SORPTION HEAT PUMP AND SORPTION CYCLE

Abstract

A sorption heat pump including a gaseous refrigerant and a liquid solvent; a diluted solution and a concentrated solution, wherein the diluted solution and the concentrated solution are single phase mixes of the solvent and the refrigerant; an absorber in which the diluted solution absorbs the refrigerant at a high-pressure level and emits a first heat; and a cooling device including plural cooling registers, each cooling register including an air cooler and an expansion valve in which the concentrated solution is expanded to a low-pressure level during normal operation of the cooling register so that the concentrated solution absorbs a second heat from ambient air in the air cooler and expels the refrigerant, wherein each air cooler is defrostable individually by supplying a third heat to the air cooler in a defrost operation of the air cooler that interrupts the normal operation of the air cooler.

Claims

1. A sorption heat pump, comprising: a gaseous refrigerant and a liquid solvent; a diluted solution and a concentrated solution, wherein the diluted solution and the concentrated solution are single phase mixes of the solvent and the refrigerant; an absorber in which the diluted solution absorbs the refrigerant at a high-pressure level and emits a first heat; and a cooling device including plural cooling registers, each respective cooling register including a respective air cooler and a respective expansion valve in which the concentrated solution is expanded to a low-pressure level during normal operation of the respective cooling register so that the concentrated solution absorbs a second heat from ambient air in the respective air cooler and expels the refrigerant, wherein each respective air cooler is defrostable individually by supplying a third heat to the respective air cooler in a defrost operation of the respective air cooler that interrupts the normal operation of the respective air cooler, wherein the cooling device includes a bypass that runs a partial flow of the concentrated solution through the respective cooling register at the high-pressure level during the defrost operation of the respective cooling register so that the partial flow of the concentrated solution emits the third heat.

2. The sorption heat pump according to claim 1, wherein the partial flow is run through a respective check valve parallel to the respective expansion valve of the respective cooling register after emitting the third heat in the defrost operation and thereafter the partial flow is run back into the concentrated solution.

3. The sorption heat pump according to claim 1, wherein the cooling device includes cut off valves which alternatively run the concentrated solution out of the respective air cooler to the absorber in the normal operation of the respective cooling register or run the concentrated solution out of the bypass to the respective air cooler in the defrost operation of the respective cooling register.

4. The sorption heat pump according to claim 1, wherein the cooling device includes a control valve that controls a residual flow of the concentrated solution parallel to the bypass.

5. The sorption heat pump according to claim 1, wherein the solvent is water and the refrigerant is ammonia.

6. A sorption cycle including a gaseous refrigerant and a liquid solvent, and a diluted solution and a concentrated solution, wherein the diluted solution and the concentrated solution are single phase mixes of the solvent and the refrigerant, the sorption cycle comprising: the diluted solution absorbing the refrigerant and emitting a first heat at a high-pressure level; expanding the concentrated solution to a low-pressure level during normal operation in plural cooling registers, each respective cooling register including a respective air cooler, so that the concentrated solution absorbs a second heat from ambient air in the respective air cooler and thereby expels the refrigerant, the respective air cooler being defrosted by supplying a third heat to the respective air cooler in a defrost operation of the respective air cooler that interrupts the normal operation of the respective air cooler; and a respective partial flow of the concentrated solution emitting the third heat at the high-pressure level during the defrost operation in the respective air cooler.

7. The sorption cycle according to claim 6, further comprising: running the concentrated solution through each respective air cooler in one direction during the normal operation and in an opposite direction during the defrost operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The invention is subsequently described based on an embodiment with reference on a drawing FIGURE showing a schematic of a sorption heat pump.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The sorption heat pump 1 according to the invention shown in the drawing FIGURE includes an absorber 2, a cooling device 3, a separator 4, a compressor 5, a pump 6 and conduits 7. The conduits 7 connect the absorber 2, the cooling device 3 and the separator 4 in this sequence to form a closed loop system, wherein the compressor 5 is arranged in a refrigerant path 8 and the pump 6 is arranged in a solvent path 9 running parallel to the refrigerant path 8 so that the separator 4 is connected with the absorber 2. The conduit 7 between the absorber 2 and the cooling device 3 and the solvent path 9 run through a solution heat exchanger 10.

[0017] The cooling device 3 includes two cooling registers 11 arranged in parallel. Starting at the absorber 2 and moving to the separator 4 each cooling register 11 includes an expansion valve 12 and a check valve 13 arranged in parallel to the expansion valve, an air cooler 14 and a first check valve 15. The air coolers 14 are connectable with a bypass 17 through a second cut off valve 16 respectively arranged parallel to the first cut off valve 15, wherein the bypass 17 branches off upstream of the expansion valves 12. The cooling device 3 includes a control valve 19 between the branch off 18 of the bypass 17 and the expansion valves 12.

[0018] The cut off valves 15, 16 are configured to switch the cooling registers 11 respectively into normal operation or defrost operation.

[0019] In the sorption cycle according to the invention using ammonia (NH.sub.3) as a refrigerant and water as a solvent, a flow of the diluted solution absorbs a flow of the refrigerant in the absorber 2 and transfers heat to a heating medium.

[0020] When both cooling registers 11 are run in normal operating mode the concentrated solution exiting the absorber 2 at a high pressure of 27 bar at a flow rate of 1.39 kg/s is evenly distributed between both cooling registers 11, expanded in both expansion valves 12 to an identical low pressure so that the concentrated solution cools down and is then heated in both air coolers 14. The concentrated solution heated in the two air coolers 14 is combined through the open first cut off valves 15 in the subsequent separator 4 and expels the refrigerant in a gaseous form. The remaining diluted solution is raised back to the high pressure in the solvent path 9 by the pump 6, and the gaseous refrigerant is raised back to high pressure in the refrigerant path 8 by the compressor 5 and fed into the absorber 2. The diluted solution absorbs the refrigerant again in the absorber 2, is cooled down and transfers heat to a heating medium.

[0021] Known non-illustrated lamella of the air cooler 14 frost over during normal operation. The cooling registers 11 are switched from normal operation to defrost operation in the sorption cycle according to the invention in an alternating pattern in order to be defrosted.

[0022] In order to defrost the first cooling register 11, the control valve 19 is closed and the first cut off valve 15 in the first cooling register 11 is closed and the second cut off valve 16 is opened. A partial flow that includes an entirety of the concentrated solution runs through the second cut off valve 16 at 30 degrees C. at high pressure into the air cooler 14 of the first cooling register 11, heats the first air cooler 14 and ambient air with a defrosting power of 138 KW, exits the first air cooler 14 at 10? C. and flows through the check valve 13 into the second cooling register 11 that continues to run in normal operation.

[0023] The concentrated solution is expanded to a low pressure of 2.2 bar by the expansion valve 12 in the second cooling register 11, cools down to ?10? C. in the process and absorbs 785 KW in the air cooler 14 from the ambient air and exits the cooling device 3 at ?5? C. through the open first cut off valve 15.

[0024] The concentrated solution expels 0.67 kg/sec gaseous refrigerant in the separator 4 and the refrigerant is compressed to the high pressure in the compressor 5 with 365 kW. The remaining 0.72 kg/sec diluted solution are fed by the pump 6 to the absorber 2 by 5 KW and thus heated to 66? C. in the solution heat exchanger 10.

[0025] When the first cooling register 11 is defrosted completely, it is switched back to normal operation by switching the control valve 19, the first cut off valve 15 and the second cut off valve 16.

[0026] The control valve 19 alternatively facilitates to only run an actual partial flow of the concentrated solution into the cooling register 11 in defrost operation. This reduces defrosting power and increases time required for defrosting.

REFERENCE NUMERALS AND DESIGNATIONS

[0027] 1 sorption heat pump [0028] 2 absorber [0029] 3 cooling device [0030] 4 separator [0031] 5 compressor [0032] 6 pump [0033] 7 conduit [0034] 8 refrigerant path [0035] 9 solvent path [0036] 10 solvent heat exchanger [0037] 11 cooling register [0038] 12 expansion valve [0039] 13 check valve [0040] 14 air cooler [0041] 15 cutoff valve [0042] 16 cutoff valve [0043] 17 bypass [0044] 18 branch off [0045] 19 control valve