JP3663006B2 - Absorption chiller / heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption chiller / heater, and more particularly to an absorption chiller / heater that can be switched from a heating operation to a cooling operation without any problem.
[0002]
[Prior art]
Conventional absorption chiller water heaters are operated to clearly distinguish between cooling and heating by cooling / heating switching operations by technical service personnel. As a result, there is an increasing demand for cold / hot automatic switching type absorption chiller / heater.
[0003]
Incidentally, since the regeneration temperature is lower during heating operation than during cooling operation, non-condensable gas is less generated. For this reason, as long as heating operation is not continued for a long time or outside air does not leak, the non-condensable gas can be extracted during normal cooling operation.
[0004]
[Problems to be solved by the invention]
However, during the heating operation, the temperature of the absorbing liquid is high. In particular, the ejector, which is the bleeder, is supplied with a high-temperature dilute solution, and thus the performance of the ejector decreases. For this reason, when the heating operation is performed for a long time or when air leaks, the non-condensable gas in the chamber increases, and not only the predetermined cooling capacity cannot be exhibited by switching to the cooling operation as it is. The cooling effect of the absorption liquid by the cooling water decreases due to the influence of the non-condensable gas accumulated around the heat exchanger tube of the absorber, the absorption liquid temperature rises and the absorption liquid crystallizes, and the absorption liquid pump and high temperature regenerator are installed. May be damaged.
[0005]
For this reason, as described above, when switching from heating to cooling, technical service personnel usually use the vacuum pump to sufficiently bleed the interior of the machine before switching to cooling operation. Switching operation is cumbersome, and the automatic bleeder that combines the vacuum pump and the motorized valve increases the initial cost and also has the problem that the vacuum pump sucks refrigerant vapor and lowers the performance. there were.
[0006]
Therefore, it is necessary to be able to switch from the heating operation to the cooling operation without any problem in any case, and this has been a problem to be solved.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems of the prior art, and is connected to an absorber, a condenser, a regenerator, etc. via an absorption liquid pump / refrigerant pump, etc. It is configured so that either a cold / warm fluid can be selectively obtained from the heat exchanger built in the evaporator to be formed, and a part of the circulating absorption liquid is used to start from the vapor phase portion of the evaporation absorber. In an extraction chiller / heater equipped with an extraction device for extracting non-condensable gas, a changeover switch / switching valve for selectively obtaining either a cold / warm fluid from the heat exchanger,
[0008]
A temperature detector for detecting the temperature of the absorbing liquid is provided, and the discharge side of the absorbing liquid pump and the sprayer provided at the upper part of the absorber are connected by an absorbing liquid pipe provided with a motorized valve in the middle, and a heat supply operation is performed. When starting from the cooling water pump of the cooling water pipe extending through the inside of the absorber and the condenser at the time of switching from the cold heat supply operation, the absorption liquid pump is started and the motor-operated valve is opened, The operation of the absorption liquid pump is continued until the temperature detector measures a predetermined temperature and a predetermined time elapses, and then is stopped, and the motor-operated valve is closed, and then the switching valve is set to the cold supply operation mode. An absorption chiller / heater having a first configuration provided with a controller that outputs a control signal necessary for starting a cooling / heating supply operation such as switching;
[0009]
In addition to providing a temperature detector for detecting the temperature of the absorbing liquid, in addition to the absorbing liquid pump (hereinafter referred to as the first absorbing liquid pump) for conveying the absorbing liquid from the reservoir of the absorber to the regenerator, The spreader provided at the upper part of the absorber is provided with a second absorption liquid pump that conveys the absorption liquid from the reservoir of the absorber, and at the time of switching from the hot heat supply operation to the cold heat supply operation, the inside of the absorber and the condenser After starting the cooling water pump of the cooling water pipe extended through, the first absorption liquid pump and the second absorption liquid pump are started, and this operation is performed by the temperature detector measuring a predetermined temperature. A second controller is provided which continues until a predetermined time elapses and then stops, and thereafter outputs a control signal necessary for starting a cooling supply operation such as switching the switching valve to a cooling supply operation mode. An absorption chiller / heater with a configuration;
[0010]
In the absorption chiller / heater of the first configuration, a bleeder for storing the non-condensable gas extracted from the vapor phase portion of the evaporative absorber instead of the time when the temperature detector measures the predetermined temperature and the predetermined time elapses. An absorption chiller / heater having a third configuration configured to stop the operation of the absorbent pump and close the motorized valve when the rate of change in pressure of the storage chamber of the storage chamber is lower than a predetermined value;
[0011]
In the absorption chiller / heater of the second configuration, a bleeder for storing the non-condensable gas extracted from the vapor phase portion of the evaporative absorber instead of the time when the temperature detector measures the predetermined temperature and the predetermined time elapses. An absorption chiller / heater having a fourth configuration configured to stop the operation of the first absorption liquid pump and the second absorption liquid pump when the pressure change rate of the storage chamber of the first storage liquid is lower than a predetermined value;
By providing the above, the problems of the prior art are solved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment will be described with reference to FIGS. 1 and 2. In the figure, reference numeral 1 is provided with a combustion device 2 such as gas / kerosene, and a high-temperature regenerator that generates a refrigerant vapor by heating a dilute liquid of an absorbing liquid to concentrate it into an intermediate liquid, and 3 is pumped from this regenerator. 4 is a low-temperature regenerator that heats the intermediate liquid with the refrigerant vapor from the gas-liquid separator to make a concentrated liquid, and 5 is from both the regenerators 1 and 4. The condenser 6 cools and condenses the refrigerant vapor, the evaporator 7 scatters and drops the refrigerant liquid from the refrigerant distributor 7A, and evaporates the refrigerant vapor from the low-temperature regenerator 4 An evaporative absorber comprising an absorber 8 that is absorbed in a concentrated liquid to maintain the inside of the vessel at a low pressure, 9 and 10 are low-temperature and high-temperature heat exchangers, 11 is an evaporative absorber 6 and the like using the “flow” of the absorbed liquid as power. An ejector 12 for drawing the gas body is provided below the ejector. A gas-liquid separation chamber 13 for separating the rare liquid and the non-condensable gas stores the non-condensable gas separated by the gas-liquid separator, and discharges the non-condensable gas from the attached palladium cell 14 to the atmosphere. These are the storage chambers, and these are the lifting liquid pipe 21, the intermediate liquid pipe 22, the concentrated liquid pipe 23, the rare liquid pipe 24 having the absorption liquid pump P1, the rare liquid pipe 25 having the electric on-off valve V1, and the rare liquid pipe 26. 27, refrigerant pipe 28, refrigerant liquid pipe 29, refrigerant liquid pipe 30 having refrigerant pump P2, cold / warm switching pipe 31 having cold / warm switching valve V2, extraction pipes 32 and 33, and non-condensable gas rise pipe 35 A heat exchanger provided inside the evaporator 7 that is connected to form a circulation cycle of refrigerant and absorbing liquid while allowing extraction of non-condensable gas from the condenser 5 and the evaporation absorber 6 to the storage chamber 13. Either cold water or hot water selectively taken out from 41 Has to be circulated and supplied through the cold water pipe 36 having a cold water pump P3 to the heat load (not shown) such as cold / heating.
[0013]
Reference numerals 42 and 43 denote coolers provided inside the condenser 5 and the absorber 8, which are connected by a cooling water pipe 37 having a cooling water pump P4, and a cooling tower, the absorber 8 and the condenser (not shown). The cooling water is configured to circulate between the two. Further, 38 is a pressure equalizing pipe having an on-off valve V3 that opens during hot water supply operation, 39 is an overflow pipe, 51 is a temperature detector that measures the temperature of the absorbent discharged from the absorber 8 to the rare liquid pipe 24, 52 is a liquid level detector, 55 is a rare liquid damper, 56 is an intermediate liquid damper, 57 is a refrigerant liquid damper, 34 is a bleed pipe for connection to a vacuum pump (not shown), and 100 is a controller of this apparatus. is there.
[0014]
In the cold / warm switching type absorption chiller / heater having the above-described configuration, the refrigerant refrigeration in the heat exchanger 41 of the evaporator 7 is performed by performing an absorption refrigeration cycle by circulating the refrigerant and the absorption liquid during the cooling operation performed by taking out the chilled water. The water in the heat exchanger can be cooled to about 6 to 8 ° C. by latent heat of vaporization and can be supplied. During the heating operation that takes out the hot water, the supply of the cooling water to the coolers 42 and 43 is stopped. By switching the cold / warm switching valve V2 from closed to open, the high-temperature absorption liquid and refrigerant vapor flow from the gas-liquid separator 3 to the evaporation absorber 6 via the cold / warm switching pipe 31, and the heat exchanger Hot water heated by the latent heat of condensation of the refrigerant at 41 (or this heat and the sensible heat of the absorbing liquid) is supplied.
[0015]
And when taking out cold water from the heat exchanger 41 of the evaporator 7 and performing cooling, when taking out warm water and heating it, the extraction pipe 32. The gas body is drawn into the ejector 11 through 33, the non-condensable gas is separated from the absorption liquid in the gas-liquid separation chamber 12, collected in the storage chamber 13, and discharged to the outside through the palladium cell 14. As described in the problem to be solved by the technology, the extraction effect is reduced during the heating operation in which the temperature of the absorbing liquid flowing into the ejector 11 via the rare liquid pipe 26 is high.
[0016]
For this reason, the controller 100 controls each functional unit such as a pump and a valve as shown in FIG. That is, when the main control is performed, a switch (not shown) provided in the controller 100 or the like is operated, a switching signal from heating to cooling is input, and a start signal is input, step S1 is started. Then, the temperature of the absorbent discharged from the absorber 8 to the diluted liquid pipe 24 is measured by the temperature detector 51.
[0017]
Then, the process proceeds to step S2, where it is determined whether or not the temperature measured by the temperature detector 51 is higher than a predetermined temperature, for example, 30.degree. C. If the result is YES, the process proceeds to step S3. The process proceeds to S7.
[0018]
In step S3, the cooling water pump P4 is activated to start circulation of the cooling water. In addition, starting / stopping of the cooling water pump P4 includes starting / stopping of equipment necessary for radiating the cooling water flowing through the cooling water pipe 37, for example, a cooling tower fan.
[0019]
In step S4, the electric on-off valve V1 is opened and the absorbent pump P1 is started.
[0020]
As a result, the absorbing liquid accumulated in the absorber 8 is supplied from the absorbing liquid spreader 8A via a part of the diluted liquid pipe 24 and the diluted liquid pipe 25 (electrical on-off valve V1) by the driving force of the absorbed liquid pump P1. Since it is sprayed on the cooler 43, it is quickly cooled by the coolant that is circulated and supplied through the coolant pipe 37 and flows inside the cooler 43.
[0021]
In step S5, the temperature of the absorbing solution is measured again by the temperature detector 51, and the process proceeds to step S6 to determine whether or not the temperature measured by the temperature detector 51 is lower than a predetermined temperature, for example, 30 ° C. If YES is determined, the process proceeds to step S7. Otherwise, the process returns to step S5.
[0022]
In step S7, a timer is started, and after waiting for a predetermined time, for example, 30 minutes, the process proceeds to step S9. In step S9, the absorption liquid pump P1 is stopped, and in step S10, the cooling water pump P4 is stopped.
[0023]
In step S11, both the electric on-off valve V1 and the cold / warm switching valve V2 are closed, the process proceeds to step S12, the cold / hot water pump P3 and the cooling water pump P4 are started, and the cold water cooled by the heat exchanger 41 is discharged. In a state in which the cooling operation to supply a cooling load (not shown) is possible, the control returns to the main control and a conventionally known proportional control operation or the like is performed.
[0024]
By performing the above control, the high-temperature absorption liquid accumulated in the absorber 8 is quickly cooled, and the cooled absorption liquid flows into the ejector 11 through the diluted liquid pipe 26 for a predetermined time. For this reason, since the bleed operation by the ejector 11 is sufficiently exerted, the bleed in the chamber is sufficiently performed at the time of switching from the heating operation to the cooling operation without installing a vacuum pump or the like. There are no problems such as lowering or crystals of the absorbing solution. Therefore, stable cold water supply, that is, cooling operation is possible. Also, during partial load operation with low load, the absorption liquid circulation amount is small due to the inverter control of the absorption liquid circulation amount, which is not suitable for large-scale extraction work, but the absorption liquid circulation amount is increased before entering the cooling operation. In addition, since the operation is performed with the temperature of the absorbing liquid lowered, there is an advantage that the extraction action can be maximized.
[0025]
(Second Embodiment)
In the absorption chiller / heater configured as shown in FIG. 1, the controller 100 can control each functional unit such as a pump and a valve as shown in FIG. That is, the pressure detector 53 is installed so that the internal pressure of the storage chamber 13 can be measured, and the pressure in the storage chamber 13 is measured by the pressure detector 53 instead of the control steps S7 and S8 shown in FIG. (Step S7a) After waiting for the rate of change to fall below a predetermined rate of change, for example, 25 Pa / min, the process may proceed to Step S9 (Step S8a).
[0026]
The control shown in FIG. 3 has an advantage that the cooling operation can be started in a shorter time than the control shown in FIG. That is, in the control of FIG. 2, the state of the storage chamber 13 in which the non-condensable gas is stored is not directly monitored, but the extraction operation time is set based on the temperature and time of the absorbing liquid. Although it is necessary to catch the eye, the control of FIG. 3 directly monitors the state of the storage chamber 13 in which the non-condensable gas is accumulated. Therefore, the cooling operation can be started after performing the minimum extraction operation.
[0027]
(Third embodiment)
A third embodiment will be described with reference to FIGS. In these drawings, the parts indicated by the same reference numerals as those in FIGS. 1 to 3 are the same as those described with reference to the drawings, and the description thereof is omitted within the scope not obstructing the understanding of the present invention.
[0028]
Unlike the absorption chiller / heater shown in FIG. 1, the absorption chiller / heater of the third embodiment is configured to absorb part of the absorption liquid discharged from the absorption liquid pump P1 by means of the electric on-off valve V1. Instead of returning to the absorber 8 from 8A, a second absorption liquid pump P5 is provided so that it can be circulated from the absorption liquid reservoir to the absorption liquid sprayer 8A.
[0029]
Then, the controller 100 controls each functional unit such as a pump and a valve as shown in FIG. That is, in step S4a after step S3 in which the cooling water pump P4 is activated to start circulation of the cooling water, the absorption liquid pump P1 and the second absorption liquid pump P5 are activated.
[0030]
In step S9a, both the absorption liquid pump P1 and the second absorption liquid pump P5 are stopped, and in step S11a, the cold / warm switching valve V2 is closed.
[0031]
Even in such a control, the absorption liquid accumulated in the absorber 8 is quickly cooled, so that the same effects as those of the first embodiment can be obtained.
[0032]
(Fourth embodiment)
Also in the absorption chiller / heater configured as shown in FIG. 4, the controller 100 can control each functional unit such as a pump and a valve as shown in FIG. That is, the pressure in the storage chamber is measured by the pressure detector 53 (step S7a), and the process proceeds to step S9a after waiting for the rate of change to fall below a predetermined rate of change, for example, 25 Pa / min (step S8a). Also good.
[0033]
Also in the control of FIG. 6 described above, the same operational effects as in the second embodiment can be obtained.
[0034]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit described in the claims.
[0035]
For example, the operation of closing the cold / warm switching valve V2 may be performed at least after the operation of the absorbent pump P1 is stopped.
[0036]
Moreover, the absorption cold / hot water machine of the structure which does not have the gas-liquid separator 3 may be sufficient, and the absorption cold / hot water machine which integrated the gas-liquid separation chamber 12 and the storage chamber 13 may be sufficient.
[0037]
【The invention's effect】
As described above, according to the absorption chiller / heater according to the present invention, the bleed in the chamber is sufficiently performed at the time of switching from the heating operation to the cooling operation without installing a vacuum pump or the like. There are no problems such as reduced capacity or crystals of the absorbing solution.
[0038]
Therefore, stable cold water supply, that is, cooling operation is possible. Also, during partial load operation with a light load, the absorption liquid circulation amount is low due to the inverter control of the absorption liquid circulation amount, which is unsuitable for large-scale extraction work, but the absorption liquid circulation amount is increased before entering the cooling operation. In addition, since the operation is performed with the temperature of the absorbing liquid lowered, there is an advantage that the extraction action can be maximized.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a device configuration of first and second embodiments.
FIG. 2 is an explanatory diagram illustrating a control example of the first embodiment.
FIG. 3 is an explanatory diagram illustrating a control example of the second embodiment.
FIG. 4 is an explanatory diagram showing a device configuration of third and fourth embodiments.
FIG. 5 is an explanatory diagram illustrating a control example of the third embodiment.
FIG. 6 is an explanatory diagram showing a control example of the fourth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Combustion device 3 Gas-liquid separator 4 Low temperature regenerator 5 Condenser 6 Evaporation absorber 7 Evaporator 8 Absorber 9 Low temperature heat exchanger 10 High temperature heat exchanger 11 Ejector 12 Gas-liquid separation chamber 13 Storage chamber 14 Palladium cell 21 Lifting pipe 22 Intermediate liquid pipe 23 Concentrated liquid pipe 24 Diluted liquid pipe 25-27 Diluted liquid pipe 28 Refrigerant conduits 29 and 30 Refrigerant liquid pipe 31 Cold / warm switching pipes 32-34 Extraction pipe 35 Noncondensable gas rise pipe 36 Cold / hot water pipe 37 Cooling water pipe 38 Pressure equalizing pipe 39 Overflow pipe 41 Heat exchanger 42/43 Cooler 51 Temperature detector 52 Liquid level detector 53 Pressure detector 55 Rare liquid damper 56 Intermediate liquid damper 57 Refrigerant liquid damper 100 Control P1 Absorption liquid pump P2 Refrigerant pump P3 Cold / hot water pump P4 Cooling water pump P5 Second absorption liquid pump V1 Electric on-off valve V2 Cold / warm switching valve

Claims (4)

Cooling / heating fluid is connected to the absorber / condenser / regenerator etc. via the absorption liquid pump / refrigerant pump, etc., and either the cold / warm fluid from the heat exchanger built in the evaporator forming the circulation cycle of refrigerant and absorption liquid. An extraction device configured to selectively obtain and extract non-condensable gas from the vapor phase portion of the evaporation absorber using a part of the circulating absorption liquid, either cold / warm from the heat exchanger In an absorption chiller / heater equipped with a changeover switch, changeover valve, etc. for selectively obtaining a fluid, a temperature detector for detecting the temperature of the absorption liquid is provided, and also provided on the discharge side of the absorption liquid pump and on the upper part of the absorber Of the cooling water pipe extended through the inside of the absorber and the condenser when switching from the hot heat supply operation to the cold heat supply operation. Absorbing liquid pump after starting the cooling water pump The startup and the opening operation of the motor-operated valve are performed, and the operation of the absorption pump is continued until the temperature detector measures a predetermined temperature and a predetermined time elapses, and then stopped, and the motor-operated valve is closed. An absorption chiller / heater having a controller that outputs a control signal necessary for starting a cooling / heating supply operation such as switching the switching valve to a cooling / heating supply operation mode. Cooling / heating fluid is connected to the absorber / condenser / regenerator etc. via the absorption liquid pump / refrigerant pump, etc., and either the cold / warm fluid from the heat exchanger built in the evaporator forming the circulation cycle of refrigerant and absorption liquid. An extraction device configured to selectively obtain and extract non-condensable gas from the vapor phase portion of the evaporation absorber using a part of the circulating absorption liquid, either cold / warm from the heat exchanger In an absorption chiller / heater equipped with a changeover switch, a changeover valve, etc. for selectively obtaining the fluid, a temperature detector for detecting the temperature of the absorption liquid is provided, and the absorption liquid is supplied from the reservoir of the absorber to the regenerator. In addition to the absorbing liquid pump to be conveyed (hereinafter referred to as the first absorbing liquid pump), a second absorbing liquid pump that conveys the absorbing liquid from the reservoir of the absorber to a spreader provided at the upper part of the absorber. And from the heat supply operation to the cold supply operation At the time of replacement, after starting the cooling water pump of the cooling water pipe extending through the inside of the absorber and the condenser, the first absorption liquid pump and the second absorption liquid pump are started, and this operation is performed as described above. The temperature detector measures a predetermined temperature and continues until a predetermined time elapses, and then stops and outputs a control signal necessary for starting the cooling / heating operation such as switching the switching valve to the cooling / heating operation mode. Absorption chiller / heater characterized by having a controller. Instead of the predetermined time after the temperature detector measures the predetermined temperature, the pressure change rate of the storage chamber of the extraction device for storing the non-condensable gas extracted from the vapor phase part of the evaporation absorber falls below the predetermined value. The absorption chiller / heater according to claim 1, wherein the absorption pump is stopped and the motor-operated valve is closed. Instead of the predetermined time after the temperature detector measures the predetermined temperature, the pressure change rate of the storage chamber of the extraction device for storing the non-condensable gas extracted from the vapor phase part of the evaporation absorber falls below the predetermined value. 3. The absorption chiller / heater according to claim 2, wherein operation of the first absorption liquid pump and the second absorption liquid pump is stopped.

Images