JP2001099474A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the freezing of cooling water even when an air temperature is lowered during stopping air conditioning operation, in an air conditioner constituted so as to be capable of effecting the cooling operation employing an absorption type refrigerating machine for an outdoor machine. SOLUTION: This air conditioner is provided with a control means C, which starts a cooling water pump 6E when the temperature T1 of cooling water in a cooling water pipe 23, which is detected by a temperature sensor 31, has become lower than 3 deg.C, for example, however, stops the cooling water pump 6E when the temperature has exceeded 5 deg.C, for example, and which operates a cooling water heating means 6D when the temperature T2 of cooling water in the cooling water storage unit 6C of a cooling tower 6 has become lower than 3 deg.C, for example, however, stops the operation of the cooling water heating means 6D when the temperature T2 has become higher than 8 deg.C, for example, during stopping of air conditioning operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly, to an air conditioner configured to be able to perform a cooling operation by using an absorption refrigerator as an outdoor unit.

[0002]

2. Description of the Related Art In an air conditioner of this type, a cooling operation is performed only in summer, and when it is known that no cooling operation is performed in winter, an accident such as bursting of piping due to freezing of cooling water is prevented. Cooling water can be drained in winter for purposes.

[0003] However, in a food section such as a supermarket, there is a demand for cooling in winter. When an air conditioner with an outdoor unit composed of an absorption refrigerator is used for such a purpose, the cooling water supplied to the absorber and condenser of the absorption refrigerator cannot be extracted every time air conditioning is stopped. While cooling water is being heated by an electric heater or the like.

[0004]

However, there is a problem in that measures for heating the cooling water with an electric heater require a considerable amount of electricity, and it is necessary to prevent the cooling water from freezing at low cost. There was a problem to be solved.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention relates to a circulation path formed between an outdoor unit and an indoor unit by transferring a thermally operated fluid radiated by an outdoor unit comprising an absorption refrigerator. Air-conditioning unit that sends heat to the indoor unit via the air conditioner and exchanges heat with the indoor air to cool the indoor air, and also exchanges heat with the indoor air at the indoor unit to return the absorbed heat-operated fluid to the outdoor unit. In the device, a cooling water storage unit that is connected to an outdoor unit through a cooling water circulation path having a cooling water pump and stores cooling water that is circulated and supplied to the outdoor unit during a cooling operation, and cooling provided in the cooling water storage unit A water heating means, a first temperature sensor for detecting the temperature of the cooling water in the cooling water circulation path, a second temperature sensor for detecting the temperature in the cooling water storage section, and a first temperature sensor during the stop of the air conditioning. Cools when a temperature lower than the specified temperature is detected When the predetermined time has elapsed or the first temperature sensor has detected a second predetermined temperature higher than the first predetermined temperature, the operation of the cooling water pump is stopped, and the second temperature sensor is activated by the third temperature sensor. When a temperature lower than the predetermined temperature is detected, the cooling water heating means is operated, and when a predetermined time elapses or when the second temperature sensor detects a fourth predetermined temperature higher than the third predetermined temperature, the cooling water heating means is operated. And a control unit for stopping the operation of the air conditioner.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
This will be described in detail with reference to FIG. FIG. 1 shows an example in which cold or hot water is supplied to an indoor unit (not shown) by a cold / hot water pipe 21.
An outdoor unit consisting of a double effect absorption refrigerator which circulates and supplies water through a refrigerant, and water as a refrigerant and lithium bromide (LiB
r) An aqueous solution is used.

In the figure, 1 is a high-temperature regenerator equipped with a gas burner 1B, 2 is a low-temperature regenerator, 3 is a condenser, 4 is an evaporator, 5 is an absorber, 6 is a blower 6A, a sprayer 6B, and a cooling water storage. Part 6C, cooling water heating means 6D comprising an electric heater, etc.
A cooling tower provided with a cooling water pump 6E, etc., 7 is a low-temperature heat exchanger, 8 is a high-temperature heat exchanger, 9 to 12 are absorbent pipes, 13 is an absorbent pump, 14 to 18 are refrigerant pipes, 19 is a refrigerant pump, 22 is a cold / hot water pump, 23 is a cooling water pipe, 2
Reference numeral 4 denotes a pressure equalizing pipe, and reference numerals 26 to 28 denote on-off valves. These devices are connected by piping as shown in FIG. 1, and the configuration itself is conventionally well known.

In the double effect absorption refrigerator having the above structure, the on-off valves 26, 27 and 28 are closed, and the blower 6A and the cooling water pump 6E of the cooling tower 6 are started to exchange heat with the outside air to radiate heat and cool. When the cooling water stored in the water storage section 6C is circulated and supplied to the absorber 5 and the condenser 3, and the gas burner 1B is ignited to heat the absorbing liquid with the high-temperature regenerator 1, the refrigerant vapor evaporates and separates from the absorbing liquid. In the high-temperature regenerator 1, the intermediate vapor having the concentration of the absorbent increased by separating the refrigerant vapor is obtained.

The high-temperature refrigerant vapor generated in the high-temperature regenerator 1 enters the low-temperature regenerator 2 through the refrigerant pipe 14, and is generated in the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 8 by the absorption liquid pipe 10. Then, the intermediate absorbing liquid that has entered the low-temperature regenerator 2 is radiated and condensed by heating and enters the condenser 3.

The refrigerant heated in the low-temperature regenerator 2 and evaporated and separated from the intermediate absorbent enters the condenser 3 and exchanges heat with cooling water supplied from the cooling tower 6 through the cooling water pipe 23 to condense and liquefy. The refrigerant enters the evaporator 4 through the refrigerant pipe 16 together with the refrigerant condensed and supplied from the refrigerant pipe 14.

The refrigerant liquid entering the evaporator 4 and stored in the refrigerant liquid reservoir is sprayed by a refrigerant pump 19 onto a heat transfer tube 21A connected to the cold / hot water pipe 21, and is supplied with water supplied through the cold / hot water pipe 21. The heat exchange evaporates and cools the water flowing inside the heat transfer tube 21A.

The refrigerant evaporated by the evaporator 4 enters the absorber 5 and is heated by the low-temperature regenerator 2 to evaporate and separate the refrigerant. It is supplied via the low-temperature heat exchanger 7 and is absorbed by the concentrated absorbing liquid sprayed from above. The reaction heat generated when the refrigerant vapor is absorbed by the concentrated absorbent is removed by cooling water supplied from the cooling tower 6 via the cooling water pipe 23.

The absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 5, that is, the diluted absorption liquid, is regenerated at a high temperature through the low-temperature heat exchanger 7 and the high-temperature heat exchanger 8 by the operation of the absorption liquid pump 13. It is sent from the absorbing liquid pipe 9 to the vessel 1.

When the operation of the absorption refrigerator is performed as described above, the cold water cooled by the heat of vaporization of the refrigerant in the heat transfer tube 21 A provided inside the evaporator 4 is cooled by the operation of the cold / hot water pump 22. Since the air is circulated and supplied to an indoor unit (not shown) via the air conditioner 21, a cooling operation such as cooling can be performed in the indoor unit.

On the other hand, the gas burner 1B is ignited without opening the on-off valves 26, 27 and 28 and without activating the blower 6A and the cooling water pump 6E, and thus without supplying cooling water to the absorber 5 and the condenser 3. When the absorbent is heated by the high-temperature regenerator 1, the refrigerant evaporated from the absorbent in the high-temperature regenerator 1 mainly enters the absorber 5 and the evaporator 4 through the refrigerant pipes 14 and 15 having a small flow path resistance. The water supplied from the cold / hot water pipe 21 exchanges heat with the water via the heat transfer tube 21A and condenses, and the water flowing inside the heat transfer tube 21A is heated mainly by the heat of condensation at this time.

The refrigerant condensed by performing the heating action in the evaporator 4 enters the absorber 5 through the refrigerant pipes 17 and 18, evaporates and separates the refrigerant in the high-temperature regenerator 1 and flows into the absorption liquid pipe 12 through the absorption liquid pipe 12. It is mixed with the liquid and is sent to the high-temperature regenerator 1 via the low-temperature heat exchanger 7 and the high-temperature heat exchanger 8 by the operation of the absorption liquid pump 13.

Then, the hot water heated by the heat transfer tube 21A inside the evaporator 4 is circulated and supplied to the indoor unit (not shown) through the cold / hot water pipe 21 by the operation of the cold / hot water pump 22, thereby heating the indoor unit such as heating. The action is performed.

Reference numeral C denotes a controller provided in the double effect absorption refrigerator having the above-described operation functions, which is provided with a microcomputer, storage means, etc., and which is connected to the heat transfer pipe 21A of the evaporator 4 through the cold / hot water pipe 21. The temperature information of the cold and hot water flowing out to the gas burner 1B is taken from a temperature sensor 30 provided at the outlet side of the evaporator 4 of the cold and hot water pipe 21 so that the cold and hot water temperature is maintained at a predetermined set temperature. A conventionally well-known capacity control function for controlling the amount of heat input to the high-temperature regenerator 1 by adjusting the opening of a heating amount control valve (not shown) is provided.

That is, the larger the difference between the predetermined set temperature and the temperature of the cold / hot water detected by the temperature sensor 30 is, the greater the opening of the heating amount control valve (not shown) connected to the gas burner 1B is provided to the controller C. Temperature sensor 3
When the temperature of the chilled / hot water reaches the set temperature, the control program for performing the normal capacity control such as controlling the opening of the heating amount control valve to the set opening or closing the same is stored in the storage means. Have.

The controller C controls the operation of the absorbent pump 13 so that the liquid level of the absorbent in the high-temperature regenerator 1 maintains a predetermined level, and the temperature sensor 30 detects the temperature during the cooling operation. The temperature of cold water is the set temperature (for example, 7 ° C)
A control program for operating the refrigerant pump 19 at a higher time is also provided in the storage means.

Further, the controller C also has, for example, a control program shown in FIGS. 2 and 3 in the storage means for maintaining the cooling water at a predetermined temperature or higher while the cooling operation is stopped.

That is, while the cooling operation is stopped, the controller C first detects the temperature T1 of the cooling water in the cooling water pipe 23 by the temperature sensor 31 in step S1.

In step S2, it is determined whether or not the temperature T1 of the cooling water detected in step S1 is equal to or lower than a first predetermined low temperature, for example, 3 ° C. If the determination is yes, the process proceeds to step S3. If the determination is no, the process returns to step S1 to repeatedly detect the temperature T1 of the cooling water.

In step S3 where it is determined that the temperature T1 of the cooling water in the cooling water pipe 23 is lower than the first predetermined temperature, the cooling water pump 6E is started.

In step S4, the temperature T1 of the cooling water in the cooling water pipe 23 is detected by the temperature sensor 31 as in step S1.

In step S5, as in step S2, it is determined whether the temperature T1 of the cooling water detected in step S4 is equal to or higher than a second predetermined temperature higher than the first predetermined temperature, for example, 5 ° C. Is determined, and when the determination is YES, the process shifts to step S6 to stop the operation of the cooling water pump 6E and returns to step S1. On the other hand, when the determination is no, the process returns to step S4 and the detection of the temperature T1 of the cooling water is repeated.

In step S11, the controller C detects the temperature T2 of the cooling water in the cooling water storage section 6C by the temperature sensor 32.

In step S12, step S1
The temperature T2 of the cooling water detected in 1 is a third predetermined low temperature,
For example, it is determined whether the temperature is 3 ° C. or less. If the determination is yes, the process proceeds to step S13. If the determination is no, the process returns to step S11 to repeat the detection of the temperature T2 of the cooling water.

The temperature T2 of the cooling water in the cooling water storage section 6C
In step S13 when it is determined that the temperature is lower than or equal to the third predetermined temperature, the cooling water heating unit 6D
Activate

In step S14, step S1
As in 1, the temperature T2 of the cooling water in the cooling water storage section 6C is detected by the temperature sensor 32.

In step S15, step S1
2, the temperature T of the cooling water detected in step S14.
2 is a fourth predetermined temperature higher than the third predetermined temperature;
For example, it is determined whether the temperature is 8 ° C. or higher. If the determination is yes, the process proceeds to step S16, in which the operation of the cooling water heating unit 6D is stopped, and the process returns to step S11. On the other hand, when the determination is no, the process returns to step S14 to repeat the detection of the temperature T2 of the cooling water.

That is, according to the present invention, when the temperature of the cooling water in the cooling water pipe 23 is liable to be affected by the outside air, and thus tends to decrease as the temperature decreases, there is a danger of freezing. The cooling water pump 6E is started, and the cooling water in the cooling water storage section 6C, which has a large heat capacity and is hardly affected by the outside air, is supplied to the cooling water pipe 23, so that the cooling water in the cooling water pipe 23 is prevented from freezing. In addition, since the cooling water heating means 6D is not operated at this stage, the cost for preventing freezing can be reduced.

Then, when the temperature of the cooling water in the cooling water storage section 6C also drops significantly and the danger of freezing occurs,
Since the cooling water is heated by appropriately operating the cooling water heating means 6D provided in the cooling water storage section 6C, there is no danger that the cooling water will freeze even when the air temperature is extremely low.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the scope of the claims.

For example, the stop of the operation of the cooling water pump 6C and the stop of the operation of the cooling water heating means 6D may be configured not to be based on the temperature of the cooling water but to be operated only for an elapsed time, that is, for a predetermined time.

[0036]

As described above, according to the present invention, the temperature of the cooling water in the cooling water pipe, which is easily affected by the outside air, and thus tends to decrease as the temperature decreases, decreases.
When there is a danger of freezing, the cooling water pump is started first, and the cooling water in the cooling water storage section, which has a large heat capacity and is not easily affected by outside air, is supplied to the cooling water pipe, so that the cooling water in the cooling water pipe is prevented from freezing. Is done. Moreover, at this stage, since the cooling water heating means such as an electric heater is not operated, the cost for preventing freezing can be reduced.

When the temperature of the cooling water in the cooling water storage section is significantly reduced, the cooling water can be heated by appropriately operating the cooling water heating means provided in the cooling water storage section. There is no danger of freezing of the cooling water at very low temperatures.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus configuration.

FIG. 2 is an explanatory diagram of a control method of a cooling water pump.

FIG. 3 is an explanatory diagram of a control method of a cooling water heating unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 1B Gas burner 2 Low temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 6 Cooling tower 6A Blower 6B Sprayer 6C Cooling water storage part 6D Cooling water heating means 6E Cooling water pump 7 Low temperature heat exchanger 8 High temperature heat exchanger 9-12 Absorbent pipe 13 Absorbent pump 14-18 Refrigerant pipe 19 Refrigerant pump 21 Cold / hot water pipe 22 Cold / hot water pump 23 Cooling water pipe 24 Equalizing pipe 25 Cooling water pipe 26-28 Open / close valve 30/31/32 Temperature sensor C controller

Continued on the front page (72) Inventor Masashi Izumi 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Hiroshi Sakamoto 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka Inside Sanyo Electric Co., Ltd. (72) Inventor ▲ Yoshihiro Hiroshi 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Osaka Gas Co., Ltd. F-term (reference) 3L060 AA02 CC05 DD01 EE34 EE35 3L093 AA01 BB29 CC00 DD02 EE14 GG02 HH14 JJ00 JJ06 KK01 LL03

Claims (1)

[Claims] 1. A heat operation fluid radiated by an outdoor unit comprising an absorption refrigerator is sent to the indoor unit via a circulation path formed between the outdoor unit and the indoor unit, and the indoor unit exchanges heat with indoor air. In the air conditioner, which cools the indoor air and exchanges heat with the indoor air in the indoor unit and returns the heat-operated fluid absorbed by the indoor unit to the outdoor unit, the outdoor unit is connected to the outdoor unit via a cooling water circulation path having a cooling water pump. A cooling water storage unit that stores cooling water that is circulated and supplied to the outdoor unit during the cooling operation, a cooling water heating unit provided in the cooling water storage unit, and a cooling water circulation path that detects a temperature of the cooling water in the cooling water circulation path. A first temperature sensor, a second temperature sensor that detects in the cooling water storage unit, and a cooling water pump that is activated when the first temperature sensor detects a temperature lower than the first predetermined temperature while air conditioning is stopped. Time has elapsed or the first temperature sensor When the second predetermined temperature higher than the first predetermined temperature is detected, the operation of the cooling water pump is stopped, and when the second temperature sensor detects a temperature lower than the third predetermined temperature, the cooling water heating means is operated, The predetermined time has elapsed or the second temperature sensor is higher than the third predetermined temperature.
And a control means for stopping the operation of the cooling water heating means when the predetermined temperature is detected.