DE1426941A1 - Refrigerant compressor - Google Patents

Description

The main patent relates to a motor-driven refrigerant compressor with suction pressure-dependent control of the Filling level and has the task of continuous regulation the degree of filling depending on the suction pressure. The basic idea of the main patent is that in an As is known, there is a shunt path between the displacement and the intake chamber during the initial section of the pressure stroke Effective valve is provided, which with increasing suction pressure increasing refrigerant volume from the displacement drains. The latter is realized in the main patent in that the opening time of the valve increases with increasing suction pressure increases.

In this way it is possible to achieve a given size in a refrigerant compressor while maintaining the limit values for Reduce the evaporator temperature or the suction pressure, the maximum required power of the motor. The refrigerant compressor works with the full stroke volume at low suction pressure (lower density of the refrigerant) higher suction pressure (greater density of the refrigerant), on the other hand, only with part of the stroke volume, with the two Sections flow into one another.

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New documents (Art. 7 b I At *. 2 No. I Sau 3 of the amendment of 4.9.1

H26941

According to the present invention, the same aim is achieved in that the opening cross-section of the valve increases with increasing suction pressure, in that the valve is controlled by a diaphragm or bellows box filled with superheated steam or gas, the outside of which is exposed to the suction pressure. The steam or gas-filled can keeps the valve closed as long as the suction pressure is lower than the can pressure. "If the suction pressure exceeds the equilibrium pressure, the can is gradually compressed and accordingly the valve is gradually opened to its full opening division. By filling the can appropriately, the suction pressure at which the valve should begin to open can be determined fairly precisely the doses filling at the operating temperature have such a pressure that the valve closes at a suction pressure according to an evaporator temperature in the range of -5 ° to -20 ⁰ C. this gives a valve assembly which opens at a defined suction pressure and with increasing suction pressure gradually up to the largest opening width is moved.

Preferably the can is with the same refrigerant as the suction chamber is filled. In the event of a leak in the can, there is no risk of the can filler leaking out and the refrigerant Contaminated in the suction chamber and causes the entire unit to fail.

Further details of the invention emerge from the following description of an exemplary embodiment in Relation to the drawing. Show it:

1 shows an exemplary embodiment in a schematic representation using the associated P-V diagram and

Fig. 2 in a diagram the power consumption TT of the. Motor above the suction pressure p "when using the usual larger motor (F ₁ ) designed for the maximum cooling capacity and the smaller motor (N _o \

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H26941

In Pig. 1 is a schematic representation of the cylinder 1 with valve cap 2 and piston 3 illustrated. A shunt path leads from the displacement 4 5 back into the suction chamber 6 outside the cylinder. The bypass path 5 has a valve seat 7 on the outside which can be covered by the valve body 8. This valve body sits on a diaphragm box 9 »with the filled with superheated steam and attached to an extension 10 of the lid? is attached. Preferably the steam is in the Can 9 the same as the refrigerant in the suction space 6.

In operation, the condenser pressure p ^ is normally specified, while the suction pressure p "fluctuates within wide limits | can. At a low suction pressure Pg ₁ , the known line I results in the PV diagram. A high suction pressure p ″ compresses the can 9 quite strongly and therefore opens the valve 7, 8 so far that all of the refrigerant conveyed during the first part of the suction stroke can escape through this bypass opening 5. The PV diagram then takes ^L > - ' form II. With a suction pressure p _{g2 in between} , the valve is only partially open, ie only part of the refrigerant conveyed during the first stroke can escape through the bypass path 5; then the PV diagram ITI results.

It can be seen that the areas enclosed by the individual lines become smaller with increasing suction pressure. This leads to the reduction in the power of the drive motor shown in FIG. 2. Without the bypass valve, a motor with the maximum power N. would be required, which would work _{according to the dashed characteristic curve N 1.} A smaller motor can be used with a bypass valve, which then has the working characteristic curve corresponding to the full line curve Np, which shows _{values smaller than N 1 for all Saup pressures.} which correspond to a compressor with a stroke only reaching as far as the valve

909806/0170 ^BAD ORIGINAL

would speak. There is a transition area between points b and c present, which is due to the only partial opening of the valve.

Between points a and b, the characteristic curve runs almost like characteristic curve N., but is slightly lower. this has the following reason: at the lowest suction pressure the Engine near idle range. The smaller motor has lower losses there than the larger motor. Consequently the suction gas is also less overheated and enters the compressor with a better filling level. Thus results In the lower suction pressure range, a better cooling performance with reduced engine performance.

The Saupdruek p _o ^ of Fig. 1 would appear in Fig.? between

oil

Points a and b lie, the suction pressure p "p between the Points b and c as well as the suction pressure p ", between the points

c and d. The maximum power required by the engine N " is much smaller than that for an engine without a bypass valve applicable power N .. You can for example in a motor compressor, which previously required a 1/3 HP motor, in the embodiment according to the invention get by with a 1/5 HP engine. In this context, there is not only a smaller engine type, but also a a lower power consumption, a higher specific power, a reduced gas outlet temperature, a reduced Capsule temperature and minor changes in winding temperature.

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0 9 8 0 6/0170

Claims (3)

- 5 claims Motor-driven refrigerant compressor with suction pressure dependent Control of the degree of flushing, with a bypass path between the displacement and the intake chamber during the initial section of the pressure stroke effective valve is provided, which a refrigerant volume increasing with increasing suction pressure discharges from the displacement, according to DBP ... (German patent application P 14 01 497.2), characterized in that the opening cross-section of the valve increases with increasing suction pressure by removing the valve from an overheated steam or gas-filled membrane or bellows can, the outside of which is exposed to the suction pressure. 2. Refrigerant compressor according to claim 1, characterized in that the can with the same refrigerant as the suction chamber is filled. 3. The refrigerant compressor according to claims 1 to 2, characterized in that the filling cans at operating temperature has a pressure such that the valve closes at a suction pressure according to an evaporator temperature in the range of -5 ° to -20 ⁰ C. 809806/0170 New documents {Art. / ä ι * & s- 2 No. ί sentence 3 of the amendment. v. 4.1.1 -