JPH07139842A - Absorption freezer - Google Patents

Abstract

PURPOSE:To provide an absorption freezer wherein advantages of a series flow type and a parallel flow type are efficiently employed, waste heat is effectually used, and auxilary machine power is saved. CONSTITUTION:There are provided a cooling water line 14C extending through an absorber 2, cooling water lines 14E, 14D including an on/off valve 19 and extending to a condenser 3, a cooling water flow passage changeover valve 18 for selectively changing over the cooling water line 14C to the cooling water line 14D, a two stage switching cooling water pump 12A, a temperature sensor S1 for driving hot water or a vapor line 15A, and a control unit for switching the changeover valve 18, the on/off valve 19, and the cooling water pump 12A using a signal from the temperature sensor S1, wherein when driving waste heat temperature is high, the operation is switched to a series flow while when the same is low, the operation is switched to a parallel flow.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an absorption refrigerator.

[0002]

2. Description of the Related Art There are a series flow type and a parallel flow type in the flow of cooling water of a conventional single-effect absorption refrigerator.

As shown in FIG. 21, the series flow type is provided with a cooling water line 14 from the cooling water pump 12 through the absorber 2 and the condenser 3 in series. In the figure, reference numeral 1 is an evaporator, 4 is a regenerator, 5 is a solution heat exchanger, 6 is a refrigerant vapor line, 7 is a refrigerant liquid line, 8 is a dilute solution line, 9 is a concentrated solution line, and 10 is a refrigerant. Pump, 1
1 is a solution pump, 13 is a cold water line, and 15 is a driving hot water or steam line.

In the parallel flow type, as shown in FIG. 22, a cooling water line 14A from the cooling water header 16 to the cooling water header 17 via the absorber 2 and cooling from the condenser 3 to the cooling water header 17 are provided. The water line 14B is provided in parallel.

Similarly, a double-effect absorption refrigerator also has a structure shown in FIG.
2 and the parallel flow type shown in FIG. 24. The two-stage absorption cycle absorption refrigerator also has a series flow type shown in FIG.
There are a series flow type shown in FIG. 5 and a parallel flow type shown in FIG. Note that in FIGS. 23 and 24, 3
1 is an evaporator, 32 is an absorber, 33 is a condenser, 33A is a pressure reducing valve, 34 is a low temperature regenerator, 35 is a high temperature regenerator, 36 is a low temperature solution heat exchanger, 37 is a high temperature solution heat exchanger, 38 is Vapor drain heat recovery device, 39 is a refrigerant vapor line, 40 is a refrigerant liquid line, 41 is a dilute solution line, 42 is a concentrated solution line,
43 is an intermediate concentration solution line, 44 is a refrigerant pump, 45 is a solution pump, 46 is a cooling water pump, 47 is a cold water line,
48 is a cooling water line, 49 is a driving hot water or steam line,
50 and 51 are cooling water headers. 25 and 26, 61 is an evaporator, 62 is a low-stage absorber, and 6
3 is a high-stage absorber, 64 is a low-stage regenerator, 65 is a condenser, 66 is a high-stage regenerator, 67 is a low-stage solution heat exchanger,
68 is a high-stage solution heat exchanger, 69 is a refrigerant vapor line, 7
0 is a refrigerant liquid line, 71-74 is a solution line, 75 is a refrigerant pump, 76 and 77 are solution pumps, 78 is a cooling water pump, 79 is a cold water line, 80 is a cooling water line, 81 is driving hot water or a steam line, Reference numerals 82 and 83 are cooling water headers.

[0006]

In the above-mentioned series flow type, when the driving exhaust heat temperature falls below a certain temperature, the performance of the absorption refrigerator is rapidly lowered. On the other hand, the parallel flow type is suitable when the exhaust heat temperature is low. But,
Since the amount of cooling water is approximately doubled, the pump auxiliary machine power increases correspondingly. Further, when a high driving exhaust heat temperature is obtained, the parallel flow type does not have much merit in the performance of the absorption refrigerator as compared with the series flow type.

FIG. 27 is a comparison of the absorption cycles of the absorption refrigerator when the cooling water is flowed in the series flow and the parallel flow in the single-effect absorption refrigerator on the Dühring diagram. Note that the reference numerals in FIG.
1 shows each device of FIG. It can be seen that the parallel flow type shown by the chain line requires a lower regenerator heating temperature than the series flow type shown by the solid line. In the absorption refrigerating machine, this temperature difference has a very large influence on the performance of the absorption refrigerating machine under the driving exhaust heat temperature condition at which the absorption cycle can be constituted.

An object of the present invention is to provide an absorption refrigerating machine which utilizes the advantages of the series flow type and the parallel flow type, makes effective use of exhaust heat, and saves auxiliary machine power.

[0009]

According to the present invention, there is provided a first cooling water line passing through the absorber, a second cooling water line including an on / off valve and reaching the condenser, and the second cooling water line. A cooling water flow path switching valve for selectively connecting the first cooling water line to the cooling water line, a two-stage switching type cooling water pump, a driving hot water or steam line temperature sensor, and a signal from the temperature sensor. Based on the above, a control unit for switching and controlling the cooling water flow path switching valve, the on / off valve, and the cooling water pump is provided.

[0010]

In the absorption refrigerating machine configured as described above, when the driving exhaust heat temperature is high, the control unit sets the cooling water pump to the small flow rate side, closes the on / off valve, and turns on the cooling water flow path switching valve. Switching The first cooling water line is connected to the second cooling water line to switch to the series flow.

When the driving exhaust heat temperature is low, the cooling water pump is set to the large flow rate side, the on / off valve is opened, and the first cooling water line is connected to the outlet header to switch to the parallel flow.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, in the cooling water header 16 from the two-stage switching type cooling water pump 12A, the cooling water flow passage is divided into two cooling water lines 14C and 14E. The cooling water line 14C is provided with the absorber 2, and the cooling water line 14E is provided with an on / off valve 19.

On the other hand, the rotary type cooling water flow path switching valve 18
Is provided, and the cooling water line 14C reaches the cooling water header 17 via the condenser 3A at one position.
4D, and connect the cooling water line 14E to the cooling water header 17
Is connected to the cooling water line 14F, the cooling water line 14C is connected to the cooling water line 14F, and the cooling water line 14E is connected to the cooling water line 14D at other positions.

Further, temperature sensors S1 and S2 for detecting the temperatures (TH, TM) of the driving hot water or steam line 15A and the cooling water line 14C are provided. The two temperature sensors S1 and S2, the cooling water pump 12A, the cooling water flow path switching valve 18 and the on / off valve 19 are connected to the control unit CU, respectively, and the others are configured substantially the same as in FIG. ing.

Next, the control mode will be described.

In FIG. 2, the control unit CU detects the temperature TH of the driving hot water or steam line 15A by the temperature sensor S1 (step S1), and determines whether or not the temperature TH is higher than a set value (step S2). . If NO,
That is, when the temperature TH is lower than the set temperature, the cooling water passage switching valve 18 is switched to the parallel flow (shown by the solid line in FIG. 1) side, the on / off valve 19 is opened, and the cooling water pump 12 is opened.
A is switched to the large flow rate side to switch to the parallel flow (step S3). If YES in step S2, that is, if the temperature TH is higher than the set temperature, the cooling water flow path switching valve 18 is switched to the series flow (shown by the chain line in FIG. 1) side, the on / on valve 19 is closed, and the cooling water pump is closed. 12A is switched to the small flow rate side to switch to the series flow (step S4).

On the other hand, the control unit CU in FIG.
The temperature TH of the driving hot water or steam line 15A is measured by the temperature sensor S1, and the cooling water line 14C is measured by the temperature sensor S2.
Of the temperature TM (step S9), and F (TH, T
M) is calculated (step S6). Here, F is a two-variable function of TH and TM for judging the flow, and is shown in the form of, for example, F = a (TM + b) + cTM (a, b, and c are constants determined by experiment). Be done.

Next, it is determined whether F (TH, TM) is higher than the set value (step S7). If NO, as in step S3, the flow is switched to the parallel flow (step S8). If YES, the flow is switched to the series flow in the same way as step S4 (step S9).

FIG. 4 shows another embodiment of the present invention, in which cooling water circuits 14C and 14E are provided with cooling water pumps 12B and 1B, respectively.
This is an example in which 2C is provided and connected to the control unit CU, and the others are configured substantially the same as in FIG.

In this embodiment, in FIG. 5, the control unit CU detects the temperature TH (step S10) and determines whether or not the temperature TH is higher than a set value (step S).
11). In the case of NO, the cooling water flow path switching valve 18 is switched to the parallel flow side indicated by the solid line, and the cooling water pump 12C is operated to switch to the parallel flow (step S1).
2). If YES, the cooling water passage switching valve 18 is switched to the series flow side indicated by the chain line, and the cooling water pump 1
Stop 2C and switch to series flow (step S
13).

On the other hand, the control unit CU in FIG.
The temperatures TH and TM are detected (step S14), and F (T
H, TM) is calculated (step S15) and F (TH,
TM) is determined to be higher than the set value (step S
16). If NO, the flow is switched to the parallel flow as in step S12 (step S17). If YES, it is switched to the series flow in the same way as step S13 (step S18).

As a result of these controls, as shown in the Duering diagram shown in FIG. 27, when the driving exhaust heat temperature is high, the series flow is switched to, and when the driving exhaust heat temperature is low, the parallel flow is shown by the chain line. Switching and saving pump auxiliary machine power.

FIG. 7 shows another embodiment of the present invention (an embodiment of a double-effect absorption cycle), in which a cooling water line 48C is turned on in a cooling water header 50 from a two-stage switching type cooling water pump 46A. Cooling water line 48E with off valve 53
Through the cooling water flow path switching valve 52 to the cooling water lines 48D, 4
8F or the cooling water lines 48F and 48D are selectively switched, and temperature sensors S1 and S2 are provided and connected to the control unit CU together with the switching valve 52 and the on / off valve 53. This is an example of a similar configuration.

In this embodiment, in FIG. 8, the control unit CU detects the temperature TH (step S20) and determines whether the temperature TH is higher than the set value (step S).
21). In the case of NO, the cooling water flow path switching valve 52 is switched to the parallel flow side indicated by the solid line, the on / off valve 53 is opened, and the cooling water pump 46A is switched to the large flow rate side to switch to the parallel flow (step S22). If YES, the cooling water flow path switching valve 52 is switched to the series flow side indicated by the chain line, the on / off valve is closed, and the cooling water pump 4
6A is switched to the small flow rate side to switch to the series flow (step S23).

On the other hand, in FIG. 9, the control unit CU is
The temperatures TH and TM are detected (step S24), and F (T
H, TM) is calculated (step S25), and F (TH,
TM) is determined to be higher than the set value (step S
26). If NO, the flow is switched to the parallel flow as in step S22 (step S27). If YES, it is switched to the series flow in the same way as step S23 (step S28).

FIG. 10 shows another embodiment of the present invention, in which cooling water passages 48C and 48E are provided with cooling water pumps 46B and 4B, respectively.
6C is provided and connected to the control unit CU, and the others are configured substantially in the same manner as in FIG. 7.

In this embodiment, in FIG. 11, the control unit CU detects the temperature TH (step S30),
It is determined whether the temperature TH is higher than the set value (step S31). In the case of NO, the cooling water flow path switching valve 52 is switched to the parallel flow side indicated by the solid line, and the cooling water pump 46C
To switch to parallel flow (step S3
2) If the answer is YES, the cooling water flow path switching valve 52 is switched to the series flow side indicated by the chain line, the cooling water pump 46C is stopped, and the series flow is switched (step S3).
3).

On the other hand, in FIG. 12, the control unit CU
Detects the temperatures TH and TM (step S34), and F
(TH, TM) is calculated (step S35), and F (T
It is determined whether (H, TM) is higher than the set value (step S36). If NO, the flow is switched to the parallel flow as in step S32 (step S37). If YES, the flow is switched to the series flow as in step S33 (step S38).

FIG. 13 shows a Duhring diagram showing the effect of the present application on the double-effect absorption refrigerator of FIGS. 7 and 10. That is, when the driving exhaust heat temperature is high, the series flow is switched to the solid line, and when the driving exhaust heat temperature is low, the parallel flow is switched to the chain flow to save the pump auxiliary power of the cooling water.

FIG. 14 shows another embodiment of the present invention (an embodiment of a two-stage absorption cycle), which is a two-stage switching type cooling water pump 7.
In the cooling water header 82 from 8A, the cooling water line 8
Cooling water line 80E via 0D and on / off valve 86,
Cooling water flow passage switching valve 84 for branching to 80F and selectively switching the cooling water passages 80D, 80E to the cooling water lines 80G, 80H or 80H, 80G, and the cooling water line 80G,
80F for cooling water line 80J, 80K or 80K, 80
A cooling water flow path switching valve 85 to be selected for J is provided, temperature sensors S1 and S2 are provided to the driving hot water or steam line 81 and cooling water line 80D, respectively, and both temperature sensors S1 and S2 are provided.
This is an example in which the cooling water pump 78A, the on / off valve 86, and the cooling water flow path switching valves 84 and 85 are respectively connected to the control unit CU, and the others are configured substantially in the same manner as in FIG.

In this embodiment, as shown in FIG. 15, the control unit CU detects the temperature TH (step S4).
0), it is determined whether or not the temperature TH is higher than the set value (step S41). If NO, cooling water flow path switching valve 8
4 and 85 are switched on to the parallel flow side indicated by the solid line
The off valve 86 is opened, the cooling water pump 78A is switched to the large flow rate side, and the parallel flow is switched (step S42). Y
If it is ES, the cooling water flow path switching valves 84 and 85 are switched to the series flow side indicated by the chain line, the on / off valve 86 is closed, and the cooling water pump 78A is switched to the small flow rate to switch to the series flow (step S43).

On the other hand, in FIG. 16, the control unit CU
Detects the temperatures TH and TM (step S44), and F
(TH, TM) is calculated (step S45), and F (T
It is determined whether (H, TM) is higher than the set value (step S46). If NO, the flow is switched to the parallel flow as in step S42 (step S47), and if YES, it is switched to the series flow in the same way as step S43 (step S48).

FIG. 17 shows another embodiment of the present invention, in which cooling water lines 80D, 80E and 80F are provided with cooling water pumps 78B, 78C and 78D, respectively, which are connected to the control unit CU, and the others are substantially shown. This is an example configured in the same manner as 14.

In this embodiment, as shown in FIG. 18, the control unit CU detects the temperature TH (step S5).
0), it is determined whether or not the temperature TH is higher than the set value (step S51). If NO, cooling water flow path switching valve 8
4, 85 is switched to the parallel flow side indicated by the solid line, and the cooling water pumps 78C, 78D are operated to switch to the parallel flow (step S52). If YES, the cooling water flow path switching valves 84, 85 are indicated by the chain flow. Then, the cooling water pumps 78C and 78D are stopped to switch to the series flow (step S53).

On the other hand, in FIG. 19, the control unit CU
Detects the temperatures TH and TM (step S54), and F
(TH, TM) is calculated (step S55), and F (T
H, TM) is higher than the set value (step S56), if NO, switch to parallel flow as in step S52 (step S57), and if YES, series flow as in step S53. (Step S58).

FIG. 20 shows a Duhring diagram showing the effect of the present invention on the two-stage absorption cycle absorption refrigerator of FIGS. 14 and 17. That is, when the driving exhaust heat temperature is high, the series flow is switched to the solid line, and when the driving exhaust heat temperature is low, the parallel flow is switched to the chain flow to save the pump auxiliary power of the cooling water.

[0038]

Since the present invention is constructed as described above, it is possible to effectively use the exhaust heat and save the auxiliary machine power. This can be expected especially in a two-stage absorption cycle absorption refrigerator.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a control flowchart showing one control mode of FIG.

FIG. 3 is a control flowchart showing another control mode of FIG.

FIG. 4 is an overall configuration diagram showing a second embodiment of the present invention.

FIG. 5 is a control flowchart showing one control mode of FIG.

6 is a control flowchart showing another control mode of FIG. 4. FIG.

FIG. 7 is an overall configuration diagram showing a third embodiment of the present invention.

8 is a control flowchart showing one control mode of FIG. 7. FIG.

FIG. 9 is a control flowchart showing another control mode of FIG. 7.

FIG. 10 is an overall configuration diagram showing a fourth embodiment of the present invention.

FIG. 11 is a control flowchart showing one control mode of FIG.

FIG. 12 is a control flowchart showing another control mode of FIG.

13 is a Duhring diagram showing the effect of FIGS. 7 and 10. FIG.

FIG. 14 is an overall configuration diagram showing a fifth embodiment of the present invention.

FIG. 15 is a control flowchart showing one control mode of FIG.

FIG. 16 is a control flowchart showing another control mode of FIG.

FIG. 17 is an overall configuration diagram showing a sixth embodiment of the present invention.

FIG. 18 is a control flowchart showing one control mode of FIG. 17;

FIG. 19 is a control flowchart showing another control mode of FIG.

FIG. 20 is a Duhring diagram showing the effect of FIGS. 14 and 17.

FIG. 21 is an overall configuration diagram showing an example of a conventional single-effect absorption refrigerator.

FIG. 22 is an overall configuration diagram showing another example of a conventional single-effect absorption refrigerator.

FIG. 23 is an overall configuration diagram showing an example of a conventional double-effect absorption refrigerator.

FIG. 24 is an overall configuration diagram showing another example of a conventional double-effect absorption refrigerator.

FIG. 25 is an overall configuration diagram showing an example of a conventional two-stage absorption cycle absorption refrigerator.

FIG. 26 is an overall configuration diagram showing another example of a conventional two-stage absorption cycle absorption refrigerator.

FIG. 27 is a Dühring diagram showing a comparison of performance between the parallel flow and the series flow.

[Explanation of symbols]

CU ... Control unit S1, S2 ... Temperature sensor 1, 31, 61 ... Evaporator 2, 32 ... Absorber 3, 3A, 33, 65 ... Condenser 4, 4A ... Regenerator 5 ... Solution heat exchanger 6, 39, 69 ... Refrigerant vapor line 7, 40, 70 ... Refrigerant liquid line 8, 41 ... Dilute solution line 9, 42 ... Concentrated solution line 10, 44, 75 ... Refrigerant pump 11, 45, 76, 77 ... Solution pump 12, 12A to 12C, 46, 46A to 46C, 78,
78A-78D ... Cooling water pump 13, 47, 79 ... Cold water line 14, 14A-14F, 48, 48A-48F, 80,
80A-80K ... Cooling water line 15, 15A, 49, 81 ... Driving hot water or steam line 16, 17, 50, 51, 82, 83 ... Cooling water header 18, 52, 84, 85 ...・ Cooling water flow path switching valve 19, 53, 86 ... On / off valve 33A ... Pressure reducing valve 34 ... Low temperature regenerator 35 ... High temperature regenerator 36 ... Low temperature solution heat exchanger 37 ...・ High temperature solution heat exchanger 38 ・ ・ ・ Steam drain heat recovery device 43 ・ ・ ・ Intermediate concentration solution line 62 ・ ・ ・ Low stage side absorber 63 ・ ・ ・ High stage side absorber 64 ・ ・ ・ Low stage side regenerator 66 ... High-stage side regenerator 67 ... Low-stage solution heat exchanger 68 ... High-stage solution heat exchanger 71-74 ... Solution line

Claims (1)

[Claims] 1. A first cooling water line passing through an absorber, a second cooling water line including an on / off valve, and reaching a condenser, and the first cooling water in the second cooling water line. A cooling water flow path switching valve for selectively connecting lines, a two-stage switching type cooling water pump, a temperature sensor for driving hot water or a steam line, and the cooling water flow path switching valve that is turned on based on a signal from the temperature sensor. An absorption refrigerator having a control unit for switching and controlling the off valve and the cooling water pump.