configured as a bellows.

6. The container according to claim 1, further comprising a separating device arranged in the housing interior, the separating device dividing the housing interior into a first partial space where the working medium is flowable, and a second partial space fluidically separated from the first partial space; and wherein the housing includes an opening for pressure equalization, the opening structured and arranged to fluidically connect the second partial space of the housing interior to an external environment.

7. The container according to claim 6, wherein the separating device includes a separating element composed of a fluid-tight and resiliently deformable material for varying a volume ratio of the first partial space and the second partial space relative to one another.

8. The container according to claim 1, further comprising a separating device arranged in the housing interior and separating the housing interior into a first partial space that receives the working medium and a second partial space fluidically separated from the first partial space, wherein the separating device includes a bellows.

9. The container according to claim 8, wherein the bellows of the separating device and a resilient membrane arranged in the second partial space are part of the sheath.

10. The container according to claim 9, wherein the separating device includes a separating element composed of a fluid-tight and resiliently deformable material for varying a volume ratio of the first partial space and the second partial space relative to one another; wherein the separating element is secured to the housing and together with a further resilient and heat-conductive membrane divides the housing interior into three partial spaces; and wherein the separating element and the further membrane are part of the sheath, such that a third partial space is the sheath interior delimited by the sheath.

11. The container according to claim 10, wherein the separating element and the further membrane are secured internally to a shared housing wall of the housing, such that the shared housing wall defines both a part of the housing and a part of the sheath.

12. The container according to claim 5, wherein the sheath is delimited by the bellows, and a separating device arranged in the housing interior has a separating element composed of a resilient and fluid-tight material, and wherein the bellows is arranged in a first partial space of the housing interior separated from a second partial space via the separating device.

13. The container according to claim 1, wherein at least one of (i) the boiling temperature of the auxiliary medium is at least 10K lower than the boiling temperature of the working medium, and (ii) the working medium is ethanol and the auxiliary medium is methanol.

14. The container according to claim 6, wherein the housing includes a fluid inlet for introducing the working medium into the first partial space, and a fluid outlet for directing the working medium out from the first partial space; and wherein at least the fluid outlet is arranged in a lower region of the housing.

15. A waste heat utilization circuit, comprising: a conveying device for conveying a working medium; an evaporator for evaporating the working medium; an expansion machine; and an equalization container, the equalization container including: a housing defining a housing interior that is flowable through by the working medium; a sheath arranged in the housing interior, the sheath defining a sheath interior of variable volume that accommodates an auxiliary medium, wherein the sheath is fluid-tight and is heat-conductive at least in certain areas; and wherein the housing interior is at least one of at least partially filled with the working medium and flowed through by the working medium, and the sheath interior is filled with the auxiliary medium in at least one of a gaseous state and a liquid state, and wherein a boiling temperature of the auxiliary medium has a lower value than a boiling temperature of the working medium.

16. A waste heat utilization device, comprising: a waste heat utilization circuit for circulating a working medium, the waste heat utilization circuit including: a conveyor pump for conveying the working medium; an evaporator for evaporating the working medium; an expansion machine; and an equalization container, the equalization container including: a housing defining a housing interior that is flowable through by the working medium; a sheath arranged in the housing interior and defining a sheath interior of variable volume for accommodating an auxiliary medium, wherein the sheath is fluid-tight and is heat-conductive at least in certain areas; a separating device arranged in the housing interior, the separating device dividing the housing interior into a first partial space where the working medium is flowable, and a second partial space fluidically separated from the first partial space; and wherein the housing includes a pressure equalization opening structured and arranged to fluidically connect the second partial space of the housing interior to an external environment.

17. The waste heat utilization device according to claim 16, wherein the first partial space of the housing interior is at least one of at least partially filled with the working medium and flowed through by the working medium, and the sheath interior is filled with the auxiliary medium in at least one of a gaseous state and a liquid state, and wherein a boiling temperature of the auxiliary medium is at least 10K lower than a boiling temperature of the working medium.

18. The waste heat utilization circuit according to claim 15, further comprising a separating device arranged in the housing interior, the separating device dividing the housing interior into a first partial space where the working medium is accommodated, and a second partial space fluidically separated from the first partial space; and wherein the housing includes a filling and venting opening structured and arranged to fluidically connected the first partial space of the housing interior to an external environment, the filling and venting opening including a connecting piece protruding outwards from the housing away from the housing interior and a sealing cap structured and arranged to close the connecting piece.

19. The waste heat utilization circuit according to claim 15, wherein: the conveying device conveys the working medium in a flow direction and is arranged downstream of the equalization container relative to the flow direction; the evaporator is arranged downstream of the conveying device; the expansion machine is arranged downstream of the evaporator; and the equalization container is arranged between the expansion machine and the conveying device relative to the flow direction, the equalization container including a fluid inlet that receives the working medium flowing downstream of the expansion machine and a fluid outlet that communicates the working medium to the conveying device.

20. The container according to claim 6, wherein the housing further includes a filling and venting opening structured and arranged to fluidically connected the first partial space of the housing interior to the external environment, the filling and venting opening being closeable via a sealing cap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) There are shown, respectively diagrammatically:

(2) FIGS. 1 to 7 illustrate various examples for a container according to the invention,

(3) FIG. 8 in diagrammatic representation the structure of a waste heat utilization circuit of a waste heat utilization device, into which the container according to the invention is integrated.

DETAILED DESCRIPTION

(4) FIG. 1 illustrates a first example of a container 1 according to the invention, as it can be operated in a waste heat utilization circuit 50 of a waste heat utilization device of a motor vehicle. The container 1 has a mechanically rigid housing 2, which delimits a housing interior 3 with a predetermined volume. The housing interior 3 is flowed through by a working medium 6. The latter can be introduced into the housing interior 3 via a fluid inlet 12 provided on the housing 2, and can be directed out from the housing interior 3 again via a fluid outlet 13, likewise provided on the housing 2.

(5) A separating device 8 is arranged in the housing interior 3. The separating device 8 divides the housing interior 3 into a first partial space 10a, which is able to be filled with the working medium 6, and a second partial space 10b, which is fluidically separated from the first partial space 10a. The fluid inlet 12 and the fluid outlet 13 are fluidically connected here to the first partial space 10a. The separating device 8 comprises a separating element 9 made of a fluid-tight and resilient material for varying the volume ratio of the two partial spaces 10a, 10b with respect to one another. The separating element 9 can be realized as a membrane and can comprise, for example, an elastomer. The separating element 9 can be fastened directly, therefore without further fastening means, by means of an adhesive connection on the inner side to the housing 2. Instead of a direct fastening by means of an adhesive connection, alternatively also the use of another fastening method, for example a clamping- or screwed connection, is conceivable. In this case, it is necessary to equip the separating device 8 with suitable fastening elements, by means of which said clamping- or respectively screwed connection of the separating element 9 to the housing 2 can be realized.

(6) As can be seen in FIG. 1, in the housing 2 of the container 1 an opening 15 is present for pressure equalization, which opening connects the second partial space 10b fluidically to the external environment 14 of the container 1, so that the fluid pressure in the second partial space 10b always corresponds to the fluid pressure in the external environment 14. In addition, a filling- and venting opening 16 is provided in the housing 2, with a filling- and venting connecting piece 17 protruding outwards from the housing 2 away from the housing interior 3. The filling- and venting opening 16 connects the first partial space 10a of the housing interior 3 fluidically to the external environment 14 of the container 1. The filling- and venting connecting piece 17 can be closed by means of a suitably constructed sealing cap 18. In the first partial space 10a of the housing interior 3 in addition a sheath 4 is arranged, which is fluid-tight and designed at least in certain areas in a heat-conductive manner. The sheath 4 delimits a sheath interior 5 of variable volume, in which an auxiliary medium 7 is arranged. The sheath 4 can be configured as a fluid-tight and resilient membrane 11, as indicated diagrammatically in FIG. 1. For this purpose, the membrane 11 has a resilient material, which comprises a heat-conductive material for the temperature equalization between the working medium 6 and the auxiliary medium 7. An elastomer also comes into consideration in an analogous manner to the separating element.

(7) As FIG. 1 shows, the auxiliary medium 7 is present in the sheath interior 5 both in a gaseous phase 7a and also in a liquid phase 7b. The boiling temperature of the auxiliary medium 7 has a value lower by 10K, preferably by at least 14K, than the boiling temperature of the working medium 6. The working medium is therefore preferably ethanol, the auxiliary medium ethanol.

(8) In the state shown in FIG. 1, the working medium 6 and the auxiliary medium 7 have an approximately identical temperature. This state can be brought about through heat transport through the heat-transferring membrane 11 from the originally hotter working medium 6 to the originally cooler auxiliary medium. Through said heat absorption through the auxiliary medium 7, the latter forms the partially liquid phase 7b shown in FIG. 1. This, in turn, is accompanied by an increase in the fluid pressure of the working medium 6, until an equilibrium between liquid phase 7a and gaseous phase 7b occurs in the sheath interior 5 delimited by the membrane 11. The fluid pressure of the working medium 6 in the housing interior 3 corresponds then to the boiling temperature of the auxiliary medium 7 in the sheath interior 5. In this way, it is ensured that in the working medium 6in particular without active assistance from the exteriorthe desired supercooling level always occurs for the operation in a waste heat utilization circuit 50: When a working medium 6 with reduced temperature arrives into the housing interior 3 out from a condenser of the waste heat utilization circuit, upstream of the container 1, then through heat transmission the temperature of the auxiliary medium 7 also decreases within a short time, and a portion of the gaseous phase 7a contained therein condenses out to the liquid phase 7b. Accompanying this, the fluid pressure of the auxiliary medium 7 reduces, and therefore also that of the working medium 6. This takes place until the supercooling of the working medium 6 has reached the desired extent again. When, on the other hand, the working medium 6 arrives with a high temperature and therefore in gaseous form, therefore in the form of vapour, out from the condenser into the housing interior 3, then the fluid pressure of working medium 6 and auxiliary medium 7 increases, so that the complete condensing is brought about automatically at the condenser outlet, therefore without the assistance of an external regulation.

(9) FIG. 1 shows the container 1 in the desired state of supercooling of the working medium. By comparison, FIG. 2 shows the container of FIG. 1 in the so-called cold shutdown of the waste heat utilization device 50 using the container 1. In order to prevent a contamination of the working fluid 6 with air owing to leakages in seals on the cold shutdown of the waste heat utilization device 50, the occurrence of an underpressure in the housing interior 3 must be prevented as far as possible. This occurs by means of the second partial space 10b, which is fluidically connected to the external environment 14 of the container 1, so that the volume of the first partial space 10a in the course of any drop in pressure which occurs in the first partial space 10a can be immediately reduced. In this way, the components of the waste heat utilization circuit 51 of the waste heat utilization device 50 which are filled with the working medium 6 in gaseous phase in operation, can be flooded with the working medium 6 in liquid phase.

(10) Therefore, when the fluid pressure in the first partial space 10a falls below a minimum permissible swelling pressure, then the first partial volume 10a contracts by means of the flexible separating device 8, so that the underpressure which has occurred can reduce again. In order to prevent said underpressure in the container 1, the second partial space 10b is in contact with the external environment 14 via the opening 15, so that a pressure equalization is possible. As a comparison of FIG. 2 with the illustration of FIG. 1 shows, by movement of the separating element 9 away from the housing wall of the housing 2, the volume of the second partial space 10b is increased compared to the state of FIG. 1, and that of the first partial space 10a is reduced. It can be seen, furthermore, from FIG. 2 that owing to the pressure reduction of the fluid pressure in the first partial space 10a, the volume of the sheath interior 5 delimited by the sheath 4 also decreases, so that the gas phase 7a of the auxiliary medium 7, still present in the state of FIG. 1, condenses out completely.

(11) FIG. 3 shows a variant of the container 1 of FIGS. 1 and 2. In the example of FIG. 3 the sheath 4 is configured in the manner of a (first) bellows 19. Furthermore, in the container of FIG. 3 the separating device 8 for the formation of two partial spaces 10a, 10b is dispensed with, so that also no opening 15 for pressure equalization is provided on the housing 2. As FIG. 3 clearly shows, the bellows 19 has a first bellows end wall 20a and a second bellows end wall 20b lying opposite the first bellows end wall 20a. The two bellows end walls 20a, 20b delimit on the face side the bellows 19 which is configured substantially in the manner of a cylinder. The two bellows end walls 20a, 20b are connected by means of the resilient and heat-conductive membrane 11 already known from FIG. 1. The membrane 11 forms a circumferential wall 21 of the substantially cylindrical bellows 19. Said circumferential wall 21 can be fastened by means of a fluid-tight adhesive connection to the two bellows end walls 20a, 20b. Alternatively thereto, other suitable fastening methods come in consideration, in particular a screwed or clamping connection.

(12) The container 1 according to FIG. 4 is a further development of the example of FIG. 3. In the container of FIG. 4, in addition to the sheath 4 configured as a first bellows 19, the separating device 8 is also configured as a second bellows 22. The volume delimited by the second bellows 22 forms the first partial space 10a, the region of the housing interior 3 complementary thereto forms the second partial space 10b. In the example of FIG. 4, the first bellows 19 is arranged in the second partial space 10b.

(13) In accordance with FIG. 4, the second bellows 21 also forms a first bellows end wall 23a, and a second bellows end wall 23b lying opposite thereto. The two bellows end walls 23a, 23b delimit on the face side the second bellows 22 configured substantially in the manner of a cylinder. The two bellows end walls 23a, 23b are connected to one another by means of the separating element 9 of the separating device 8, therefore of the second bellows 22, in the form of a fluid-tight membrane 24. For this, the separating element 9 is configured as a resilient circumferential wall 25 delimiting the second bellows 22 on the circumferential side. The circumferential wall 25 can be fastened to the two end walls 23a, 23b by means of a fluid-tight adhesive connection. Alternatively thereto, the fastening methods for the first bellows 19, named in connection with the example of FIG. 3, also come into consideration, therefore in particular a screwed or clamping connection.

(14) In the example of FIG. 4, in an analogous manner to the container of FIGS. 1 and 2, a fluid inlet 12 and a fluid outlet 13 are provided on the housing 2, which are both in fluid connection with the volume delimited by the second bellows 22, therefore the first partial space 10a. As can be seen from FIG. 4, the end walls 20a and 23b of the two bellows 19, 22 can lie opposite one another. The end wall 23a, as shown in FIG. 4, can be formed by a housing wall 26 of the housing 2, or the end wall 23a can be fastened, for instance by means of an adhesive connection, flat against this housing wall 26.

(15) Furthermore, on the housing 2 of FIG. 4, in an analogous manner to the container of FIGS. 1 and 2, a filling- and venting opening 16 is provided, having a filling- and venting connecting piece 17 protruding outwards from the housing 2, away from the housing interior 3. The filling- and venting opening 16 fluidically connects the first partial space 10a of the housing interior 3 to the external environment 14 of the container 1. The filling- and venting connecting piece 17 can be closed in a sealing manner by means of a sealing cap 18. The container 1 according to FIG. 4 has an opening 15, which fluidically connects the second partial space 10b to the external environment 14 of the container for the purpose of pressure equalization. A pressure relief valve 28 can be constructed on the filling- and venting connecting piece 17.

(16) FIG. 5 shows a further technical realization possibility for the container 1. In this variant, the separating device 8, configured as a (second) bellows 22, is part of the sheath 4. A resilient membrane 29, which is arranged in the second partial space 10b, and a housing wall 26 of the housing 2 complete the part of the (second) bellows 22, which is part of the sheath 4, to the sheath 4.

(17) In a further variant, which is illustrated in FIG. 6, the separating device 8 comprises a separating element 9 made of a fluid-tight and resiliently deformable material for varying the volume ratio of the two partial spaces 10a, 10b relative to one another. The separating element 9 is fastened to the housing 2 together with a further resilient and heat-conductive membrane 11, and divides the housing interior 3 into three partial spaces 10a, 10b, 10c. The separating element 9 and the membrane 11 are part of the sheath 4. The third partial space 10c forms the sheath interior 5 delimited by the sheath 4. The fastening of separating element 9 and membrane 11 can take place such that the shared housing wall 26, as illustrated in FIG. 6, forms both a part of the housing 2 and also of the sheath 4.

(18) In the variant according to FIG. 7, the membrane 11 is replaced by a first bellows 19, which with regard to its structure corresponds substantially or exactly to the bellows 19 of FIG. 3. The sheath 4 is formed by the bellows 19, as in the example of FIG. 3. The separating device 8 is configured in an analogous manner to FIG. 6 and is realized as membrane 29 from a resilient and fluid-tight material. As FIG. 7 shows, the first bellows 19 is arranged in the first partial space 10a. The bellows end wall 20a of the bellows 19 can be formed by the housing wall 26 of the housing 2. Alternatively, said bellows end wall 20a can, however, also be fastened internally on the housing wall 26, for example by means of a flat adhesive connection.

(19) In the example of FIGS. 5 to 7, the housing 2 is configured in a pot-like manner with a housing pot 27, which is closed by the housing wall 26, so that the housing wall 26 acts in the manner of a cover.

(20) FIG. 8 shows diagrammatically the structure of a waste heat utilization device with a waste heat utilization circuit 51, in which the previously presented container 1 is arranged, and in which the working medium 6 circulates. In the waste heat utilization circuit 51, a conveying device 52 in the form of a conveyor pump for conveying the working medium 6 is arranged downstream of the container 1. Downstream of the conveying device 52, two evaporators 53 are arranged, in which the working medium 6 is evaporated. Downstream of the evaporators 53, an expansion machine 54 is arranged. Downstream of the expansion machine 54, a condenser 55 is provided, which is followed by the container 1, so that the waste heat utilization circuit 51 forms a closed circuit. Between the condenser 55 and the container 1, a filter device 56 can be optionally provided for filtering the working medium 6.