JPH0694321A - Device for controlling absorption heat pump - Google Patents

Abstract

PURPOSE:To provide hot water efficiently through the year by improving the coefficient of performance of the whole system by a method wherein the temperature of a hot water circulation path which thermally connect two absorption heat pumps, is cascade- controlled by the temperature of a low-temperature heat source for one of the absorption heat pumps. CONSTITUTION:An absorber 5 and condenser 3 for a first absorption heat pump A and an evaporator 13 for a second absorption heat pump B are thermally connected by a hot water circulation path 21. Also, to an evaporator 4 for the first pump A, a low-temperature heat source water circulation path 8 is connected, and river water, etc., flows in as a low-temperature heat source 9. In addition, a high-temperature water circulation path 16 is connected to the second pump B, and high temperature water is fed to a hot water supply/heating load 17. In this case, the temperature of the hot water circulation path 21 is cascade-controlled by the temperature of the low-temperature heat source 9. That is, the set temperature is corrected by a controller 46 which is connected to a water temperature sensor 45 of the low-temperature heat source 9, and at the same time, the heating quantity of a high-temperature regenerator 1 is controlled by a controller 42 which is connected to a water temperature sensor 41 of the hot water circulation path 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump device, and more particularly to a combination of two absorption heat pumps, using river water or the like as a low temperature heat source of the first absorption heat pump, and increasing the temperature from the second absorption heat pump. The present invention relates to a device for efficiently extracting water.

[0002]

2. Description of the Related Art Conventionally, as this type of heat pump device, for example, a device proposed in Japanese Patent Laid-Open No. 58-60172 is known. In the heat pump device proposed here, since the first absorption heat pump controls the heating amount according to the cold water outlet temperature, the amount of heat radiation to the hot water system becomes volatile and a heat radiation device is required. That is, when the heat radiation amount of the first absorption heat pump is larger than the predetermined heat input amount of the evaporator of the second absorption heat pump, it is necessary to radiate the excess heat amount to the outside of the system, and conversely, the first absorption heat pump. When the heat radiation amount of the heat pump is smaller than the evaporator heat input amount of the second absorption heat pump, there is a problem that sufficient high temperature water cannot be obtained from the second absorption heat pump.

Further, when the cold water outlet temperature decreases, the amount of heat released to the hot water system also decreases, so the temperature level of the hot water system also decreases, and the coefficient of performance (hereinafter referred to as COP) of the second absorption heat pump decreases. There were also points.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to improve the COP as compared with the conventionally proposed system and to reduce the cost of incidental equipment by eliminating the need for a heat dissipation device.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and includes a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator, an absorber, a high temperature heat exchanger and a low temperature regenerator. A first absorption heat pump consisting of a heat exchanger, and a second absorption heat pump consisting of a regenerator, a condenser, an evaporator, an absorber and a heat exchanger, and an absorber and a condenser of the first absorption heat pump. A hot water circulation path that thermally connects to the evaporator of the second absorption heat pump is provided, and river water or the like is introduced to the evaporator of the first absorption heat pump as a low temperature heat source, and high temperature water is taken out from the second absorption heat pump. In the absorption heat pump device, the temperature of the hot water circulation path is cascade-controlled by the temperature of the low-temperature heat source, which is a control device of the absorption heat pump. Absorption heat pump is composed of a regenerator, a condenser, an evaporator, an absorber and a heat exchanger together, and hot water that thermally connects the absorber and condenser of the first absorption heat pump and the evaporator of the second absorption heat pump. In the absorption heat pump device in which a circulation path is provided, river water or the like is introduced into the evaporator of the first absorption heat pump as a low temperature heat source, and high temperature water is taken out from the second absorption heat pump, the temperature of the hot water circulation path is changed by the temperature of the low temperature heat source. The present invention provides a control device for an absorption heat pump, which is characterized by performing cascade control.

[0006]

When the heating amount of the first absorption heat pump is controlled by the condenser outlet temperature of the hot water flowing through the hot water circulation path, the constant temperature hot water always flows into the evaporator of the second absorption heat pump. Therefore, the hot water outlet temperature is easily controlled to be constant, and the controllability is improved. During operation, if the load of the high temperature water system is reduced and the heating amount of the regenerator of the second absorption heat pump is reduced, the amount of heat exchanged in the evaporator of the second absorption heat pump decreases and its outlet temperature rises. As a result, hot water having a temperature higher than a predetermined temperature is returned to the absorber of the first absorption heat pump.
Therefore, the hot water temperature at the outlet of the condenser rises, so by operating the first absorption heat pump so as to reduce the heating amount of the (high temperature) regenerator, and always performing a balanced operation that matches the load. No heat dissipation device is required.

Since the temperature of the river water flowing into the evaporator of the first absorption heat pump is 12 ° C. or more in winter even in winter due to the heat island phenomenon due to urban exhaust heat,
It has a sufficient temperature as a heat source to evaporate the liquid refrigerant,
Moreover, it is not necessary to control the outlet temperature because the waste water is used after use.

Further, in summer, the temperature of the river water rises to about 25 ° C., and the temperature is detected and the hot water temperature set value at the condenser outlet of the first absorption heat pump is cascaded to the temperature of the river water. The temperature of the hot water flowing into the evaporator of the second absorption heat pump becomes higher and the COP increases by changing the value and correcting the set value upward, so that the high temperature water can be efficiently taken out from the second absorption heat pump.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The absorption heat pump device illustrated in FIG. 1 has a structure in which a first absorption heat pump A and a second absorption heat pump B are combined, and the absorption heat pump A is a high temperature regenerator 1, a low temperature regenerator 2, It is a double-effect absorption heat pump composed of a condenser 3, an evaporator 4, an absorber 5, a high-temperature heat exchanger 6 and a low-temperature heat exchanger 7, and an absorption heat pump B is a regenerator 11, a condenser 12, and an evaporator. It is a single-effect absorption heat pump composed of a vessel 13, an absorber 14, and a heat exchanger 15, and an absorber 5 of the first absorption heat pump A and a condenser 3 and a second absorption heat pump B by a hot water circulation path 21. The evaporator 13 is thermally connected and connected. Reference numeral 31 is a pump installed between the absorber 5 and the evaporator 13 for circulating hot water.

In the first absorption heat pump A, the low-temperature heat source water circulation path 8 flows the river water 9 or the like into the evaporator 4 as a low-temperature heat source having a stable temperature, and is connected to the second absorption heat pump so as to be drainable. In B, the hot water circulation path 16 is connected to the hot water supply / heating load 17 so that hot water can be supplied. 32 and 33 are circulation pumps installed in the respective circulation paths. The river water 9 may be lake water, well water, sewage, etc.
It is desirable that the water content is large and the temperature change is small.

By the way, the first absorption heat pump A
The devices themselves that constitute the second absorption heat pump B are not particularly different from those conventionally known, and unless otherwise stated, the respective devices are connected and piped in the same manner as in the prior art so that they function smoothly.

The heating amount of the high temperature regenerator 1 of the first absorption heat pump A is controlled by the data of the water temperature measuring sensor 41 provided on the outlet side of the condenser 3 of the hot water circulation path 21, the controller 42, and the river water 9. The data of the water temperature measuring sensor 45 and the controller 46 are cascade-controlled. That is, the controller 46 operates based on the data of the water temperature measuring sensor 45, outputs a correction signal of the set temperature to the controller 42, the set temperature of the controller 42 is changed, and the condenser 3 outlet is set to the changed set temperature. The controller 42 controls the heating amount of the high temperature regenerator 1 based on the data of the water temperature measuring sensor 41 so that the temperature on the side becomes equal. Then, in the winter when the temperature of the river water 9 is low, for example, 12 ° C., the set temperature of the hot water circulation passage 21 is set to 30 ° C., and in the summer when the temperature of the river water 9 reaches 25 ° C., the set temperature is set to 38 ° C., for example. The temperature is automatically raised to ℃ to control the heating amount of the high temperature regenerator 1. In this way river water 9
FIG. 2 shows how the preset temperature of the controller 42 is changed by the cascade control at the above temperature. The case of FIG. 2 is linear cascade control, but it is of course possible to perform cascade control with an arbitrary curve. The controller 44 controls the heating amount of the regenerator 11 of the second absorption heat pump B based on the data of the water temperature measuring sensor 43 provided on the outlet side of the condenser 12 of the high temperature water circulation path 16. 34, 35, 36 and 37 are pumps provided in the respective circulation paths.

Next, a specific example of hot water supply and heating operation using the absorption heat pump device having the above configuration will be described.

The hot water flowing through the hot water circulation passage 21 is controlled so that the temperature of the outlet side of the condenser 3 of the first absorption heat pump A is constant, for example, 30 ° C. when the river water 9 is 12 ° C. To be done. That is, the sensor 41 measures the outlet side water temperature of the condenser 3, and when the temperature is lower than a predetermined 30 ° C., for example, the heating amount of the high temperature regenerator 1 is increased based on the instruction of the controller 42, and a large amount of refrigerant vapor (for example, steam). Is sent to the low temperature regenerator 2, and a large amount of the absorbing liquid (for example, LiBr) concentrated to an intermediate concentration is discharged to the high temperature heat exchanger 6 side, and in the absorber 5, the refrigerant vapor evaporated on the evaporator 4 side. Is heated by the absorption heat when the absorption liquid absorbs,
Since the condenser 3 is also heated by the refrigerant vapor generated on the low temperature regenerator 2 side, the warm water reaches a predetermined temperature of 30 ° C. and is discharged to the evaporator 13 side of the second absorption heat pump B.

The temperature of the river water 9 sent to the evaporator 4 via the low-temperature heat source water circulation path 8 is considerably high even in winter in the case of urban areas. This is due to the heat island phenomenon, which has become remarkable in recent years, and reaches as high as 12 ° C., for example. Therefore, the liquid refrigerant sent from the condenser 3 can be heated to evaporate (the evaporator 4 has a low boiling point because the pressure is reduced to, for example, 6 mmHg). Then, the pumped river water 9 is cooled by the heat of vaporization when the refrigerant evaporates, reaches, for example, 7 ° C., and is discharged to a river or the like.

Since the temperature of the hot water flowing into the evaporator 13 of the second absorption heat pump B via the hot water circulation passage 21 is controlled to 30 ° C. by the first absorption heat pump A as described above, It is not necessary to install a heat dissipation device such as a cooling tower in front of the evaporator 13 of the absorption heat pump B.

In this way, the warm water at a predetermined temperature of 30 ° C. flows into the evaporator 13 of the second absorption heat pump B, so that the refrigerant flowing from the condenser 12 is effectively evaporated and a large amount of refrigerant vapor is generated. The absorbing liquid is absorbed by the adjacent absorber 14. Therefore, the absorption heat at this time causes the absorber 14
The internal temperature of the hot water rises, and the temperature of the hot water flowing through the high temperature water circulation path 16 rises. The hot water is also reheated in the condenser 12 by the refrigerant vapor sent from the regenerator 11, and is heated to a predetermined high temperature, for example, 80 ° C. to supply hot water / heating load 17.
Is supplied to the absorber 14 to perform work (heat exchange) and then return to the absorber 14.

Since the heating amount of the regenerator 11 is controlled so that the outlet side temperature of the condenser 12 of the hot water flowing through the high temperature water circulation path 16 becomes a predetermined temperature, for example, 80 ° C., as described above.
When the hot water supply / heating load 17 is large, for example, when the temperature falls below a predetermined temperature of 60 ° C. and hot water flows back to the absorber 14, the hot water is discharged from the condenser 12 at a temperature lower than a predetermined temperature of 80 ° C. Playback device 1 according to instructions from 44
The heating amount of 1 is increased, a large amount of refrigerant vapor is sent to the condenser 12, and the concentrated and regenerated absorption liquid is sent to the absorber 14 via the heat exchanger 15. When the heating amount of the regenerator 11 is increased in this way, in the absorber 14, the absorption liquid having the increased concentration actively absorbs the refrigerant vapor evaporated in the adjacent evaporator 13, and the absorption heat flows through the high temperature water circulation path 16. Since the hot water is heated and further reheated in the condenser 12 by a large amount of refrigerant vapor, it becomes hot water of a predetermined temperature of 80 ° C. and is supplied to the hot water supply / heating load 17.

On the contrary, when the hot water supply / heating load 17 is small, warm water having a temperature higher than the predetermined 60 ° C. flows back to the absorber 14, so that the heating amount of the regenerator 11 is the same as before. Since it is sent from the condenser 12 to the hot water supply / heating load 17 at a temperature higher than the predetermined 80 ° C., the heating amount of the regenerator 11 is reduced or the heating is temporarily stopped according to the instruction of the controller 44, and the supply of the refrigerant vapor is reduced. Alternatively, when stopped, the heating effect in the absorber 14 and the condenser 12 is reduced, and high temperature water of a predetermined temperature of 80 ° C. is supplied.

When the temperature of the river water 9 which is the low temperature heat source of the first absorption heat pump A rises, the sensor 45 detects the rise of the water temperature and the controller 46 automatically cascades the set temperature of the controller 42. (Increase according to FIG. 2), the heating amount of the high temperature regenerator 1 is controlled. For example, if the temperature of river water 9 changes from 12 ℃ to 25 ℃,
When the temperature rises by 3 ° C., the heating amount of the high temperature regenerator 1 is controlled so that the outlet temperature of the condenser 3 of the hot water flowing through the hot water circulation passage 21 rises by 8 ° C. to 38 ° C. It is possible to reduce the heating amount from when the temperature is 12 ° C.
Also in the absorption heat pump B, since the temperature of the hot water in the hot water circulation passage 21 flowing into the evaporator 13 has risen by 8 ° C.,
The heating amount of the regenerator 11 can be reduced. Therefore,
When the temperature of the river water 9 rises in summer or the like, C of the first absorption heat pump A and the second absorption heat pump B
Since each OP rises as shown in FIGS. 3 and 4, it is possible to efficiently take out high-temperature water having a predetermined temperature from the second absorption heat pump B.

FIG. 5 shows a first absorption heat pump A and a second absorption heat pump A.
Of the absorption heat pump B of the regenerator 11, the condenser 12,
It is an absorption heat pump device including absorption heat pumps for single effect, which are composed of an evaporator 13, an absorber 14, and a heat exchanger 15. The function and operation control of this device are the same as those of the absorption heat pump device described in FIG.

[0022]

As described above, in the control apparatus for the absorption heat pump according to the present invention, the temperature of the hot water circulation path that thermally connects the first absorption heat pump and the second absorption heat pump is the first absorption heat pump. Cascade control is performed according to the temperature of the low-temperature heat source water of the heat pump, so the water temperature is 12 even in winter.
The hot water can be taken out from the second absorption heat pump by using the municipal wastewater of about ℃ as a low temperature heat source, and the set temperature of the hot water circulation path is set to this high wastewater temperature in the summer when the water temperature reaches 25 ℃. By operating in cascade control, COP (of the entire system) increases. Therefore, it became possible to take out hot water efficiently throughout the year.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example.

FIG. 2 is an explanatory diagram of cascade control in one embodiment.

FIG. 3 C of the first absorption heat pump in one embodiment
It is explanatory drawing which shows OP.

FIG. 4 C of the second absorption heat pump in one embodiment
It is explanatory drawing which shows OP.

FIG. 5 is an explanatory diagram showing another embodiment.

[Explanation of symbols]

 1 High Temperature Regenerator 2 Low Temperature Regenerator 3 Condenser 4 Evaporator 5 Absorber 6 High Temperature Heat Exchanger 7 Low Temperature Heat Exchanger 8 Low Temperature Heat Source Water Circulation 9 River Water 11 Regenerator 12 Condenser 13 Evaporator 14 Absorber 15 Heat Exchange 16 High-temperature water circuit 17 Hot water supply / heating load 21 Hot-water circuit 31 Pump 41 Sensor 42 Controller 43 Sensor 44 Controller 45 Sensor 46 Controller A First absorption heat pump B Second absorption heat pump

Front page continuation (72) Inventor Takao Okuma 3-14-9 Sakuradai, Nerima-ku, Tokyo (72) Inventor Toshiyuki Kaneko 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Yamazaki Shioku Osaka Prefecture Moriguchi City Keihan Hon-dori 2-chome 18 Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A first absorption heat pump comprising a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator, an absorber, a high temperature heat exchanger and a low temperature heat exchanger, and a regenerator, a condenser, an evaporator,
A second absorption heat pump including an absorber and a heat exchanger, and a hot water circulation path that thermally connects the absorber and condenser of the first absorption heat pump to the evaporator of the second absorption heat pump, In the absorption heat pump device that introduces river water or the like as a low-temperature heat source into the evaporator of the first absorption heat pump and takes out high-temperature water from the second absorption heat pump, it is possible to perform cascade control of the temperature of the hot water circulation path according to the temperature of the low-temperature heat source. Characteristic absorption heat pump control device. 2. The first absorption heat pump and the second absorption heat pump both include a regenerator, a condenser, an evaporator, an absorber and a heat exchanger, and the first absorption heat pump has an absorber and a condenser and a second absorption heat pump. A hot water circuit is provided to thermally connect the evaporator of the absorption heat pump to the first absorption heat pump, and river water or the like is introduced to the evaporator of the first absorption heat pump as a low temperature heat source.
In the absorption heat pump device for extracting high-temperature water from the absorption heat pump, the control device of the absorption heat pump, wherein the temperature of the hot water circulation path is cascade-controlled by the temperature of the low-temperature heat source.