JPH0829006A - Absorptive air-conditioner - Google Patents

Abstract

PURPOSE:To improve the durability of a solution pump by avoiding cavitation when the solution pump produces cavitation during a heating operation. CONSTITUTION:When an absorption liquid in an absorber 19 boils during a heating operation to cause a solution pump 47 to produce cavitation, a rotating speed of the solution pump 47 detected by rotating speed detecting means 86 rises for detection of production of cavitation. Then a control device 6 stops a cool water pump 63. This operation causes a temperature rise in an evaporator 18, so that pressures in the evaporator 18 and the absorber 19 are raised. Accordingly, a boiling point of the absorption liquid rises to have boiling in the absorber 19 gone, so that the cavitation is avoided. When the solution pump 47 absorbs the absorption liquid to be lowered in rotation, the control device 6 actuates the cool water pump 63 so that a cool water heated by the evaporator 18 is fed to an indoor heat exchanger 61.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption air conditioner for cooling and heating a room using an absorption refrigeration cycle.

[0002]

2. Description of the Related Art The basic structure of an absorption refrigeration cycle is
A regenerator that heats the absorption liquid and vaporizes a part of the absorption liquid,
A condenser that cools and liquefies the vaporized refrigerant generated in the regenerator, an evaporator that evaporates the liquefied refrigerant liquefied in the condenser under low pressure, and an absorbent that absorbs the vaporized refrigerant evaporated in the evaporator. The absorption liquid, which is composed of an absorber and has absorbed the vaporized refrigerant in the absorber, is sent to the regenerator by the solution pump. When the refrigerant evaporates in the evaporator, latent heat is taken from the heat medium (water or the like) sent from the evaporator to the indoor heat exchanger via the heat medium circuit. Then, the heat medium that has been deprived of heat and cooled is sent to the indoor heat exchanger to exchange heat with the indoor air and cool the room. The heat medium that has exchanged heat with the indoor air in the indoor heat exchanger is again guided to the evaporator via the heat medium circuit.

On the contrary, when the heating operation is performed, the hot absorption liquid heated by the regenerator is guided to the evaporator, and the heat medium sent to the indoor heat exchanger is heated by the hot absorption liquid. Then, the heat medium heated by the absorber exchanges heat with the indoor air in the indoor heat exchanger to heat the room.

[0004]

During the heating operation, the hot absorption liquid of the regenerator is supplied to the evaporator and the absorber, so that the pressures inside the evaporator and the absorber are higher than those during the cooling operation. High pressure. However, since the internal pressure in the entire absorption refrigeration cycle is set to be low, the absorption liquid sucked from the absorption container to the solution pump is likely to boil. And when the room is under high load,
When the low-temperature heat medium is supplied from the indoor heat exchanger to the evaporator, the inside of the evaporator and the inside of the absorber may be cooled to lower the pressure. When the pressure in the absorber decreases, the boiling point of the absorbing liquid in the absorbing device lowers, the absorbing liquid boils, and the solution pump may cause cavitation. If the solution pump causes cavitation, the durability of the solution pump is likely to deteriorate, and if the cavitation continues, the amount of absorption liquid supplied to the regenerator will be insufficient, resulting in overheating of the regenerator. When the solution pump causes cavitation during heating operation, a technique for avoiding cavitation is desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is to improve the durability of a solution pump by avoiding the cavitation when the solution pump causes cavitation during heating operation. To provide the absorption type air conditioner.

[0006]

The absorption type air conditioner of the present invention employs the following technical means in order to achieve the above object. [Means for Claim 1] In the absorption type air conditioner, a heating means for heating the absorbing liquid, a regenerator for vaporizing a part of the absorbing liquid by heating the absorbing liquid by the heating means, and a regenerator are used. A condenser that cools and liquefies the vaporized refrigerant, an evaporator that evaporates the liquefied refrigerant liquefied by this condenser under low pressure,
An absorption type refrigeration cycle equipped with an absorber that absorbs the vaporized refrigerant evaporated in this evaporator into an absorption liquid, a solution pump that pressurizes the absorption liquid in this absorber to the regenerator, and indoor air An indoor heat exchanger that exchanges heat with a heat medium,
When the liquefied refrigerant is vaporized in the evaporator, the latent heat of vaporization is removed and the cooled heat medium is guided to the indoor heat exchanger, and the heat medium heat-exchanged with the indoor air in the indoor heat exchanger is again returned. A heat medium circuit for leading to the evaporator; and an indoor air conditioning means provided in the heat medium circuit and provided with a heat medium pump for circulating the heat medium, and guiding the absorption liquid heated by the heating means to the evaporator. By heating the heat medium supplied from the evaporator to the indoor heat exchanger, heating operation for heating the room is provided.

In this absorption type air conditioner, during the heating operation, a cavity phenomenon detecting means for detecting the occurrence of cavitation of the solution pump due to boiling of the absorbing liquid in the absorber, and this cavity phenomenon detecting means And a cavity phenomenon avoiding means for controlling the heat medium pump to reduce the flow rate of the heat medium flowing through the heat medium circuit when the occurrence is detected.

[Means for Claim 2] In the absorption type air conditioner according to Claim 1, the cavity phenomenon detecting means includes a rotation speed detecting means for detecting a rotation speed of the solution pump, and the cavity speed detecting means detects the rotation speed. Occurrence of cavitation is detected when the rotation speed of the solution pump is increased by a predetermined amount above the target rotation speed.

[Means for Claim 3] In the absorption type air conditioner according to Claim 1, the cavity phenomenon avoiding means stops the heat medium pump when the cavity phenomenon detecting means detects the occurrence of cavitation.

[0010]

[Operation and effect of the invention]

[Operation of Claim 1] During the heating operation, the high-temperature absorption liquid heated by the heating means is introduced from the regenerator to the evaporator, and the high-temperature absorption liquid heats the heat medium passing through the evaporator. And
The heated heat medium heats the indoor air by the indoor heat exchanger in the room to heat the room. On the other hand, the absorption liquid obtained by heating the heat medium is sucked by the solution pump from the absorber and pressure-fed to the regenerator.

The temperature inside the evaporator is lowered due to the temperature drop of the heat medium of the evaporator due to the increase of the load in the indoor heat exchanger, the pressure inside the evaporator is lowered and the boiling point is lowered, and the solution pump causes cavitation. In this case, the cavity phenomenon detecting means detects the occurrence of cavitation. When the cavity phenomenon detecting means detects the occurrence of cavitation, the cavity phenomenon avoiding means controls the heat medium pump to reduce the flow rate of the heat medium (including stopping the heat medium pump). Then, the flow rate of the heat medium supplied to the evaporator decreases, and the temperature inside the evaporator rises. Then, the pressures in the evaporator and the absorber rise, and the boiling of the absorbing liquid in the absorber is stopped. As a result, cavitation of the solution pump is avoided. If cavitation occurs repeatedly, the above operation is repeated. When the room warms, the temperature of the heat medium supplied to the evaporator rises, so that the occurrence of cavitation is suppressed.

According to the absorption type air conditioner of the present invention, as described above, when the solution pump causes cavitation, the cavitation phenomenon is detected by the cavitation phenomenon detecting means, and the cavitation phenomenon is avoided. In order to avoid the occurrence of cavitation by raising the pressure in the absorber by the operation of the means, the time during which cavitation is occurring,
Significantly shorter than before. As a result, deterioration of the durability of the solution pump due to cavitation can be suppressed.

[Operation and Effect of Claim 2] In the cavity phenomenon detecting means, during heating operation, when the rotation speed of the solution pump by the rotation speed detecting means rises above the target rotation speed by a predetermined amount, the load of the solution pump due to cavitation. The occurrence of cavitation is detected by deciding that the rotation speed has increased due to a decrease in the rotation speed. It is desirable that the rotation speed of the solution pump corresponds to the temperature of the absorbing liquid heated by the heating means, particularly during cooling. Therefore, when the solution pump is provided with a rotation speed detecting means in order to control the rotation speed of the solution pump, the occurrence of cavitation can be detected by utilizing this rotation speed detecting means. As a result, there is no need to newly provide a dedicated sensor for detecting the occurrence of cavitation, and the cost of the absorption air conditioner can be kept low.

[Operation and Effect of Claim 3] When the cavitation phenomenon detecting means detects the occurrence of cavitation, the cavitation phenomenon avoiding means stops the heat medium pump. When the heat medium pump is stopped, the temperature inside the evaporator rises faster than when the heat medium pump is operated at a low speed. Therefore, the pressures in the evaporator and the absorber also rise quickly, and the boiling of the absorbing liquid in the absorber stops quickly. That is, by stopping the heat medium pump, it is possible to quickly avoid the occurrence of cavitation.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an absorption type air conditioner of the present invention will be described based on the embodiments shown in the drawings. [Configuration of Embodiment] FIGS. 1 and 2 show an embodiment, and FIG. 1 is a schematic configuration diagram of an absorption air conditioning system using a double-effect absorption refrigeration cycle for air conditioning the room. The absorption type air conditioner 1 of this embodiment is roughly classified into heating means 2 for heating an absorbing liquid (lithium bromide aqueous solution in this embodiment).
And a double-effect absorption refrigeration cycle 3, and an indoor air conditioning means 4 for air conditioning the room with cold / hot water cooled or heated by the absorption refrigeration cycle 3 (heat medium of the present invention, water in this embodiment). A cooling water cooling means 5 for cooling the cooling water mainly used for cooling the vaporized refrigerant (steam in the present embodiment) in the absorption refrigeration cycle 3; and a control device for controlling each of the mounted electric functional parts. 6 and 6.

[Explanation of Heating Means 2] The heating means 2 of the present embodiment is a gas combustor for combusting a gas which is a fuel to generate heat and heating the absorbing liquid by the generated heat. It comprises a gas burner 11 for performing, a gas supply means 12 for supplying gas to the gas burner 11, a combustion fan 13 for supplying air for combustion to the gas burner 11, and the like.
Then, the heat obtained by the gas combustion of the gas burner 11 heats the boiling device 14 of the absorption refrigeration cycle 3, and the boiling device 14 is heated.
It is provided so as to heat the low-concentration absorption liquid therein.

[Description of Absorption-type Refrigeration Cycle 3] The absorption-type refrigeration cycle 3 includes a boiling device 14 that is heated by the heating means 2. By heating the low-concentration absorption liquid in the boiling device 14, the absorption-type freezing cycle 3 has a low concentration. The high temperature regenerator 15 that vaporizes (evaporates) the refrigerant (water) contained in the absorption liquid to convert the low concentration absorption liquid into the medium concentration absorption liquid, and the condensation heat of the vaporized refrigerant in the high temperature regenerator 15 The low-temperature regenerator 16 that heats the concentrated absorbent to vaporize the refrigerant contained in the medium-concentrated absorbent to convert the medium-concentrated absorbent into a high-concentrated absorbent, and the vaporized refrigerant from the high-temperature regenerator 15 and the low-temperature regenerator 16 ( A condenser 17 for cooling and liquefying (steam) and an evaporator 18 for evaporating the liquefied refrigerant (water) liquefied by the condenser 17 under a pressure close to vacuum;
It is composed of an absorber 19 for absorbing the vaporized refrigerant evaporated in the evaporator 18 into the high-concentration absorption liquid obtained in the low temperature regenerator 16.

[Description of High Temperature Regenerator 15] High Temperature Regenerator 15
As described above, includes the boiling device 14 that heats the low-concentration absorption liquid by the heating means 2. The low-concentration absorbent liquid boiled in the boiling device 14 is blown out into a high-temperature regeneration container 22 in the shape of a cylindrical container from a blowing cylinder 21 extending upward from the boiling device 14. The high-temperature low-concentration absorption liquid blown out into the high-temperature regeneration container 22 collides with the gas-liquid separation baffle 23. Then, the low-concentration absorption liquid blown into the high-temperature regeneration container 22 partially evaporates to become a vaporized refrigerant, and the rest drops around the blow-out cylinder 21 to become a medium-concentration absorption liquid. The vaporized refrigerant is cooled by the wall of the high-temperature regenerator 22 as the heat of vaporization during evaporation of the medium-concentration absorption liquid in the low-temperature regenerator 16 to be cooled and become liquefied refrigerant (water).

A liquefied refrigerant (water) is placed in the high temperature regeneration container 22.
A partition cylinder 24 is provided between the blow-out cylinder 21 and the high-temperature regeneration container 22 to separate the medium-concentration absorbent.
Then, the liquefied refrigerant (water) cooled in the high-temperature regeneration container 22 and liquefied and separated to the outside of the partition tube 24 is supplied to the condenser 17 through the liquid refrigerant pipe 25 connected to the lower part. Further, the medium-concentration absorbing liquid separated between the inside of the partition cylinder 24 and the blow-off cylinder 21 is supplied to the low temperature regenerator 16 through the middle liquid pipe 26 connected to the lower portion. The medium liquid pipe 26 is provided with throttle means 27 such as an orifice. When the cooling / heating switching valve 55 described later is closed, the throttle means 27 is
When the temperature difference between the high temperature regenerator 15 and the low temperature regenerator 16 is maintained, the medium-concentration absorbent is flown, and when the cooling / heating switching valve 55 is opened, the medium-concentration absorbent is hardly flowed.

[Description of Low Temperature Regenerator 16] Low Temperature Regenerator 16
Is equipped with a tubular low-temperature regeneration container 31 that covers the high-temperature regeneration container 22, and injects the medium-concentration absorption liquid supplied through the medium-liquid pipe 26 toward the ceiling portion of the high-temperature regeneration container 22. . Since the temperature inside the low temperature regeneration container 31 is lower than the temperature inside the high temperature regeneration container 22, the pressure inside the low temperature regeneration container 31 is lower than the pressure inside the high temperature regeneration container 22. Therefore, the medium-concentration absorption liquid supplied from the middle liquid pipe 26 into the low temperature regeneration container 31 is easily evaporated. Then, when the medium-concentration absorbing liquid is injected into the ceiling portion of the high-temperature regenerating container 22, the wall of the high-temperature regenerating container 22 heats the medium-concentrating absorbing liquid, and a part of the refrigerant contained in the medium-concentrating absorbing liquid evaporates. It becomes a vaporized refrigerant, and the rest becomes a high-concentration absorbent.

Here, the upper part of the low temperature regeneration container 31 communicates with the upper part of the condensing container 32 in the shape of an annular container by a communication part 33. Therefore, the vaporized refrigerant evaporated in the low temperature regeneration container 31 is supplied into the condensing container 32 through the communication part 33. On the other hand, the high-concentration absorption liquid drops to the lower portion of the low temperature regeneration container 31 and is supplied to the absorber 19 through the high liquid pipe 34 connected to the lower portion of the low temperature regeneration container 31. A ceiling plate 35 is provided on the upper side inside the low temperature regeneration container 31, and a gap 36 through which the vaporized refrigerant passes is provided between the outer peripheral end of the ceiling plate 35 and the low temperature regeneration container 31.

[Description of Condenser 17] The condenser 17 is covered with a condensing container 32 having an annular container shape. Inside the condensing container 32, a condensing heat exchanger 37 for cooling and liquefying the vaporized refrigerant in the condensing container 32 is arranged. The condensing heat exchanger 37 is an annular coil through which cooling water flows. Then, the liquefied refrigerant supplied from the low temperature regenerator 16 into the condensing container 32 is the condensing heat exchanger 3
It is cooled by 7 and liquefied, and is dripped below the condensation heat exchanger 37.

On the other hand, below the condensing container 32, the refrigerant is supplied from the above-mentioned high temperature regenerator 15 through the liquid refrigerant pipe 25. In addition, when the supply refrigerant is supplied into the condensing container 32, a difference in pressure (about 70 mmHg in the condensing container 32 is generated.
From the low pressure), re-boiling, and the vaporized refrigerant and the liquefied refrigerant are supplied in a mixed state. A low liquid supply pipe 38 that guides the liquefied refrigerant to the evaporator 18 is connected to the condensing container 32. The low liquid supply pipe 38 has a refrigerant valve 3 for adjusting the supply amount of the liquefied refrigerant supplied from the condensation container 32 to the evaporator 18.
9 are provided.

[Explanation of Evaporator 18] The evaporator 18 is provided in the lower part of the condensing container 32 together with the absorber 19, and is constituted by an annular container-shaped evaporative absorbing container 41 provided around the low temperature regeneration container 31. Is covered. An evaporation heat exchanger 42 that evaporates the liquefied refrigerant supplied from the condenser 17 is arranged outside the inside of the evaporation / absorption container 41. This evaporation heat exchanger 42 is an annular coil,
Heat medium (cold hot water) supplied to the indoor air conditioning means 4 inside
Flows. Then, the liquefied refrigerant supplied from the condenser 17 through the low-liquid supply pipe 38 is scattered on the evaporation heat exchanger 42 from the refrigerant distribution tool 43 arranged on the evaporation heat exchanger 42. .

Since the inside of the evaporative absorption container 41 is maintained in a substantially vacuum (for example, 6.5 mmHg), the boiling point is low, and the liquefied refrigerant dispersed in the evaporative heat exchanger 42 easily evaporates. Then, the liquefied refrigerant scattered on the evaporation heat exchanger 42 deprives the heat of vaporization from the heat medium flowing inside the evaporation heat exchanger 42 to evaporate. As a result, the heat medium flowing in the evaporation heat exchanger 42 is cooled. Then, the cooled heat medium is guided to the indoor air conditioning unit 4 to cool the room.

[Description of Absorber 19] The absorber 19 is covered with the evaporative absorption container 41 as described above. The absorber 19 is provided inside the evaporative absorption container 41 inside the high liquid pipe 3
An absorption heat exchanger 44 for cooling the high-concentration absorption liquid supplied from No. 4 is arranged. This absorption heat exchanger 44 is
Cooling water that cools the high-concentration absorbent dispersed on the coil is supplied to the inside of the annular coil. The cooling water that has passed through the absorption heat exchanger 44 passes through the condensation heat exchanger 37 of the condenser 17 and is then guided to the cooling water cooling means 5 to be cooled. Then, the cooling water cooled by the cooling water cooling means 5 is again guided to the absorption heat exchanger 44.

On the other hand, above the absorption heat exchanger 44, there is arranged an absorption liquid sprinkler 45 for distributing the high-concentration absorption liquid supplied from the high liquid pipe 34 to the absorption heat exchanger 44. The high-concentration absorption liquid sprinkled on the absorption heat exchanger 44 is vaporized by evaporation in the evaporation heat exchanger 42 while traveling along the coil surface of the absorption heat exchanger 44 and falling from above. Absorbs refrigerant. As a result, the evaporation absorption container 41
The absorption liquid that has dropped to the bottom of the bottom becomes a low-concentration absorption liquid with a reduced concentration. At the bottom of the evaporation / absorption container 41, the evaporation / absorption container 4 is provided.
A low liquid pipe 46 for supplying the low-concentration absorption liquid at the bottom of No. 1 to the boiling device 14 is connected. The low liquid pipe 46 is provided with a solution pump 47 for flowing the low-concentration absorption liquid from the evaporation absorption container 41 in a substantially vacuum state toward the boiling device 14.

[Explanation of Components Other than Above in Absorption Refrigeration Cycle 3] Reference numeral 51 shown in FIG. 1 is a medium-concentration absorption liquid flowing from the high temperature regenerator 15 to the low temperature regenerator 16, and the absorber 19 to the boiling device 14. A high-temperature heat exchanger that exchanges heat with the low-concentration absorbent flowing to the high-temperature regenerator 15 to the low-temperature regenerator 1
The medium-concentration absorption liquid flowing to 6 is cooled, and conversely, the low-concentration absorption liquid flowing from the absorber 19 to the boiling device 14 is heated. Reference numeral 52 shown in FIG. 1 is a low-temperature heat exchanger for exchanging heat between the high-concentration absorption liquid flowing from the low-temperature regenerator 16 to the absorber 19 and the low-concentration absorption liquid flowing from the absorber 19 to the boiling device 14. The high-concentration absorption liquid flowing from the low-temperature regenerator 16 to the absorber 19 is cooled, and conversely, the low-concentration absorption liquid flowing from the absorber 19 to the boiling device 14 is heated.

Further, the absorption refrigeration cycle 3 of this embodiment is provided with heating operation means 53 for performing heating operation in addition to the cooling operation by the above-mentioned operation. The heating operation means 53 is branched from the middle liquid pipe 26 that guides the medium-concentration absorption liquid from the high-temperature regenerator 15 to the low-temperature regenerator 16, and evaporates the high-temperature absorption liquid in the evaporator 18 and the absorber 19. It is composed of a heating pipe 54 that leads to the absorption container 41 and a cooling / heating switching valve 55 that opens and closes the heating pipe 54. The cooling / heating switching valve 55 is opened during the heating operation to guide the high temperature absorption liquid into the evaporation / absorption container 41, and the evaporation heat exchanger 42 of the evaporator 18 is heated.
The hot and cold water flowing inside is heated.

[Explanation of Indoor Air-Conditioning Unit 4] An indoor heat exchanger 61 installed indoors, a cold / hot water circuit 6 for circulating cold / hot water.
2 (corresponding to the heat medium circuit of the present invention), and a cold / hot water pump 63 (corresponding to the heat medium pump of the present invention) for circulating the heat medium in the heat medium circuit. The indoor heat exchanger 61 is a gas and liquid heat exchanger that exchanges heat between the hot and cold water that has passed through the evaporator 18 and the indoor air, and forcibly heats the cold and hot water and the indoor air that flow through the indoor heat exchanger 61. An indoor fan 64 is provided for exchanging and blowing the heat-exchanged air into the room.

The cold / hot water circuit 62 guides the cold / hot water passing through the evaporator 18 to the indoor heat exchanger 61 installed in the room,
A cold / hot water circuit that stores cold / hot water in the cold / hot water circuit 62 in addition to the indoor heat exchanger 61 and the cold / hot water pump 63 by a water pipe for guiding cold / hot water that has exchanged heat with room air to the evaporator 18 again. A cistern 65 for replenishing cold and warm water is provided in 62.
A water supply pipe 66 for supplying cold / hot water (tap water) to the interior is connected to the systern 65. The water supply pipe 66 is provided with a water supply valve 67 for supplying and stopping cold / hot water into the systern 65. The cistern 65 is provided with a water level sensor (not shown) so that when the cooling water in the cistern 65 drops, the water supply valve 67 is opened to replenish the cistern 65 with cold / hot water. Further, the systern 65 is provided with overflow water supply means 68 for guiding the overflowing cold / warm water into a cooling water tank 78 described later.

[Explanation of Cooling Water Cooling Unit 5] The cooling water cooling unit 5 includes an evaporative cooling tower 71, a cooling water circuit 72 for circulating cooling water, and a cooling water pump for circulating cooling water in the cooling water circuit 72. 73 is provided. The cooling tower 71 is the absorber 1
The cooling water that has passed through the condenser 9 and the condenser 17 flows from the upper side to the lower side to exchange heat with the outside air to radiate heat while flowing, and also to partially evaporate while flowing, and cooling that flows at the time of evaporation. A sprinkling unit 74 that disperses the heat of vaporization from water and cools the flowing cooling water, and sprinkles the cooling water above.
And an evaporating section 75 having a large surface area through which the cooling water flows, and a collecting section 76 that collects the cooling water that has passed through the evaporating section 75. The cooling tower 71 also includes a cooling water fan 77 that causes an air flow in the evaporation unit 75 and promotes evaporation and cooling of cooling water in the evaporation unit 75.

The cooling water circuit 72 passes the absorber 19 and the condenser 17 to cool the cooling water having an increased temperature.
1, which is a water pipe for sending the cooling water cooled in the cooling tower 71 to the absorber 19 and the condenser 17 again. In the cooling water circuit 72, in addition to the cooling tower 71 and the cooling water pump 73,
A cooling water tank 78 for storing cooling water is provided. This cooling water tank 78 is located below the cooling tower 71
5 is installed below the cooling tower 71, and is provided so that the cooling water that has passed through the cooling tower 71 is supplied and the water that overflows at the cistern 65 is supplied. The cooling water tank 78 is provided with a water level sensor (not shown). When the cooling water in the cooling water tank 78 drops, the water supply valve 67 is opened to overflow the water from the systern 65, and the overflow water is supplied from the overflow water supply means 68. It is provided so as to lead into the cooling water tank 78 and supplement the cooling water.

[Description of Control Device 6] The control device 6 includes the above-described refrigerant valve 39, solution pump 47, cold / hot water pump 63, indoor fan 64, cooling / heating switching valve 55, water supply valve 67, cooling water pump 73, and cooling water. Electrical functional parts such as fan 77,
And electric functional parts of the heating means 2 (combustion fan 13, gas amount control valve 81, gas on-off valve 82, ignition device 83, etc.)
Is to control energization according to an operation instruction of a controller (not shown) manually set by the user or an input signal of each of a plurality of sensors.

The control device 6 of this embodiment includes a solution pump 47.
Pump speed control means 84 for controlling the rotation speed of the is provided. The pump speed control means 84 controls the rotation speed of the solution pump 47 based on the temperature of the absorbing liquid heated by the heating means 2 during the cooling operation, and during the heating operation,
The rotation speed of the solution pump 47 is controlled to a constant speed. Therefore, the control device 6 is, as an example of the sensor,
A temperature sensor 85 for detecting the temperature of the low-concentration absorption liquid in the boiling device 14 and a rotation speed detecting means 86 for detecting the rotation speed of the solution pump 47 (a Hall element which generates two pulses when the solution pump 47 makes one rotation). Used)) and. Then, during the cooling operation, the control device 6 determines that the target rotation speed set based on the temperature of the low-concentration absorption liquid in the boiling device 14 detected by the temperature sensor 85 is the rotation speed detection means 86.
The rotation speed of the solution pump 47 is controlled so as to obtain. Specifically, when the temperature detected by the temperature sensor 85 is low, the target rotation speed is reduced to reduce the flow rate so as to prevent the problem that the cooling capacity cannot be obtained due to insufficient heat quantity in the high temperature regenerator 15. There is. Further, during the heating operation, the control device 6 is controlled so that the rotation speed detected by the rotation speed detection means 86 becomes constant (for example, 85 Hz).

The controller 6 controls the solution pump 47.
Is controlled by the target value (FF) by feedforward + proportional value of rotational difference (P) + integral value of rotational difference (I).

Further, the controller 6 has a cavity phenomenon detecting means 87 for detecting the occurrence of cavitation when the solution pump 47 causes cavitation during heating operation.
And a cavity phenomenon avoiding means 88 for avoiding cavitation when the occurrence of cavitation is detected. The cavity phenomenon detecting means 87 of the present embodiment detects the occurrence of cavitation by using the rotation speed detecting means 86. During the heating operation, the target rotation speed of the solution pump 47 is 2550 rpm (detected by the rotation speed detecting means 86). When the value detected by the rotation speed detection means 86 reaches 88 Hz or higher, the load of the solution pump 47 is reduced by cavitation, and it is determined that the rotation speed has increased. The cavitation phenomenon avoiding means 88 operates when the cavitation phenomenon detecting means 87 detects the occurrence of cavitation, and stops the cold / hot water pump 63.

Next, the operation of the cavity phenomenon detecting means 87 and the cavity phenomenon avoiding means 88 will be described with reference to the flow chart of FIG. When the heating operation is started (start), the solution pump 47 is rotationally driven at 85 Hz, and the cold / hot water pump 63 is also rotationally driven (step S1).
). Next, the detected value of the rotation speed detection means 86 is 88 Hz.
It is determined whether or not the above (step S2). If the result of this determination is NO, the process returns to step S2.

If the decision result in the step S2 is YES,
The operation of the cold / hot water pump 63 is stopped (step S3).
Next, it is judged whether or not the detection value of the rotation speed detecting means 86 has dropped to 85 Hz (step S4). If the determination result is NO, the process returns to step S4, and if the determination is YES, the cold / hot water pump 63 is started (step S5), and thereafter,
Return to step S2.

[Operation of the Embodiment] During the heating operation, when the indoor temperature is low at the beginning of heating and the cold heat water having a low temperature is supplied from the indoor heat exchanger 61 to the evaporator 18, the inside of the evaporative absorption container 41 is cooled. As a result, the pressure drops, and in the absorber 19,
The boiling point of the absorption liquid sucked by the solution pump 47 may be lowered and the absorption liquid may boil. Then, the solution pump 47
Cannot absorb the absorbing liquid, and causes cavitation. When cavitation occurs, the load on the solution pump 47 decreases and the rotation speed increases to 88 Hz or higher, and the occurrence of cavitation is detected. Then, the control device 6 stops the operation of the cold / hot water pump 63. As a result, the supply of low-temperature cold / hot water to the evaporator 18 is stopped, the temperature of the cold / hot water in the evaporator 18 rises,
The temperature inside the evaporator 18 also rises. Then, the pressure in the evaporator 18 and the absorber 19 rises, and the boiling point of the absorbing liquid rises, so that the boiling of the absorbing liquid in the absorber 19 stops.

As a result, the solution pump 47 sucks the absorbing liquid to avoid cavitation, and the rotation speed of the solution pump 47 stabilizes at 85 Hz. Then, the control device 6
The operation of the cold / hot water pump 63 is restarted, and the cold / hot water heated by the evaporator 18 is guided to the indoor heat exchanger 61 to heat the room. In addition, since the time for which the operation of the cold / hot water pump 63 is stopped in order to avoid cavitation is relatively short (several seconds), the effect of the cold / hot water pump 63 on the indoor heating has almost no effect on the sensation.

[Effects of Embodiment] In the absorption type air conditioner of this embodiment, as described above, when the solution pump 47 causes cavitation, the cold / hot water pump 63 is stopped to stop the evaporator 18 and the absorber. The pressure inside 19 is increased to avoid the occurrence of cavitation. Therefore, the time during which cavitation is occurring is significantly shorter than before,
The solution pump 47 can be protected from cavitation for a long period of time, and durability can be improved.

[Modification] In the above-described embodiment, the rotation speed detecting means for detecting the rotation speed of the solution pump is used as the cavity phenomenon detecting means, but the invention is not limited to this. For example, a change in the power consumption of the solution pump is detected. Alternatively, a sensor that detects a decrease in temperature or pressure in the evaporation / absorption container, or a sensor that detects a decrease in temperature of cold / hot water in the evaporation heat exchanger may be used. Also, when judging the occurrence of cavitation, an example was shown in which the cold / hot water pump was stopped to completely reduce the flow rate of the heat medium flowing through the heat medium circuit, but the cold / hot water pump was not stopped and the rotation speed was reduced. By doing so, the flow rate of the heat medium flowing through the heat medium circuit may be reduced.

In the above embodiment, the double-effect absorption refrigeration cycle 3 is shown as an example, but a single-effect absorption refrigeration cycle may be used, or a triple-effect multiple-effect absorption refrigeration cycle. It can be a cycle. Further, when the medium-concentration absorption liquid is injected into the low temperature regenerator, an example in which it is injected from above the low temperature regenerator has been shown, but it may be injected from below.

Although the gas burner is used as the heating source of the heating means, a petroleum burner or an electric heater may be used, or exhaust heat of another device (for example, an internal combustion engine) may be used. Although an example in which a condensing heat exchanger, an evaporating heat exchanger, and an absorbing heat exchanger are provided in a coil shape is shown, other types of heat exchangers such as a tube-and-fin or a laminated heat exchanger may be used. Is also good. Although an aqueous lithium bromide solution has been shown as an example of the absorbing liquid, other absorbing liquids such as an ammonia aqueous solution using ammonia as a refrigerant and water as an absorbent may be used.

As an example of the heat medium, tap water is used and shared with the cooling water of the cooling water circuit. However, other heat medium such as antifreeze liquid or oil different from the cooling water of the cooling water circuit may be used. good. The numerical values shown in the above embodiments are examples used for making the embodiments easy to understand, and the present invention is not limited to the numerical values of the embodiments, and is suitable for the purpose of use and the scale of the device. Numerical values can be appropriately adopted.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an absorption air conditioner.

FIG. 2 is a flowchart showing the operation of the control device.

[Explanation of symbols]

 1 Absorption type air conditioner 2 Heating means 3 Absorption type refrigeration cycle 4 Indoor air conditioning means 5 Cooling water cooling means 6 Control device 15 High temperature regenerator 16 Low temperature regenerator 17 Condenser 18 Evaporator 19 Absorber 47 Solution pump 61 Indoor heat exchanger 62 cold / hot water circuit (heat medium circuit) 63 cold / hot water pump (heat medium pump) 86 rotational speed detecting means 87 cavity phenomenon detecting means 88 cavity phenomenon avoiding means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Kaoru Kawamoto 4-1-2, Hirano-cho, Chuo-ku, Osaka City Osaka Gas Co., Ltd. (72) Shinsuke Takahashi 4-1-2, Hirano-cho, Chuo-ku, Osaka Within Osaka Gas Co., Ltd.

Claims (3)

[Claims] 1. A) heating means for heating an absorbing liquid; b) a regenerator for vaporizing a part of the absorbing liquid by heating the absorbing liquid by the heating means; cooling a vaporized refrigerant generated in the regenerator. A condenser for liquefying the liquefied refrigerant, an evaporator for evaporating the liquefied refrigerant liquefied by the condenser under a low pressure, an absorber for absorbing the vaporized refrigerant evaporated by the evaporator into an absorbing liquid, and the absorbing liquid in the absorber as described above. An absorption refrigeration cycle equipped with a solution pump for pressure-feeding to a regenerator, and c) an indoor heat exchanger installed in the room for exchanging heat between indoor air and a heat medium, and evaporated when the liquefied refrigerant is evaporated in the evaporator. A heat medium circuit that guides the heat medium cooled by removing the latent heat to the indoor heat exchanger, and also guides the heat medium heat-exchanged with the room air in the indoor heat exchanger to the evaporator, the heat medium. Provided in the circuit to circulate the heat medium An indoor air conditioner equipped with a heat medium pump is provided, and the absorption liquid heated by the heating means is guided to the evaporator, and by heating the heat medium supplied from the evaporator to the indoor heat exchanger, In an absorption type air conditioner capable of performing heating operation for heating a room, the absorption type air conditioner is a cavity phenomenon detecting means for detecting occurrence of cavitation of the solution pump due to boiling of an absorbing liquid in the absorber during heating operation. And a cavity phenomenon avoiding means for controlling the heat medium pump to reduce the flow rate of the heat medium flowing through the heat medium circuit when the cavity phenomenon detecting means detects the occurrence of cavitation. Absorption type air conditioner. 2. The absorption air conditioner according to claim 1, wherein the cavity phenomenon detection means includes a rotation speed detection means for detecting a rotation speed of the solution pump, and the solution pump detected by the rotation speed detection means. The absorption type air conditioner is characterized in that the occurrence of cavitation is detected when the rotation speed of the vehicle rises by a predetermined amount above the target rotation speed. 3. The absorption air conditioner according to claim 1, wherein the cavity phenomenon avoiding means stops the heat medium pump when the cavity phenomenon detecting means detects the occurrence of cavitation. Air conditioner.