JPH07218025A - Absorption chilled and warm water machine - Google Patents

Abstract

PURPOSE:To provide an absorption chilled and warm water machine in which a liquid level of solution in a high temperature regenerator can be obtained. CONSTITUTION:A first temperature sensor 9a detects a temperature of an upper position of a high temperature regenerator 1. A second temperature sensor 9b detects a temperature of a lower position of the regenerator 1. A controller 10 controls an operation of a solution pump 12 based on detection signals from the sensors 9a, 9b. Thus, firing of the regenerator without water can be prevented.

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 which evaporates a refrigerant and lowers the temperature of water in a pipe by its latent heat of evaporation, and in particular, can secure a good liquid level in a high temperature regenerator. It relates to an absorption chiller / heater that can be used.

[0002]

2. Description of the Related Art As a conventional absorption chiller-heater, there is a device as shown in FIG. The absorption chiller-heater shown in FIG. 4 heats a dilute solution containing an absorbent and a refrigerant to evaporate the refrigerant to form an intermediate concentration solution, and a water content of the dilute solution heated by the high temperature regenerator 1. A separator 2 for evaporating the vapor and separating the vapor and the solution to thicken the solution to an intermediate concentration;
The low-temperature regenerator 3 that further concentrates the intermediate concentration solution supplied from the high-temperature regenerator 1 into a concentrated solution by the steam supplied from the high-temperature regenerator 1 and the steam supplied from the low-temperature regenerator 3 into a liquid A condenser 4 for condensing, a refrigerant storage chamber 5 for storing the refrigerant condensed by the condenser 4, an evaporator 7 for evaporating the refrigerant supplied from the refrigerant storage chamber 5, and an evaporator 7 for evaporating the refrigerant. An absorber 8 that absorbs vapor into a concentrated solution to form a dilute solution, a temperature sensor 9 that detects the temperature of an upper portion of the high-temperature regenerator, and a valve that adjusts the supply of combustion gas that serves as a heat source in the high-temperature regenerator 1. Gas adjustment valve 14
And a controller 40 for controlling the opening and closing of the gas regulating valve 14 in accordance with the detection signal of the temperature sensor 9, and a cooling water passage which is a pipe through which cooling water for cooling the absorber 8 and the condenser 4 is flown. A pipe 11, a solution pump 12 that sends the diluted solution that has absorbed the refrigerant in the absorber 8 to the high temperature regenerator 1, and a check valve 13 that prevents the diluted solution from flowing back from the high temperature regenerator 1 to the absorber 8. Made of.

[0003]

However, in the above-mentioned conventional absorption chiller-heater, the high-temperature regenerator 1 is operated at a high load due to overheating by the heating gas or the like, and the temperature of the condenser rises due to the dirt inside the cooling water coil. There is a case where the cooling operation is performed below, or the cooling operation is performed in the state where the solution leaks due to clogging of the check valve 13 or the like. If the operation is stopped without doing anything after operating in such a state, the solution may flow out due to the pressure increase in the high temperature regenerator 1, or the solution may flow back from the check valve 13. As a result, the liquid level of the high temperature regenerator drops to a level lower than the normal level.

When the cooling operation is restarted with the low liquid level, the temperature sensor 9 detects the temperature of the upper portion of the high temperature regenerator 1, and the detected portion is above the liquid level. Since the temperature sensor 9 is in the position, the temperature sensor 9 has a large heat capacity, so that the temperature detected by the temperature sensor 9 rises later than the rise in the heat transfer surface temperature of the high temperature regenerator 1, as shown in FIG. The response speed of the sensor 9 may slow down.

Then, when the controller 10 controls the temperature abnormality switch (not shown) based on the abnormal temperature rise of the high temperature regenerator 1 detected by the temperature sensor 9, the heat transfer surface in the high temperature regenerator 1 is controlled. Is not sufficiently cooled by the solution, and the temperature of the heat transfer surface in the high temperature regenerator 1 has already become abnormally high. Thereby, in the high temperature regenerator 1,
Non-condensable gases such as hydrogen are likely to be generated due to local heating by the high-temperature combustion gas, and the generated gas reduces the cooling capacity.

Therefore, an object of the present invention is to provide an absorption chiller-heater capable of ensuring the liquid level of a solution in a high temperature regenerator.

[0007]

The absorption chiller-heater of the present invention comprises a high temperature regenerator which heats a dilute solution containing an absorbent and a refrigerant to evaporate the refrigerant to an intermediate concentration solution, and a high temperature regenerator from this high temperature regenerator. A low-temperature regenerator that further concentrates the intermediate-concentration solution supplied from the high-temperature regenerator with the supplied steam to form a concentrated solution, a condenser that condenses the vapor supplied from the low-temperature regenerator into a liquid, and a condenser In the absorption chiller-heater having an evaporator that evaporates the refrigerant supplied from the container and an absorber that absorbs the vapor evaporated in the evaporator into the concentrated solution to form the diluted solution, in the high-temperature regenerator A first temperature sensor that detects the temperature of the upper portion, a second temperature sensor that detects the temperature of the lower portion of the high temperature regenerator, and the high temperature based on the detection signals of the first temperature sensor and the second temperature sensor. Regenerator And having a controller for controlling the solution of the liquid level.

Further, the absorption chiller-heater of the present invention is provided with a solution pump for sending the dilute solution which has absorbed the refrigerant in the absorber to the high temperature regenerator, and the controller uses the detection signals of the first temperature sensor and the second temperature sensor. It is preferable to control the solution pump based on the above.

Further, in the absorption chiller-heater of the present invention, the controller operates the solution pump for a predetermined time when the difference between the temperatures detected by the first temperature sensor and the second temperature sensor becomes a predetermined value or more. It is preferable to control.

[0010]

In the absorption chiller-heater of the present invention, the controller inputs the detection signals of the first temperature sensor and the second temperature sensor and judges the liquid level of the solution in the high temperature regenerator from the temperature difference between them. To do. And the controller
When the temperature difference is larger than a predetermined value, it is determined that the liquid level is low, and the solution pump or the like is operated to raise the liquid level. These ensure the liquid level of the solution in the high temperature regenerator.

[0011]

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

FIG. 1 is a block diagram showing an absorption chiller-heater according to an embodiment of the present invention. The absorption chiller-heater of this embodiment includes a high temperature regenerator 1, a separator 2, a low temperature regenerator 3, a condenser 4, a refrigerant storage chamber 5, an evaporator 7, an absorber 8 and a first temperature. It is composed of a sensor 9a, a second temperature sensor 9b, a controller 10, a cooling water passage pipe 11, a solution pump 12, a check valve 13, and a gas regulating valve 14. In FIG. 1, the same components as those of the conventional absorption chiller-heater shown in FIG. 4 are designated by the same reference numerals.

Here, the high temperature regenerator 1 heats a dilute solution containing an absorbent and a refrigerant to evaporate the refrigerant to an intermediate concentration solution. The separator 2 evaporates the water content of the dilute solution heated in the high temperature regenerator 1 and separates the vapor and the solution to thicken the solution to an intermediate concentration. The low temperature regenerator 3 further concentrates the intermediate concentration solution supplied from the separator 2 with the steam supplied from the separator 2,
It is a concentrated solution. The condenser 4 condenses the vapor supplied from the low temperature regenerator 3 into a liquid. The refrigerant storage chamber 5 stores the refrigerant condensed by the condenser 4. The evaporator 7 evaporates water, which is a refrigerant sent from the refrigerant storage chamber 5, and cools a cold water pipe (not shown) by its latent heat of evaporation. The absorber 8 absorbs the vapor evaporated in the evaporator 7 into the concentrated solution sent from the low temperature regenerator 3.

The first temperature sensor 9a detects the temperature of the upper portion of the high temperature regenerator 1. Here, the upper portion refers to a portion above the substantially middle position in the vertical direction in the high temperature regenerator 1. The second temperature sensor 9b detects the temperature of the lower portion of the high temperature regenerator 1. Here, the lower portion means a portion located below a substantially middle position in the vertical direction in the high temperature regenerator 1. The controller 10 controls the operating state of the absorption chiller-heater based on the detection signals of the first temperature sensor 9a and the second temperature sensor 9b.

The cooling water pipe 11 includes an absorber 8 and a condenser 4.
It is a pipe through which cooling water for cooling etc. is flowing. The solution pump 12 sends the diluted solution, which has absorbed the refrigerant in the absorber 8, to the high temperature regenerator 1. The check valve 13 prevents the dilute solution from flowing back from the high temperature regenerator 1 to the absorber 8.
The gas regulating valve 14 controls the supply amount of combustion gas for heating the high temperature regenerator 1.

Next, the operation of the absorption chiller-heater of this embodiment will be described. FIG. 2 is a graph showing changes with time of the liquid level of the high temperature regenerator 1 and the indicated values of the temperature sensors 9a and 9b in the absorption chiller-heater of this embodiment. In this figure, the time when the liquid level is reduced corresponds to the time when the cooling operation is stopped.

The high temperature regenerator 1 is operated by a high load operation due to an excessive amount of steam for heating or the like in the high temperature regenerator 1, or an operation under a rise in the temperature of the condenser due to dirt inside the cooling water coil.
Operation may be stopped while the internal temperature and pressure remain high. In this case, the solution in the high temperature regenerator 1 flows out to the separator 2 more than necessary through a pumping pipe (not shown) or the like, causing a decrease in the liquid level of the solution in the high temperature regenerator 1. Sometimes. Further, due to a solution leak in the check valve 13 or the like, when the operation is stopped, the solution becomes high temperature regenerator 1.
The liquid may flow backward from the side to the absorber 8 side, leading to a decrease in the liquid level of the solution in the high temperature regenerator 1.

When the liquid level decreases for these reasons,
The upper part in the high temperature regenerator 1 which is the detection part of the temperature sensor 9a is in the vapor phase, and the lower part in the high temperature regenerator 1 which is the detection part of the temperature sensor 9b is in the liquid phase. Therefore, as shown in FIG. 2, the rate of decrease in the temperature detected by the temperature sensor 9a detecting the vapor phase portion is faster than the rate of decrease in the temperature detected by the temperature sensor 9b detecting the liquid phase portion. . That is, there is a difference between the temperature detected by the temperature sensor 9a and the temperature detected by the temperature sensor 9b due to the passage of time after the operation is stopped.

Therefore, the controller 10 in the absorption chiller-heater of this embodiment controls the operation of the absorption chiller-heater based on the above phenomenon. FIG. 3 shows the controller 1
It is a flowchart figure which shows an example of the control operation of 0.

First, the cooling operation is started. By performing this cooling operation, solution leakage or the like occurs in the check valve 13 and the liquid level of the solution in the high temperature regenerator 1 is lowered (S
1). Then, the cooling operation is stopped (S2). Then, it is determined whether or not the difference between the detected temperatures of the temperature sensor 9a and the temperature sensor 9b is a predetermined temperature difference T1 or more (S).
3). If the temperature difference is not T1 or more, the process returns to step S1.

On the other hand, when the temperature difference is T1 or more, it is judged that the liquid level is too low, and the solution pump 12 is operated for a predetermined time to raise the liquid level by a predetermined value (S4). Then, it is determined whether or not the difference between the detected temperatures of the temperature sensor 9a and the temperature sensor 9b is a predetermined temperature difference T2 or more (S5). Here, if the temperature difference is not T2 or less, it is determined that the liquid level is not yet sufficiently raised, and the process returns to step S4. If it is T2 or less, the liquid level is determined to be appropriate. Return to step S1.

As a result, in the absorption chiller-heater of this embodiment, the controller 10 detects the level of the liquid surface level of the solution in the high temperature regenerator 1 from the difference in the detected temperature between the temperature sensor 9a and the temperature sensor 9b. The liquid level is the solution pump 12
Since it can be adjusted by, for example, it is possible to secure an appropriate liquid level and prevent the high temperature regenerator 1 from being boiled. Therefore, it is possible to prevent the generation of non-condensable gas such as hydrogen due to local heating in the high temperature regenerator 1, suppress the deterioration of the capacity of the cooling operation, and provide an absorption chiller-heater with durability and reliability.

Further, the method of detecting the liquid level of the solution in the high temperature regenerator 1 based on the difference in the detected temperature between the temperature sensor 9a and the temperature sensor 9b in the present embodiment is used for the conventional liquid level measurement. It is cheaper than the known float type or electrode type, and a highly reliable detection operation can be performed without causing a malfunction due to wear of a movable part or deterioration of an electrode.

[0024]

As described above, according to the present invention, the controller catches the level of the liquid level of the solution in the high temperature regenerator from the difference in the detected temperature between the first temperature sensor and the second temperature sensor, Since the liquid surface level can be adjusted with a solution pump or the like, an appropriate liquid surface level can be secured and it is possible to prevent the high temperature regenerator from being heated in the empty state.

[Brief description of drawings]

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

FIG. 2 is a graph showing changes with time of liquid level and temperature sensor indication value of a high temperature regenerator in the absorption chiller-heater of FIG.

FIG. 3 is a flowchart showing an example of the operation of a controller in the absorption chiller-heater of FIG. 1.

FIG. 4 is a block diagram showing an example of a conventional absorption chiller-heater.

FIG. 5 is a graph showing the operating state of the absorption chiller-heater of FIG. 4, the liquid level of the high-temperature regenerator, the temperature sensor instruction value, and the heat transfer surface temperature over time.

[Explanation of symbols]

 1 High Temperature Regenerator 2 Separator 3 Low Temperature Regenerator 4 Condenser 5 Refrigerant Storage Room 7 Evaporator 8 Absorber 9a First Temperature Sensor 9b Second Temperature Sensor 10, 40 Controller 11 Cooling Water Pipe 12 Solution Pump 14 Gas Control Valve

Claims (3)

[Claims] 1. A high temperature regenerator which heats a dilute solution containing an absorbent and a refrigerant to evaporate the refrigerant to an intermediate concentration solution,
A low-temperature regenerator that further concentrates the intermediate-concentration solution supplied from the high-temperature regenerator into a concentrated solution with the steam supplied from the high-temperature regenerator, and a condenser that condenses the vapor supplied from the low-temperature regenerator into a liquid. In an absorption chiller-heater having an evaporator, an evaporator that evaporates the refrigerant supplied from the condenser, and an absorber that absorbs the vapor evaporated in the evaporator into the concentrated solution to form the dilute solution, A first temperature sensor that detects a temperature of an upper portion of the high temperature regenerator, a second temperature sensor that detects a temperature of a lower portion of the high temperature regenerator, and detection signals of the first temperature sensor and the second temperature sensor. And a controller for controlling the liquid level of the solution in the high temperature regenerator based on the above. 2. The absorption chiller-heater according to claim 1,
A solution pump for feeding the dilute solution that has absorbed the refrigerant in the absorber to the high temperature regenerator is provided, and the controller includes the first temperature sensor and second
An absorption chiller-heater characterized by controlling the solution pump based on a detection signal of a temperature sensor. 3. The absorption chiller-heater according to claim 2,
The controller controls the solution pump to operate for a predetermined time when the difference between the temperatures detected by the first temperature sensor and the second temperature sensor exceeds a predetermined value.