DE3609301A1 - Method for operating a sorption heat pump - Google Patents

Abstract

Method for operating an absorption heat pump having a driving-out member heated by a gas burner, a condenser, an evaporator and an absorber, which are connected to one another via pipes, in which method, on start-up of the heat pump, the driving-out member is heated with a reduced output of the burner until a balance between solvent supply and discharge to/from the suction device takes place.

Description

Jon. Vaiilant GmbH u.Co DE 1232

1 f. 03,

Method for operating a sorption heat pump

The present invention relates to a method for operating a sorption heat pump, in particular an absorption heat pump, according to the preamble of the main claim .

When starting such an absorption heat pump If the level in the expeller is too high, it can lead to a Sudden boiling of the solution (milk pot effect) come, with the expeller in the Kaitemittel-Dampfweg downstream condenser not only with refrigerant vapor, but also with entrained solution is flooded.

The present invention is therefore based on the object of this boiling up of the solution and entrainment to prevent solvent in the condenser, but on the other hand after reaching stable operating conditions to release the full required energy throughput to the burner.

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The solutions to this problem enable the characterizing features of the main claim.

Further refinements and particularly advantageous ones Developments of the invention emerge from the subclaims and the following description, which explains an embodiment of the invention using three alternatives.

Show it:

Figure one shows a first circuit of an absorption heat pump,

Figure two an equivalent circuit to achieve the same goal and

Figure three a third variant.

In all three figures, the same reference symbols denote the same details.

In the figure one, an absorption heat pump is shown, which has an expeller 1, which is from an atmospheric gas burner 2 is heated. Instead of an atmospheric gas burner, a forced draft gas or oil burner could also come into question, and would continue to be electrical heating is also conceivable. The gas burner

2 receives its fuel via one with a valve

3 provided gas supply line 4. The valve 3 is provided with an electromagnet 5, which allows the Solenoid valve to continuously adjust every possible passage cross-section for the gas supply, so that the heat supply to the expeller is continuously adjustable.

In the case of electrical heating, constant power control would be via a vibration packet control the electrically heated resistors alternatively conceivable. A level electrode protrudes into the interior 6 of the expeller 7, which is connected via a line 8 to a control and regulating device 9 that controls the electromagnet 5 is able to be adjusted via a control line 10. In the expeller there is a middle one Level 11 of a solvent / caustic mixture a, which is between a maximum level 12 and a Minimum level 13 can fluctuate. Corresponding transmitters for these extreme levels are used as setpoint transmitters for the control 9 available. Kaitemitteldampf leaves the expeller via a line 14 into which a condenser 15 is looped and which leads to an expansion valve 18 leads, the servomotor 19 via a control line 19 with the control and regulating device 9 is connected. Downstream of the expansion valve 20, an evaporator 21 is provided, which via a Line 22 is connected to an absorber 23. The interior 6 of the expeller 1 leads to the absorber 23 one provided with a further expansion valve 26 Line 27 for poor solution, the absorber 23 leaves a line provided in a solvent pump 28 for rich solution that leads back into the interior 6 of the expeller. A drive motor 30 for the solvent pump is connected to the control and regulating device 9 via a control line 30. The expansion valve 26 has a servomotor 33 connected to the control and regulating device 9 by a line 32.

The absorption heat pump described in figure one has the following function:

If the heat pump is put into operation from a cold state, corresponding control commands result from the control and regulating device 9 once to the solenoid valve 5 of the burner 2 and to the other Motor 30 of solvent pump 28. At each restart the absorption heat pump, be it from a completely cold state or just a cooled down state, a soft start takes place. With this soft start the solenoid valve 3/5 is moved to a cross-section, which does not correspond to the full performance contribution. Preferred the burner output is released between a third and half of the burner output at an electrical heating only a third to half of the resistance heating output.

In both variants, this can be done gradually or continuously. This decreased power input is now maintained until the expansion valve 26 is triggered by a plurality of switching pulses the line 32 was actuated in a corresponding multiple. This multiple actuation of the expansion valve causes a discharge of poor solution from the Expeller and a guarantee that it will not too high levels in the expeller occur. This also prevents the liquid from boiling over in the expeller avoided.

According to the alternative of Figure two, a temperature sensor 40 is provided in the expeller, which has a

Line 41 is connected to the control and regulating device 9. According to this alternative, the temperature detected in the expeller and not the frequency of switching the expansion valve 33/26. With everyone Start-up, be it a start-up from a cooled down or a completely cold state of the absorption heat pump, is the power supply via the burner or the electrical heating of the expeller for a certain time only partially released for a third to a half, like the temperature in the expeller has held its setpoint for a certain period of time. This certain period of time is on the timer 42 adjustable.

After the time set on the timer has elapsed the full or the desired output is given to the expeller.

According to the embodiment of Figure three is a Pressure sensor 16 assigned to the condenser 15, which is connected to the control and regulating device via a pressure measuring line 17 9 is connected. There is also a pressure sensor

24 arranged in the absorber 23, which has a measuring line

25 is also connected to the control and regulating device 9. Thus it is possible to use both the Condenser pressure as well as the differential pressure between To determine the condenser and absorber and to feed them to the control and regulating device. A setpoint generator 44 is for the pressure or differential pressure Connected via the line 45 to the control and regulating device 9, likewise the timing element 42. Thus

ORIGINAL INSPECTED

is it possible to reduce the burner output or limit electrical power for the soft start as long as the condenser pressure or respectively the differential pressure between the condenser and absorber has a predefinable, adjustable setpoint via a has held for a certain time. After this period of time, the full or from the system deviation necessary gas throughput to the burner can be released.

In parallel to this soft start control is preferred a level control in the expeller 1 takes place, namely by comparing the actual value, supplied by the level electrode 11, compared to the two setpoint values, here the extreme levels that are in the control device 9 are stored. After the end of the soft start, the controller takes over within the control and control device 9, the control of the manipulated variables, that is, the gas supply to the burner or respectively the solvent throughput by adjusting it accordingly the data of the solvent pump or its associated motor 30.

The solvent pump operates during the soft start 20 one according to the partial burner output limited solvent throughput.

It is also possible to run the solvent pump during the soft start 28 to operate with such a throughput that is actually higher than the burner output would normally be necessary. Incidentally, the flow rate of the rich solution is determined by the solvent pump controlled according to the level control.

Claims (1)

Joh.Vaillant GmbH u.Co DE 1232 3/11/86 Expectations Method for operating a sorption heat pump, in particular an absorption heat pump, with an expeller heated by a heat source, a condenser and a Evaporator and an absorber and lines connecting these, characterized in that that the expeller (1) at startup for so long with a reduced output of the heat source (2) is heated until there is an equilibrium between the solvent supply and removal takes place from the absorber (23). Method according to claim 1, characterized in that the reduced performance of the Maintain heat source (2) for such a time remains until the expansion valve (26), which removes the poor solution dominated the expeller (1), cyclically operated for a certain number of cycles became. 36093C Method according to claim 2, characterized in that the reduced performance of the Maintain heat source (2) for such a time remains, as with a continuously adjustable expansion valve (26) in the Line (27) for discharging the poor solution from the expeller (1) for a certain Time was kept open. Method according to Claim 1, characterized in that the reduced power supply the heat source (2) to the expeller (1) is maintained as long as for one adjustable time the condenser pressure has held a certain value. Method according to claim 4, characterized in that the reduced performance of the Heat source (2) is maintained as long as the pressure difference between the Pressure of the condenser and the pressure of the absorber for a certain time a certain Has held the setpoint. Method according to claim 1, characterized in that the reduced performance of the Heat source (2) is maintained as long as the temperature in the expeller (1) held their value for a period of time COPY