JP3147767B2 - Absorption heat pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type heat pump in which the characteristic deterioration of the solution pump due to gas running or cavitation of the solution pump is improved.

[0002]

2. Description of the Related Art Conventionally, an ammonia-water-based absorption refrigerator using ammonia as a refrigerant and water as an absorbent generally uses a full-fill cycle. In this type, the stability of the cycle system is high under steady load conditions,
Although there is an advantage that the operation can be performed by simple control, there are disadvantages such as an increase in the shape of the liquid reservoir portion and an increase in the amount of ammonia as the refrigerant. Therefore, we have proposed a system that combines a once-through cycle and a trochoid-type solution pump, which is a rotary volume pump, that can be reduced in size and weight.

[0003] Fig. 12 shows this system. This absorption heat pump system comprises an outdoor unit 1 and an indoor unit 2, and the outdoor unit 1 and the indoor unit 2 are connected by a cold / hot water pipe 3. I have. The outdoor unit 1 is an ammonia-water absorption heat pump using ammonia as a refrigerant and water as an absorbent, and has a built-in mechanism for generating cold and hot water by gas combustion. The discharge side of the solution pump 6 is divided into two directions, one of which is a path from the stack type solution heat exchanger 7 to the through-flow type regenerator 8 to the rectifier 9 and the other one. Is a path leading from the capillary 11 to the decompression unit 10 of the rectifier 9. There is an outlet for the dilute solution from below the rectifier 9 to form a dilute solution line extending to the solution heat exchanger 7 via the capillary 12 and further to the stacked absorber 14 via the capillary 13. Above the rectifier 9, there is an outlet for the rectified ammonia gas, which is connected to a stacked condenser 15. The ammonia that has exited from the condenser 15 passes through a laminated subcooler 16 to an expansion valve 17 or the laminated evaporator 1.
8 and connected to the absorber 14. The concentrated solution generated in the absorber 14 returns to the pump receiver 4. As described above, the ammonia refrigerant circuit and the aqueous ammonia solution circuit are configured, and each of the component parts constitutes a once-through type cycle with a small amount of refrigerant charge.

[0004] The circuit of the cold / hot water system is composed of a laminated heat exchanger 2 integrally formed to exchange heat with the condenser 15 and the absorber 14 through the circulating pump 20 and the four-way valve 21 from the radiator 19.
2 and the radiator 19 itself is cooled by the radiating fan 23. The indoor unit 2 includes an evaporating heat exchanger 25 for exchanging heat with the evaporator 18 through the cold / hot water pipe 3 and the four-way valve 24, and the four-way valve 2
1 and connected to the circulation pump 26 to form a path returning to the indoor unit 2. The indoor unit 2 is provided with an indoor fan 27.

[0005]

However, according to the above-described structure, the amount of refrigerant to be charged is small and the size and weight of the system can be reduced because of its structure. The challenge was to provide a stable supply of the aqueous ammonia solution to the suction side of the solution pump 6, and to establish a refrigerant circuit configuration for securing the aqueous ammonia solution to the suction side of the solution pump 6 and a system control method for a once-through cycle.

The trochoid pump used as the solution pump 6 is a kind of rotary displacement pump, and can be reduced in size and weight as compared with a diaphragm pump. It has weak characteristics against cavitation generated when the degree of subcooling is small, and there is a problem in securing the degree of supercooling of the aqueous ammonia solution on the suction side of the solution pump.

Further, the degree of supercooling of the aqueous ammonia solution at the outlet of the absorber, that is, the suction side of the solution pump, has a correlation with the system efficiency. In order to enhance the system efficiency, the smaller the degree of supercooling of the aqueous ammonia solution, the better. It was an issue to control the degree to a minimum without adversely affecting the solution pump 6.

That is, in the present system, there is a problem that the stability of the system is lacking due to each of the above problems.

[0009]

According to the present invention, a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, and a primary side of an evaporator are provided. An absorber, a solution pump, and a solution heat exchanger, and a pump receiver and a liquid level detecting means for detecting the liquid level of the pump receiver above the solution pump on the suction side of the solution pump. And control means for controlling the number of revolutions of the solution pump to keep the liquid level of the pump receiver constant.

According to the present invention, the liquid level of the pump receiver is detected by the liquid level detecting means provided on the pump receiver above the solution pump on the suction side of the solution pump. By controlling the number of revolutions of the solution pump so that the flow rate of the refrigerant solution sent from the solution pump to the system system and the circulation flow rate of the refrigerant solution returning from the system system to the pump are balanced, the continuous condition of the flow becomes In addition to being filled, the refrigerant solution can be supplied with a constant positive pressure constantly applied to the solution pump.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An absorption heat pump according to claim 1 of the present invention comprises a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, and a primary side of an evaporator. And an absorber, a solution pump, and a solution heat exchanger connected by piping, and a pump receiver above the solution pump on the suction side of the solution pump and a liquid level detecting means for detecting a liquid level of the pump receiver. And a control means for controlling the number of revolutions of the solution pump to keep the liquid level of the pump receiver constant, and a pump located above the solution pump on the suction side of the solution pump. The liquid level of the pump receiver is detected by the liquid level detecting means provided in the receiver,
By controlling the rotation speed of the solution pump so that the liquid level is constant, the circulating flow rate of the refrigerant solution sent from the solution pump to the system and the circulation flow of the refrigerant solution returning from the system to the pump are balanced. In addition to satisfying the continuous flow condition, the refrigerant solution can be supplied with a constant positive pressure constantly applied to the solution pump.

An absorption heat pump according to a second aspect of the present invention is configured such that a supercooling section A is provided on a suction side of a solution pump in a pipe connecting the solution pump and a pump receiver. Item 3. The absorption heat pump according to item 3, wherein the evaporator is provided with a supercooling section B connected to the suction side of the solution pump, and in any case, the supercooling section B in the pipe connecting the pump receiver and the solution pump is provided with a supercooling section. As a result, the refrigerant solution on the suction side of the solution pump can be supercooled.

According to a fourth aspect of the present invention, there is provided an absorption heat pump comprising a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, a primary side of an evaporator, an absorber, And a solution pump and a solution heat exchanger are connected by piping, and a flow path is provided at the bottom of the pump receiver on the suction side of the solution pump, and cooling water that exchanges heat with the condenser flows through the flow path. The non-equilibrium gas component due to bubbling, which is generated when the refrigerant solution returns to the pump receiver in a saturated state and flows down into the pump receiver, can be effectively cooled while separating the liquid from the liquid.

According to a fifth aspect of the present invention, there is provided an absorption heat pump comprising a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, a primary side of an evaporator, an absorber, A first temperature sensor provided on the suction side of the solution pump, and a second temperature sensor provided on the outlet side of the expansion valve, wherein The degree of supercooling of the refrigerant solution on the suction side of the solution pump, the pressure on the suction side of the solution pump estimated from the temperature of the expansion valve outlet detected by the first temperature sensor provided on the expansion valve outlet side, and Inferring from the temperature of the refrigerant solution on the suction side of the solution pump detected by a first temperature sensor provided on the suction side of the solution pump, the rotation speed of the solution pump or the opening of the expansion valve, The degree of supercooling of the refrigerant solution on the suction side of the solution pump is Control means for controlling the pressure to a constant value, and the degree of subcooling of the refrigerant solution on the suction side of the solution pump is estimated from the refrigerant evaporation temperature on the outlet side of the expansion valve. By estimating the pressure of the solution pump and the temperature of the refrigerant solution on the suction side of the solution pump, the required NPSH (Net Posi
It is possible to directly evaluate the margin for the tive suction head, and to control the rotation speed of the solution pump and the opening of the expansion valve to satisfy this condition.

According to a sixth aspect of the present invention, there is provided an absorption heat pump comprising a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, a primary side of an evaporator, an absorber, A solution sensor for connecting a solution pump and a solution heat exchanger with a pipe, and detecting a drive current of a motor for driving the solution pump; and a variation range of a current value detected by the current sensor is a predetermined value. When larger, reduce the rotation speed of the solution pump or increase the opening of the expansion valve,
The control means for controlling the fluctuation width of the drive current of the motor for driving the solution pump to be within a predetermined value is provided, and the drive torque of the pump is changed by gas pumping or cavitation. It is detected by the fluctuation range of the current value of the drive current of the motor for driving the pump. By doing so, it is possible to improve the suction condition of the refrigerant solution on the suction side of the solution pump and control the fluctuation range of the drive current of the motor that drives the solution pump to be within a predetermined value.

According to a seventh aspect of the present invention, there is provided an absorption heat pump comprising a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, a primary side of an evaporator, an absorber, And a solution pump and a solution heat exchanger connected to a pipe, and a vibration sensor for detecting the vibration of the solution pump, and when the vibration of the solution pump detected by the vibration sensor is larger than a predetermined value, Reduce the speed of the solution pump or
Alternatively, control means for increasing the opening degree of the expansion valve and controlling the vibration of the solution pump to be within a predetermined value is provided, and the solution pump is operated abnormally due to gas seepage or cavitation. Vibration is detected by a vibration sensor attached to the solution pump, and when the amplitude of the vibration of the solution pump exceeds a predetermined vibration width, by reducing the rotation speed of the solution pump or increasing the opening of the expansion valve. It is possible to improve the suction condition of the refrigerant solution on the suction side of the solution pump and control the solution pump to a stable operation state in which abnormal vibration does not occur.

An absorption heat pump according to claim 8 of the present invention comprises a regenerator, a rectifier, a primary side of a condenser, a subcooler, an expansion valve, a primary side of an evaporator, an absorber, A third temperature sensor that connects the solution pump and the solution heat exchanger with a pipe, and detects a temperature of a discharge side of the solution pump;
When the temperature fluctuation range detected by the third temperature sensor is larger than a predetermined value, the rotation speed of the solution pump is reduced, or the opening of the expansion valve is increased, and the temperature of the third temperature sensor is increased. Fifth control means for controlling the detected temperature fluctuation range on the discharge side to be within a predetermined value is provided, and the solution pump fluctuates the instantaneous flow rate of the pump due to gas or cavitation. The temperature fluctuation of the refrigerant solution on the discharge side of the solution pump caused by mixing the gas component into the refrigerant solution is detected, and the rotation speed of the solution pump is reduced, or the opening of the expansion valve is increased to suck the solution pump. It is possible to improve the suction condition of the refrigerant solution on the side and to avoid the operation of the gas pumping or cavitation of the solution pump.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same parts as those in the prior art will be denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described.

(First Embodiment) FIG. 1 is a system configuration diagram of a first embodiment, and FIG. 2 is a system control diagram relating to a solution pump of the first embodiment.

In the figure, 4 is a pump receiver,
A liquid level detecting means 5 for detecting the liquid level of the pump receiver 4 is attached to a side surface of the pump receiver 4. As the liquid level detecting means 5, a float having a built-in magnetic substance is provided in the pump receiver 4, and the position of the float is detected from outside the pump receiver 4 by a plurality of provided magnetoresistive elements. it can. In order to stably control the fluctuation of the liquid level, it is desirable that the liquid level detecting means 5 can detect the liquid level to some extent continuously. The pump receiver 4 is installed above the solution pump 6, and is configured such that a static pressure of only a difference in height acts on the suction side of the solution pump 6.

The liquid level detecting means 5 of the pump receiver 4
Is connected to a control means 28A, the solution pump 6 is connected to a motor driver 29, and the motor driver 29 is controlled by the control means 28A. Expansion valve 17
The temperature sensor 30 provided at the outlet of the control unit 28A
And the expansion valve 17 is controlled by the control means 28A.

The operation of the above configuration will be described. The aqueous ammonia solution heated in the regenerator 8 is separated in the rectifier 9 into a nearly pure ammonia gas and a dilute solution containing low-concentration ammonia. The ammonia gas, which has been rectified almost purely, is cooled by the condenser 15 to be a liquid, further supercooled by the supercooler 16, adiabatically expanded by the expansion valve 17, becomes low-temperature wet steam, and becomes a low-temperature wet vapor. Heat exchange at 18 and absorber 1
4 The ammonia gas that has been subjected to the cooling operation is absorbed by the absorber 14 into the dilute solution containing low-concentration ammonia separated by the rectifier 9. The dilute solution of the aqueous ammonia solution that has absorbed the ammonia gas in the absorber 14 becomes a concentrated solution containing high-concentration ammonia, and reaches the suction side of the solution pump 6 via the pump receiver 4.

The cycle on the ammonia refrigerant side is constituted by this series of cycles. Regarding the opening degree of the expansion valve 17, the second temperature sensor 3 provided at the outlet of the expansion valve 17
The control means 28A controls so that 0 becomes a predetermined temperature. Since the regenerator 8 is a once-through boiler, it is necessary to sufficiently match the amount of solution circulated with the amount of combustion, and the amount of combustion is controlled so that the temperature of ammonia gas at the outlet of the regenerator 8 does not exceed a predetermined temperature. And the pump speed is controlled.

The indoor unit 2 and the radiator 19 of the present embodiment exchange heat with cold and hot water into which antifreeze is injected.
In the case of the cooling operation, the indoor unit 2 and the evaporating heat exchanger 25 containing the evaporator 18 are connected, and the radiator 19 and the condenser 1 are connected.
5 so as to be connected to the laminated heat exchanger 22 containing
The four-way valve 21 and the four-way valve 24 are switched. In the case of the heating operation, the indoor unit 2 and the laminated heat exchanger 22 containing the condenser 15 are connected, and the radiator 19 and the evaporator 1 are connected.
8 so as to be connected to the evaporative heat exchanger 25 containing
The four-way valve 21 and the four-way valve 24 are switched.

The pump receiver 4 is for stably supplying an aqueous ammonia solution to the suction side of the solution pump 6, and the capacity of the pump receiver 4 is large in order to stabilize the operation of the solution pump 6 alone. The better. But,
Even if the capacity of the pump receiver 4 is simply increased, if the pump circulation amount and the required circulation amount of the system do not match, local over-filling or under-filling of the refrigerant may occur, thereby stabilizing the final system operation. Can not. The liquid level of the pump receiver 4 is a position where the amount of the ammonia aqueous solution returning to the solution pump 6 and the amount of the solution sent out of the solution pump 6 are balanced. It means that the ammonia aqueous solution is being sent too much, and conversely, that the liquid level is rising means that the flow rate of the solution pump is insufficient.

Since the fluctuation of the liquid level actually includes a transient fluctuation, it is necessary that the balance point of the liquid level of the pump receiver 4 has a certain width. 5, the level of the aqueous ammonia solution is detected, a signal of the level is input to the control means 28A, and the number of revolutions of the solution pump 6 is determined by the control means so that the level of the solution is constant at a certain width. By controlling the rotation speed of the solution pump 6 by the driver 29, the system system can be stably controlled.

(Embodiment 2) FIG. 3 is a system configuration diagram of Embodiment 2. The second embodiment differs from the first embodiment in that a supercooling unit A32 is provided on the suction side of the solution pump 6. The supercooling section A32 is an annular heat exchanger in which a pipe 33 connecting the pump receiver 4 and the solution pump 6 is covered with an outer cylinder 34, and radiates heat to an annular flow path formed by the pipe 33 and the outer cylinder 34. By flowing the antifreeze cooled by the vessel 19, the ammonia aqueous solution flowing through the pipe 33 is cooled.
In order to operate the solution pump 6 stably, it is necessary to obtain a required degree of supercooling (2 to 3 deg). In the second embodiment, a supercooling section A32 is provided on the suction side of the solution pump 6, This is for forcibly cooling the suction side of the pump 6. The required degree of supercooling is stably obtained. Piping 3
Since the circulation amount of the aqueous ammonia solution flowing through the pipe 3 is almost one digit lower than the circulation amount of the antifreeze flowing through the radiator 19, the heat transfer coefficient of the aqueous ammonia solution inside the pipe 33 becomes dominant.

Therefore, in order to increase the heat transfer coefficient inside the pipe 33, the diameter of the pipe 33 is reduced, or
It is desirable to insert a heat transfer enhancer such as a spiral wire into the inside. As described above, in the second embodiment, by forcibly cooling the aqueous ammonia solution on the suction side of the solution pump 6, the degree of supercooling of the aqueous ammonia solution is reliably obtained.
The operation of the solution pump 6 can be stabilized.

(Embodiment 3) FIG. 4 is a system configuration diagram of Embodiment 3. The third embodiment differs from the second embodiment in that a supercooling section B33 is provided integrally with a laminated heat exchanger 25A containing an evaporator 18 and connected to the suction side of a solution pump 6. The supercooling section B33 provided integrally with the laminated heat exchanger 25A on the suction side of the solution pump 6 forcibly cools the aqueous ammonia solution on the suction side of the solution pump 6 to stably maintain the required degree of subcooling. Can be taken. Further, since the laminated heat exchanger 25A having the built-in evaporator 18 can easily take a low temperature and has high heat transfer efficiency, the supercooling section B33
Can be configured very compactly.

(Embodiment 4) FIG. 5 is a system configuration diagram of Embodiment 4 of the present invention. The fourth embodiment differs from the first embodiment in that a subcooling flow path 36 is provided at the bottom of the pump receiver 4 on the suction side of the solution pump 6, and the antifreeze liquid cooled by the radiator 19 flows through this flow path 36. On the point. When the solution pump 6 is in a gas-filled operating state, the pump receiver 4
Unsaturated ammonia gas bubbles are also generated in the inside, and it is a problem how to efficiently eliminate the bubbles. However, by cooling the bottom of the pump receiver 4, the bubbles to be absorbed by the solution pump 6 are reduced. Can be efficiently absorbed into the ammonia aqueous solution, and the gas pumping operation of the solution pump 6 can be prevented. According to the fourth embodiment, since the heat exchange between the ammonia gas and the aqueous ammonia solution is performed in the pump receiver 4 having a large volume, the ammonia gas can be efficiently absorbed by supercooling the aqueous ammonia solution. .

(Embodiment 5) Next, Embodiment 5 of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. FIG. 6 is a system configuration diagram of the fifth embodiment, FIG. 7 is a system control diagram of the fifth embodiment, and FIG. 8 is a determination diagram of a two-phase state of the ammonia aqueous solution of the fifth embodiment. The fifth embodiment is different from the first embodiment in that the temperature sensor 31 is provided on the suction side of the solution pump 6 except for the liquid level detecting means 5 for detecting the liquid level of the pump receiver 4.
The second control means 28B for maintaining the degree of supercooling of the aqueous ammonia solution on the suction side at a required value is provided.

In this embodiment, the temperature sensor 31 provided on the suction side of the solution pump 6 is connected to the second control means 28B, and the second control means 28B controls the rotation speed of the solution pump 6 via the motor driver 29. Control. Aqueous ammonia solution of a predetermined concentration returns to the suction side of the solution pump 6, but the suction side of the solution pump 6 is at a low pressure side and is in a state close to saturation. If the temperature of the aqueous ammonia solution becomes too high, cavitation or In a two-phase state. The determination of the two-phase state of the aqueous ammonia solution is represented by a function of pressure, concentration and temperature as shown in FIG. Since the concentration of the aqueous ammonia solution can be estimated in advance from the operating conditions of the system, the state of the solution on the suction side of the solution pump 6 can be determined by knowing the pressure and temperature on the suction side of the solution pump 6.

With respect to the pressure on the suction side of the solution pump 6,
The temperature of the temperature sensor 30 on the outlet side of the expansion valve 17 is the saturation temperature of the ammonia refrigerant on the low pressure side (the suction side of the solution pump 6), and the pressure on the suction side of the solution pump 6 can be estimated at this saturation temperature. . For example, the concentration of the aqueous ammonia solution on the suction side of the solution pump 6 is 40%, and the pressure is 3 kg / cm ^2.
In this case, the solution temperature at which equilibrium is reached is about 48 ° C. Since the degree of supercooling needs to be 2 to 3 deg for stable operation of the pump, the temperature of the aqueous ammonia solution on the suction side of the solution pump 6 needs to be suppressed to 45 ° C to 46 ° C.
Therefore, the state of the aqueous ammonia solution on the suction side of the solution pump 6 can be known from the above concentration, pressure and temperature states.

If it is determined from the concentration, pressure, and temperature states that the two-phase state is established, two controls are performed to maintain the degree of supercooling of the aqueous ammonia solution on the suction side of the solution pump 6 constant. There is a means, one is to decrease the rotation speed of the solution pump 6 and increase the pressure on the low pressure side, and the other is to open the expansion valve 17 and increase the pressure on the low pressure side. is there. Balancing the entire system so that the degree of supercooling of the aqueous ammonia solution on the suction side of the solution pump 6 is kept constant also makes it necessary to balance the required circulation amount of the system system with the transport amount of the aqueous ammonia solution by the solution pump 6. Become.
The operating efficiency COP of the absorption heat pump is such that the degree of supercooling of the ammonia aqueous solution on the suction side of the solution pump 6 is infinitely zero.
Since the temperature increases as the temperature approaches deg, in order to improve the system efficiency, it is necessary to stably control the supercooling degree of 2 to 3 deg which is a stable operation condition of the solution pump 6.

In the fifth embodiment, the degree of supercooling of the aqueous ammonia solution on the suction side of the solution pump 6 necessary for the stable operation of the system is estimated based on temperature conditions and the like. By stable control,
The operating conditions of the solution pump 6 can be stabilized, and the system efficiency can be improved.

(Sixth Embodiment) FIG. 9 is a system control diagram of the sixth embodiment. The sixth embodiment differs from the first embodiment in that the liquid level detecting means 5 for detecting the liquid level of the pump receiver 4 is excluded, and the fluctuation of the torque of the solution pump 6 that occurs when the solution pump 6 is operated by gas is detected. When a torque fluctuation due to gas leakage operation is detected,
The point is that a control means 28C for reducing the number of rotations of the solution pump 6 is provided.

The means 29A for detecting the torque fluctuation of the solution pump 6 is constituted by a current sensor provided on the output line of the motor driver 29 for driving the motor 6A for driving the solution pump 6, and The output is determined by the control means 28C, and when the fluctuation range of the current value is larger than a predetermined value, the solution pump 6 determines that the gas pumping operation is performed, and lowers the output of the motor driver 29 to reduce the output of the solution pump 6 Is controlled by the control means 28C so as to decrease the rotation speed. Since the solution pump 6 is a positive displacement pump, when gas is seen or cavitation occurs, a large torque fluctuation occurs.
It is possible to clearly determine that the gas pumping operation is performed, and it is possible to reliably prevent the gas pumping operation of the solution pump 6.

(Embodiment 7) FIG. 10 is a system control diagram of Embodiment 7. The seventh embodiment differs from the first embodiment in that, except for the liquid level detecting means 5 for detecting the liquid level of the pump receiver 4, the vibration of the solution pump 6 that occurs when the solution pump 6 performs the gas bleeding operation is detected. Control means 28D for reducing the number of revolutions of the solution pump 6 when the vibration of the pump caused by the gas leakage operation is detected.

Means 3 for detecting abnormal vibration of solution pump 6
Reference numeral 7 denotes a vibration sensor using a piezoelectric element. The output of the vibration sensor is determined by the control means 28D. When it is determined that there is, the control means 28D controls the output of the motor driver 29 so as to lower the rotation speed of the solution pump 6.

(Eighth Embodiment) FIG. 11 is a system control diagram of the eighth embodiment. The difference of the eighth embodiment from the first embodiment is that, except for the liquid level detecting means 5 for detecting the liquid level of the pump receiver 4, the discharge side of the solution pump 6 which is generated when the solution pump 6 performs the gas running operation. A means 38 for detecting the temperature fluctuation of the aqueous ammonia solution is provided, and when the temperature fluctuation on the discharge side of the pump due to the gas leakage operation is detected, the solution pump 6
The fifth control means 28E for reducing the number of rotations is provided.

The means 38 for detecting the temperature fluctuation of the aqueous ammonia solution on the discharge side of the solution pump 6 comprises a temperature sensor provided on the discharge side of the solution pump 6, and the fluctuation of the output of this temperature sensor is controlled by the control means 28E. When it is determined that the fluctuation of the output of the temperature sensor is larger than the predetermined value, the solution pump 6 determines that the gas pumping operation is performed, and lowers the output of the motor driver 29 to lower the rotation speed of the solution pump 6. As described above, the control is performed by the control unit 28E.
This temperature fluctuation occurs not only when the gas runs out but also when the operation of the system becomes unstable. By controlling the expansion valve 17 to stabilize the temperature fluctuation, the system operation is stabilized. Can be achieved.

[0042]

As described above, according to the absorption heat pump of the present invention, the following effects can be obtained.

(1) The liquid level of the pump receiver is detected by the liquid level detecting means provided on the pump receiver above the solution pump on the suction side of the solution pump, and the solution level is kept constant. By controlling the rotation speed of the pump, the circulating flow rate of the refrigerant solution sent from the solution pump to the system system and the circulating flow rate of the refrigerant solution returning from the system system to the pump are balanced, and the continuous flow condition is satisfied. Since the refrigerant solution can be supplied while a constant positive pressure is constantly applied to the pump, the amount of circulation of the solution pump is stabilized, which is effective for the stable operation of the system.

(2) A supercooler is provided on the suction side of the solution pump to forcibly cool the suction side of the solution pump, thereby always maintaining the required degree of supercooling of the aqueous ammonia solution on the suction side of the solution pump. And the solution pump can be operated stably.

(3) A subcooling flow path is provided at the bottom of the pump receiver on the suction side of the solution pump, and an antifreeze liquid cooled by a radiator is caused to flow through this flow path, so that the refrigerant almost saturated in the pump receiver. The non-equilibrium gas component due to bubbling generated by the inflow of the solution and the refrigerant solution are effectively cooled while being separated from each other, and only the supercooled refrigerant solution is supplied to the solution pump. Can be prevented.

(4) The degree of supercooling of the refrigerant solution on the suction side of the solution pump is estimated from the refrigerant evaporation temperature on the outlet side of the expansion valve, and the pressure on the suction side of the solution pump and the refrigerant solution on the suction side of the solution pump. The supercooling degree is directly estimated and controlled because it is estimated based on the temperature and controlled so that the required supercooling degree is obtained, so that the supercooling degree can be accurately controlled. Therefore, the degree of supercooling can be controlled to a minimum, which is effective in increasing the system efficiency together with the stable operation of the solution pump.

(5) Means for detecting the torque fluctuation of the solution pump are provided, and when the torque fluctuation due to the gas bleeding operation is detected, control is performed to reduce the number of revolutions of the solution pump to thereby improve the reliability of the solution pump. Can be enhanced.

(6) A means for detecting the vibration of the solution pump is provided, and when the vibration caused by the gas leakage operation is detected, control is performed to reduce the rotation speed of the solution pump.
The reliability of the solution pump can be improved.

(7) By providing a means for detecting the temperature fluctuation of the aqueous ammonia solution on the discharge side of the solution pump, the gas pump operation of the solution pump can be detected, and the instability of the system operation can be detected. System operation can be stabilized.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an absorption heat pump according to a first embodiment of the present invention.

FIG. 2 is a system control diagram of the first embodiment.

FIG. 3 is a system configuration diagram of an absorption heat pump in Embodiment 2 of the present invention.

FIG. 4 is a system configuration diagram of an absorption heat pump according to a third embodiment of the present invention.

FIG. 5 is a system configuration diagram of an absorption heat pump according to a fourth embodiment of the present invention.

FIG. 6 is a system configuration diagram of an absorption heat pump according to a fifth embodiment of the present invention.

FIG. 7 is a system control diagram of the absorption heat pump in the fifth embodiment.

FIG. 8 is a diagram showing a two-phase determination of an aqueous ammonia solution in Example 5;

FIG. 9 is a system control diagram of an absorption heat pump in Embodiment 6 of the present invention.

FIG. 10 is a system control diagram of an absorption heat pump according to a seventh embodiment of the present invention.

FIG. 11 is a system control diagram of an absorption heat pump in Embodiment 8 of the present invention.

FIG. 12 is a system configuration diagram showing a conventional absorption heat pump.

[Explanation of symbols]

Reference Signs List 4 pump receiver 5 liquid level detecting means 6 solution pump 7 solution heat exchanger 8 regenerator 9 rectifier 14 absorber 15 condenser 16 supercooler 17 expansion valve 18 evaporator 28, 28A, 28B, 28C, 28D, 28E Control means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F25B 15/00 306

Claims (8)

(57) [Claims] 1. A regenerator, a rectifier, a primary side of a condenser,
A subcooler, an expansion valve, a primary side of an evaporator, an absorber,
A solution pump and a solution heat exchanger are connected by piping, and a pump receiver and a liquid level detecting means for detecting a liquid level of the pump receiver are provided above the solution pump on the suction side of the solution pump, An absorption heat pump provided with control means for controlling the pump revolutions to keep the liquid level of the pump receiver constant. 2. The absorption type heat pump according to claim 1, wherein a supercooling section A is provided on a suction side of the solution pump in a pipe connecting the solution pump and the pump receiver. 3. The absorption heat pump according to claim 1, wherein the evaporator is provided with a supercooling section B connected to the suction side of the solution pump. 4. A regenerator, a rectifier, a primary side of a condenser,
A subcooler, an expansion valve, a primary side of an evaporator, an absorber,
A solution pump and a solution heat exchanger are connected by piping, and a flow path is provided at the bottom of the pump receiver on the suction side of the solution pump,
An absorption heat pump configured to pass cooling water that exchanges heat with the condenser through this flow path. 5. A regenerator, a rectifier, a primary side of a condenser,
A subcooler, an expansion valve, a primary side of an evaporator, an absorber,
A solution pump having a first temperature sensor provided on a suction side of the solution pump and a second temperature sensor provided on an outlet side of an expansion valve; The degree of supercooling of the refrigerant solution on the suction side of the expansion pump, the pressure on the suction side of the solution pump estimated by the temperature of the expansion valve outlet detected by the first temperature sensor provided on the expansion valve outlet side, The temperature of the refrigerant solution on the suction side of the solution pump detected by a first temperature sensor provided on the suction side of the solution pump is estimated, and the rotation speed of the solution pump or the opening degree of the expansion valve is determined by the solution An absorption heat pump having control means for controlling the degree of supercooling of the refrigerant solution on the suction side of the pump to a predetermined value. 6. A regenerator, a rectifier, a primary side of a condenser,
A subcooler, an expansion valve, a primary side of an evaporator, an absorber,
A solution pump connected to the solution heat exchanger via a pipe, and a current sensor for detecting a drive current of a motor for driving the solution pump; and a fluctuation range of a current value detected by the current sensor is larger than a predetermined value. At this time, control means for reducing the rotation speed of the solution pump or increasing the opening of the expansion valve to control the fluctuation range of the drive current of the motor for driving the solution pump to be within a predetermined value. Absorption heat pump equipped. 7. A regenerator, a rectifier, a primary side of a condenser,
A subcooler, an expansion valve, a primary side of an evaporator, an absorber,
A solution pump, a solution heat exchanger, which is connected to a pipe, and a vibration sensor for detecting vibration of the solution pump, and when the vibration of the solution pump detected by the vibration sensor is larger than a predetermined value, the solution pump An absorption heat pump comprising a control means for controlling the vibration of the solution pump to be within a predetermined value by reducing the number of revolutions or increasing the degree of opening of the expansion valve. 8. A regenerator, a rectifier, a primary side of a condenser,
A subcooler, an expansion valve, a primary side of an evaporator, an absorber,
A third temperature sensor that connects the solution pump and the solution heat exchanger with a pipe, and detects a temperature on the discharge side of the solution pump; and a temperature fluctuation width detected by the third temperature sensor is a predetermined value. When it is larger, the rotation speed of the solution pump is reduced or the opening of the expansion valve is increased so that the temperature fluctuation range on the discharge side detected by the third temperature sensor is within a predetermined value. An absorption heat pump including a fifth control unit for controlling.