PISTON COMPRESSOR, MORE PARTICULARLY FOR A HEAT PUMP

Abstract

The invention relates to a piston compressor, comprising a cylinder, a piston mounted for linear movement along a cylinder longitudinal axis (L), and a working chamber. The working chamber is fluidically connected to a working-medium inlet chamber by means of a first valve portion and to a working-medium outlet chamber by means of a second valve portion. The working chamber is delimited by an inner lateral surface, a piston end face and a working-chamber head portion, and the working-chamber head portion is formed from a geometric arrangement of the first and second valve portions. For improved efficiency, the first and second valve portions are arranged such that the working chamber is tapered toward the working-chamber heat portion.

Claims

1. A piston compressor for a heat pump, comprising a cylinder, a piston mounted in the cylinder for linear movement along a cylinder longitudinal axis, a working chamber formed in the cylinder with its volume capable of being changed via a piston movement, a valve device comprising a first and second valve portion, wherein the working chamber is fluidically connected to a working-medium inlet chamber by means of the first valve portion of the valve device and to a working-medium outlet chamber by means of the second valve portion of the valve device, wherein the working chamber is delimited by an inner lateral surface of the cylinder, a piston end face formed on the piston end of the piston and a working-chamber head portion arranged opposite from the piston end face, wherein the working-chamber head portion is formed from a geometric arrangement of the first and second valve portions, and the first and the second valve portion are arranged in such a way that the working chamber tapers in the direction of the working-chamber head portion.

2. The piston compressor according to claim 1, wherein the first and second valve portions are each arranged at an angle not equal to 90? to the cylinder longitudinal axis (L).

3. The piston compressor according to claim 1, wherein the first and second valve portions are arranged at an angel deviating from one another relative to the cylinder longitudinal axis (L).

4. The piston compressor according to claim 1, wherein the first and second valve portions are arranged at the same angle relative to the cylinder longitudinal axis (L).

5. The piston compressor according to any one of the claim 1, wherein the working-chamber head portion terminates at an acute or obtuse angle with respect to its cross-section, wherein the acute or obtuse angle is spanned by the first and second valve portions.

6. The piston compressor according to any one of the claim 1, wherein the working-chamber head portion terminates at a right angle with respect to its cross-section, wherein the right angle is spanned by the first and second valve portions.

7. The piston compressor according to claim 1, wherein the working-chamber head portion has a concave cross-sectional shape in the direction of the working chamber.

8. The piston compressor according to claim 1, wherein the first and second valve portions define a working-chamber head portion shaped like a hemisphere.

9. The piston compressor according to claim 1, wherein the piston end face geometrically corresponds to the working-chamber head portion.

10. The piston compressor according to claim 1, wherein the working-medium inlet chamber and the working-medium outlet chamber are separated from each other by a separator adjacent to the working-chamber head portion.

11. The piston compressor according to claim 10, wherein the separator comprises an insulation layer arranged between a wall of the working-medium inlet chamber and a wall working-medium outlet chamber.

12. A high-temperature heat pump with a piston compressor according claim 1.

13. The piston compressor of claim 11 wherein the insulation layer is an air gap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1 illustrates a portion of a piston-cylinder unit of a piston compressor known from the prior art;

[0037] FIG. 2 illustrates a portion of a piston-cylinder unit of a piston compressor designed according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 shows a portion of a piston-cylinder unit of a piston compressor known from the prior art. A cylinder 1 (this can also be referred to as a cylinder housing) as well as a piston 2, which is mounted in the cylinder 1 for linear movement along a cylinder's longitudinal axis, are shown. In the cylinder 1, a working chamber 3 is formed, wherein its volume can be changed via a movement of the piston 2.

[0039] The working chamber 3 is flow-connected via a first valve portion 11 of a valve device 4 to a working-medium inlet chamber 5 and flow-connected to a working-medium outlet chamber 6 via a second valve portion 12 of the valve device 4. The working chamber 3 is delimited by an inner lateral surface 7 of cylinder 1, a piston end face 8 formed at one end of the piston 2 and a working-chamber head portion 9 opposite to the piston end face 8, wherein the working-chamber head portion 9 is formed from a geometric arrangement of the first and second valve portions 11, 12. In the case of the arrangement known from the prior art and shown in FIG. 1, the first valve portion 11 is arranged at the same height as the second valve portion 12 (which is positioned in the center). The valve portions 11, 12 are arranged at an angle of 90? relative to the cylinder's longitudinal axis L. The piston 2 has an outer diameter that corresponds to the inner diameter of the cylinder 1. The piston end face 8 comprises a geometry corresponding to the working-chamber head portion 9. In the present example, the piston end face 8 is also arranged perpendicular to the cylinder's longitudinal axis L and has a flat shape.

[0040] In the case of such piston compressors, the working chamber 3as mentioned comprises a working-chamber head portion 9. This is flat and perpendicular to the cylinder's longitudinal axis L of cylinder 1, which is mounted for movement along the cylinder's longitudinal axis L of piston 2. The piston end faces 8 lying opposite valve portions 11, 12 are also flat. Part of the surfaces of the first valve portions 11 (in the present case, there are two first valve portions 11 on the outer sides) are used for suction valves. The same applies to the area of the second valve portion (centered), which is used in part for the arrangement of outlet valves. Such an arrangement causes the suction gas to flow directly past the ejected gas, which can cause unwanted energy or heat losses.

[0041] FIG. 2 shows a portion of a piston-cylinder unit of a piston compressor designed according to the invention. The first and second valve portions 11, 12 are arranged in such a way that the working chamber 3 is tapered toward the working-chamber head portion 9. In this case, the working-chamber head portion 9 is designed in the shape of a roof. The first and second valve portions 11, 12 are each arranged at an angle not equal to 90? to the cylinder's longitudinal axis L. The piston end face 8 corresponds geometrically to the working-chamber head portion 9. In the present case, the dotted line indicates that the piston end face 8 is also roof-shaped, and, in particular, it has a cross-sectional triangular shape.

[0042] The tapered geometry of the working chamber 3 in the direction of the working-chamber head portion 9 ensures that the contact surface between the working chamber 3 and the respective chambers (working-medium inlet chamber 5, working-medium outlet chamber 6) is increased. This increases the area available for valve portions 11, 12. With the increased area of the valve portions 11, 12, the pressure loss is reduced. With the proposed geometry, the working medium flowing into and out of the working chamber 3 does not flow directly past each otheras is the case in the prior art. Flow separation is improved, which avoids unwanted heat transfers.

[0043] The working-medium inlet chamber 5 and the working-medium outlet chamber 6 are separated from each other by a separator 10 (shown by the dotted line) adjacent to the working-chamber head portion 9. The separator 10 comprises an insulation layer arranged between a wall of the working-medium inlet chamber 5 and a wall of the working-medium outlet chamber 6, which can be designed, in particular, in the form of an air gap. This also reduces heat loss.

REFERENCE LIST

[0044] 1 cylinder [0045] 2 piston [0046] 3 working chamber [0047] 4 valve device [0048] 5 working-medium inlet chamber [0049] 6 working-medium outlet chamber [0050] 7 inner lateral surface [0051] 8 piston end face [0052] 9 working-chamber head portion [0053] 10 separator [0054] 11 first valve portion [0055] 12 second valve portion [0056] L cylinder's longitudinal axis