JPH11257782A - Absorption cold heat generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an absorption cold heat generator employing a variable phase fluid as a secondary cold heat carrier in which stabilized cooling output control can be ensured at the time of cooling the secondary cold heat carrier by controlling a solution bypass valve for introducing a concentrated absorbing solution to the bottom of an absorber depending on the evaporator temperature. SOLUTION: The absorption cold heat generator 1 comprises a regenerator 3 for heating a dilute absorbing solution with exhaust hot water from a heat carrier pump 28, a condenser 11 for cooling and condensing refrigerant vapor generated therefrom, an evaporator 13 for cooling the refrigerant vapor in an evaporation coil by evaporating the liquid refrigerant, and an absorber 16 for absorbing the refrigerant vapor through a concentrated solution. A solution bypass valve 33 is provided in a pipeline 51 connecting the lower part of the absorber 16 with a concentrated solution rising pipe 42 which connects the heating fluid side of a solution heat exchanger 20 with the upper part of the absorber 16. Efficient cooling operation following up the fluctuation of cooling load is realized by controlling the bypass valve 33 depending on the evaporator temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption-type chiller using an absorption refrigeration cycle, and more particularly to an absorption-type chiller using a phase-change (latent heat) fluid as a secondary cooling medium. It is.

[0002]

2. Description of the Related Art FIG. 5 is a system diagram showing an example of a hot water-fired absorption type chiller / heater according to the prior art. This hot-water-fired absorption chiller / heater 2a uses a heat medium such as waste water as a heat source heat source of the regenerator 3, and is usually used for a single effect, and has a refrigeration capacity coefficient of performance (COP). , COP
= (Refrigeration capacity) / (actual input (heat input)))
It is about 7.

In this hot water-fired absorption type chiller / heater 2a,
When performing the cooling operation, the cold / hot water pump 26, the cooling water pump 27, the heat medium pump 28, and the solution circulation pump 25 are operated. The two-way valves 32, 32 at the heat medium inlet / outlet are opened manually or automatically, and the waste water 73a having a rated flow rate of 100% is supplied. The temperature of the heat medium inlet 74 is determined within the range of 70 to 90 ° C., although there is a difference depending on each device. The temperature of the heat medium inlet 74 under rated conditions, for example, 88 ° C., is set. The temperature difference from 75 is Δt = 5 ° C. In hot water firing, the input (heat input) = heat medium inlet / outlet temperature difference Δt × heat medium circulation amount × specific heat × specific weight.

In the regenerator 3, waste water 73a is supplied, and the absorbing solution is heated by a heating source and discharged as waste water 73b. The dilute solution sent to the regenerator 3 boils on the surface of the regenerator coil and separates into a refrigerant vapor and a concentrated solution. The refrigerant vapor is guided to the upper condenser 11 and condensed on the coil surface by the cooling water in the condenser coil to become a water refrigerant, which is sent to the refrigerant storage chamber 9 having a solution concentration adjusting function. The water refrigerant is a water refrigerant pipe 4
0 to the water refrigerant distributor 14. The water refrigerant is dropped on the surface of the evaporator coil of the evaporator 13 and is scattered to evaporate to form refrigerant vapor. At this time, the cold water 7 circulating in the evaporation coil
9a (cold / hot water) is deprived of heat of vaporization (latent heat) and its temperature drops to become cold water 79b.

Further, the concentrated solution separated in the regenerator 3 is guided to the absorber 16 via the concentrated solution down pipe 41, the solution heat exchanger 20, and the concentrated solution up pipe 42, and the refrigerant vapor evaporated in the evaporator 13 And heat exchange with the cooling water 83a to become a dilute solution,
The solution circulation pump 25 sends the solution to the regenerator 3 via the diluted solution downcomer 43, the solution heat exchanger 20, and the diluted solution ascending tube 44, and repeats the same cooling cycle.

[0006] The output control during the cooling operation is performed by a chilled water temperature sensor ("W
T sensor 61). Operation is started and stopped by a WT sensor 61 and an evaporator temperature sensor (also referred to as an “LT sensor”) 60 for detecting the temperature of the evaporator 13 as a protection function for preventing freezing damage of the water refrigerant and cold water and crystallization trouble of the solution. Controlling. In particular, when the evaporator temperature decreases, the evaporator temperature sensor 60 operates the antifreeze valve 34 to open, so that the solution flows into the water refrigerant distributor 14 through the dilute solution branch pipe 45 to prevent freezing. Aim.

[0007] In general, an absorption type chiller / heater utilizing waste heat mainly performs a cooling operation, and is rarely used in a heating operation. This is because many heaters directly control the temperature of hot water via a heat exchanger and send it to an indoor unit in terms of initial cost. However, depending on how the system is assembled, it may be cheaper to have a heating function in the hot water-fired absorption chiller / heater.

[0008] Since the hot water-fired absorption type chiller / heater 2a can also perform a heating operation, the heating action will be described. The hot-water-fired absorption-type hot / cold water heater 2a includes a concentrated solution branch pipe 47, a cooling / heating switching valve 35, a solution bypass valve 33, and a baffle plate 17
During the heating operation, the cooling water pump 27 is turned off (in the meaning of off and fully closed, the same applies hereinafter), and the cooling / heating switching valve 35 is turned on.
(The meaning of ON, fully open, the same applies hereinafter), and the solution heated by the regenerator 3 is directly led to the bottom of the absorber 16. The baffle plate 17 has a gas-liquid separation function and prevents a high-temperature solution from scattering to the absorber coil. Absorber 16 and evaporator 13
The surrounding heated steam exchanges heat with cold and hot water circulating in the evaporating coil to become hot water. Also, during the heating operation, the concentrated solution riser pipe 42
The solution bypass valve 33 is opened to escape to the bottom of the absorber 16 so that the hot solution does not flow into the absorber 16.

FIG. 6 is a diagram for explaining the control of the hot water absorption type chiller / heater shown in FIG. 5, (A) is a diagram showing the relationship between the evaporator temperature and the start and stop of each pump, (B) () Is a diagram showing the relationship between the chilled water outlet temperature and the start and stop of each pump.

As described above, the hot water-fired absorption chiller / heater 2a has the evaporator temperature sensor 60 as temperature detecting means for detecting the evaporator temperature (also referred to as "LT"). As shown in FIG. 6A, when the evaporator temperature is lower than 5 ° C., the evaporator temperature sensor 60 turns on the antifreeze valve 34, turns off the solution circulation pump 25, and turns off the solution circulation pump 25 (delay stop, the same applies hereinafter). Turn off the heat medium pump 28 and the cooling water pump 27
f. On the other hand, when the evaporator temperature rises from a temperature lower than 5 ° C. to 5 ° C., the temperature is switched, and the anti-freezing valve 34 is turned off, the solution circulation pump 25, and the heat medium pump 2
8 and the cooling water pump 27 are each On. On the other hand, when the evaporator temperature drops from a temperature exceeding 2 ° C. to 2 ° C., the antifreeze valve 34 is turned off, the solution circulation pump 25 and the heat medium pump 2 are turned off.
8 and the cooling water pump 27 are turned on, respectively, and switched at 2 ° C., the antifreeze valve 34 is turned on, the solution circulation pump 25 is turned off, the heat medium pump 28 and the cooling water pump 27 are turned off.
f, and the above cycle is repeated.

The hot-water-fired absorption-type chiller / heater 2a has a chilled-water temperature sensor 61 as a temperature detecting means.
As shown in FIG. 5, when the chilled water outlet temperature is lower than 10 ° C., the solution bypass valve 33 is turned on, the solution circulation pump 25 is turned off, the heat medium pump 28 and the cooling water pump 27 are turned on.
ff. On the other hand, when the chilled water outlet temperature rises from a temperature lower than 10 ° C. to 10 ° C., it is switched, and the solution bypass 33
Is Off, and the solution circulation pump 25, the heat medium pump 28, and the cooling water pump 27 are On. On the other hand, the temperature is lowered from a temperature exceeding 6 ° C., and the solution bypass 33 is turned off, the solution circulation pump 25, the heating medium pump 28 and the cooling water pump 27
Is switched on at 6 ° C., the solution bypass valve 33 is turned on, the solution circulation pump 25 is turned off, and the heat medium pump 2 is turned on.
8 and the cooling water pump 27 are turned off, and the above cycle is repeated.

FIG. 7 is a system diagram showing an example of an air conditioner having an absorption type cold heat generator according to the prior art. As shown in this figure, in recent years, an air conditioner including an absorption-type cold heat generator 2b that increases a heat transfer amount per unit flow rate by using a fluid that changes phase as a secondary-side cooling medium has been proposed. (For example, JP-A-9-26223).

The air conditioner is arranged in a space to be air-conditioned by being connected to an absorption-type cold heat generator 2b surrounded by a frame and connected to the absorption-type cold heat generator 2b by a refrigerant liquid pipe 54 and a refrigerant vapor pipe 55. Air-conditioning indoor unit that performs heat exchange with air
For example, the indoor units 90a to 90d, the refrigerant pump 102 for returning the liquid of the secondary-side cooling medium to the absorption-type cold-heat generator 2b, the controller 98 and the system for controlling the absorption-type cold-heat generator 2b, the indoor units 90a to 90d, and the like And a controller 100. In this example, the controller 98
Is provided in the absorption-type cold heat generator 2b. The absorption-type cold heat generator 2b is connected to the cooling water pipes 48 and 49 to cool the cooling water, and the cooling water pipe 49 interposed between the cooling tower 69 and the cooling water from the cooling tower 69 to the absorber 16 and the condenser 11. And a cooling water pump 27 that circulates the water.

Further, an absorption-type cold heat generator 2b, usually called an outdoor unit, comprises a high-temperature regenerator 4 for burning fuel and heating a dilute solution with the heat, and a refrigerant vapor from the dilute solution heated by the high-temperature regenerator 4. A low-temperature regenerator 5 for heating the intermediate-concentrated solution using the separated refrigerant vapor as a heat source to further generate a refrigerant vapor, and a refrigerant vapor passing through the low-temperature regenerator 5 And a condenser 11 for cooling and condensing and liquefying the refrigerant vapor generated in the low-temperature regenerator 5 to generate a liquid refrigerant, and a water refrigerant distributor 14 in which the liquid refrigerant generated in the condenser 11 is mounted. Drop on the evaporation coil, evaporate and make the secondary refrigerant in the evaporation coil (for example,
Evaporator 13 for cooling the HFC 134);
An absorber 16 that absorbs the refrigerant vapor evaporated in the concentrated solution into a diluted solution, and a low-temperature solution heat exchanger 22 that pressurizes the diluted solution,
A solution circulating pump 25 which feeds the high-temperature solution heat exchanger 21 to the high-temperature regenerator 4 via the fluid to be heated, and an intermediate concentrated solution separated by the separator 7 during the heating operation at the bottom of the evaporator 13 and the absorber 16 And a cooling / heating switching valve 35 that leads to

The operation of the air conditioner shown in FIG. 7 is as follows. That is, during cooling, the cooling / heating switching valve 104 is open. The refrigerant vapor (HFC 134) is cooled and condensed by the evaporating coil of the evaporator 13 to become a refrigerant liquid, flows downward through the refrigerant liquid pipe 54 by gravity, and exchanges heat with the indoor units 90a to 90d via expansion valves 94a to 94d. Flows into the vessel. The refrigerant liquid that has flowed into the heat exchanger evaporates by removing the heat of the air in the air-conditioned space, becomes refrigerant vapor, rises through the refrigerant vapor pipe 55, and flows into the evaporation coil of the evaporator 13. Since the absorption-type cold heat generator (outdoor unit) 2b is operated in the cooling mode,
The evaporation coil of the evaporator 13 is cooled by evaporation of the water refrigerant dropped on the surface thereof, and condenses and liquefies the refrigerant vapor flowing into the evaporation coil. Due to this condensation and liquefaction, the pressure inside the evaporation coil decreases, and the refrigerant vapor evaporated in the heat exchangers of the indoor units 90a to 90d is sucked into the evaporator 13. Since the refrigerant liquid condensed and liquefied inside the evaporation coil flows into the indoor unit by gravity, the secondary-side refrigerant naturally circulates during cooling, and there is no need to drive the refrigerant by a pump.

When the cooling operation is started, as described above, the pressure inside the evaporator coil decreases, and the saturated refrigerant vapor in the refrigerant vapor pipe 55 flows into the evaporator coil due to the pressure difference. The refrigerant liquid generated by condensing in the evaporation coil flows down in the refrigerant liquid pipe 54 by its own weight, and the head (liquid column) of the refrigerant liquid rises. In order to achieve the natural circulation of the refrigerant, the difference between the refrigerant liquid head and the refrigerant vapor head only needs to be equal to or greater than the total pressure loss of the secondary refrigerant circulation circuit. That is, the natural circulation of the refrigerant is not started until a liquid head satisfying the following equation is formed. This means that the heat load supplied to the evaporator 13 at the start of the cooling operation is small.

[0017]

(Equation 1)

The main purpose of the solution bypass valve 33 is to open and bypass the heating operation in order to prevent the high-temperature solution from flowing into the absorber coil during the heating operation. During the cooling operation, the secondary side refrigerant is closed except for OFF.

[0019]

However, the control by the evaporator temperature and the outlet temperature of the chilled water performed by the conventional hot water-fired absorption type chiller / heater 2a shown in FIG. When the cooling water inlet temperature is low and when the cooling water inlet temperature is low, the evaporator temperature sensor 60 frequently operates, and as a result, when the operation is applied to the absorption type cold heat generation device 2b of FIG. , Anti-freeze valve 3
4 is on-off, the temperature of each part fluctuates greatly, stable operation is not possible, and a trouble occurs in the natural circulation cycle of the secondary refrigerant, and rapid temperature fluctuation is not preferable in the secondary circulation circuit. .

An object of the present invention is to provide an absorption-type cold heat generator using a phase-changing fluid as a secondary cooling medium, in which cooling output control is stabilized when cooling the secondary cooling medium.
That is, the cooling operation can be performed efficiently.

[0021]

In order to solve the above-mentioned problems, the present invention connects various devices including a regenerator, a condenser, an evaporator, an absorber, a heat exchanger, and a circulation pump, and supplies the equipment to the regenerator. A primary-side circulation circuit for circulating the absorption solution heated by the heat medium to be heated is formed, and a secondary-side cooling / heating medium flowing through a secondary-side circulation circuit including a pipe of an evaporation heat transfer tube of the evaporator is supplied to the evaporator. In an absorption-type cold heat generating apparatus that performs a phase change by cooling or heating by the absorption solution through an evaporation heat transfer tube, when the secondary-side cooling medium is cooled, a concentrated solution of the absorption solution heated and separated by the regenerator is cooled. A solution bypass valve for introducing a gas to the bottom of the absorber, and a temperature for detecting at least one of a cooling water inlet temperature of the absorber, an evaporator temperature of the evaporator, and a secondary cooling medium outlet temperature of the evaporator. Detecting means and the temperature Knowledge means is that has a controller that outputs the solution bypass valve control signals for controlling the flow rate of the solution bypass valve in response to temperature detected.

When cooling the secondary cooling medium, the temperature is detected by temperature detecting means for detecting at least one of a cooling water inlet temperature, an evaporator temperature, and a secondary cooling medium outlet temperature of the evaporator. Upon receiving the temperature signal, the controller outputs a control signal for controlling the flow rate of the solution bypass valve corresponding to the temperature. The solution bypass valve receives the control signal and introduces the absorbing solution to the bottom of the absorber. This prevents the absorption capacity from becoming excessive due to the low-temperature cooling water, thereby preventing the cooling-water inlet temperature from lowering, so that the cooling output control is stabilized and the cooling operation can be performed efficiently.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of an absorption-type cold heat generator according to the present invention will be described in detail with reference to the drawings.
In FIGS. 1 to 4, the same reference numerals are given to the same structures and working parts as in FIGS.

FIG. 1 is a system diagram showing an embodiment of an air conditioner including an absorption type cold heat generator according to the present invention. The air conditioner of the present embodiment includes an absorption-type cold heat generating device 1 surrounded by a frame, and connected to the absorption-type cold heat generation device 1 by a refrigerant liquid pipe 54 and a refrigerant vapor pipe 55 and arranged in a space to be air-conditioned. A plurality of indoor units that exchange heat with the air in this space,
For example, it includes the indoor units 90a to 90d, a refrigerant pump 102 for returning the refrigerant liquid to the absorption-type cold heat generator 1, a controller 98 for controlling the absorption-type cold heat generator 1, the indoor units 90a to 90d, and the like, and a system controller 100. In. Further, the absorption-type cold-heat generator 1 is connected to the absorption-type cold-heat generator 1 by the cooling water pipes 48 and 49 to cool the cooling water, and the cooling tower 69 interposed in the cooling water pipe 49 to cool the cooling water from the cooling tower 69. It has an absorber 16 to be described later and a cooling water pump 27 circulating through the condenser 11. Here, in the case of this embodiment, the controller 98 is provided on the side of the absorption-type cold-heat generator 1, calculates based on the temperature or pressure detected by each temperature or pressure sensor, and sends a control signal to each control valve. Is output. Further, the system controller 100 controls the indoor units 90a to 90d, the refrigerant pump 102, and the like.

Further, the absorption-type cold-heat generating apparatus 1 includes a heat medium pump 28 for sending out a heat medium such as waste heat generated by cogeneration as a heat source, for example, waste water, and an exhaust gas sent from the heat medium pump 28. A regenerator 3 for heating a dilute solution of an absorption solution as a primary-side cooling medium with hot water, a condenser 11 for cooling a refrigerant vapor generated by the regenerator 3 to condense and liquefy to generate a liquid refrigerant; An evaporator 13 for dropping and evaporating the liquid refrigerant generated in step 11 from a refrigerant distributor 14 provided therein on a vaporizing coil also provided therein to cool a refrigerant vapor as a secondary cooling medium in the vaporizing coil; Vessel 1
An absorber 16 that absorbs the refrigerant vapor evaporated in 3 into a concentrated solution to generate a dilute solution; a solution circulation pump 25 (circulation pump) that sucks and pressurizes the dilute solution from the evaporator 13 and the bottom of the absorber 16; It has a solution heat exchanger 20 (heat exchanger) that passes the dilute solution sent from the solution circulation pump 25 to the heated fluid side and exchanges heat with the concentrated solution from the regenerator 3.

Further, the absorption-type cold heat generator 1 includes a regenerator 3
A pipe 50 communicating the bottom of the absorber 16 with the bottom of the absorber 16 via a cooling / heating switching valve 35; a concentrated solution riser 42 connecting the heated fluid outlet side of the solution heat exchanger 20 to the upper part of the absorber 16; A conduit 51 connecting the concentrated solution riser pipe 42 and the lower part of the absorber 16 via a solution bypass valve 33;
A conduit 52 communicating the outlet side of the water refrigerant distributor 14 provided in the evaporator 5 via an antifreeze valve 34, and a condenser 11
And a water refrigerant pipe 46 for guiding the water refrigerant to the water refrigerant distributor 14. Further, the water refrigerant distributor 14 is equipped with an evaporator temperature sensor (LT sensor) 60 for detecting the temperature of the water refrigerant in the water refrigerant distributor 14.

Further, the absorption-type cold-heat generating apparatus 1 is connected to respective devices such as a regenerator 3, a condenser 11, an evaporator 13, an absorber 16, a solution heat exchanger 20, a solution circulation pump 25, and the like by pipes. It has a primary circulation circuit that circulates an absorption solution (primary cooling medium) formed and heated by waste water supplied to the regenerator 3. And the previous indoor units 90a to 90d,
The refrigerant pump 102 and a pipe of an evaporating coil (evaporating heat transfer tube) of the evaporator 13 are connected to each other by a refrigerant liquid pipe 54 and a refrigerant vapor pipe 55 to form a refrigerant (secondary cooling medium) in the evaporator 13. It has a secondary side circulation circuit for cooling or heating with an absorbing solution through a coil to cause a phase change (latent heat). Here, the refrigerant liquid pipe 54 is connected to the outlet side of the evaporator coil of the evaporator 13, and the refrigerant vapor pipe 55 is connected to the inlet side of the evaporator coil of the evaporator 13.

Further, a cooling water coil is provided in each of the absorber 16 and the condenser 11, and an outlet of the cooling water coil of the absorber 16 is connected to an inlet of the cooling water coil of the condenser 11. Cooling water coil inlet is cooling water pipe 4
9, the outlet of the cooling water coil of the condenser 11 is connected to a cooling water pipe 48.
, Respectively. In the vicinity of the inlet of the cooling water coil of the absorber 16, a CT1 sensor 64 (temperature detecting means) for detecting the temperature of the inlet of the cooling water coil was cooled by the cooling tower 69 near the lower part of the cooling tower 69. A CTS sensor 65 for detecting the temperature of the cooling water is mounted.

A refrigerant outlet (liquid) temperature sensor (also referred to as a “CRI sensor”) 62 for detecting the refrigerant (liquid) outlet temperature of the evaporator evaporation coil, and a refrigerant vapor A refrigerant vapor temperature sensor (also referred to as a “CRO sensor”) 63 for detecting the temperature is installed. On the other hand, when performing the cooling operation, the flow rate of the discharged hot water is controlled in accordance with the cooling load (cooling load) of the secondary refrigerant. A three-way valve 31 is provided.

In the absorption-type cooling / heating apparatus 1 having the above-described structure, the cooling / heating switching valve 35 switches between cooling and heating, and is closed during cooling and opened during heating. Antifreeze valve 34
Is a valve that opens when the temperature of the evaporator drops to 1 ° C. and allows the dilute solution to flow into the refrigerant distributor 14 to prevent freezing of the water refrigerant. The solution bypass valve 33 has a flow rate adjusting function. When the evaporator temperature is lowered at the start of cooling and at the time of low-load operation, the concentrated solution is bypassed to a lower portion of the absorber 5 so as to bypass the absorber 5.
Is a control valve for reducing the absorption capacity of the evaporator and preventing the temperature of the evaporator from lowering further. Also, the solution bypass valve 33 is
In order to prevent the high-temperature solution from flowing into the absorber coil during the heating operation, it is opened during the heating operation and functions to bypass.

Further, the absorption-type cold-heat generating apparatus 1 having the above structure calculates the cooling load of the refrigerant based on the temperature detected by the refrigerant outlet temperature sensor 62 when the secondary-side refrigerant is cooled. A controller 98 for outputting a control signal.

On the other hand, a refrigerant outlet (liquid) temperature sensor (CR)
The I sensor 62 and the refrigerant vapor temperature sensor (CRO sensor) 63 can also transmit a control signal by detecting pressure instead of temperature.

Next, the heating operation will be described. During the heating operation, the cooling / heating switching valve 104 is closed. Refrigerant liquid (HF
C134) is heated by the evaporating coil of the evaporator 13 to become refrigerant vapor, flows down the refrigerant vapor pipe 55, and flows into the heat exchangers of the indoor units 90a to 90d. The refrigerant vapor that has flowed into the heat exchanger is deprived of heat by the air in the air-conditioned space, condensed and liquefied, becomes a refrigerant liquid, flows down the refrigerant liquid pipe 54, and flows into the inlet side of the refrigerant pump 102. The refrigerant liquid is pressurized by the refrigerant pump 102, returns to the evaporator coil of the evaporator 13, and repeats the above cycle. At this time, the absorption-type cold heat generator (outdoor unit) 2b is operated in the heating mode, the high-temperature concentrated solution separated by the regenerator 3 is guided to the evaporator 13, and the evaporator coil is heated by this heat.

Next, the operation of the solution bypass valve 33 in the air conditioner including the absorption-type cold heat generator 1 having the above-described configuration will be described.

Table 1 and FIG. 2 describe the operation of the absorber cooling water inlet temperature and the operation of the solution bypass valve 33. During the cooling operation, the solution bypass valve 33 is activated by the cooling water inlet temperature, for example, Hi-Low-Off (Hi is fully open, L
As shown in FIG. 2, two-stage control of CT1H and CT1L is performed according to the cooling water inlet temperature, assuming that the solenoid valve has a mechanism of "ow means half open, Off means fully closed, the same applies to the following). If the cooling water inlet temperature is lower than 18 ° C. during the low temperature cooling water operation at a cooling water inlet temperature of 20 ° C. or less, the solution bypass valve 33 is operated at a Hi flow rate until the cooling water inlet temperature reaches 18 ° C. When the cooling water inlet temperature rises and exceeds 18 ° C., the flow rate is switched to the low flow rate, and the operation is performed at a low flow rate up to 20 ° C. When the cooling water inlet temperature exceeds 20 ° C., it turns off. Conversely, when the cooling water inlet temperature drops from a value exceeding 18 ° C. and reaches 18 ° C., the flow rate is switched to a low flow rate, and the cooling water inlet temperature becomes 15 ° C.
It is operated at a low flow rate up to that. Cooling water inlet temperature is 15 ℃
When it becomes less than the above, the flow rate is switched to the Hi flow rate, and the above cycle is repeated. Table 1 shows the cooling water inlet temperature, the valve opening degree of the solution bypass valve 33, its concentrated solution bypass amount, and the absorber 16.
The flow of concentrated solution into the system is shown. The control of the solution bypass valve 33 prevents the absorption capacity from becoming excessive due to the low-temperature cooling water, thereby preventing the cooling water inlet temperature from dropping. However, the main purpose is to increase the water refrigerant evaporation amount in the evaporator when the absorption capacity becomes excessive. In order to prevent the evaporator (LT) temperature from lowering and leading to freezing of the water refrigerant and crystallization of the solution, the cooling water inlet temperature is kept at 20 ° C. or higher.

As shown in Table 1, when the solution bypass valve 33 is a two-way valve (On-Off), the Low flow rate can be adjusted by an intermittent operation using a timer. For example, when the temperature is within the set temperature range, On-Off time can be set by repeating On-10 seconds and Off-15 seconds.

Table 2 and FIG. 3 illustrate the evaporator temperature and the operation of the solution bypass valve 33. During the cooling operation, the solution bypass valve 33 also operates according to the evaporator temperature, and as shown in FIG.
Step control is performed. When the evaporator temperature drops from a value exceeding 3 ° C. to 3 ° C., the solution bypass valve 33 is off and the evaporator temperature is 3 ° C.
From below to 2 ° C., it is operated at a low flow rate, and below 2 ° C., it is operated at a Hi flow rate. On the other hand, the operation is performed at the Hi flow rate between less than 2 ° C. and 3.5 ° C., switched to the Low flow rate when the temperature rises to 3.5 ° C., and is operated at the Low flow rate until 4.5 ° C. When the temperature reaches ° C, the cycle becomes Off, and the above cycle is repeated.

As shown in Table 2, when the solution bypass valve 33 is a two-way valve (On-Off), the Low flow rate can be adjusted by an intermittent operation using a timer. It is also possible to set On-Off time by repeating Off-15 seconds for 10 seconds.

Table 3 and FIG. 4 explain the operation of the evaporator secondary-side refrigerant outlet temperature and the solution bypass valve 33.
At the time of cooling operation, the solution bypass valve 33 is also operated by the evaporator secondary-side refrigerant outlet temperature, for example, Hi-Low-Of.
In the case of the solenoid valve of f, as shown in FIG. 4, two-stage control of CRH and CRL is performed based on the secondary-side refrigerant outlet temperature. Hi when the secondary refrigerant outlet temperature is lower than 6 ° C.
It is operated at a flow rate and switches to a low flow rate when the secondary-side refrigerant outlet temperature rises to 6 ° C.
It operates at a flow rate of w and turns off at 7 ° C. On the other hand, when the secondary-side refrigerant outlet temperature exceeds 6 ° C., the temperature becomes Off, and when the temperature decreases to 6 ° C., the flow rate is switched to the low flow rate, and 6 ° C.
In the following, operation is performed at a low flow rate up to 5 ° C.
Operation starts and the above cycle is repeated.

As shown in Table 3, when the solution bypass valve 33 is a two-way valve (On-Off), the Low flow rate can be adjusted by an intermittent operation using a timer. It is also possible to set On-Off time by repeating Off-15 seconds for 10 seconds.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

As described above, when the secondary refrigerant is cooled, that is, during the cooling operation, the temperatures at which the inlet temperature of the absorber cooling water, the temperature of the evaporator, and the temperature of the secondary refrigerant outlet of the evaporator are detected. These temperatures are detected by the detecting means 60, 62, 64, and upon receiving these temperature signals, the controller 98 outputs a control signal for controlling the flow rate of the solution bypass valve 33 corresponding to these temperatures. Solution bypass valve 3
3 receives the control signal and introduces a concentrated solution, which is a high-temperature absorbing solution, into the bottom of the absorber 16. As a result, the absorption capacity of the low-temperature cooling water is not excessive, and as a result, the cooling water inlet temperature and the evaporator temperature are prevented from lowering, so that the cooling output control is stabilized, and the efficient cooling operation that follows the fluctuation of the cooling load is performed. I can do it. A stable cooling operation can be performed by suppressing the stop operation due to the absorber cooling water inlet temperature, the evaporator temperature, or the secondary-side refrigerant outlet temperature. Further, the cooling can be smoothly started with the low temperature cooling water (low outside air temperature).

[0045]

According to the absorption-type cold heat generator of the present invention,
When cooling the secondary-side cooling medium, the cooling output control is stable, and the cooling operation can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of an air conditioner including an absorption type cold heat generator according to the present invention.

FIG. 2 is a diagram showing a relationship between an inlet temperature of an absorber cooling water of the absorption-type cold heat generator shown in FIG. 1 and a valve opening degree of a solution bypass valve.

FIG. 3 is a diagram showing the relationship between the evaporator temperature of the absorption-type cold heat generator shown in FIG. 1 and the valve opening of the solution bypass valve.

FIG. 4 is a diagram showing a relationship between an evaporator secondary-side refrigerant outlet temperature of the absorption-type cold heat generator shown in FIG. 1 and a valve opening degree of a solution bypass valve.

FIG. 5 is a system diagram showing an example of a hot-water-fired absorption-type cold / hot water machine according to the related art.

6A and 6B are diagrams for explaining the control of the hot water-fired absorption chiller and hot water machine shown in FIG. 5, wherein FIG. 6A is a diagram showing the relationship between evaporator temperature and starting and stopping of each pump, and FIG. FIG. 4 is a diagram illustrating a relationship between an outlet temperature and activation and stop of each pump.

FIG. 7 is a system diagram showing an example of an air conditioner having an absorption-type cold heat generator according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorption-type cold-heat generator 3 Regenerator 11 Condenser 13 Evaporator 16 Absorber 20 Solution heat exchanger (Heat exchanger) 25 Solution circulation pump (Circulation pump) 33 Solution bypass valve 60 Evaporator temperature sensor (Temperature detection means) 62 Refrigerant outlet temperature sensor (temperature detecting means) 64 Cooling water inlet temperature sensor (temperature detecting means) 98 Controller

Claims (1)

[Claims] 1. A primary side for connecting each device including a regenerator, a condenser, an evaporator, an absorber, a heat exchanger, and a circulation pump, and circulating an absorbing solution to be heated by a heat medium supplied to the regenerator. Forming a circulation circuit, cooling or heating the secondary cooling medium flowing through the secondary circulation circuit including the pipe of the evaporator heat transfer tube of the evaporator by the absorption solution via the evaporator heat transfer tube of the evaporator. In the absorption-type cold heat generating device that performs a phase change, when cooling the secondary-side cooling medium, a solution bypass valve that is heated by the regenerator and that introduces a concentrated solution of the separated absorbing solution into the bottom of the absorber. Temperature detecting means for detecting at least one of a cooling water inlet temperature of the absorber, an evaporator temperature of the evaporator, and a secondary cooling medium outlet temperature of the evaporator; and a temperature detecting means corresponding to the temperature detected by the temperature detecting means. And the solution bypass A controller for outputting a control signal for controlling the flow rate of the valve to the solution bypass valve.