EP2212627A1

EP2212627A1 - Refrigerator

Info

Publication number: EP2212627A1
Application number: EP08802795A
Authority: EP
Inventors: Jürgen Misselhorn
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-10-05
Filing date: 2008-10-06
Publication date: 2010-08-04
Also published as: DE102007047642B4; DE102007047642A1; WO2009046953A1; US20100263392A1

Abstract

The invention relates to a refrigerator, which, in contrast to conventional refrigerators, consists of a number of heat exchangers (10), which are divided into two halves, in which the same cyclic refrigerating process takes place at the same time but temporally offset. However, all the heat exchangers are supplied by the same compressor (20). During certain sections of time, a cool medium (evaporator) flows around the one half of the heat exchanger and a warm medium (liquefier) around the other half. The refrigerating cycle consists of six changes of state: isochoric heating, isothermal expansion, isobaric liquefaction, isochoric cooling, isothermal compression and isobaric evaporation. In the model described, the compressor is a piston compressor, which acts in two ways, in that a connection to the heat exchangers can be established on both sides of the piston over valves at specified times within a cycle period. The piston is driven by a linear motor or by a crankshaft and connecting rod. While the working gas is being compressed on one side of the piston in the heat exchanger, it is aspirated on the other side from a different heat exchanger. It is pointed out that other types of compressors may also be used. Because of the six changes of state realized with this machine, a new cycle is formed, with which an efficiency (refrigeration number) is achieved, which exceeds that of conventional refrigerators or heat pumps.

Description

Refrigeration technical area

In the present invention is a chiller, which operates on the principle of a circular process with six state changes: two isochores, two isobars, two isotherms.

In this chiller find several of the above-described cooling processes simultaneously, but offset in time instead. The state changes expansion and compression of the individual cycle processes are effected by a common refrigeration compressor.

State of the art

Various cooling machine processes are used for cooling purposes and as heat pumps, which are briefly described below:

The cold air machine (left-handed Joule process)

In this process, air is sucked in at ambient temperature and compressed isentropically. The adiabatically heated air is then cooled isobaric and then isentropically relaxed. Finally, the air is heated isobarically again. This process is mainly used for aircraft air conditioning and mine ventilation.

Philips gas refrigerator (left-handed Stirling process)

This closed process is mainly used for the liquefaction of air and other gases. The theoretical process consists of the following state changes: isothermal compression in the compression chamber isochore cooling in the regenerator isothermal expansion in the expansion chamber isochoric heating in the regenerator Steam chiller (plank process)

This process is used in different variants in the general refrigeration of refrigerators, cold rooms, chilled water production, etc. The theoretical process essentially consists of the following state changes:

- isentropic compression by means of a compressor

isobaric (also isothermal) cooling in a condenser

- isenthalpe relaxation by throttling through an expansion valve or capillary

isobaric (also isothermal) heating in an evaporator

Other non-mechanical refrigeration circuits, such as those of the adsorption refrigeration machine, are not relevant to comparison with the subject matter of this invention.

The object of the present invention is to provide a refrigeration process with improved efficiency as well as a refrigeration machine using this process.

According to the present invention, this object is achieved by a refrigeration process in which six changes in state of a trapped working gas between two temperature levels occur in the following order: isochoric heat absorption, isothermal compression (compression), isobaric liquefaction, isochoric heat release, isothermal expansion (expansion) , isobaric evaporation.

Preferably, in this cooling process, the compression and the relaxation take place simultaneously by a compressor.

Preferably, the cooling process takes place in parallel but offset in time in several heat exchangers. This allows an even higher efficiency can be achieved.

The cooling process preferably takes place at least in three heat exchangers. It is particularly advantageous if the cooling process takes place in six heat exchangers. det. The advantage of this is that then each step of the process is performed simultaneously by a heat exchanger.

Furthermore, the object of the invention is achieved by a refrigerating machine comprising: at least one heat exchanger having two regions which are fluidly interconnected by a closure device such that the gaseous and liquid state agent flows from one half to the other and flows smoothly can distribute. The one area of the heat exchanger is surrounded by a warm medium and the other area is flowed around by a cold medium. Means for turning the heat exchanger are provided to flow liquid fluid from one area of the heat exchanger to the other area. A working cylinder is provided which is selectively connected to a portion of the heat exchanger by a connecting tube and a valve when the valve is in its open position and is separate from the heat exchanger when the valve is in its closed position. Furthermore, a control device is provided which selectively actuates the valves and the closure device to carry out the steps of the above-described refrigeration process.

Advantageously, in the refrigerating machine, the two regions of the heat exchanger are thermally insulated from each other by insulation. The warm and the cold medium can each be gaseous or liquid.

In the chiller advantageously the connection between the warmed and cooled half can be temporarily closed by the closure device.

It is preferable that the refrigerator has at least three heat exchangers. In particular, it is preferable that the refrigerator has six heat exchangers. The advantage of this is that then each step of the process is performed simultaneously by a heat exchanger.

Advantageously, a refrigerating machine in which the heat exchangers are arranged in a star shape around the longitudinal axis of the working cylinder and the connecting pipes off alternately connected to both sides of the working cylinder. The heat exchangers are rigidly connected to the working cylinder and are suspended with this rotatable about the common longitudinal axis. Furthermore, a motor for rotating the heat exchanger and the working cylinder is provided, and wherein conducting means are provided which direct the hot and the cold medium so that the individual heat exchangers during one half of the rotation through the cold medium and during the other half of the rotation through the warm medium are led.

In the refrigerating machine, it is preferable that the working cylinder is a double-acting working cylinder in which the compressions and expansions take place not only on one side but on both sides of the piston.

The control device for controlling the valves is preferably a cam.

The chiller may advantageously be used as a heat pump to generate heat that may be delivered to a heating system or other process by removing this heat from a colder gaseous or liquid medium.

In the chiller can be used advantageously for the heating and evaporation radiant heat and for the cooling and liquefaction, the heat are emitted by radiation, rather than deliver it to gaseous or liquid medium.

Particular advantages arise when a refrigerator arrangement is provided, which consists of several refrigerators according to one of the preceding claims, which are placed in series behind the other in the warm and cold medium, wherein the warm medium flows through the individual chillers in succession cascade and wherein the temperature Flow through the heat exchanger of the individual chillers decreases. The cool medium flows through the same chillers in the opposite direction in the reverse order cascade-like, the temperature of the cool medium during the Durch- flow of the heat exchanger of the individual chillers increases and wherein a temperature difference between the warm and the cool medium is maintained. The goal is to achieve very high cooling or heating.

The present invention is a refrigeration machine having a high refrigeration rate with six state changes. With this chiller, which can also be used as a heat pump, a heat exchange between two media is to be effected by external work, the heat flow from the medium with the lower temperature to the medium with the higher temperature.

In principle, these are a number of heat exchangers in which evaporation and liquefaction take place, all but not simultaneously connected to a compressor. The compressor may consist of a cylinder with pistons, which is used to simplify the description below.

Short description of the drawing

In the drawing, the figures show the following:

Fig. 1 is a schematic representation of a refrigerator model, in which the essential components and their relationship are shown to each other to represent the realization of the refrigeration cycle.

Fig. 2, the valve control as a cam with cam-controlled valves.

Fig. 3 is a schematic representation of a rotor of a refrigerator with six heat exchangers.

Fig. 4A is a description of the symbols used in Figs. 4B and 4C.

4B is a representation of bars 1 to 4 of the refrigeration process.

4C is a representation of bars 5 and 6 of the refrigeration process.

Fig. 5 is a pressure-enthalpy diagram for C2H ₂ F2, refrigerant R134a, as a working substance.

6 shows a P-V diagram with reference to the P-H diagram shown in FIG. 5.

Fig. 7 is a Ts diagram with respect to the Ph diagram shown in Fig. 5. As best seen in Figures 1 and 3, a refrigerator 100 according to the present invention comprises six heat exchangers 10, each consisting of two halves. Each heat exchanger 10 is connected to a compressor cylinder 20 through a connecting pipe 30. In the connecting tube 30 is a valve 40. The compressor cylinder 20 has a double-acting piston 22.

As shown in Fig. 1, each heat exchanger 10 consists of two halves 11, 12 which are thermally insulated by an insulation 13. Each heat exchanger 10 has opposite pipe pairs 14 (in the drawing, two pipe pairs 14 are shown for each heat exchanger 10), which are each connected to each other via a common closure device 16. When the shutter 16 is opened as shown at "A" and "X", the tubes of each tube pair 14 are connected together. If the closure device 16 is closed, then the connection between the two tubes of the individual pairs of tubes is sealed gas-tight.

The individual tubes of the heat exchangers 10 may have ribs 15, as shown, or they may be smooth. Also, the heat exchangers 10 need not be made of tubes, but may take any other form which is pressure resistant. The two halves 11, 12 of the heat exchanger 10 may also be different. It depends solely on the appropriate heat exchange.

The closure device 16 is arranged between the two halves 11, 12 of the heat exchanger 10. In the present embodiment, the closure device 16 is spring-biased to a closed position. An actuating device 17 opens the closure device 16. The actuating device 17 consists in the present embodiment of a roller 18 which rolls on a cam plate 19.

From the refrigerant compressor, only the main components are shown, ie the compressor cylinder 20 and the piston 22. The piston 22 is doubly effective. While it is compressed on one side of the piston 22, is relaxed or sucked on the other side. The piston 22 can be driven in different ways. For example, it can be controlled by a crankshaft and a piston rod or pleu- or be driven by a linear electric motor. As a result, the compressions and expansions can take place not only on one side but on both sides of the piston 22. While compression takes place on one side, expansion takes place on the other.

In the embodiment described here, the double action of the piston during each movement of the piston, the working gas is compressed into a heat exchanger 10, while at the same time the working gas is sucked from another heat exchanger 10.

The valves 40 between the heat exchangers 10 and compressor cylinders 20 are mechanically open and close in the present embodiment. As best shown in FIG. 2, the valves 40 each have a plunger 41 and a roller 42. The valves 40 are arranged in a star shape around a cam disk 50 around. The cam plate 50 has cams 51 and a base circle 52. Other types of valve controls, such as e.g. Magnetic or pneumatic valves, but are also used. In the illustration, the valve A is opened while the valves B and C are closed. The valves 40 are located in the connecting pipe 30.

As best seen in Fig. 3, the heat exchangers 10 are arranged in a star shape around the compressor cylinder 20 and fixedly connected thereto. One half of the heat exchanger 10 is connected to the front and the other half on the back of the compressor cylinder 20. The heat exchangers 10 are shown as simple tubes 14, which, however, represent a gallery of tubes 14. In the middle of the cam plate 50 of FIG. 2 can be seen. An unillustrated engine is provided to rotate the entire assembly of the heat exchangers (heat exchanger block) about the central axis. The direction of rotation is counterclockwise. The half 12 of the heat exchanger 10, to which the connecting pipe 30 is connected to the compressor cylinder 20 is flowed around by a warm medium or circulated, while the other half 11 flows around or is surrounded by a cooling medium. Operation of the chiller will proceed as set forth below. In FIGS. 3, 4A-4C, the cycles of the refrigerator are shown one after the other. FIGS. 4A-4C show a representation of the process flow on the basis of the model shown in FIG. The respective piston movement, the valve position and the position of the closure device between the individual heat exchanger halves, the progress of the individual heat exchangers within a rotation are shown schematically. Between the heat exchanger halves 11, 12, the closure device 8 is shown as a circle with bars. If the beam is aligned parallel to the longitudinal axis of the heat exchanger 10, then the closure device 16 is opened. If the bar is transverse to the longitudinal axis of the heat exchanger 10, it is closed.

Valves that are opened with the plunger from the cam and closed with spring pressure are shown "from above." The operation corresponds to the representation in Fig. 2. This type of valves can best represent, but it can be any other Type of suitable valves are used.

The heat exchangers 10 revolve around the central axis according to the arrows shown. The areas where the valves 40 are opened and the shutters are closed are shown in the figures. The compressor cylinder 20 can be seen from the front side and is shown in Fig. 3 as a circle. On the basis of this representation, the course of the refrigeration cycle process will be explained.

In Fig. 3, the direction of rotation is indicated by arrows. The separation of the individual state changes of the working substance are identified by the numbers on the outside of the rotor consisting of the heat exchangers 10 and the working cylinder 20. These numbers are also registered at corresponding points in the thermodynamic diagrams in Figs. 5-7.

The sequence of the individual state changes is briefly described below.

1-2 isochore heat absorption

In Fig. 3, the heat exchanger 10 in the position (1) has just left the cooling section. The contained material has completely evaporated. The closure device 16 is closed. During further rotation, the internal heat exchanger half 12 in the heating section and is warmed up there. Since the closure device 16 and the valve 40 are closed, the vapor of the working substance is enclosed in a space with constant content. Due to the heat exchange with the circulating medium, the working fluid heats up at a constant volume to the temperature of the warm medium. The pressure increases. In Figs. 5 to 7, this process is shown as the route (1) - (2).

2-3 isothermal compression

As soon as the heat exchanger 10 reaches position (2) in FIG. 3, the valve 40 opens and further vapor of the working substance is pressed out of the compressor cylinder 20 through the piston 22 into the heat exchanger 10. The pressure within the heat exchanger 10 increases. The adiabatic heat of the compression is dissipated by the warm medium, so that an isothermal compression takes place. Since the pressure in the heat exchanger 10 is higher than the vapor pressure of the working fluid, the working fluid liquefies. In the position (3), the valve 40 closes. In Figs. 5 to 7, this process is shown as the distance (2) - (3).

3-4 isobaric liquefaction

In the prevailing overpressure in the heat exchanger 10, the working fluid is liquefied until the vapor pressure of the working fluid is reached at the temperature of the warm medium. The liquefaction heat is dissipated by the warm medium. The heat exchangers 10 are designed so that this process is completed when the position (4) is reached. In Figs. 5 to 7, this process is shown as the distance (3} - (4).

4-5 Isochore heat removal

In position (4), the closure device 16 is opened. The condensate of the working fluid can now flow into the cooled half 11 of the heat exchanger 10 (condenser). The heat exchange between the medium and the working substance cools the condensate down to the lower temperature level of the cool medium. Due to the, at this temperature low vapor pressure of the working fluid, more steam is condensed until the vapor pressure of the working fluid is reached at this temperature. The entire mass of the working substance is cooled at the position (5) to the lower temperature level. Since during the entire route the VoIu menu in the heat exchanger 10 remains unchanged (valve 40 closed, shutter 16 open), the cooling takes place at the same volume. In Figs. 5 to 7, this process is shown as the distance (4} - (5).

5-6 Isothermal expansion

The valve 40 is opened in the position (5). From the compressor cylinder 20, the working fluid is sucked out by a negative pressure from the heat exchanger 10. The pressure falls below the vapor pressure of the working substance at the lower temperature. To get the vapor pressure, the working fluid evaporates. Since heat is constantly supplied by the cool medium, this evaporation takes place at a constant temperature. There is thus an isothermal expansion and evaporation. In the position (6), the valve 40 closes. In Figs. 5 to 7, this process is shown as the distance (5) - (6).

6-1 isobaric evaporation

At reduced pressure in the heat exchanger 10, the working fluid evaporates until the vapor pressure of the working fluid is reached at the lower temperature. The heat of vaporization is brought about by the cool medium. The heat exchangers 10 are designed so that this process is completed when the position (1) is reached again. In Figs. 5 to 7, this process is shown as the route (6) - (1).

In FIGS. 4A to 4C, the alternation of the processes in the various heat exchangers and the relationship between them and the compressor cylinder 20 can be understood. The rotation of 10 has progressed by 60 ° at each bar shown. Based on the sequence shown, it should be noted that the piston 3 changes direction after a rotation by 60 ° and has completed three complete cycles (back and forth) during a complete revolution of the rotor consisting of the heat exchangers and the compressor cylinder. In this construction, the piston will complete exactly as many cycles as heat exchangers 10 are connected to one side of the compressor cylinder 20.

It is considered that in the refrigerator, the number of heat exchangers is a multiple of three. Furthermore, an advantageous possibility that the Number of heat exchangers is a multiple of six. Then a correspondingly connected working cylinder can be selectively connected at its one side to a heat exchanger to be pumped straight into, and at its opposite side it can be connected to another heat exchanger from which it is to be pumped straight out.

The main difference of this invention with the prior art is that several heat exchangers consisting of evaporator and condenser, are operated simultaneously, but the processes of the refrigeration cycle process take place staggered in each heat exchanger, but the state changes expansion and compression always at each heat exchanger by the same Compressor be triggered.

The operation of this invention differs from all other conventional refrigeration cycles by the six required state changes. Common cycles have essentially four state changes (apart from overheating of the working vapor or integrated intermediate circuits).

This invention is also characterized by a higher theoretical efficiency than the conventional refrigeration circuits.

Claims

claims

1. refrigeration process in which six changes in state of an enclosed working gas between two temperature levels occur in a cycle in the following order: isochoric heat absorption, isothermal compression (compression), isobaric liquefaction, isochoric heat release, isothermal expansion, isobaric evaporation.

2. Refrigeration process according to claim 1, wherein the compression and the relaxation take place simultaneously by a compressor.

3. cooling process according to claim 1 or 2, wherein the cooling process takes place in parallel but offset in time in a plurality of heat exchangers.

4. Refrigeration process according to one of the preceding claims, wherein the cooling process takes place at least in three heat exchangers.

5. Refrigeration process according to one of the preceding claims, wherein the cooling process takes place in six heat exchangers.

6. A refrigeration machine, comprising: at least one heat exchanger having two regions which are fluidly interconnected by a closure device such that the gaseous and liquid state agent may flow from one region to the other and evenly distribute; wherein one area of the heat exchanger flows around a warm medium and the other area is surrounded by a cold medium; Means for conducting liquid fluid from an area of the Heat exchanger in the other area; a working cylinder selectively connected to a portion of the heat exchanger by a connecting pipe and a valve when the valve is in its open position and separated from the heat exchanger when the valve is in its closed position; a control device that selectively actuates the valves and the closure device to perform the steps of the refrigeration process of claim 1.

7. A refrigerator according to claim 6 wherein the two regions of the heat exchanger are thermally insulated from each other by an insulation.

8. A refrigerator according to claim 6 or 7, wherein the hot and the cold medium can each be gaseous or liquid.

9. chiller according to one of the preceding claims, wherein the connection between the heated and cooled half can be temporarily closed by the closure device.

10. chiller according to one of the preceding claims, which has at least three heat exchangers.

11. Refrigerating machine according to one of the preceding claims, which has six heat exchangers.

12. A refrigerator according to any one of claims 10 to 13, wherein the heat exchangers are arranged in a star shape around the longitudinal axis of the working cylinder and the connecting pipes are alternately connected to both sides of the working cylinder, wherein the heat exchangers are rigidly connected to the working cylinder and with this about the common longitudinal axis are rotatably suspended, wherein a motor for rotating the heat exchanger and the working cylinder is provided, and wherein guide means are provided, the warm and the cold medium so lei- that the individual heat exchangers are guided through the cold medium during one half of the revolution and through the warm medium during the other half of the revolution.

13. chiller according to one of the preceding claims, wherein the working cylinder is a double-acting cylinder, in which the compression and expansion take place not only on one side but on both sides of the piston.

14. Refrigerating machine according to one of the preceding claims, wherein the control device is a cam.

15. A refrigerator according to one of the preceding claims, wherein the refrigerator is used as a heat pump to generate heat that can be delivered to a heating system or other process by this heat is removed from a colder gaseous or liquid medium.

16. A refrigerator according to any one of the preceding claims, wherein for the heating and evaporation radiant heat is used and for the cooling and liquefaction, the heat is emitted by radiation, rather than deliver it to gaseous or liquid medium.

17. refrigerating machine arrangement, which consists of a plurality of refrigerating machines according to one of the preceding claims, which are placed in series one behind the other in the hot and cold medium, wherein the warm medium flows through the individual chillers in succession cascade and wherein the temperature decreases as it flows through the heat exchanger of the individual chillers in which the cool medium cascades through the same refrigerating machines in the opposite direction in the reverse order, the temperature of the cool medium increasing as it flows through the heat exchangers of the individual refrigerating machines and maintaining a temperature difference between the warm and the cool medium remains, with the aim of achieving very high cooling or heating.