JPH08105662A - Absorption chiller / heater and control method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an absorption chiller-heater and a control method thereof that can smoothly start up the cooling operation when a power failure occurs during the cooling operation and the operation is restarted after the power is restored. [Structure] During a power failure, a bypass pipe 24 connecting the low temperature regenerator 2 and the evaporator 4 is opened by opening a pressure equalizing valve 25 to lower the pressure of the condenser 3 and increase the pressure of the evaporator 4. Let [Effect] The pressure difference between the evaporator and condenser that occurs during a power outage
It is possible to reduce the size by opening the bypass pipe, and the refrigerant sealed in the U-shaped seal pipe does not blow through to the evaporator side, so that the cooling operation after the power is restored can be started up smoothly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller-heater used in an air conditioner and the like and a control method therefor, and more particularly to an absorption chiller-heater adapted to take out cold water and hot water from an evaporator through a common pipe. And its control method.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Examined Patent Publication No. SHO 220-22072.
In the technique described in the publication, the condenser and the evaporator are mainly connected via a U-shaped seal tube. Cooling water that performs liquid cooling with a U-shaped seal tube and keeps the pressure difference between the condenser and the evaporator to perform cooling operation, and also circulates cooling water between the refrigerant pump, the absorber, and the condenser in the cooling operation. Stop the pump, increase the pressure in the condenser, blow the liquid-sealed refrigerant in the U-shaped seal tube and the refrigerant accumulated in the lower part of the evaporator to the evaporator side, and use the U-shaped seal tube as a bubble pump. By doing so, heating operation is performed.

[0003]

SUMMARY OF THE INVENTION In an absorption chiller-heater having the above-mentioned conventional condenser and evaporator connected via a U-shaped seal tube, for example, when the power is suddenly turned off during cooling operation, The refrigerant pump, the solution pump, the regenerator heating source are stopped, and further, the cooling water pump for circulating the cooling water to the absorber and the condenser is stopped, so that the pressure of the condenser is increased. As a result, the pressure difference between the condenser and the evaporator increases, and the refrigerant that is liquid-sealed in the U-shaped seal tube blows out toward the evaporator. Even when the operation is restarted after the power is restored, the refrigerant for liquid sealing in the U-shaped seal tube is lifted as a bubble pump until the pressure of the condenser and the evaporator stabilizes after the refrigerant blows to the evaporator side. Since it is liquefied, the refrigerant cannot be liquid-sealed in the U-shaped seal pipe, and the cooling operation may not be performed.

The present invention has been made to solve the above-mentioned problems of the prior art, and its object is to smoothly start up the cooling operation even if the operation is restarted when the power is suddenly turned off during the cooling operation. It is an object of the present invention to provide an absorption chiller-heater and a control method thereof.

[0005]

The above-mentioned object is to perform cooling operation between both ends of a U-shaped seal tube provided for absorbing a pressure difference between a condenser and an evaporator of an absorption chiller-heater. A U-shaped seal is provided between both ends of a U-shaped seal pipe, which is achieved by bypassing during a power outage and is provided to absorb the pressure difference between the condenser and the evaporator of the absorption chiller-heater. Achieved by bypassing when the temperature of the lower part of the condenser side of the pipe exceeds a prescribed value, and after the power supply of the absorption chiller / hot water generator has failed during cooling operation, power is restored and the cooling operation is restarted. At times, the refrigerant pump, the cooling water pump, and the cold water pump are operated, and at the same time, a bypass pipe is provided between both ends of the U-shaped seal pipe provided to absorb the pressure difference between the condenser and the evaporator. State and after a predetermined time has passed Close the serial bypass pipe is achieved by starting the operation.

[0006]

In the absorption type hot and cold water machine in which the condenser and the evaporator are connected via the U-shaped seal pipe, when the power of the condenser suddenly turns off during the cooling operation and the pressure of the condenser rises, the U-shaped seal By bypassing both ends of the pipe with a bypass pipe, the pressure on the high-pressure condenser side and the pressure on the low-pressure evaporator side are in an equilibrium state before the refrigerant liquid-sealed in the U-shaped seal pipe blows out to the evaporator side. Therefore, the refrigerant sealed in the U-shaped seal tube does not blow through to the evaporator side. Therefore, even if the operation is restarted after the power is restored, the cooling operation can be started up smoothly.

Further, when the pressure of the condenser rises excessively, such as when non-condensed gas is generated, this is detected by the temperature of the lower portion of the U-shaped seal tube on the condenser side, and the refrigerant is bypassed by a bypass pipe. Can be prevented from passing through.

Also, when the blow-through occurs at the time of a power failure and then the power is restored, the pumps are first operated for a certain period of time while bypassing the bypass piping, thereby lowering the temperature of the evaporator and allowing the cooling operation. After that, you can restart the operation smoothly.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an absorption chiller-heater according to the present invention, in which a high temperature regenerator 1, a low temperature regenerator 2, a condenser 3,
Evaporator 4, absorber 5, solution pump 6, refrigerant pump 7, high temperature heat exchanger 8, low temperature heat exchanger 9, U-shaped seal tube 12 connecting the condenser and the evaporator, liquid refrigerant spray conduit 22, refrigerant dispersion Device 27, solution spraying device 26, ejector pump 14,
Gas-liquid separator 13, solution conduit 15, mixing chamber 16 for mixing a refrigerant and a solution, pipe 19 for guiding the refrigerant accumulated in the lower part of gas-liquid separator 13 to mixing chamber 16, cooling water pump 1
0, the cooling tower 11, the pipe 20 for supplying the refrigerant of the evaporator 4 when the U-shaped seal pipe 12 is used as a bubble pump, the movable valve 21, the bypass pipe 24 connecting the low temperature regenerator 2 and the evaporator 4, and the uniform pipe. It consists of a pressure valve 25 and the like.

The normal operation of such an absorption chiller-heater during the cooling operation will be described. During cooling operation, the movable valve 1
8, 21 and the pressure equalizing valve 25 are closed. The refrigerant vapor generated when the solution is heated by the external heat source and concentrated in the high temperature regenerator 1 is introduced into the heating pipe of the low temperature regenerator 2 to heat and concentrate the solution in the low temperature regenerator 2 to remove the refrigerant vapor. It is generated, condensed and liquefied, and flows into the condenser 3. The refrigerant vapor generated in the low temperature regenerator 2 is guided to the condenser 3, cooled by cooling water to condense and liquefy, and is sent to the evaporator 4 together with the refrigerant from the high temperature regenerator 1 via a liquid refrigerant conduit (not shown). To be

A part of the liquid refrigerant in the evaporator 4 is supplied to the U-shaped seal tube 12 via the liquid refrigerant supply pipe 23 by the refrigerant pump 7, and the other is sent to the refrigerant spraying device 27 via the liquid refrigerant spray conduit 22. The refrigerant is sprayed from the refrigerant spraying device 27 onto the evaporator heat transfer tube group and exchanges heat with the cold water flowing in the tube to evaporate and vaporize, and then flow into the absorber 5. The latent heat of vaporization at that time exerts a cooling effect.

In the absorber 5, the concentrated solution concentrated in the high temperature regenerator 1 and the low temperature regenerator 2 is sprayed by the ejector pump 14 onto the absorber heat transfer tube group via the solution spraying device 26, and the cooling water flowing in the tubes is flown. It is cooled by and absorbs the refrigerant vapor from the evaporator 4 to produce a dilute solution. A part of the diluted solution in the absorber 5 becomes a driving liquid for the ejector pump 14 by the solution pump 6 and is recirculated to the absorber 5. The remaining dilute solution is divided into two via the low temperature heat exchanger 9, one of which is the low temperature regenerator 2
And the other is further supplied to the high temperature regenerator 1 via the high temperature heat exchanger 8. The cooling cycle is configured as described above.

The above is the outline of the operation of the cooling operation. When this operation is stopped normally, the external heat source in the high temperature regenerator 1, the refrigerant pump 7 and the cooling water pump 10 are stopped,
After that, the cold water pump (not shown) circulating the cold water in the evaporator heat transfer tube group and the solution pump 6 are configured to be stopped. Further, the movable valve 18 of the pipe 17 which is closed at the time of operation is opened, the refrigerant accumulated in the condenser 3 is caused to flow to the absorber 5 through the mixing chamber 16, and the solution dilution operation is performed. .

As described above, when the operation is stopped, the condenser 3
Since the cooling water pump 10 for cooling the
At this point, the pressure rises and the refrigerant liquid-sealed in the U-shaped seal tube 12 tries to blow through to the evaporator 4 side. However, as the solution dilution operation, the movable valve 18 of the pipe 17 that is closed during operation is opened to condense. The refrigerant accumulated in the container 3 is caused to flow into the absorber 5 through the mixing chamber 16 and the solution pump 6 circulates the solution. As a result, it is possible to prevent the refrigerant liquid-sealed in the U-shaped seal pipe 12 from blowing through to the evaporator 4 side when the cooling operation is stopped.

However, if the power is cut off due to some cause during the cooling operation, for example, a power failure, the external heat source in the high temperature regenerator 1, the refrigerant pump 7, the solution pump 6, the cooling water pump 10, the cold water. Since the pump (not shown) stops at the same time and the movable valve 18 of the pipe 17 remains closed, the solution dilution operation cannot be performed. FIG. 2 shows the changes over time in the pressures of the condenser 3 and the evaporator 4 at this time. If the power supply is cut off at time A, the pressure of the condenser 3 begins to rise from this time, and Similarly, the differential pressure of increases. Due to this pressure difference, the U-shaped seal tube 12 cannot seal, but when the pressure difference at this time is D and the time is B, the refrigerant sealed in the U-shaped seal tube 12 at time B evaporates. It blows off to the side of the evaporator 4, and the pressure of the evaporator 4 suddenly rises. In this case, the refrigerant that was liquid-sealed in the U-shaped seal tube 12 was blown out toward the evaporator 4 side, and while the U-shaped seal tube 12 was operating as a bubble pump, the power was restored and the operation was restarted. The temperature inside the evaporator 4 has risen and the cooling operation cannot be started.

Therefore, in this embodiment, the pressure equalizing valve 25 of the bypass pipe 24 provided so as to connect the low temperature regenerator 2 and the evaporator 4 is opened at the same time when the power is turned off.
Here, it is assumed that the pressure equalizing valve 25 is an electromagnetic valve that is closed when the power is on, but opens when the power is turned off. The pressures of the condenser 3 and the evaporator 4 at this time are, as shown in FIG. 3, when the power is cut off at time A, the pressure equalizing valve 25 is opened from the time A, so that the refrigerant vapor generated in the high temperature regenerator 1 is generated. Part of the gas flows into the evaporator 4, which prevents an excessive pressure rise in the condenser 3 and also changes the pressure of the evaporator 4 together with the condenser 3. Therefore, the condenser 3 and the evaporator 4 can be changed. It is possible to maintain a small pressure difference between the U-shaped seal tube 12 and the refrigerant evaporator 4
It is possible to prevent blow-through to the side. As described above, the cooling operation can be smoothly started up when the operation is restarted after the power is restored, regardless of the elapsed time after the power is turned off.

FIG. 4 shows another embodiment of the absorption chiller-heater according to the present invention, in which a U-shaped seal pipe 12 is provided between the liquid surface of the U-shaped seal pipe 12 on the condenser 3 side and the bottom. A control device 2 for mounting a temperature detection device 28 for detecting the temperature inside 12 and taking in the output thereof to control the pressure equalizing valve 25 and the extraction valve 30 provided in the pipe connecting the extraction device 31 and the condenser 3
9 are installed.

In the embodiment of FIG. 1, the purpose was to prevent blow-through of the U-shaped seal tube 12 at the time of power failure.
In addition to when there is a power outage, (1) when non-condensed gas accumulates in the condenser 3, (2) when the liquid level in the low temperature regenerator 2 drops due to poor solution circulation around the low temperature regenerator 2. ,
(3) When excessive gas is input to the high temperature regenerator 1,
(4) It may occur when the cooling water circulates poorly. In these cases, the pressure / temperature in the condenser 3 rises, the refrigerant liquid in the U-shaped seal tube 12 is pushed from the condenser 3 side, and the liquid level decreases. Along with this, the temperature of the temperature detector 28 portion rises. Therefore, during the cooling operation, the control device 28 checks the temperature detected by the temperature detection device 28 at regular intervals, and when it determines that the temperature becomes higher than the preset temperature, the control device 29 opens the pressure equalizing valve 25. , So that the refrigerant sealed in the U-shaped seal tube 12 does not blow through to the evaporator 4 side.

When the pressure rise is caused by the non-condensable gas by the control device 29 alone or in conjunction with the pressure equalizing valve 25, the extraction valve 30 is opened to activate the extraction device 31, and the high temperature regeneration is performed. In the case of excessive gas input to the regenerator 1 or poor cooling water circulation, the amount of gas input to the high temperature regenerator 1 is forcibly suppressed. If you do this, U
It is possible to directly prevent the pressure increase in the condenser 3 that causes the refrigerant in the character seal tube 12 to blow through to the evaporator 4 side.

As described above, when the temperature inside the U-shaped seal tube 12 is grasped by the control device 29 during the cooling operation, U
It is possible to prevent an excessive increase in pressure on the condenser 3 side such that the refrigerant sealed in the character seal tube 12 blows to the evaporator 4 side.

The pressure equalizing valve 25 is controlled by the control device 29 according to the output of the temperature detecting device 28.
If the pressure equalizing valve 25 is an electromagnetic valve similar to that of the embodiment shown in FIG. 1, the valve is automatically opened even when a power failure occurs, and the same effect as that of the embodiment of FIG. 1 is obtained.

FIG. 5 is a modification of the embodiment of FIG. 1, and in FIG. 1, the bypass pipe 24 via the pressure equalizing valve 25 bypasses the U-shaped seal pipe 12, so that the low temperature regenerator 2 and the evaporator 4 are provided.
It was provided between the U-shaped seal tube 12 itself and the U-shaped seal tube 12 itself. When the power is cut off for some reason during the cooling operation, the pressure equalizing valve 25 of the bypass pipe 24 connected to the U-shaped seal pipe 12 is opened, so that FIG.
The same effect as in the first embodiment shown in FIG.
Since the refrigerant in the character seal tube 12 can be stopped without blowing through to the evaporator 4 side, the cooling operation can be smoothly started up when the operation is resumed after the power is restored regardless of the elapsed time after the stop.

In the above embodiment, the pressure equalizing valve 2
5 is a solenoid valve that automatically opens when the power is turned off and closes when the power is turned on. However, the present invention can also be configured by using a pressure equalizing valve that requires a power source for opening and closing. One of the methods is the configuration shown in FIG. 4, in which the control device 29 is provided with a power source of a different system from the absorption chiller-heater, for example, a backup power source at the time of power failure, and the pressure equalizing valve is opened by this backup power source when power failure occurs. It is a thing.

If a separate power source is not prepared, FIG.
With the above configuration, the control device 29 performs control as shown in FIG. That is, when power is restored after a power failure (step 60
1), it is checked whether the temperature detected by the temperature detecting device 28 is equal to or higher than a set value (step 602). The set value here is a value for detecting a temperature that is measured when the inside of the U-shaped seal tube is hot due to blowout of the U-shaped seal tube due to a power failure. If the detected temperature is less than or equal to the set value, the normal cooling operation is immediately started (step 608).
However, when the temperature exceeds the set value, the pressure equalizing valve 25 is opened (step 603, at this time, the valve driving power source is alive because it is immediately after power recovery), and the refrigerant pump 7 and the cooling water pump 1
0, and the cold water pump (not shown) is operated and waits for a fixed time (steps 604 to 606). This allows the evaporator 4
Since the internal temperature is lowered and the cooling operation can be performed, the pressure equalizing valve 25 is closed (step 607) and the cooling operation is started (step 608).

According to this embodiment, even if the U-shaped seal tube blows through during a power failure, the evaporator can be started after the cooling operation is possible.

[0026]

As described above, according to the present invention,
By connecting the bypass pipe 24 via the pressure equalizing valve 25 so as to bypass the liquid level of the refrigerant sealed in the U-shaped seal pipe 12 during the cooling operation, when the power is suddenly turned off during the cooling operation, the bypass By opening the pressure equalizing valve 25 of the pipe 24, the refrigerant liquid-sealed in the U-shaped seal pipe 12 does not blow through to the evaporator 4 side, and the operation can be restarted after the power is restored, so that the cooling operation can be smoothly started up. .

Further, even if the U-shaped seal tube is turned off during a power failure, the state of the evaporator can be automatically restored when the power is restored, so that the cooling operation can be started up smoothly.

Further, even when the pressure of the condenser 3 rises for some reason during the cooling operation and the refrigerant liquid-sealed in the U-shaped seal tube 12 blows off to the evaporator 4 side, the pressure equalizing valve 25
By opening, it is possible to prevent an excessive increase in pressure of the condenser 3 that would cause the refrigerant sealed in the U-shaped seal tube 12 to blow through to the evaporator 4 side.

[Brief description of drawings]

FIG. 1 is a cycle configuration diagram showing an embodiment of an absorption chiller-heater according to the present invention.

FIG. 2 is a diagram showing an example of pressure changes in a condenser and an evaporator when power is cut off in a conventional cooling cycle.

FIG. 3 is a diagram showing an example of pressure changes in a condenser and an evaporator when power is cut off in the cooling cycle of FIG.

FIG. 4 is a cycle configuration diagram showing a second embodiment of an absorption chiller-heater according to the present invention.

5 is a modification of the embodiment of FIG.

FIG. 6 is a flowchart showing a control method at the time of a power failure when a pressure equalizing valve that requires a power source to open and close is used.

[Explanation of symbols]

 1 High-temperature regenerator 2 Low-temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 12 U-shaped seal pipe 24 Bypass pipe 25 Pressure equalizing valve 28 Temperature detecting device 29 Control device 30 Extraction valve 31 Extraction device

Claims (15)

[Claims] 1. An absorption chiller-heater in which a condenser and an evaporator are connected via a U-shaped seal tube in order to absorb a pressure difference between the condenser and the evaporator. An absorption chiller-heater having a bypass pipe for equalizing the pressure between both ends via a pressure equalizing valve. 2. The absorption chiller-heater according to claim 1, wherein the bypass pipe is a pipe for connecting a low temperature regenerator and an evaporator. 3. The absorption pipe according to claim 1, wherein the bypass pipe is provided between both ends of the U-shaped seal pipe so as to bypass the liquid surface of the refrigerant sealed in the U-shaped seal pipe. Type water heater. 4. The absorption-type cold temperature controller according to claim 1, wherein the pressure equalizing valve is controlled so as to be in an open state when the power source of the absorption-type chiller / heater is cut off. Water machine. 5. A temperature detecting means is provided in the lower part of the U-shaped seal tube condenser side, and when the temperature detected by the means exceeds a predetermined value, the pressure equalizing valve is controlled to be opened. The absorption type cold / hot water machine according to any one of claims 1 to 3, which is characterized. 6. A bleeding device for discharging the gas in the condenser is connected to the condenser via a bleeding valve, and the bleeding valve is opened when the temperature detected by the temperature detecting means exceeds a predetermined value. The absorption chiller-heater according to claim 5, wherein the absorption chiller-heater is controlled as follows. 7. The absorption cold temperature according to claim 5, further comprising means for suppressing an input amount of an external heat source to the high temperature regenerator when the temperature detected by the temperature detecting means exceeds a predetermined value. Water machine. 8. The absorption chiller-heater according to claim 1, wherein the pressure equalizing valve is an electromagnetic valve that is opened when the power supplied thereto is cut off. . 9. A power source different from the power source for the absorption chiller-heater, and the opening and closing of the pressure equalizing valve is performed by the power source different from the one described above. Absorption chiller-heater described. 10. The pressure equalizing valve operates a refrigerant pump, a cooling water pump, and a chilled water pump when the absorption-type chiller-heater power supply is restored from a power failure during cooling operation and then resumes cooling operation. The absorption type chiller-heater according to claim 1, wherein the absorption-type chiller-heater is controlled so that it is opened at the same time as it is opened, and is closed after a lapse of a predetermined time. 11. A method for controlling an absorption chiller-heater having an evaporator, an absorber, a condenser, a low temperature regenerator, a high temperature regenerator, a low temperature heat exchanger, and a high temperature heat exchanger, wherein the condenser is a condenser. A method for controlling an absorption chiller-heater, characterized in that a space between both ends of a U-shaped seal tube provided to absorb a pressure difference between the evaporator and the evaporator is bypassed during a power failure during cooling operation. 12. A method for controlling an absorption chiller-heater having an evaporator, an absorber, a condenser, a low-temperature regenerator, a high-temperature regenerator, a low-temperature heat exchanger, and a high-temperature heat exchanger, wherein the condenser is a condenser. Between both ends of a U-shaped seal tube provided to absorb the pressure difference between the U-shaped seal tube and the evaporator when the temperature of the lower part of the U-shaped seal tube on the condenser side exceeds a predetermined value. Control method for absorption type water heater and chiller. 13. A method of controlling an absorption chiller-heater having an evaporator, an absorber, a condenser, a low-temperature regenerator, a high-temperature regenerator, a low-temperature heat exchanger, and a high-temperature heat exchanger. When the power of the chiller / heater power is cut off during the cooling operation, and when the power is restored and the cooling operation is restarted, the refrigerant pump, the cooling water pump, and the chilled water pump are operated, and at the same time, the pressure between the condenser and the evaporator is reduced. An absorption type characterized in that a space between both ends of a U-shaped seal pipe provided to absorb the difference is put into a bypass state by a bypass pipe, and after the lapse of a predetermined time, the bypass pipe is closed to start the operation. How to control the water heater. 14. The bypass of the U-shaped seal pipe is performed by ventilating a bypass pipe provided between the condenser and the evaporator of the absorption chiller-heater. A method for controlling an absorption chiller-heater according to any one of 1. 15. The bypass of the U-shaped seal pipe is performed by making a bypass pipe connecting between upper portions of the liquid surfaces at both ends of the U-shaped seal pipe in a vented state.
1. A method for controlling an absorption chiller-heater according to any one of 1) to 13).