JPH0810090B2 - Double-effect air cooling absorption type water heater - Google Patents

Description

The present invention relates to a double-effect air-cooled absorption type chiller-heater, and particularly water as a refrigerant and lithium bromide as an absorbent,
The present invention relates to a double-effect air-cooled absorption type chiller-heater suitable for operation even when the outside air temperature rises abnormally.

[Conventional technology]

The water-cooled double-effect absorption chiller that has been widely used in the past has a problem that it costs a lot to install, maintain, and manage water for a cooling water system such as a cooling tower. The development of the machine has proceeded rapidly.

Therefore, as an air-cooled absorption type chiller using water as a refrigerant and lithium bromide as an absorbent, for example, JP-A-61-49
The technology described in Japanese Patent No. 970 was developed. That is, the one described in the publication has a structure in which fins are provided outside the vertical pipe so that the absorber and the condenser are cooled by the air flow by the fan, while the temperature of the high temperature regenerator is increased. By increasing the degree of supercooling of the refrigerant in the condenser, the solution exiting the air-cooled absorber or the solution mixed with the refrigerant vapor is cooled by the supercooled refrigerant liquefied in the condenser, air-cooled absorption type Realizes a chiller.

That is, when the outside air dry-bulb temperature is about 33 ° C., the internal pressure becomes equal to or lower than the atmospheric pressure, and the double-effect air-cooled absorption chiller-heater capable of operating while keeping the solution temperature within a practical range was provided.

[Problems to be solved by the invention]

As described above, for example, in the technique described in Japanese Patent Laid-Open No. 61-49970, the absorption cycle, the air-cooled absorber, and the air-cooled condenser are specially devised, but when the outside temperature becomes abnormally high, It was never considered.

In general, the outside air dry-bulb temperature is 30.8 ° C in Tokyo, which is the monthly average of the daytime maximum temperature in summer, and it is possible to operate the double-effect air-cooled absorption chiller-heater with the above technology. However, according to meteorological statistics, the maximum value of the outside temperature in the summer will rise to 38.4 ° C in Tokyo, and if the outside temperature becomes abnormally high in this way, the solution temperature inside the air-cooled absorber will rise, and The pressure in the high-pressure regenerator) is higher than atmospheric pressure, and there is a problem that refrigeration cannot be performed when cooling is required. Further, the solution temperature in the high-pressure regenerator becomes high, which causes a problem of corrosion due to lithium bromide.

The present invention has been made to solve the above-mentioned problems of the conventional technique. Even when the outside air temperature rises abnormally, the temperature of the solution inside the air-cooled absorber is lowered, and the pressure inside the high temperature regenerator is kept at atmospheric pressure. It is an object of the present invention to provide a double-effect air-cooled absorption type chiller-heater that can continue operation without exceeding it.

[Means for solving problems]

In order to achieve the above object, the structure of the double-effect air-cooled absorption type chiller-heater according to the present invention includes an evaporator, an air-cooled absorber, an air-cooled condenser, a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, and a solution. In the double-effect air-cooled absorption chiller-heater, which comprises a pump, a refrigerant pump, and a piping system that operatively connects these, and which has a fan that supplies cooling air to the air-cooled absorber and the air-cooled condenser, the high-temperature regeneration is performed. A heating amount control valve is provided in the heat source supply system for the regenerator, and a control means for controlling the heating amount control valve in a direction of reducing the heating amount of the high temperature regenerator according to the rise of the temperature of the cooling air is provided. .

The concept of developing the present invention is as follows.

It is the solution temperature in the low-temperature regenerator that determines the internal pressure of the dual-effect air-cooled absorption type refrigerator with water as a refrigerant and lithium bromide as the absorbent, particularly the high-temperature regenerator internal pressure,
This solution temperature is determined by the refrigerant condensation temperature in the air-cooled condenser.

In addition, the air-cooled type has a large temperature difference between the inlet and outlet of cooling air,
When the cooling rate is slightly reduced, the pressure and temperature drop significantly. Therefore, the inlet / outlet temperature difference of the cooling air temperature is reduced by slightly reducing the heating amount in the high temperature regenerator. As a result, the solution temperature in the air-cooled absorber and the condensation temperature in the air-cooled condenser are lowered, so that the internal pressure drop is doubled, and the internal pressure (high-temperature regenerator internal pressure) drops significantly. To do.

[Action]

The above operation will be described with reference to the solution concentration diagram of FIG.

FIG. 4 is a solution concentration diagram of a double-effect air-cooled absorption type chiller-heater, showing an air-cooled absorption cycle with the concentration of the absorption solution as a parameter, and showing a case where the heating amount control valve is not controlled. The broken line and the solid line show the case where the heating amount is controlled by controlling the heating amount control valve.

In Fig. 4, the horizontal axis represents temperature, and the reference outside air temperature,
The air absorber solution temperature is shown. Further, the vertical axis represents pressure, and each of the isobaric pressure levels of the evaporation pressure, the condensation pressure, and the high temperature regenerator pressure in the air cooling cycle is indicated by a two-dot chain line.
The diagonal one-dot chain line shows the water saturation curve of the refrigerant.

When the heating amount control valve is not controlled and the outside air temperature rises, the air-cooled condenser pressure becomes the intersection point a with the condensation pressure level water saturation curve, and the corresponding solution temperature in the low temperature regenerator becomes b. From this, the low-temperature regenerator heating vapor condenses at a temperature higher by Δt, and the pressure becomes point c, so the internal pressure of the high-temperature regenerator exceeds atmospheric pressure.

On the other hand, when the heating amount control valve is provided to reduce the heating amount of the high temperature regenerator, the heat exchange amount of the air cooling absorber and the air cooling condenser is reduced.
As a result, the inlet / outlet temperature difference of the cooling air temperature becomes small,
The inlet / outlet temperature of the air-cooled absorber and air-cooled condenser becomes low. As a result, the solution temperature inside the air-cooled absorber is lowered, the condensing pressure is lowered to a'in FIG. 4, and the corresponding solution temperature in the low temperature regenerator is lowered to b '. In this way, if the heating amount of the high temperature regenerator is reduced, the condensing pressure of the low temperature regenerator heating vapor greatly changes from c to c ′ due to the synergistic effect of the decrease of the solution concentration in the air-cooled absorber and the decrease of the condensation temperature. The temperature of the high temperature regenerator drops below atmospheric pressure.

The heating amount control valve that controls the heating amount of the high temperature regenerator controls the steam generated in the high temperature regenerator.By giving an appropriate throttle, the condensing pressure of the low temperature regenerator heating steam decreases and Can be maintained below atmospheric pressure.

As a means for controlling the heating amount control valve, a pressure controller, a temperature controller or the like that outputs a control signal according to a detection signal such as the internal pressure of the high temperature regenerator, the temperature of the condensed refrigerant liquid, the temperature of the outside air, etc. is used.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

First, FIG. 1 is a cycle system diagram of a double-effect air-cooled absorption type chiller-heater according to an embodiment of the present invention.

In FIG. 1, 1 is an evaporator, 2 is a refrigerant pump, and 3 is a cold water pipe through which cold water passes.

Reference numeral 4 denotes an air-cooled absorber. In this air-cooled absorber 4, a fin 4b for cooling is formed outside the vertical pipe 4a, an upper header is formed by a vapor passage 5 above the vertical pipe 4a, and a lower portion is formed below the vertical pipe 4a. This is a configuration including a Hezda 4c.

6 is a solution pump, 7 is a solution heat exchanger, 10 is a high temperature regenerator, and 11 is a low temperature regenerator.

15 is an air-cooled condenser, and this air-cooled condenser 15 is a vertical pipe 15a.
A fin 15b for cooling is formed outside the pipe, the upper part of the vertical pipe 15a is provided with an upper header by the steam passage 14, and the lower part of the vertical pipe 15a is provided with a lower header 15c.

The air-cooled absorber 4 and the air-cooled condenser 15 are air-cooled by the flow of outdoor air by the fan 20, and the thick arrow in the figure indicates the flow direction of the cooling air.

The above devices are operatively connected by a refrigerant pipe and a solution pipe to form a cycle.

Reference numeral 21 is a temperature detector provided in the cold water pipe 3 for detecting the temperature of the cold water, 22 is a heating amount control valve provided in the supply pipeline of the external heat source 12 to the high temperature regenerator 10, and 23 is the high temperature regenerator 10. A pressure detector for detecting the refrigerant vapor pressure in the inside, 24 is a low selector for sending a control signal to the heating amount control valve, and 25 is a temperature controller for outputting a control signal according to the detection result of the temperature detector 21. , 26 are pressure regulators that output a control signal in accordance with the detection result of the pressure detector 23. The temperature detectors 21, 23, the pressure detector 23, the temperature controller 25, the pressure controller 26, and the low selector 24 constitute control means for controlling the opening / closing of the heating amount control valve 22, and their electrical The connections are shown with dashed lines in the figure.

With regard to the double-effect air-cooled absorption type chiller-heater having such a configuration, the basic operation of the cycle will be described first.

The refrigerant (water) in the evaporator 1 is sprinkled by the refrigerant pump 2 onto the cold water pipe 3 through which the cold water passes, and the heat of evaporation is taken from the cold water to become low-pressure refrigerant vapor, which passes through the vapor passage 5 and the air-cooled absorber 4 Flow into. The air-cooled absorber 4 is directly cooled by the outside air by the fan 20, and the refrigerant vapor is sprayed from the upper header and is absorbed by the concentrated lithium bromide solution flowing down the vertical pipe 4a to become a dilute solution.

This dilute solution is sent out by the solution pump 6, passes through the solution heat exchanger 7, and passes through the dilute solution pipes 8 and 9 to obtain the high temperature regenerator 10,
It is sent to the low temperature regenerator 11.

An external heat source 12 is supplied to the high temperature regenerator 10, and the dilute solution is concentrated by the heat generated when burning in the furnace 10a, and steam is generated at this time. This generated refrigerant vapor heats and concentrates the dilute solution in the low-temperature regenerator 11 via the heat transfer pipe portion 13a of the refrigerant pipe 13, condenses and liquefies from the refrigerant itself into a liquid refrigerant, and the lower header 15c of the air-cooled condenser 15 is condensed. Sent to.

The vapor generated from the dilute solution concentrated in the low temperature regenerator 11 flows into the vertical pipe 15a of the air-cooled condenser 15 through the vapor passage 14 and is cooled by the fan 20 to the outside to become a liquid refrigerant. It returns from the lower header 15c to the evaporator 1 through the refrigerant pipe 16.

The solutions concentrated respectively in the high temperature regenerator 10 and the low temperature regenerator 11 pass through the solution heat exchanger 7 by the concentrated solution pipes 17 and 18, and then are sent to the upper head of the air-cooled absorber 4 via the concentrated solution pipe 19 and spread. The absorption process is repeated again.

Next, the operation of the heating amount control valve and its control means will be described.

During normal operation, the detection signal of the temperature detector 21 in the cold water pipe 3 is received, and the high temperature regenerator is controlled by the control signal of the temperature controller 25.
The heating amount control valve 22 in the heat source supply conduit 10 is controlled to keep the cold water temperature constant.

When the outside air temperature is particularly high, the solution temperature in the air-cooled absorber 4 rises, the solution concentration rises, the air-cooling concentrator temperature rises, and the solution temperature in the low-temperature regenerator 11 rises. Internal pressure rises.

When the internal pressure of the high temperature regenerator 10, that is, the refrigerant vapor pressure rises, the pressure regulator 26 receives the detection signal of the pressure detector 23,
A signal for controlling the heating amount control valve 22 in the closing direction is output. The low selector 24 compares this signal with the signal of the temperature controller 25, selects a signal in the direction of reducing the heating amount of the high temperature regenerator 10, and outputs it to the heating amount control valve 22.

When the heating amount for the high-pressure regenerator 10 is reduced, the heat exchange amount of the air-cooled absorber 4 and the air-cooled condenser 15 is reduced. Therefore, the temperature of the solution inside the air-cooled absorber 4 decreases, and a low-temperature regenerator corresponding to this decreases.
The solution temperature in 11 drops. Due to the synergistic effect of the decrease of the solution concentration in the air-cooled absorber 4 and the decrease of the condensation temperature, the condensation pressure of the low-temperature regenerator heating vapor is significantly reduced, and the internal pressure of the high-temperature regenerator 10 is reduced to the atmospheric pressure or lower.

According to this embodiment, even when the outside air temperature is extremely high, the temperature of the solution inside the air-cooled absorber 4 can be lowered, the inside pressure of the high temperature regenerator 10 can be kept below the atmospheric pressure, and the refrigeration operation can be continued.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a cycle system diagram of a double-effect air-cooled absorption type chiller-heater according to another embodiment of the present invention. In the figure, the same reference numerals as in FIG. Since they are equivalent, the description thereof will be omitted.

In FIG. 2, 27 is a temperature detector for detecting the temperature of the condensed refrigerant at the outlet of the low temperature regenerator of the heat transfer tube portion 13a for heating the solution of the low temperature regenerator 11, and 28 is the result of detection by the temperature detector 27. It is a temperature controller that outputs a control signal.

Since the condensed refrigerant temperature in the refrigerant line 13 and the refrigerant vapor pressure in the high temperature regenerator 10 have a one-to-one correspondence,
Temperature controller 28 that operates according to the detection result of temperature detector 27
Even if the heating amount control valve 22 is controlled by the output signal of, the same effect as that of the embodiment shown in FIG. 1 can be expected.

Similarly, although not shown, a pressure detector that detects the pressure of the condensed refrigerant in the air-cooled condenser is provided, and the heating amount control valve is controlled by the output signal of the pressure regulator that operates according to the detection result. You may

Next, still another embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a cycle system diagram of a double-effect air-cooled absorption type hot and cold water machine according to still another embodiment of the present invention. In the figure, the same reference numerals as those in FIG. The description is omitted because it is the same as the example.

In FIG. 3, 29 is a temperature detector for detecting the outside air temperature.

When the outside temperature becomes abnormally high, the temperature detector 29
High temperature regenerator 10 when it detects the outside temperature and exceeds a specific temperature
A signal in the direction of reducing the heating amount of is output to the heating amount control valve 22.

According to the present embodiment, the heating amount for the high temperature regenerator 10 is controlled in accordance with the outside air temperature corresponding to the cooling air by the fan 20, so that it is exactly the same as the respective embodiments of FIGS. 1 and 2 above. You can expect an effect.

〔The invention's effect〕

As described above, according to the present invention, even when the outside air temperature rises abnormally, the solution temperature inside the air-cooled absorber is lowered, and the operation can be continued without the pressure inside the high temperature regenerator exceeding the atmospheric pressure. It is possible to provide a heavy-duty air-cooled absorption type chiller-heater.

[Brief description of drawings]

FIG. 1 is a cycle system diagram of a double-effect air-cooled absorption type water heater / cooler according to an embodiment of the present invention, and FIG. 2 is a double-effect air-cooled absorption type water heater / chiller according to another embodiment of the present invention. FIG. 3 is a cycle system diagram of a double-effect air-cooled absorption type chiller-heater according to still another embodiment of the present invention, and FIG. 4 is a solution of the double-effect air-cooled absorption type chiller-heater. It is a concentration diagram. 1 ... Evaporator, 2 ... Refrigerant pump, 4 ... Air-cooled absorber,
6 ... Solution pump, 7 ... Solution heat exchanger, 10 ... High temperature regenerator, 11 ... Low temperature regenerator, 15 ... Air cooling condenser, 20 ... Huan, 22 ... Heating amount control valve, 23 ... … Pressure detector, 25,28
...... Temperature controller, 26 …… Pressure controller, 21,27,29 …… Temperature detector.

Front page continuation (72) Inventor Yoshikazu Nagaoka 5-22-4 Kamisoshiya, Setagaya-ku, Tokyo Kamisoshiya Heights No. 302 (72) Inventor Shinichi Kanno 4-9-4-303 Takawashi, Habikino-shi, Osaka ( 72) Inventor Sadaju Takemoto 11-8 Toyonen-cho, Chikusa-ku, Nagoya-shi, Aichi Prefecture (72) Inventor Shigero Sugimoto 603, Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitate Works Co., Ltd. Tsuchiura Plant (72) Inventor Tomihisa Ouchi Ibaraki 502 Jinritsucho, Tsuchiura City, Japan (56) References, Hiritsu Seisakusho Co., Ltd. (56) Reference JP-A-55-95073 (JP, A) JP-A-58-136957 (JP, A)

Claims (5)

[Claims] 1. An evaporator, an air-cooled absorber, an air-cooled condenser, a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, a solution pump, a refrigerant pump, and a piping system for operatively connecting them, In a dual-effect air-cooled absorption type hot and cold water machine equipped with a fan that supplies cooling air to an absorber and an air-cooled condenser, a heating amount control valve is provided in a heat source supply system for the high temperature regenerator, and the temperature of the cooling air rises. A double-effect air-cooled absorption-type chiller-heater equipped with control means for controlling the heating amount control valve in a direction to reduce the heating amount of the high-temperature regenerator. 2. The device according to claim 1, wherein the control means for controlling the heating amount control valve is at least:
A double-effect air-cooled absorption chiller-heater equipped with a pressure detector that detects the refrigerant vapor pressure in the high-temperature regenerator and a pressure regulator that operates according to the detection result. 3. The control means for controlling the heating amount control valve according to claim 1, wherein:
A pressure detector for detecting the pressure of the condensed refrigerant in the air-cooled condenser,
A double-effect air-cooled absorption type hot and cold water machine, comprising: a pressure regulator that operates according to the detection result. 4. The control means for controlling the heating amount control valve according to claim 1, wherein:
A double-effect air-cooled absorption chiller-heater, comprising a temperature detector for detecting the temperature of condensed refrigerant at the outlet of the low-temperature regenerator, and a temperature controller that operates according to the detection result. 5. The control means for controlling the heating amount control valve according to claim 1, wherein
A temperature detector that detects the temperature of the cooling air by the fan,
A double-effect air-cooled absorption type hot and cold water machine, comprising: a temperature controller that operates according to the detection result.