HEATING DEVICE

Description

[0001] The invention relates to a thermal engineering device according to the preamble of claim 1.

[0002] A heat recovery device of the type mentioned above is known from the final report "Noise Reduction in Air / Water Heat Pump Systems" by Sulzer Innotec from 2002. This final report is attached to the application documents and is also available at http: / / www.laerm.ch / dokumente / laermsorgen / waermepumpen_bae.pdf. The heat recovery device described therein consists of a refrigerant circuit through which a refrigerant flows and which is equipped with a compressor for compressing the refrigerant. An interference silencer (more precisely: a lambda / 4 resonator; see, for example, document WO 1998 / 037541 A1) is provided for noise reduction of the heat recovery device. In the Sulzer solution, the aforementioned interference silencer serves to reduce airborne noise in the air ducts of the heat pump.

[0003] The invention is based on the objective of improving a thermal device of the type mentioned above. In particular, the thermal device is to be even better insulated. Furthermore, the device is to be as compact as possible.

[0004] This problem is solved with a thermal engineering device of the type mentioned at the outset by the features listed in the characterizing portion of claim 1.

[0005] According to the invention, the interference silencer for reducing low-frequency pulsation caused by the compressor is designed as a pipe leading from the refrigerant circuit and flooded with refrigerant. In other words, the solution according to the invention is characterized by the fact that the interference silencer, preferably a lambda / 4 resonator, is fluidically connected to the compressor via the refrigerant circuit or directly via the refrigerant and thus reduces the resulting noise particularly effectively.

[0006] In order to take particular account of the typically limited space available in thermal engineering equipment, it is especially preferred, as will be explained in more detail below, that the pipeline has at least one bend.

[0007] Other advantageous embodiments of the thermal engineering device according to the invention are set out in the dependent claims.

[0008] For the sake of completeness, reference is also made to the following, more distant prior art: Document EP 2 048 457 A1 discloses a thermal engineering device according to the preamble of claim 1.

[0009] Document DE 10 2006 053 277 B4 discloses a combustion chamber device in which sound occurring in the exhaust gas is dampened by a resonator device.

[0010] Furthermore, "Helmholtz resonators for damping the pressure pulsations of screw compressors" are known from a project by ISMB Dautermann GmbH. A corresponding report is included in the application documents. This report is also available at https: / / www.ismb.de / index.php?Helmholtz_Resonator.

[0011] Finally, there are also so-called chamber silencers (see for example https: / / www.skh-kaeltetechnik.de / Geraeuschdaempfer-Frigo-Mec-22-mm), which are designed in general and not specifically for the operating frequency of the compressor.

[0012] According to the present invention, the above-mentioned objective is achieved by the features of claim 1. Preferred embodiments are defined in the dependent claims.

[0013] The thermal device according to the invention, including its advantageous further developments according to the dependent claims, is explained in more detail below with reference to the graphic representation of a preferred embodiment.

[0014] It shows Figure 1 shows the thermal device according to the invention, specifically the interference silencer in perspective and the refrigerant circuit schematically; Figure 2 shows the interference silencer as a front view according to the invention. Figure 1; and Figure 3 as a side view of the interference silencer according to the Figures 1 and 2 .

[0015] The in Figure 1 The illustrated thermal device consists in a known manner of a refrigerant circuit 2 through which a refrigerant flows and which is equipped with a compressor 1 for compressing the refrigerant, wherein an interference silencer 3 is provided for noise reduction of the thermal device.

[0016] Essential for the thermal engineering device is that the interference silencer 3, for the reduction of a low-frequency pulsation caused by the compressor 1, is designed as a pipe 4 leading from the refrigerant circuit 2 and flooded with refrigerant.

[0017] Furthermore, it is preferred that the refrigerant circuit 2 comprises, in addition to the compressor 1, a condenser 5, an expansion valve 6, and an evaporator 7. In particular, it is preferred that a condenser 5 is arranged downstream of the compressor 1 in the direction of refrigerant flow. Additionally, it is preferred that the interference silencer 3 is arranged downstream of the compressor 1 in the refrigerant circuit 2 in the direction of refrigerant flow (see Figure 1 ). In more detail, it is particularly preferred that the interference silencer 3 is arranged between the compressor 1 and the condenser 5 on the refrigerant circuit 2.

[0018] In this context, a first alternative particularly preferable provision is that a pipe section of the refrigerant circuit 2 provided between the compressor 1 and a connection point to the pipeline 4 of the interference silencer 3 is not longer than 100 cm, preferably not longer than 75 cm, particularly preferably not longer than 50 cm, and most preferably not longer than 35 cm.

[0019] According to a second alternative, it is particularly preferred in this context that a pipe section of the refrigerant circuit 2 provided between the condenser 5 and a connection point to the pipeline 4 of the interference silencer 3 is not longer than 100 cm, preferably not longer than 75 cm, particularly preferably not longer than 50 cm, and most preferably not longer than 35 cm.

[0020] As corresponding investigations of the so-called pipeline modes have shown, both alternatives lead to particularly effective sound attenuation due to the particularly high mode density in the vicinity of the compressor or condenser.

[0021] It is further preferred that the pipe 4 has a cross-sectional area corresponding to the cross-sectional area of ​​the refrigerant circuit 2. Preferably, the pipe 4 also has a length corresponding to a multiple of its diameter. Furthermore, it is preferred that the pipe 4 is closed at the end facing away from the refrigerant circuit 2.

[0022] Furthermore, the pipeline 4 preferably has at least one bend 4.1. The bend 4.1 is preferably optionally designed as a 90° or a 180° pipe bend (see Figures 2 and 3It is also preferred that the pipe 4, after branching off from the refrigerant circuit 2, first has a 90° pipe bend and further along its course has at least one 180° pipe bend.

[0023] Additionally, it is preferred that the pipe 4 extends vertically upwards from the refrigerant circuit 2. Furthermore, it is preferred that the pipe 4 extends upwards at a right angle from the refrigerant circuit 2. It is also preferred that, to prevent oil accumulation in the pipe 4, it is located entirely above its branch point 4.2 on the refrigerant circuit 2. Finally, it is preferred that the pipe 4 is hydraulically connected to a horizontal pipe section of the refrigerant circuit 2.

[0024] Furthermore, the interference silencer 3 is preferably formed from several pipes 4 of different lengths. It is preferred that at least some, preferably all, of the longer sections of the pipes 4 are arranged parallel to each other.

[0025] Furthermore, the interference silencer 3 is preferably designed as a lambda / 4 resonator. Finally, it is also preferred that the interference silencer 3 is designed to reduce frequencies in the range of 20 to 200 Hertz, preferably from 30 to 120 Hertz.

[0026] The heat engineering device according to the invention functions as follows: When the heat engineering device is put into operation, the compressor 1 is started. During operation, the compressor 1 generates sound vibrations, in particular low-frequency pulsations, which propagate through the refrigerant circuit 2 and can thus be transmitted to other components of the heat engineering device or even to external components or rooms, which is an undesirable side effect of the operation of the device.

[0027] In a heat engineering device according to the invention, as illustrated in the figures, the low-frequency pulsations of the compressor 1 propagate via the refrigerant circuit 2 to the interference silencer 3 connected directly behind the compressor 1. The interference silencer 3 consists of several coiled pipes 4, each with a closed end. These pipes 4 each act like a lambda / 4 resonator, meaning that the sound waves / pulsations of the compressor 1 are reflected at the closed end of the pipes 4 in such a way that the reflected waves interfere destructively with the incoming sound waves and thus cancel each other out. For this purpose, the length of the pipes 4 is dimensioned in a manner known per se such that the destructive interference occurs in the range of the compressor pulsations, i.e., depending on the type of compressor 1, in the range of 20 to 200 Hertz, preferably in the range of 30 to 120 Hertz.

[0028] A heat recovery unit of the type described above, in which the compressor 1 is preferably arranged in a first housing intended for outdoor installation and the condenser 5 in a second housing intended for indoor installation (i.e., a so-called split unit), has the advantage that the pulsations generated by the compressor 1 are dampened near their source and thus cannot propagate far along the refrigerant circuit 2. The preferably designed coiled shape of the pipes 4 also makes the interference silencer 3 comparatively space-saving. Reference symbol list

[0029] 1 Compressor 2 Refrigerant circuit 3 Interference silencer 4 Piping 4.1 Bend 4.2 Branch 5 Condenser 6 Throttle 7 Evaporator

Claims

1. A thermotechnical device comprising a refrigerant circuit (2), through which a refrigerant flows and which is provided with a compressor (1) for compressing the refrigerant, wherein the thermotechnical device contains an interference silencer (3) for reducing the noise of the thermotechnical device, wherein the interference silencer (3) is designed in the form of a pipe (4) that originates from the refrigerant circuit (2) and is flooded with refrigerant in order to reduce a low-frequency pulsation caused by the compressor (1), wherein a condenser (5) is assigned to the compressor (1) and arranged downstream of the compressor viewed in the flow direction of the refrigerant, and wherein the interference silencer (3) is arranged on the refrigerant circuit (2) between the compressor (1) and the condenser (5), characterized in that a pipe section of the refrigerant circuit (2), which is selectively provided between the compressor (1) and a connection point to the pipe (4) of the interference silencer (3) or between the condenser (5) and a connection point to the pipe (4) of the interference silencer (3), is not longer than 75 cm, wherein the pipe (4) has at least one bend (4.1), wherein the bend (4.1) is selectively designed in the form of a 90° pipe bend or in the form of a 180° pipe bend, wherein the pipe (4) initially has a 90° pipe bend after branching off from the refrigerant circuit (2) and at least one additional 180° pipe bend along its further extent, wherein the pipe (4) is designed in a closed manner on its end facing away from the refrigerant circuit (2), and wherein the pipe (4) is designed so as to extend vertically upward from the refrigerant circuit (2).

2. The thermotechnical device according to claim 1, characterized in that the pipe (4) is completely arranged above its branch-off point (4.2) on the refrigerant circuit (2) in order to prevent an oil accumulation in the pipe (4).

3. The thermotechnical device according to claim 1 or 2, characterized in that the interference silencer (3) is composed of multiple pipes (4) with different lengths.

4. The thermotechnical device according to claim 3, characterized in that at least a few longer sections of the pipes (4) are arranged so as to extend parallel to one another.

5. The thermotechnical device according to one of claims 1 to 4, characterized in that the interference silencer (3) is designed in the form of a lambda / 4 resonator.

6. The thermotechnical device according to one of claims 1 to 5, characterized in that the pipe (4) is hydraulically connected to a horizontally extending pipe section of the refrigerant circuit (2).

7. The thermotechnical device according to one of claims 1 to 6, characterized in that a pipe section of the refrigerant circuit (2), which is provided between the compressor (1) and a connection point to the pipe (4) of the interference silencer (3), is no longer than 50 cm, particularly no longer than 35 cm.

8. The thermotechnical device according to one of claims 1 to 7, characterized in that a pipe section of the refrigerant circuit (2), which is provided between the condenser (5) and a connection point to the pipe (4) of the interference silencer (3), is no longer than 50 cm, particularly no longer than 35 cm.

9. The thermotechnical device according to one of claims 1 to 8, wherein a condenser (5) is assigned to the compressor (1) and arranged downstream of the compressor viewed in the flow direction of the refrigerant, characterized in that the compressor (1) is arranged in a first housing intended for being installed outdoors and the condenser (5) is arranged in a second housing intended for being installed in a building.