JP2002206818A - Absorbing type heat pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain an effective utilization of heat held in discharged gas from a regenerator. SOLUTION: There are provided a re-boiling unit 7 and a condenser 6. Absorbing solution of high concentration transferred from an absorbing unit 4 at the re-boiling unit 7 is evaporated by the discharging gas flowed from a regenerator 1, the evaporated vapor is transferred to a condenser 6, wherein high concentrated liquid and discharged liquid are attained through condensation at the condenser 6, the high concentrated liquid is heated at a low temperature segment of the absorbing unit 4, thereafter it is transferred to the regenerator 1, the discharged liquid is heated at a high temperature segment of the absorbing unit 4 and transferred to the regenerator 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption heat pump device, and more particularly to an absorption heat pump device using various fuels and high-temperature gas used for cooling and freezing in the food and chemical industries, and for air-conditioning of buildings and houses.

[0002]

2. Description of the Related Art A conventional absorption heat pump performs heat exchange by moving a refrigerant high-concentration absorption solution and a low-concentration absorption solution between a high-pressure regenerator and a low-pressure absorber, thereby generating heat and absorbing heat. Heat is generated in a low-pressure absorber and absorbed in a high-pressure regenerator.

[0003] Usually, such absorption heat pumps are used in combination with several types of heat exchange systems.
As a specific heat exchange system, the heat of the absorber is transferred to the regenerator, GAX used for rectifying the refrigerant, and the heat for circulating the high-concentration absorption solution having completed heat absorption to the high-temperature side of the absorber. An AHE in which an exchanger is provided and heat of the high-concentration absorbing solution is given to the absorber, or GHE in which heat exchange between the high-temperature low-concentration absorbing solution in the regenerator and the high-concentration absorbing solution or the low-temperature portion of the regenerator is known. ing.

[0004]

However, in these systems, despite the fact that the heat of absorption up to the liquid temperature of the regenerator of that concentration is higher than the minimum temperature of the absorber on the During line, the absorption of the absorber The heat generated in the low-temperature part cannot be moved effectively because the temperature of the regenerator to be transferred is high.

For this reason, Japanese Patent No. 2978563 discloses that
The following method has been proposed as a heat pump of a different type from the above. That is, the absorption complete liquid (high concentration absorption solution) is heated in the low temperature part of the absorber, and the high concentration absorption solution is put into the intermediate regenerator and the intermediate condenser operated at the intermediate pressure between the regenerator and the absorber. A strong solution and a bottom liquid are obtained by evaporation of the refrigerant. The strong solution is endothermic and heated in the absorber, and then sent to a high-pressure regenerator. The bottoms are heated in the absorber and sent to the regenerator, and the heat of the absorber can be sent to the regenerator.

However, a drawback of this method is that, first, a strong solution is obtained by using the heat of the absorber, thereby reducing the load on the rectification column as a vapor-rich gas-liquid mixture. In order to obtain a high strong solution, it is necessary to use heat of absorption, and the overall efficiency is not good. Secondly, the absorption complete liquid is used to cool the lowest temperature part with cooling water in order to cool the absorption part where the liquid has just come out, and to create a temperature difference with the absorption liquid on the upper part, and Although it is possible to remove heat,
The heat in this area is discarded outside and cannot be used. Third, the lift (temperature difference between the evaporator and the condenser) is 60-70.
When used for refrigerators as high as ° C., the maximum temperature of the absorber approaches the temperature of the reboiler and heat transfer to the reboiler is not possible. Therefore, high-lift operation is not possible.

As a method of effectively utilizing the absorption heat pump, a GAX cycle is configured, and a mechanical compressor driven by an internal combustion engine is inserted between the evaporator and the absorber to compress the refrigerant and further reduce the waste heat of the internal combustion engine. There is a proposal for using a heat pump as a heat source for an overall effect. However, in the conventional heat pump, even when the lift is low, for example, at a lift of 20 ° C., the coefficient of performance COPt (total heat supply) is 1.
With about 5 to 2.0, the coefficient of performance COPc (regenerator heat receiving standard) to be taken over by the heat pump does not reach 3-4. This increases the burden on the mechanical compressor, and does not lead to a composite efficiency improvement.

In any case, in a conventional heat pump system using a high-temperature gas, the exhaust gas from the regenerator is not effectively used in the heat pump. Also,
BACKGROUND ART Efficient and small internal combustion engines using natural gas, city gas, kerosene, light oil and the like have been put to practical use and are being widely used.
The heat of the exhaust gas from these internal combustion engines has not been effectively used except for cogeneration.

Therefore, a first object of the present invention is to effectively use the heat of a heat source of a regenerator. The second problem is that the production of a strong liquid capable of absorbing and moving heat is not performed by using the absorbed heat as in the conventional example, but the heat of the heating source of the regenerator is effectively used. Therefore, it is possible to recover heat even in a low temperature part of the absorber. A third object is to provide a heat pump having high thermal efficiency by incorporating a refrigerant compressor driven by an internal combustion engine into a heat pump and combining a lift of the refrigerant compressor and a lift of the heat pump.
Other issues will become apparent from the following description.

[0010]

The present invention which has solved the above-mentioned problems is as follows. <Invention according to claim 1> Combination of a low-pressure side evaporator and absorber, and a high-pressure side regenerator and condenser using a non-azeotropic refrigerant and an absorbent, and refrigerant vapor evaporated in the evaporator Is brought into contact with and absorbed by the low-concentration absorption solution in the absorber, the high-concentration absorption solution is pressurized and sent to the generator, heated and concentrated by a heating source provided to the generator, and the refrigerant vapor is cooled. An absorption heat pump that repeats the operation of sending to the condenser, returning the low-concentration absorption solution reduced in concentration by the delivery to the absorber, and reducing the pressure of the refrigerant liquefied in the condenser and evaporating the refrigerant in the generator. A system comprising a reboiler and a condenser as an intermediate pressure section, wherein the high concentration absorbing solution is transferred from the absorber in the reboiler, and is evaporated by exhaust heat of a heating source passing through the regenerator. evaporation Send over path to the condenser,
Strong liquid and bottom liquid are obtained by condensation in this condenser,
The strong liquid is heated in a low temperature part of the absorber, and then sent to a regenerator. The bottom liquid is heated in a high temperature part of the absorber, and then sent to a regenerator. Heat pump device.

<Invention according to claim 2> The exhaust gas of the reciprocating internal combustion engine is used as a heating source of the regenerator, a second reboiler is provided in addition to the reboiler, and the absorber of the strong liquid is provided. 2. A strong liquid reheater is provided in a path for feeding from the to the regenerator, and a configuration is adopted in which hot waste water or low-pressure steam from the cylinder of the internal combustion engine is sent to the second reboiler and the strong liquid reheater. Absorption heat pump equipment.

According to a third aspect of the present invention, a mechanical compressor for a gas turbine driven refrigerant is incorporated between the evaporator and the absorber, and the exhaust gas of the gas turbine is used as a heat source for a regenerator. The absorption heat pump device according to claim 1, wherein the absorption heat pump device is configured.

<Invention according to claim 4> A part of the high-concentration absorbing solution transferred from the absorber to the reboiler is also transferred to the condenser and used for dilution in the condenser. Item 4. The absorption heat pump device according to any one of Items 1 to 3. In the present invention, non-azeotropic working fluids, in other words, specific examples of the refrigerant and the absorbent include a water-ammonia system, a TFE-DMI system, and a TFE-
NMP-based ones are industrially preferred, but are not limited thereto, and may be any working fluid that has an appropriate vapor-liquid equilibrium, does not cause ultraviolet destruction, and is harmless to an environment with a low global warming potential.

(Function and Effect) Next, the function of the absorption heat pump of the present invention will be described. In the absorption heat pump of the present invention, similarly to the conventional absorption heat pump, the refrigerant condensed in the condenser is supercooled in the subcooler, and then evaporated in the evaporator to generate cold heat. The refrigerant vapor is sent to the absorber, absorbed by the high-concentration absorption solution and releases heat, and the obtained high-concentration absorption solution is heated by the regenerator by the absorption liquid pump,
Separated into refrigerant and low-concentration absorption solution, refrigerant is returned to the condenser again
Also, the low concentration absorbing solution is sent to the absorber, and this is repeated. In the present invention, separately from the above-described refrigerant and heat flows, a driving heating source is used for heating a high-concentration absorbing solution from an absorber, and then a reboiler and a condenser (including a condenser with a reboiler). To obtain a strong liquid and a bottom liquid. Absorption heat is not used as a heat source at this time. The strong liquid is sent to the low-temperature part of the absorber, where the so-called difficult-to-recover heat of the overlapping part is recovered, evaporated and sent to the regenerator. In this case, since the amount of vapor is large, the load of rectification in the regenerator is reduced. On the other hand, the bottom liquid is sent to a high-temperature portion of the absorber, heated by absorption heat, recovers heat, and guided to a regenerator. The outlet temperature of the high-concentration absorbing solution of the absorber is 25-40 ° C, and the temperature of the bottoms is 70-9.
At 0 ° C., heat can be recovered from the exhaust gas, and it is not necessary to use the heat of the absorber to obtain a strong liquid. Therefore, the heat of the absorber can be transferred to the regenerator by that much, thereby improving the heat efficiency. When the lift is large, the disadvantage that the maximum temperature of the absorber approaches the temperature of the reboiler and heat transfer from the absorber to the reboiler cannot be performed is possible. It becomes possible to operate at a high lift evaporation temperature of −20 ° C.

[0015]

Embodiments of the present invention will be described below in more detail with reference to the drawings. ◇

<First Embodiment> FIG. 1 is a schematic configuration diagram of a heat pump device according to a first embodiment of the present invention, in which a regenerator 1, a condenser 2, an evaporator 3, and , An absorber 4, a supercooler 5, a condenser 6 having a reboiler 7, a high-concentration absorption solution pump P1, a strong solution pump P2, a bottom solution pump (pressure increase) P3, and a driving heating source 12. And In FIG. 1, it is illustrated that the pressure is higher on the upper side and the temperature is higher on the right side.

The regenerator 1 is provided with a heater 1a by a driving heating source 12 and a can bottom liquid heat exchanger 1b. The right side of the dotted line in the regenerator 1 is a high temperature side recovery section 1c, and the left side is a low temperature side. This is the concentration section 1d. The condenser 2 has a cooling means 2a.
However, the evaporator 3 has a heating means 3a, the absorber 4 has a strong liquid heater 4a, a bottoms heater 4b, and a water cooler 4c, and the subcooler 5 has a condensed refrigerant and a refrigerant vapor. Heat exchange means
The condenser 6 is provided with a condenser 6a and a separating means 6b, and the reboiler 7 is provided with a heater 7a which is heated by exhaust heat of the driving heating source 12. In the present embodiment, similarly to a normal absorption heat pump, cold heat can be generated by the following flow. That is, the refrigerant condensed by the cooling means 2a of the condenser 2 passes through the pressure reducing valve G1, is supercooled by the heat exchange means in the subcooler 5, and is then evaporated by the evaporator 3, thereby obtaining cold heat. The refrigerant vapor exchanges heat with the condensed refrigerant sent from the condenser 2 by the heat transfer means in the subcooler 5, absorbs the heat of the condensed refrigerant, and is sent to the low-pressure absorber 4. The refrigerant vapor is absorbed by the high-concentration absorbing solution in the absorber 4 to release heat, and the obtained high-concentration absorbing solution is sent to the reboiler 7 by the high-concentration absorbing solution pump P 1, and the drive heating source 12 is discharged. The refrigerant is evaporated by being heated by the heater 7a heated by heat, and condensed by the condenser 6 to become a strong liquid,
The remaining liquid becomes bottoms. The strong liquid and the bottom liquid are supplied to the absorber 4 by the strong liquid pump P2 and the bottom liquid pump (pressure increase) P3, respectively.
The strong liquid is heated by a strong liquid heater 4a, and the bottom liquid is heated by a bottom liquid heater 4b.
c, each is supplied to the low temperature side enrichment section 1d, where rectification is performed. The regenerator 1 is provided with a heater 1a by the driving heating source 12 heated by the driving heating source 12, and is heated by this. In the high-temperature side recovery section 1c of the regenerator 1, after the low-concentration absorption solution releases heat by heat exchange in the low-concentration absorption solution heat exchanger 1b, the pressure reducing valve G
2 and is returned to the low-pressure absorber 4. On the other hand, the refrigerant obtained by rectification is sent to the condenser 2. Such a circulation described above is repeated.

In the present invention, in addition to the movement and circulation of the refrigerant and heat as in the ordinary absorption heat pump, the provision of the condenser 6 further causes the movement and circulation of new refrigerant and heat. That is, the strong solution from the condensing part of the condenser 6 absorbs the heat absorbed by the strong liquid heater 4a at the lowest temperature part of the absorber 4 by the pump P2, and is heated and regenerated.
Supplied to The high concentration absorption solution in the absorber 4 is supplied to the reboiler 7 by the high concentration absorption solution pump P1, where it is evaporated. The evaporative vapor is condensed by the condenser 6 to be a strong liquid with a large amount of refrigerant, and the un-evaporated matter is transferred to the high temperature part of the regenerator 1 as a bottom liquid with little refrigerant, heated, and then returned to the absorber 4. . A strong liquid having a large amount of vapor and a bottom liquid having a low refrigerant concentration but a high temperature are provided with a regenerator 1 suitable for the concentration.
The heating stage is heated by the driving heating source supplied to the driving heating source heater 1a, and the rectification of the refrigerant is performed. On the other hand, the exhaust heat of the driving heating source from the regenerator 1 is guided to the condenser 6. The refrigerant rectified by the regenerator 1 is transferred to the condenser 3, condensed by cooling water, supplied to the evaporator 3 via the supercooler 5, and heated by the brine, and the brine is cooled to generate cold heat. Can occur. The evaporation vapor in the evaporator 3 is sent to the absorber 4 to complete the cycle of the heat pump. The water cooler 4c attached to the absorber 4 for sending cooling water is used for adjusting the temperature of the entire absorber 4.

<Second Embodiment> FIG. 2 shows a second embodiment of the present invention, in which exhaust gas of a reciprocating internal combustion engine 8 driven by supply of fuel 8a and air 8b is regenerated. It is used for the heating source 12 of the vessel 1. Further, a second reboiler 7b is provided in the reboiler 5, and a strong liquid reheater 9 is provided in a path for feeding the strong liquid from the absorber 4 to the regenerator 1. Cooling water 8 to cylinders of internal combustion engine 8
The warm drainage or low-pressure steam accompanying the heating of c is sent to the second reboiler 7b and the strong liquid reheater 9.
The waste heat of the cylinder is usually 30 to 40% of the waste heat, and although the calorie of the regenerator 1 is small, hot wastewater or low-pressure steam is sent to the second reboiler 7b and used for producing a strong liquid. In addition, by sending it to the strong liquid reheater 9 and using it for heating the strong liquid, the overall coefficient of performance COPt is about 0.
It becomes 85. When the lift is high and the temperature of the bottom liquid is high, heat exchange in the absorber cannot be performed, so that the bottom liquid can be sent directly to the regenerator.

<Third Embodiment> FIG. 3 shows a third embodiment of the present invention. A refrigerant machine driven by a gas turbine 10 is provided between an evaporator 3 and an absorber 4. The exhaust gas of the gas turbine 10 driven by the supply of the fuel supply 10 a and the air 10 b is incorporated into the compressor 11, and the exhaust gas is used as the heating source 12 of the regenerator 1. The mechanical compressor 11 is used for increasing the pressure of the vapor generated in the evaporator 3 and supplying it to the absorber 4. The exhaust gas from the gas turbine 8 is used for heating the regenerator 1, and the exhaust gas is guided to the condenser 6, and the heat of the absorber 4 for producing a strong liquid is sent to the regenerator 1. At this time, since the lift of the heat pump is low, the coefficient of performance COPc is as high as 4 to 6 at the lift of 15 ° C., and the overall efficiency is high.

<Fourth Embodiment> As shown in FIG. 2, a part of the high-concentration absorption solution transferred from the absorber 4 to the reboiler 7 is also transferred to the condenser 6, and 6 can be used for dilution. For example, when a water-ammonia system is used as the working fluid, when the concentration of the high-concentration absorbing solution transferred from the absorber 4 to the reboiler 7 becomes 40% or more, the intermediate pressure becomes 0.8 to 0.8%.
At 1.0 MPa, the ammonia concentration becomes 80% or more, and no condensation occurs in the condenser 6. Therefore, in order to prevent this, it is desirable to transfer a part of the high-concentration absorption solution to the condenser 6 and use it for dilution in the condenser 6.

[0022]

Next, an embodiment will be described. ◇

<Example 1> In the absorption heat pump device of the first embodiment, the working fluid was ammonia-water, and the driving heating source heater 1a of the regenerator 1 was supplied with 100 KW as the driving heating source. The gas turbine exhaust at 590 ° C was averaged at 2775 kg /
By supplying at hrs, cold heat was generated under the following conditions. From the regenerator 1, 1050 to 1250 kg / hr of ammonia vapor is sent to the condenser 2 and condensed to 40 ° C. The supercooler 5 exchanges heat with the ammonia vapor sent from the evaporator 3 to 25 to 28 ° C. After cooling, supply to evaporator 3,
Therefore, the pressure of 1.51MPa is returned by cold water.
a, evaporated at 5 ° C. to obtain a refrigeration capacity of 370 kW of 7 ° C. cold water. After performing heat exchange in the supercooler 5, the ammonia vapor is sent to the low-temperature part of the low-pressure absorber 4, while the low-concentration absorption solution from the regenerator 1 is put into the high-temperature part of the absorber 4,
Here, the heat of absorption was removed by the following method. That is, the high-concentration absorbing solution in the absorber 4 has a concentration of 50%, is transferred to the reboiler 7 and the condenser 6, and is heated by the heater 7a, and ammonia is sent to the condenser 6, and the strong condensing solution is removed. A bottoms was obtained. On the other hand, the bottom liquid was heated by the high-temperature bottom liquid heater 4 b of the absorber 4 to 160 ° C. and led to the regenerator 1. The strong liquid was received from the condenser 6 at 500 to 600 kg / hr in the strong liquid heater 4 a, evaporated at a refrigerant pressure of 1.53 MPa by heat of absorption, and sent to the regenerator 1. The water cooler 4c has 25
The heat was removed at 0 Kw. During the operation of the system, the temperature of the regenerator 1 was set to 180 ° C., and the low-concentration absorbing solution (can bottom liquid) was sent to the absorber 4 at 140 ° C. in the can bottom liquid heat exchanger 1b. On the other hand, the refrigerant concentrated in the regenerator 1 was condensed in the condenser 2 and used as a frozen refrigerant. In this embodiment, the required pump powers of the high concentration absorption solution pump P1, the strong solution pump P2 and the bottoms pump P3 are respectively 2.
2, 0.75 and 2.2 Kw. This COPc is 1.4 to 1.5, and the overall coefficient of performance COPt is about 0.4.
In No. 9, the improvement was 15 to 20% compared to the conventional method.

<Embodiment 2> ◇ In the absorption heat pump apparatus according to the third embodiment, a 30 kW gas turbine driven screw-type compressor is provided in the system of Embodiment 1, and exhaust gas of 650 ° C. is heated by a driving heating source. Put in the vessel 1a and reach 180 ° C.
It was put into the reboiler 7 and discharged at 75 ° C. When the outlet temperature is 80 ° C., the pressure of the regenerator 1 and the condenser 2 is 1.55MP.
a, evaporator pressure 0.515 MPa, absorber pressure 1.
05 MPa. The COPt of this heat pump was 2.8 at a lift of 35 ° C.

[0025]

As described above, in the absorption heat pump apparatus of the present invention, the condenser and the reboiler are provided to produce a strong liquid capable of recovering the absorbed heat from the exhaust gas regardless of the operation of the absorber. Conventionally, unused waste heat of the absorber can be recovered in a wide range of lift without loss of absorbed heat, and an absorption heat pump with a high COP can be constructed. Also, the exhaust gas of the reciprocating internal combustion engine is used as a heat source for the regenerator,
A second reboiler is provided in addition to the reboiler, a strong liquid reheater is provided in a path for sending the strong liquid from the absorber to the regenerator, and the hot waste water or low-pressure steam of the cylinder of the internal combustion engine is supplied to the second reboiler. By adopting a configuration in which the heat is sent to the boiler and the strong liquid reheater, highly efficient heat utilization becomes possible. In addition, a gas turbine driven mechanical compressor for refrigerant is installed between the evaporator and the absorber, and the exhaust gas of the gas turbine is used as the heat source of the heat pump. Can be constructed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a heat pump device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a heat pump device according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a heat pump device according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Regenerator, 2 ... Condenser, 3 ... Evaporator, 4 ... Absorber, 5
... supercooler, 6 ... condenser, 7 ... reboiler, 7a ...
(1) reboiler, 7b: second reboiler, 8: reciprocating internal combustion engine, 9: strong liquid reheater, 10: gas turbine,
11: mechanical compressor for refrigerant, P1: high concentration absorption solution pump, P2: strong liquid pump, P3: bottom discharge pump, 12: drive heating source.

Claims (4)

[Claims] A low-pressure side evaporator and an absorber, and a high-pressure side regenerator and a condenser are combined using a non-azeotropic refrigerant and an absorbent, and the refrigerant vapor evaporated in the evaporator is supplied to the absorber. The absorption solution having a high concentration is brought into contact with and absorbed by the low-concentration absorption solution in the container, and the absorption solution having a high concentration is pressurized and sent to the generator, heated and concentrated by a heating source provided to the generator, and the refrigerant vapor is sent to the condenser. An absorption heat pump system that repeats an operation of discharging the low-concentration absorption solution having a low concentration by the delivery to the absorber, reducing the pressure of the refrigerant liquefied in the condenser, and evaporating the refrigerant in the generator. A reboiler and a condenser are provided as an intermediate pressure section. In the reboiler, the high-concentration absorption solution is transferred from the absorber, and evaporated by the exhaust heat of a heating source passing through the regenerator, and the evaporation vapor is condensed. The strong liquid is heated in the low temperature part of the absorber and sent to the regenerator, and the strong liquid is heated in the high temperature part of the absorber. An absorption heat pump device, wherein the heat is sent to a regenerator after being heated. 2. An exhaust gas from a reciprocating internal combustion engine is used as a heating source for the regenerator, and a second reboiler is provided in addition to the reboiler, so that a path for sending the strong liquid from the absorber to the regenerator is provided. The absorption heat pump device according to claim 1, further comprising a strong liquid reheater, wherein hot water discharged from a cylinder of the internal combustion engine or low-pressure steam is sent to the second reboiler and the strong liquid reheater. 3. The gas turbine driven mechanical compressor according to claim 1, wherein a gas turbine driven refrigerant compressor is incorporated between the evaporator and the absorber, and the exhaust gas of the gas turbine is used as a heating source of a regenerator. Absorption heat pump device. 4. The method according to claim 1, wherein a part of the high-concentration absorbing solution transferred from the absorber to the reboiler is also transferred to the condenser and used for dilution in the condenser. Item 2. An absorption heat pump device according to item 1.