JPH0353538B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an absorption chiller/heater capable of supplying hot water by operating a heat pump.

Absorption refrigerators are often used as devices that supply cold water for air conditioning, but they can be
It is also possible to perform so-called heat pump operation in which high-temperature hot water is extracted to perform heating or the like. Particularly, such heat pump operation has great utility value in places where a large amount of low-heat source water can be obtained in the form of heated wastewater or solar hot water. Therefore, conventionally, low heat source water is supplied to the evaporator of a dual-effect absorption refrigerator that can efficiently extract cold water for cooling, and the absorber and condenser are used as heaters, and hot water is extracted for heating, etc. The current trend is to switch to so-called single-effect heat pump operation, which is used for

However, in a dual-effect absorption refrigerator whose original purpose is to efficiently extract cold water by performing double-effect refrigeration operation, it is possible to switch to single-effect heat pump operation to extract hot water from the absorber and condenser. Conventional systems have various problems and are particularly unsuitable for large machines that require a large amount of refrigerant vapor. This is because the specific volume of refrigerant vapor generated in the high-temperature regenerator during single-effect heat pump operation is approximately four times larger than that during dual-effect refrigeration operation, and the refrigerant vapor is transferred from the high-temperature regenerator to the condenser via the low-temperature regenerator. This is because large-diameter piping must be used to send steam, and non-standard opening/closing valves must be used to adjust the refrigerant flow rate depending on the chilled water load or hot water load in the piping. . In other words, if a large-diameter pipe is used, during refrigeration operation, the refrigerant drain in the pipe via the low-temperature regenerator may not flow smoothly into the condenser, resulting in a stable and efficient flow. Problems with the performance of the water cooler/heater, such as not being able to take out cold water,
Alternatively, there are manufacturing and cost problems such as the need to specially manufacture the on-off valve and special equipment to control the valve with high precision, making it impractical for large machines.

In view of this, the present invention connects a second condenser to a conventional double-effect absorption refrigerating machine through refrigerant piping and a branch water pipe, and performs single-effect heat pump operation when hot water is required. The refrigerant and absorption liquid circulation cycle can be switched so that hot water is extracted using the heat obtained from the condenser, and when cold water is required, the so-called conventional dual-effect refrigeration operation is performed to extract cold water. The purpose is to realize a large-sized absorption chiller/heater for supplying water at low cost and with good performance. Note that the large-scale absorption chiller/heater referred to herein refers to one with large outputs of cold water and hot water.

Embodiments of the present invention will be described below with reference to the drawings. 1 is a high-temperature regenerator for driving, which heats and separates refrigerant vapor from an absorption liquid using a high-temperature heat source such as combustion gas and concentrates it into an intermediate liquid; 2 is a driving high-temperature regenerator that uses the heat of the refrigerant vapor from the high-temperature regenerator 1 to further convert refrigerant from the intermediate liquid; A regenerated condensing shell 5 is formed with a low-temperature regenerator 3 that heats and separates vapor to convert it into a concentrated liquid, and a condenser 4 that condenses and cools the refrigerant separated in the low-temperature regenerator and the high-temperature regenerator 1; an evaporator-absorbing shell 8 formed with an evaporator 6 for vaporizing the liquid refrigerant from the vessel 4 and an absorber 7 for absorbing the refrigerant vaporized in the evaporator into the concentrated liquid from the low-temperature regenerator 3;
and 9 are low-temperature and high-temperature solution heat exchangers, which are refrigerant pipes (refrigerant pipes) 11 having on-off valves 10;
A refrigerant liquid flow pipe 13 having an on-off valve 12, a refrigerant liquid circulation path 15 having a refrigerant pump 14, and a solution pump 1
Dilute liquid pipe 17 with 6, intermediate liquid pipe (intermediate liquid piping)
18 and a concentrated liquid pipe 19, a water pipe 20 is housed in the evaporator 6, and a water pipe 21 is housed in the absorber 7 and condenser 4.

When cold water is required, water is circulated through the water pipe 20, cooling water is supplied to the water pipe 21, and a heat source is supplied to the high temperature regenerator 1 to form a refrigerant and absorption liquid circulation cycle. , which operates as a so-called conventional dual-effect absorption refrigerator, and obtains cold water from the water pipe 20.

Next, 22 is a second condenser, an upper part of which is connected to a branch pipe 23 of the refrigerant conduit 11, and a lower part thereof is connected to a condensed refrigerant liquid downflow pipe 25 having an on-off valve 24. The downflow pipe is also equipped with a pressure reducing device 26 such as a steam trap or orifice, and is connected to the refrigerant liquid downflow pipe 13. The refrigerant reaches the evaporator 6 from the high-temperature generator 1 via the second condenser 22 through the refrigerant conduit 11, branch pipe 23, condensed refrigerant down-flow pipe 25, and refrigerant liquid down-flow pipe 13 connected to the high-temperature generator 1. Piping is configured. Reference numeral 27 indicates a water pipe branched from the water pipe 21 on the condenser 4 inlet side, and the branch water pipe is connected to the on-off valve 2.
8, and is housed in the second condenser 22. Further, 29 is an on-off valve provided in the water pipe 21. In addition, the branch water pipe 27 is connected via the on-off valves 28 and 29.
Instead of providing this, a branch water pipe 27 may be provided via a three-way valve (not shown). 30 is a bypass solution pipe connected to the intermediate liquid pipe 18 at one end and the low temperature solution heat exchanger 8 at the other end; the intermediate liquid pipe 18 connected to the high temperature regenerator 1 and the bypass solution pipe 30 and the concentrated liquid pipe 19 constitute a solution piping that runs from the high temperature regenerator 1 to the absorber 7 by bypassing the low temperature regenerator 3 and the high temperature solution heat exchanger 9. The bypass solution conduit 30 is provided with an on-off valve 31 . Further, 32 is an on-off valve provided in the intermediate liquid pipe 18. 33 is a pressure equalizing pipe connected at one end to the refrigerant conduit 11 and at the other end to the regeneration condensation shell 2;
The pipe is provided with an on-off valve 34.

Therefore, when hot water is required, the on-off valves 10, 1
2, 29 and 32 are fully closed, and the on-off valves 24, 28,
With 31 and 34 open, low-heat source water is supplied to the water pipe 20, and a high-temperature heat source is supplied to the high-temperature regenerator 1, and water is passed through the water pipe 21 and branch water pipe 27 to perform a so-called single-effect heat pump operation. Water pipe 2
Take out the hot water from 7.

Next, the circulation cycle of the refrigerant and absorption liquid during operation of the heat pump will be explained. The absorption liquid concentrated in the high temperature regenerator 1 passes through the intermediate liquid pipe 18, the bypass solution pipe 30, the low temperature solution heat exchanger 8 and the concentrated liquid pipe 19, and reaches the absorber 7, where it absorbs the vaporized refrigerant from the evaporator 6. diluted. The absorbed heat generated in the absorber 7 is used to raise the temperature of the water in the water pipe 21. The diluted absorption liquid is then returned to the high temperature regenerator 1 from the bottom of the absorber 7 via the solution pump 16 and the diluted liquid pipe 17.

In addition, during heat pump operation, the regeneration condensation shell 2 and the high temperature regenerator 1 are short-circuited by the pressure equalization pipe 33 to maintain the same pressure, so the absorption liquid flowing into the low temperature solution heat exchanger 8 flows back into the low temperature regenerator 3. Never.

Further, the refrigerant vapor generated in the high-temperature regenerator 1 passes through the refrigerant conduit 11 and the branch pipe 23, reaches the second condenser 22, and becomes a condensed refrigerant liquid. Note that the latent heat of condensation generated in the second condenser 22 is transferred to the branch water pipe 2.
7 is used to heat up the water in the tank. The condensed refrigerant liquid is transferred to the condensed refrigerant liquid down pipe 25 and the pressure reducing device 2.
6. The refrigerant passes through the refrigerant reservoir 35, the refrigerant pump 14, and the refrigerant circulation path 15, reaches the evaporator 6, is heated by the low heat source water and vaporized, is absorbed by the absorption liquid in the absorber 7, and is refluxed to the high-temperature regenerator 1. It is.

In this way, during heat pump operation, the second condenser 22 is used instead of the condenser 4, so the refrigerant conduit 11 is connected to the high temperature regenerator 1.
It is sufficient that the pipe has a large diameter only between the pipe and the branch pipe 23. Therefore, during refrigeration operation, the refrigerant conduit 11 is sufficiently small in diameter to smoothly flow the refrigerant drain generated when the refrigerant vapor from the high temperature regenerator 1 exchanges heat with the intermediate liquid in the low temperature regenerator 3 to the condenser 4. can be used between the low-temperature regenerator 3 and the condenser 4, which is a disadvantage of the conventional method in that the flow of the refrigerant drain becomes poor, resulting in a decrease in the refrigerating capacity and unstable phenomena [especially when the refrigerant conduit 11 has a large diameter]. This eliminates the drawbacks that tend to occur in large machines that use
Note that the refrigerant vapor may be supplied to the second condenser 22 through the large-diameter refrigerant vapor conduit 36 instead of through the refrigerant conduit 11 and branch pipe 23.

Moreover, the on-off valve 10 can also be used within the standard, and if this valve is used as a refrigerant flow rate control valve whose opening degree is adjusted according to the chilled water load, inexpensive and simple control becomes possible. Note that the on-off valve 32 does not necessarily need to be provided in the intermediate liquid pipe 18. This is because, during heat pump operation, the high temperature regenerator 1 and the regeneration condensation shell 2 are made to have the same pressure through the pressure equalization pipe 33, and the absorption liquid flows from the high temperature regenerator 1 to the low temperature regenerator 3 via the high temperature solution heat exchanger 9. This is because it prevents them from doing so. However, since it takes some time for the high temperature regenerator 1 and the regeneration condensation shell 2 to reach the same pressure, it is preferable to provide the on-off valve 32. For the same reason, an on-off valve (not shown) may be provided in the concentrated liquid pipe 19 between the low-temperature regenerator 3 and the low-temperature solution heat exchanger 8. Also, during heat pump operation, the refrigerant conduit 11 is used instead of the pressure equalization pipe 33.
The high-temperature regenerator 1 and the regenerated condensation shell 2 may be brought to the same pressure by using. In this case, it is sufficient to open the on-off valve 10. However, as described above, it takes time to reach the same pressure and the initial performance of the heat pump operation deteriorates, so it is preferable to provide a pressure equalizing pipe 33 with an on-off valve 34.

As described above, when cold water is needed, the absorption chiller/heater of the present invention operates with the on-off valves 24, 28, 31, and 34 fully open and the on-off valves 10, 12, 29, and 32 open, and the evaporator 6 is used as a so-called double-effect absorption refrigerator which is used as a cooler, and when hot water is needed, the on-off valves 10, 12, 29 and 32 are fully opened, and the on-off valves 24, 28, 31 and 34 are switched to open. Absorber 7 and second condenser 22
It is used as a single-effect absorption heat pump that uses the heat pump as a heater. In addition, when the pressure equalization pipe 33 or the on-off valve 32 is not provided, the on-off valve 10
Needless to say, keep it open during both operations. Furthermore, adjusting the pressure reducing device 26,
When the pressure difference between the second condenser 22 and the evaporator 6 is adjusted appropriately during the heat pump operation and the refrigeration operation, the on-off valve 24 may not be provided.

As described above, the present invention provides on-off valves in the refrigerant pipes, intermediate liquid pipes, refrigerant liquid flow pipes, and water pipes of a double-effect absorption refrigerator, and bypasses the low-temperature regenerator and condenser from the high-temperature regenerator to evaporate. A refrigerant pipe is provided that reaches the vessel and has a second condenser and an on-off valve, and a solution pipe that bypasses the high-temperature regenerator, a low-temperature regenerator and a high-temperature solution heat exchanger, and leads to the absorber and has an on-off valve. By installing a branch water pipe that branches from the water pipe to the second condenser and has an on-off valve, and by switching the on-off valve on and off, when hot water is needed, the absorber and the second condenser can be used as a heater and branched. Since hot water is extracted from the water pipe, there is no need to make the refrigerant pipe from the high temperature regenerator to the condenser via the low temperature regenerator large in diameter, making it a simple improvement to the conventional dual effect absorption refrigerator. Therefore, it is possible to put into practical use a large-scale absorption chiller/heater that is inexpensive and has good performance.

[Brief explanation of drawings]

The drawing is a schematic explanatory diagram of a circuit configuration showing an embodiment of the present invention. 1...High temperature regenerator, 3...Low temperature regenerator, 4...
Condenser, 6... Evaporator, 7... Absorber, 8, 9...
...Low temperature, high temperature solution heat exchanger, 10...Opening/closing valve, 1
1... Refrigerant conduit, 12... Open/close valve, 13... Refrigerant liquid flow down pipe, 18... Intermediate liquid pipe, 19... Concentrated liquid pipe,
21... Water pipe, 22... Second condenser, 23... Branch pipe, 24... On-off valve, 25... Condensed refrigerant liquid down pipe, 27... Branch water pipe, 28, 29... On-off valve,
30... Bypass solution pipe line, 31, 32... On-off valve, 33... Pressure equalization pipe, 34... On-off valve.

Claims (1)

[Claims] 1 High temperature regenerator, low temperature regenerator, condenser, evaporator,
In a dual-effect absorption refrigerator that connects a condenser, a low-temperature solution heat exchanger, and a high-temperature solution heat exchanger to form a refrigeration cycle, the refrigerant piping is connected from a high-temperature regenerator to a condenser via a low-temperature regenerator and has an on-off valve. , an intermediate liquid pipe that runs from the high-temperature regenerator to the low-temperature regenerator via a high-temperature solution heat exchanger and has an on-off valve, a refrigerant liquid down-flow pipe that leads from the condenser to the evaporator and has an on-off valve, and condensation from the absorber. a water pipe leading to the vessel and having an on-off valve, and a refrigerant pipe passing from the high-temperature regenerator to the low-temperature regenerator and the condenser to the evaporator and having a second condenser and an on-off valve;
A solution pipe that bypasses the high-temperature regenerator through the low-temperature regenerator and the high-temperature solution heat exchanger to the absorber and has an on-off valve, and a branch water pipe that branches from the water pipe and leads to the second condenser and has an on-off valve. By switching these on-off valves, high-temperature refrigerant vapor is sent from the high-temperature regenerator to the second condenser via the refrigerant liquid pipe, and high-temperature absorption liquid is sent from the high-temperature regenerator to the second condenser through the solution pipe. An absorption chiller/heater characterized in that the absorber and the second condenser are used as heaters during heat pump operation, and hot water is taken out from a branch water pipe.