JPH0411779B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention forms a refrigerant circulation path for a refrigerant and an absorption liquid, and also attaches a water heater to a generator to form a refrigerant circulation path between these devices. This invention relates to an improvement in an absorption chiller/heater that is capable of taking out cold and hot water at the same time.

(b) Conventional technology The conventional technology of the above type of absorption chiller/heater is as follows:
For example, as seen in Special Publication No. 52-584,
Equipped with a capacity control device (temperature control capacity control device) that controls the heating amount of the generator or a combination of this heating amount control and refrigerant flow rate control based on the chilled water temperature or hot water temperature, and is equipped with a protective thermostat in the cold water pipe, It is known that this thermostat stops the operation of the refrigerant liquid pump at a specific chilled water temperature (for example, 3°C), and the capacity control device stops heating the generator at a temperature lower than this specific chilled water temperature. .

(c) Problems to be solved by the invention In the above-mentioned type of absorption chiller/heater that can take out hot and cold water at the same time, when the hot water load is large and the cold water load is small, it is difficult to adjust the heating amount of the generator to match the hot water load. As a result, the chilled water output for the chilled water load, that is, the refrigerant evaporation capacity in the evaporator, or in other words, the refrigerant absorption capacity of the absorption liquid in the absorber, that is, the degree of concentration of the absorption liquid in the generator, may become excessive. This tends to cause freezing of the refrigerant in the evaporator and freezing of the cold water.

For this reason, in the above-mentioned conventional absorption chiller/heater, a protective thermometer provided in the chilled water pipe stops the operation of the refrigerant liquid pump at a specific temperature of the chilled water, and furthermore, the generator stops operating at a temperature lower than this specific temperature. A method is used to prevent the cold water from freezing by cutting off the heating and stopping the concentration of the absorption liquid. However, with this method, it takes time for the concentration of the absorption liquid in the absorber to drop, or in other words, for the saturation temperature in the evaporator and absorber to rise to its normal value. Problems such as liquid crystallization could not be overcome. In addition, in order to prevent freezing, the heating of the generator was often cut off, which caused the problem that the hot water output for the hot water load was likely to be unstable and insufficient.

In view of these problems, the present invention has been developed to more reliably prevent harmful effects such as freezing of refrigerant and cold water and crystallization of absorption liquid than conventional methods, and also to obtain hot water output more stably. The purpose is to provide an absorption chiller/heater.

(d) Means for Solving the Problems In order to solve the above problems, the present invention provides a pipe line that extends from the evaporator to the absorber and has a pump for blowing the refrigerant liquid, and also provides a pipe line for heating the generator. A temperature regulator (controller) that controls the amount by the cold water outlet temperature of the evaporator or hot water outlet temperature of the water heater, and a temperature regulator (controller) that controls the operation of the refrigerant liquid blowing pump and the refrigerant liquid pump depending on the cold water outlet temperature of the evaporator. The present invention provides an absorption chiller/heater equipped with a controller for controlling the water.

(e) Function In the absorption chiller/heater of the present invention, when the temperature at the outlet side of the chilled water reaches a set value (for example, 5.0°C), the controller 40 stops the operation of the refrigerant liquid pump, and stops the operation of the refrigerant liquid blowing pump. By controlling the operation of the evaporator, it is possible to cut off heat exchange between the cold water flowing through the evaporator and the refrigerant, and to quickly reduce the concentration of the absorption liquid in the absorber.
Due to these effects, the saturation temperature in the evaporator and absorber recovers to normal values (e.g. 6 to 8 degrees Celsius) in a shorter time than in conventional systems, and this occurs when the hot water load is significantly larger than the cold water load. It is possible to significantly reduce the frequency of stopping the heating of the vessel, thereby more reliably preventing freezing of the cold water and refrigerant and crystallization of the absorption liquid, and also stably obtaining hot water output for hot water loads. In addition, in this case, the concentration of the absorption liquid returned from the absorber side to the generator decreases, and the boiling temperature of the absorption liquid circulating in the generator is lowered, so the sensible heat consumption in the generator is reduced. This results in a saving effect and allows efficient hot water output to be obtained. Furthermore, the blowing of refrigerant liquid to the absorber and the dispersion of refrigerant liquid to the evaporator are stopped by operating the refrigerant liquid blowing pump and stopping the refrigerant pop, thereby avoiding the use of three-way valves that are prone to leaks. Compared to absorption chiller-heating machines that use a three-way valve to switch the refrigerant flow path, leakage of outside air into the equipment can be prevented, and operation can be carried out over long periods of time. It can be stabilized.

(F) Embodiment The absorption chiller/heater will be explained below according to Fig. 1. 1 is an evaporator/absorption shell that has a built-in evaporator 2 and an absorber 3, and 4 has a built-in condenser 5 and a low-pressure generator 6. The condensation generating cylinder 7 is a high pressure generator having a heater 8, which produces hot water by introducing water from an inlet pipe 11 to a water heater 10 connected via a heating control valve 9, and a hot water outlet pipe 12. At the same time as hot water is taken out, cold water is introduced into the evaporator 2 from an inlet pipe 13, cold water is produced in a heat exchanger 14, and cold water is taken out from a cold water outlet pipe 15.

That is, the refrigerant separated from the absorption liquid by heating the diluted liquid in the high-pressure generator 7 with a heater 8 such as a combustion flame is condensed in a water heater 10 and gives latent heat to circulating water to produce hot water. On the other hand, heat is also applied in the low pressure generator 6 to further heat and separate the unseparated refrigerant, causing it to flow into the condenser 5, and the refrigerants from both generators 7 and 6 are mixed in the condenser 5 and flow into the evaporator 2. While being circulated by the refrigerant pump 16, latent heat of vaporization is obtained by the heat exchanger 14 to cool the water from the inlet pipe 13 to produce cold water. The refrigerant evaporated in the evaporator 2 is absorbed by the absorption liquid in the absorber 3, passes through the absorption liquid control valve 17 and the heat exchangers 18, 18', and is again separated into the absorption liquid and the refrigerant in the high pressure generator 7.

Note that 19 is a pump that circulates the absorption liquid to the absorber 3, and 20 and 21 are heat exchangers that cool the absorber 3 and condenser 5 with cooling water.

Therefore, the hot water temperature detector 2 is installed in the hot water outlet pipe 12.
2. A cold water temperature detector 23 is attached to the cold water outlet pipe 15, and each of the detectors 22, 23 controls the amount of absorption liquid circulated by one of the detectors via cold/temperature changeover switches 24, 25. control valve 17,
Furthermore, the capacity control device for the entire absorption type water chiller/heater, such as the fuel control valve 26, which is the heat source supplied to the heater 8, is adjusted to the cold water outlet temperature of the evaporator 2 (hereinafter referred to as cold water temperature) or the hot water inlet temperature of the water heater 10. (hereinafter referred to as hot water temperature).In addition, the hot water temperature and heating capacity alone can be controlled by the heating control valve 9 via the temperature regulator 27 by the refrigerant liquid level in the water heater 10. Control by changing the heat area. Further, the chilled water temperature and the cooling capacity alone are controlled by the opening degree of the refrigerant control valve 29 via the temperature regulator 28.

30 is a load detector composed of a chilled water outlet temperature detector 31, a chilled water inlet temperature detector 32, a switching control comparator 33, etc. When the chilled water load is larger than a set value, the chilled water temperature is changed; is smaller than the set value, a cold/temperature changeover switch 24,
25 is automatically switched to cold junction C or hot junction H.

To explain the operation of the control by such a configuration in detail, when the chilled water load exceeds a certain amount (for example, 30% of the total chilled/hot water load), the cold/hot temperature changeover switch 24, 2
5 are both connected to the cold junction C, the cold water outlet temperature is detected by the cold water temperature detector 23, and the absorption liquid control valve 17 is proportionally controlled by the cold water side temperature regulator (controller) 34. The fuel control valve 26 is operated to control the chilled water capacity. On the other hand, the hot water is supplied by detecting the hot water outlet temperature with the detector 22, operating the heating control valve 9 with the temperature regulator 27, increasing or decreasing the refrigerant liquid level in the water heater 10, and controlling the hot water pipes in the water heater. Obtain hot water at a constant temperature by changing the heat transfer area.

Next, when the chilled water load is below a certain level, the load detector 30 automatically switches the cold/temperature changeover switch 24.
is switched to the hot junction H, the hot water outlet temperature is detected by the detector 22, and the temperature regulator (controller) 34' operates the absorption liquid control valve 17 and further the fuel control valve 26 to mainly control the hot water side. The temperature control ability of the water cooler/heater will be controlled.

In this case, the load detector 30 detects, for example, the temperature at the inlet and outlet of the chilled water with detectors 31 and 32, and transmits the detected temperature to the comparators 35 and 36, which have preset temperatures, so that both the outlet and inlet temperatures of the chilled water are detected by the respective comparisons. instrument settings
When it becomes lower than t ₁ , t ₂ (t ₂ > t ₁ ), the chilled water load is small, and conversely, when it becomes higher than the set values t ₁ +α, t ₂ +β, the chilled water load is assumed to be large and the changeover switch is activated. .

When the hot water side is mainly controlled, the cold water side is controlled by controlling the refrigerant control valve 29 using the chilled water temperature sensor to control the amount of heating by refrigerant vapor to the low pressure generator 6, and controlling the amount of refrigerant from the low pressure generator. Controls the amount of steam and maintains the chilled water temperature within a certain temperature range.

Further, 37 is connected to the refrigerant pump 1 via the three-way valve 38.
This is a refrigerant blowing conduit connecting the discharge side conduit 6 and the liquid reservoir of the absorber 3, and the temperature sensor 39 controls the opening and closing of the three-way valve 38 of this conduit and the start/stop of the refrigerant pump 16.
The connected controller 40 is controlled, for example, according to the following schedule. That is, as an example of the control schedule, when the temperature sensed by the temperature detector 39 drops to the lower limit set temperature of 5° C. of the temperature setting section of the controller 40, the controller controls the three-way valve 3.
8 is switched to open and close, the refrigerant liquid is blown into the absorption liquid, and the concentration of the absorption liquid is rapidly lowered, while the distribution of the refrigerant liquid to the heat exchanger 14 is cut off, and then the operation of the refrigerant pump is stopped. It is becoming more and more common. Note that when the temperature detected by the temperature detector 39 returns to the set temperature of the controller 40 of 5.5°C, the opening and closing of the three-way valve 38 is switched to the original state, and thereafter,
Refrigerant pump 16 is now in operation again. Although not shown, the controller 40 has a built-in circuit such as a delay relay or a timer.

FIG. 2 is a schematic structural explanatory diagram showing one embodiment of the absorption chiller/heater according to the present invention, and in this figure, the same components as those of the absorption chiller/heater shown in FIG. 1 are given the same reference numerals. are doing. In Figure 2,
C _C is the controller for main cold water control of the absorption chiller/heater.
This is the temperature controller 28, 34, 4 shown in FIG.
C _H is the controller for hot water main control, and this is the temperature controller 2 shown in Figure 1.
It has the functions of 7 and 34'. That is, in this embodiment, the detectors 22, 23, the controllers C _C , C _H ,
The heating control valve 9, the fuel control valve 26, and the refrigerant control valve 29 constitute a capacity control device for the absorption chiller/heater. In addition, this capacity control device is equipped with a controller.
Of course, control of the discharge amount of the pump 19 using C _C and/or C _H may be incorporated.

In addition, the controller C _C also has the functions of the controller 40 shown in FIG. For example, it is controlled as shown in FIG. During the main control of the hot water of the absorption chiller/heater, in other words, the signal from the hot water outlet temperature detector 22 is sent to the fuel control valve 2 via the controller _CH .
When controlling the opening degree of 6, the cold water outlet temperature is 5℃
As shown in FIG. 3, the operation of the refrigerant pump 16 is stopped and the operation of the refrigerant liquid blowing pump P is started at the same time as shown in FIG. At the same time, the absorption liquid in the absorber 3 is diluted and its saturated vapor pressure and saturation temperature are promoted to rise. Even if the temperature is slightly lower than the above, it is possible to prevent freezing of the refrigerant and cold water and crystallization of the absorption liquid without stopping the heating of the high temperature generator 1, and it is also possible to stably obtain a hot water outlet commensurate with the load. becomes. Also,
At this time, the concentration of the absorption liquid returned to the high-temperature generator 1 becomes lower, so the boiling temperature of the absorption liquid in this generator drops, the sensible heat consumption of the absorption liquid decreases by the amount of the drop, and the hot water output It also improves thermal efficiency. moreover,
Since the refrigerant liquid is blown into the absorber 3 by turning on and off the refrigerant liquid blowing pump P and the refrigerant pump 16, problems within the equipment that are likely to occur when blowing the refrigerant liquid using a three-way valve, etc. As a result, even when the refrigerant liquid is blown, the operation of the absorption chiller/heater can be stabilized over a long period of time. Note that 41 is a liquid level controller, which also controls the operation of the pumps 16 and P.

Then, when the cold water outlet temperature rises and returns to 5.5°C, the refrigerant pump 16 is operated again, and at the same time, the operation of the refrigerant liquid blowing pump P is stopped, and cold and hot water are simultaneously taken out by normal capacity control during hot water main control. Back to driving. Note that the control of the pumps P and 16 is not limited to ON/OFF control, but may also be discharge amount control. Furthermore, in this example, the temperature range of cold water temperature control ability control is 6 to 8 degrees Celsius, and that of hot water is 48 to 52 degrees Celsius.
is set to .

It goes without saying that the control shown in FIG. 3 is performed not only during hot water main control, but also during cold water main control or when only cold water is taken out.
In this embodiment, the cold/hot selector switches 24, 2
5, the contacts are switched manually. However, in this embodiment as well, the controller
For example, a microcomputer is built into C _C and C _H to calculate the magnitude of the hot water load and the cold water load based on the signals from the detectors 22 and 23, as well as to calculate their ratio. , 25 may be provided with a function of automatically switching the contacts.

(G) Effects of the Invention As described above, the present invention includes a pipe line that extends from the evaporator to the absorber and has a pump for blowing refrigerant liquid, and also provides control for controlling the heating amount of the generator based on the cold water temperature or hot water temperature. This system is equipped with a controller that controls the operation of the refrigerant liquid blowing pump and the refrigerant pump depending on the chilled water outlet temperature, so when the chilled water outlet temperature drops, the heat exchange between the refrigerant and the chilled water is cut off and the refrigerant is turned off. The effect of preventing the temperature drop of chilled water due to vaporization as well as the excessive decrease of the saturated vapor pressure and saturation temperature in the evaporator and absorber In other words, it has the effect of preventing freezing of the refrigerant and chilled water, and in particular,
During main hot water control, which controls the heating amount of the generator based on the hot water temperature, the generator continues to be heated and a stable hot water output commensurate with the hot water load is obtained while preventing refrigerant freezing, cold water freezing, and crystallization of the absorption liquid as described above. It can be applied to various types of absorption chiller/heater, and can also avoid leakage of outside air into the equipment of the absorption chiller/heater, ensuring stable operation over a long period of time, and has high practical value. It is something.

It should be noted that the present invention is not limited to application to a triple-effect absorption chiller/heater, but can of course be applied to a single-effect absorption chiller/heater.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the general structure of the absorption chiller/heater, Figure 2
The figure is a schematic structural explanatory diagram showing one embodiment of the absorption chiller/heater according to the present invention, and FIG. 3 is an explanatory diagram showing an example of the operation of the refrigerant pump and the refrigerant liquid blowing pump in the embodiment of FIG. 2. It is. 1... Evaporative absorption shell, 2... Evaporator, 3... Absorber, 5
...Condenser, 7...High pressure generator, 9...Heating control valve, 1
0... Water heater, 14... Heat exchanger, 16... Refrigerant pump, 18, 18'... Heat exchanger, 19... Pump, 2
2, 23...Detector, 24, 25...Cold/hot selector switch, 26...Fuel control valve, 27, 28...Temperature regulator, 34, 34'...Temperature regulator, 37...Pipe line, 3
8...Three-way valve, 39...Temperature detector, 40...Controller, C _C , C _H ...Controller, P...Refrigerant liquid blowing pump.

Claims (1)

[Claims] 1 Connect equipment such as the generator, condenser, evaporator, absorber, solution heat exchanger, refrigerant liquid pump, and solution pump with piping to form a circulation path for the refrigerant and absorption liquid, and also supply hot water to the generator. In an absorption chiller/heater equipped with a water heater, a pipe line from the evaporator to the absorber is equipped with a pump for blowing refrigerant liquid, and the heating amount of the generator is adjusted to the cold water outlet temperature of the evaporator or the hot water outlet temperature of the water heater. 1. An absorption chiller/heater comprising: a controller that controls the operation of a refrigerant liquid blowing pump and an operation of a refrigerant liquid pump based on the chilled water outlet temperature of an evaporator.