JP3175040B2 - Absorption type cold heat generator - 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 cold heat generator, and more particularly, to an absorption type cold heat generator using a fluid utilizing a phase change as a secondary refrigerant.

[0002]

2. Description of the Related Art Conventionally, an air conditioner using an absorption chiller / heater having the structure shown in FIG. 4 has been known as an absorption chiller. The illustrated device is an absorption chiller / heater 100 that generates cold heat.
And a cooling tower 42 connected to the absorption chiller / heater 100 by cooling water pipes 40 and 41 to cool the cooling water, and a cooling tower 42 connected to the absorption chiller / heater 100 by cooling and hot water pipes 43 and 44 and arranged in the space to be air-conditioned. An air-conditioning indoor unit (not shown) for exchanging heat with air, and an absorption chiller / heater 1 for cooling water interposed in the cooling water pipe 41 from a cooling tower 42.
A cooling water circulation pump 14 for circulating the cooling water and a cooling water circulation pump 14 for circulating the secondary refrigerant interposed in the cooling and heating water pipe 43 between the absorption cooling and heating water heater 100 and the air conditioning indoor unit. And a pump 15.

[0003] In contrast to the indoor unit for air conditioning, an absorption chiller-heater 100, which is usually called an outdoor unit together with a cooling tower 42, is provided with a high-temperature regenerator 1 for burning fuel and heating a dilute solution by the heat thereof. A separator 2 for separating the refrigerant vapor and the intermediate concentrated solution from the dilute solution heated by the regenerator 1, and a low-temperature regenerator 3 for heating the intermediate concentrated solution using the separated refrigerant vapor as a heat source to further generate the refrigerant vapor 3 A condenser 4 that cools and condenses and liquefies the refrigerant vapor that has passed through the low-temperature regenerator 3 and the refrigerant vapor that has been generated by the low-temperature regenerator 3, and a liquid refrigerant that is generated by the condenser 4. An evaporator 6 that drip-evaporates from a refrigerant distributor 6 </ b> B having the inside thereof onto an evaporation coil also housed therein to cool a secondary refrigerant in the evaporation coil;
An absorber 5 that absorbs the refrigerant vapor evaporated by the evaporator 6 into a concentrated solution to generate a dilute solution, and pressurizes the dilute solution to form a low-temperature solution heat exchanger 8 and a high-temperature solution heat exchanger 7 on the heated fluid side. A solution circulating pump 9 which sends the solution to the high-temperature regenerator 1 via a pipe 10A which communicates the bottom of the separator 2 with the bottom of the evaporator 6 via a cooling / heating switching valve 10;
A concentrated solution pipe 8A connecting the outlet side of the heated fluid to the upper part of the absorber 5, a pipe line 13A connecting the concentrated solution pipe 8A and the lower part of the absorber 5 via a solution bypass valve 13, A pipe line 12A that connects the solution pipe 8A and the refrigerant distributor provided in the evaporator 5 via an antifreeze valve 12, and an evaporator that is attached to the refrigerant distributor and detects the temperature of the refrigerant in the refrigerant distributor. And a water refrigerant pipe 11B for guiding liquid refrigerant from the condenser 4 to the refrigerant distributor 6B, and a pipe 11A connected in parallel to the water refrigerant pipe 11B and having a water refrigerant proportional valve 11 interposed therebetween. , Is configured.

Further, the intermediate concentrated solution separated by the separator 2 is led to the low temperature regenerator 3 via the heating fluid side of the high temperature solution heat exchanger 7, and the low temperature regenerator 3 evaporates the refrigerant to remove the concentrated solution. After that, the conduit is configured to be led to the concentrated solution pipe 8A via the heating fluid side of the low temperature solution heat exchanger 8. Each of the absorber 5 and the condenser 4 is provided with a cooling water coil, and an outlet of the cooling water coil of the absorber 5 is connected to an inlet of the cooling water coil of the condenser 4. The inlet of the coil is the cooling water pipe 4
1, the outlet of the cooling water coil of the condenser 4 is connected to the cooling water pipe 4
0, respectively. The cold / hot water pipe 43 is provided at the entrance side of the evaporator coil of the evaporator 6.
Is connected to the outlet side of the evaporator coil of the evaporator 6, and a chilled water outlet temperature sensor 16 for detecting the temperature of the secondary refrigerant is mounted near the outlet of the evaporator coil of the chilled / hot water pipe 44.

In the apparatus having the above-mentioned structure, the cooling / heating switching valve 10
Switches between cooling and heating, and is closed during cooling and opened during heating. The water refrigerant proportional valve 11 is a valve whose opening degree is controlled by inputting the temperature of the evaporator (output of the evaporator temperature sensor 17) to adjust the solution concentration. Antifreeze valve 12
Is opened when the evaporation temperature drops to 1 ° C. and the concentrated solution flows into the refrigerant distributor 6B, and the refrigerant (usually water is used as the refrigerant of the absorption chiller / heater, hereinafter also referred to as water refrigerant). This is a valve to prevent freezing. The solution bypass valve 13 bypasses the concentrated solution to the lower part of the absorber 5 before the antifreeze valve operates when the evaporator temperature is lowered at the start of cooling and low-load operation, thereby increasing the absorption capacity of the absorber 5. An on-off control valve to lower the temperature and prevent further temperature reduction of the evaporator.

The absorption chiller / heater suffers the greatest damage from the fact that the water refrigerant in the machine freezes during the cooling operation and performs the crystallization operation, and that the chiller / heater circuit freezes and breaks at a low load. In order to prevent these situations from occurring, various protection controls are performed based on the cold / hot water outlet temperature and the evaporator temperature.

[0007] For example, in the case where cold water of 7 ° C is taken out at 100% load, if the load is small, the cold water temperature is reduced as the capacity is excessive with respect to the load. When the normal cold water outlet temperature reaches 5 to 6 ° C., the combustion of the high-temperature regenerator 1 is stopped. At the start of cooling or at a low load, the evaporator temperature may be lower than the appropriate temperature range by more than the chilled water outlet temperature.Therefore, the evaporator temperature should be adjusted to prevent the water refrigerant inside the machine from freezing and crystallizing. Various protection controls based on the above are performed.

FIG. 3 shows an example of control based on the evaporator temperature. In the figure, LT0 to LT2 indicate control types of evaporator temperature control. LT0: The solution bypass valve 13 is opened when the evaporator temperature drops to 2 ° C., and the solution bypass valve 13 is closed when the evaporator temperature rises to 3 ° C. LT1: anti-freeze valve 12 when evaporator temperature drops to 1 ° C
Open the antifreeze valve 12 when the evaporator temperature rises to 2 ° C.
Close. LT2: high temperature regenerator 1 when evaporator temperature drops to -2 ° C
Is stopped, the cooling water circulation pump 14 is stopped, and when the evaporator temperature rises to -1 ° C., the combustion in the high temperature regenerator 1 is started, and the cooling water circulation pump 14 is started.

[0009]

In the air conditioner shown in FIG. 4, a non-phase-change fluid, generally a liquid, has been used as a secondary refrigerant that circulates heat between an indoor unit and an outdoor unit to carry heat. However, in recent years, a method has been devised in which a secondary refrigerant undergoes a phase change to increase the heat transfer amount per unit flow rate. FIG. 5 shows an example of such a configuration. In the configuration shown in FIG. 4, the refrigerant liquid pipe 50 and the refrigerant vapor pipe 51 are replaced with the lower end of the evaporating coil instead of the cold and hot water pipes 43 and 44.
Each is connected to the upper end. The other ends of the refrigerant liquid pipe 50 and the refrigerant vapor pipe 51 are branched by the number of the indoor units 52 and 53 arranged below the evaporating coil.
Are connected via expansion valves 54 and 55 to lower inlets of heat exchangers respectively installed in the indoor units, and branch ends of the refrigerant vapor pipes 51 are connected to upper inlets of the heat exchangers, respectively. Have been. A refrigerant liquid temperature sensor 21 that detects the temperature of the secondary refrigerant and outputs it to the controller 59 as an electric signal is mounted near the connection portion of the refrigerant liquid pipe 50 with the evaporation coil.

The refrigerant liquid pipe 50 is provided between the indoor units 52 and 53 on the way.
There is a portion located at a lower position, and a refrigerant pump 57 for pressurizing the refrigerant liquid and sending the pressurized refrigerant liquid to the evaporation coil is mounted thereon. On the discharge side of the refrigerant pump 57, a check valve 58 is provided.
The suction side of 7 is connected via a cooling / heating switching valve 56. HFC-134a is filled in a refrigerant liquid pipe as a secondary refrigerant that changes phase (hereinafter, also simply referred to as a refrigerant).
The other configuration is the same as the description of FIG. 4, and the description is omitted.

The operation of the air conditioner shown in FIG. 5 during cooling is as follows. During cooling, the cooling / heating switching valve 56 is open. The refrigerant vapor (HFC-134a) is cooled and condensed by the evaporator coil of the evaporator 6 to become a refrigerant liquid, flows downward through the refrigerant liquid pipe 50 by gravity, passes through expansion valves 54 and 55, and flows through the indoor units 52 and 53. Flow into heat exchanger. 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 51, and flows into the evaporator coil of the evaporator 6. Since the outdoor unit (absorption type cold heat generator) is operated in the cooling mode, the evaporation coil of the evaporator 6 is cooled by the evaporation of the water refrigerant dropped on the surface thereof, and the refrigerant vapor ( HF
C-134a) condenses and liquefies. Due to this condensation and liquefaction, the pressure inside the evaporating coil decreases, and the refrigerant vapor evaporated in the heat exchanger of the indoor unit is sucked into the evaporator. Since the refrigerant liquid condensed and liquefied inside the evaporation coil flows into the indoor unit by gravity, the refrigerant (HFC-134a) during cooling naturally circulates, 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 evaporating coil decreases, and the saturated refrigerant vapor in the refrigerant vapor pipe flows into the evaporating coil due to the pressure difference. The refrigerant liquid generated by condensation in the evaporating coil is supplied to the refrigerant liquid pipe 5.
0 flows down by its own weight, and the head (liquid column) of the refrigerant liquid rises. In order to achieve the natural circulation of the refrigerant described above, it is sufficient that (the refrigerant liquid head-the refrigerant gas head) is equal to or more than the total pressure loss of the refrigerant circulation path. 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 6 at the start of the cooling operation is small.

[0013]

(Equation 1)

During heating, the cooling / heating switching valve 56 is closed. The refrigerant liquid (HFC-134a) is heated by the evaporator coil of the evaporator 6 to become refrigerant vapor, flows down the refrigerant vapor pipe 51, and flows into the heat exchangers of the indoor units 52 and 53. The refrigerant vapor flowing into the heat exchanger is deprived of heat by the air in the air-conditioned space, condensed and liquefied, becomes a refrigerant liquid, flows downward through the refrigerant liquid pipe 51, and flows into the refrigerant pump 57 inlet side.
The refrigerant liquid is pressurized by the refrigerant pump 57, flows into the evaporation coil of the evaporator 6, and repeats the above cycle. At this time,
The outdoor unit is operated in the heating mode, and the evaporator 6 has the separator 2
The high-temperature solution separated by the above is led, and the evaporation coil is heated by this heat.

If the control based on the evaporator temperature (LT control) described with reference to FIGS. 3 and 4 is directly applied to the outdoor unit of the above-described absorption type refrigerant natural circulation cooling device, the cooling operation is performed.
There are the following problems. 1) The temperature range of LT0 and LT1 is narrow, and the evaporator temperature overshoots due to a rapid drop to fall to the LT1 operating temperature (freezing valve opening temperature). The concentrated solution is mixed in the refrigerant, and the cooling capacity of the evaporator is significantly reduced. When the cooling capacity of the evaporator decreases, the pressure in the evaporator coil increases, and the natural circulation of the refrigerant with the indoor unit is hindered. The cooling capacity of the evaporator did not recover until the concentrated solution mixed in the refrigerant distributor almost disappeared,
In addition, it takes time for the concentrated solution mixed in the refrigerant distributor to almost disappear. For this reason, the cooling capacity of the evaporator is restored,
It takes time for the cooling operation to start. The sudden drop in the evaporator temperature is due to the fact that there is no pump in the refrigerant circuit on the indoor unit side that forces the refrigerant to circulate during cooling. This is because the amount of heat supplied to the evaporating coil of the evaporator 6 is also small. For this reason, the cooling capacity of the evaporator at the start of the cooling operation of the outdoor unit becomes excessive with respect to the load supplied to the evaporating coil, which causes a sudden drop in the evaporator temperature. Such a sharp drop in the evaporator temperature is more remarkable when the temperature of the cooling water for cooling the absorber 5 is low. When the cooling water temperature is low, the absorption capacity of the absorber 5 increases,
Accordingly, the evaporating ability of the evaporator 6, that is, the cooling ability increases.

2) Before the evaporator temperature falls to the LT1 operating temperature, the solution bypass valve 13 is opened by LT0 control to bypass the concentrated solution to the upper part of the absorber and to bypass the concentrated solution to the bottom of the absorber to reduce the absorption capacity. To suppress the evaporation of the water refrigerant in the evaporator, but the use of CFC refrigerant (HFC-134a)
The temperature change is fast, and the LT1 operation is not stopped at the split ratio (bypass amount of about 10 to 20%) of the solution bypass valve 13 of the conventionally used on-off control.

Note that the LT1 control is effective in preventing freezing of the water refrigerant in the outdoor unit, but lowering the set temperature impairs the antifreezing effect. That is, the antifreeze valve is opened at an evaporator temperature of 1 ° C. However, if the antifreeze valve is opened at 0 ° C., for example, the water refrigerant substantially starts to freeze, and the evaporator temperature sensor 1
Considering the accuracy and variation of 7, there is a high possibility that at 0 ° C., freezing of the water refrigerant circuit will lead to crystallization operation.

As described above, when a phase-change fluid is used as the secondary refrigerant and the secondary refrigerant is naturally circulated during cooling,
At the start of the cooling operation, especially when the cooling water temperature is lower than the planned temperature, the absorption capacity of the absorber becomes larger than the required capacity corresponding to the load, the evaporator temperature drops rapidly, the LT1 control is activated, and the cooling rises. Takes a long time.
On the other hand, the opening degree of the water refrigerant proportional valve 11 is controlled based on the evaporator temperature in order to adjust the solution concentration in the apparatus as described above. FIG. 6 shows an example of the evaporator temperature and the opening degree of the water refrigerant proportional valve corresponding to the evaporator temperature. Since the evaporator temperature also fluctuates in response to the fluctuation of the cooling water temperature accompanying the change of the outside air condition, the fluctuation of the evaporator temperature from 2 ° C. to 6 ° C., as shown in FIG. Approximately corresponds to a cooling water temperature fluctuation of 24 ° C. to 32 ° C. The opening of the water refrigerant proportional valve is controlled based on the evaporator temperature. At the start of the cooling operation, as shown in FIG. 6, the evaporator temperature drops from the initial fully closed state to 6 ° C. And start to open for the first time. This means that the supply of the water refrigerant from the condenser 4 to the evaporator 6 is restricted during the period from the start of operation to the storage amount of the water refrigerant in the condenser 4. That is, the amount of the water refrigerant that is not dissolved in the absorbing solution and is excluded from the circulation cycle increases, and the concentration of the circulating absorbing solution increases. Therefore, the fact that the water-refrigerant proportional valve is kept closed at the start of cooling increases the absorption capacity of the absorber 5 and amplifies the above-described imbalance between the cooling capacity of the evaporator and the load supplied to the evaporation coil. Act like so. That is, L
It acts as a cause of the easy operation of T1.

An object of the present invention is to smoothly start up a cooling operation in accordance with a load factor even when a phase-change fluid is used as a secondary refrigerant and the secondary refrigerant is naturally circulated during cooling. .

[0020]

An object of the present invention is to provide an absorber 5
A pipe connecting the concentrated solution pipe 8A for guiding the concentrated solution to the upper part and the refrigerant distributor 6B provided in the evaporator 6 through the anti-freezing valve 12, and the water refrigerant from the condenser to the refrigerant distributor 6B. A water refrigerant pipe 11B, a pipe line 11A interposed with a water refrigerant proportional valve 11 connected in parallel to the water refrigerant pipe and having an opening controlled based on the evaporator temperature, and a cooling water coil installed in the absorber A cooling water pipe that supplies cooling water to the cooling water, and a cooling tower 42 that has a blower 42A that blows cooling air to the cooling water and cools the cooling water, wherein the blower cools the cooling water flowing into the cooling tower. An absorption type in which a fluid that changes phase is used as a secondary refrigerant circulating between the evaporator and the load, and is configured to stop blowing when the temperature of the water falls below a first temperature set in advance. For cold heat generator A cooling water inlet temperature sensor 25 for detecting and outputting a cooling water inlet temperature near the inlet of the absorber 5 of the cooling water pipe; and cooling the water refrigerant proportional valve 11 to the cooling water output by the cooling water inlet temperature sensor 25. This is attained by arranging such that when the water temperature is lower than the second temperature set lower than the first temperature, it is fully opened regardless of the evaporator temperature. When setting the second temperature, the first temperature
Is desirably set so that the temperature difference from the temperature of 2 ° C. becomes 2 ° C. to 5.5 ° C.

[0021]

When the cooling operation is started, the water refrigerant proportional valve is closed, and the water refrigerant in the condenser is supplied to the evaporator through the water refrigerant pipe. The water refrigerant proportional valve remains closed until the temperature of the evaporator drops to a preset temperature, during which part of the water refrigerant is stored in the condenser and excluded from the circulation cycle as working fluid. And the concentration of the absorbing solution is increased. That is, the absorption capacity of the absorber tends to increase. Also, when the cooling water temperature is lower than the planned temperature, this further increases the absorption capacity of the absorber, amplifies the imbalance between the evaporator cooling capacity at the start of cooling and the load supplied to the evaporator, and increases the evaporator temperature. This means bringing the temperature closer to the operating temperature of the antifreeze valve.

However, the cooling water temperature is set to be lower than the second temperature which is set in advance, or the first temperature at which the cooling water returned to the cooling tower is sufficiently low that cooling by the blower is not necessary. If the temperature is less than the temperature of 2, the water refrigerant proportional valve is fully opened regardless of the evaporator temperature,
The water refrigerant stored in the condenser is supplied to the refrigerant distributor of the evaporator. The water refrigerant supplied to the refrigerant distributor via the water refrigerant proportional valve is excess water refrigerant, and most of the water flows down to the bottom of the evaporator without being evaporated, and is mixed with the absorbing solution that has absorbed the refrigerant vapor in the absorber. Into a dilute solution. That is, the concentration of the absorbing solution is reduced by returning the water refrigerant outside the circulation cycle to the circulation cycle, and the absorption capacity of the absorber is reduced. The reduction in the absorption capacity reduces the imbalance between the cooling capacity of the evaporator and the load supplied to the evaporator, and prevents the temperature of the evaporator from decreasing to the operating temperature of the antifreeze valve. LT1 operation (freezing prevention valve opening) can be avoided.

[0023]

An embodiment of the present invention will be described below with reference to FIG. The difference of the embodiment of FIG. 1 from that shown in FIG.
The cooling water inlet temperature sensor 25 for detecting and outputting the cooling water inlet temperature near the connection of the cooling water pipe 41 with the absorber 5 is provided. The controller 59 sets the water refrigerant proportional valve 11 to an evaporator temperature sensor, in that the opening is controlled steplessly and also controlled by the cooling water inlet temperature output from the cooling water inlet temperature sensor 25. 17, the opening degree is controlled based on the cooling water inlet temperature sensor 25, and the evaporating coil outlet side rising part of the refrigerant vapor pipe 51 and the evaporating coil connection part of the refrigerant liquid pipe 50 This is a point of communication via the solenoid valve 60, and the other configuration is the same as that of FIG. 6, and therefore detailed description of the configuration is omitted. In addition, the blower 42A of the cooling tower 42
When the cooling water temperature at the cooling tower entrance is 24 ° C. or higher, the cooling tower is operated. The planned operating temperature of the evaporator in this embodiment is 5 ° C., and the LT control is performed in the same manner as that described with reference to FIG.

FIG. 2 shows temperature conditions for controlling the opening degree of the water refrigerant proportional valve 11 in this embodiment. FIG. 2 shows the relationship between the evaporator temperature, the cooling water inlet temperature and the water refrigerant proportional valve opening by taking the evaporator temperature on the X axis, the cooling water inlet temperature on the Y axis, and the water refrigerant proportional valve opening on the Z axis. The controller 59 controls the opening of the water refrigerant proportional valve 11 so as to satisfy this relationship. When the cooling water inlet temperature is lower than 22 ° C., the water refrigerant proportional valve 11 is fully opened regardless of the evaporator temperature, and when the cooling water inlet temperature is lower than 22 ° C.
If the temperature is not lower than 6 ° C., it starts to open when the evaporator temperature becomes 6 ° C. or lower, and is fully opened at 2 ° C. When the cooling water inlet temperature is 22 ° C. or more and the evaporator temperature is between 6 ° C. and 2 ° C., the opening degree is controlled to be (6-evaporator temperature) ÷ 4 × 100%, and 6 ° C. or more Then, fully closed at 2 ° C or less.

The operation of the embodiment shown in FIG. 1 when the cooling operation is started will be described. First, when the cooling operation is started, the evaporator temperature starts to decrease. The controller 59 controls the opening of the water refrigerant proportional valve 11 based on the output of the evaporator temperature sensor 17 if the input cooling water inlet temperature is 22 ° C. or higher, and if the cooling water inlet temperature is lower than 22 ° C. For example, the water refrigerant proportional valve 11 is fully opened immediately regardless of the evaporator temperature. Water refrigerant proportional valve 1
When the valve 1 is fully opened, the water refrigerant stored in the condenser 4 is supplied to the refrigerant distributor 6B of the evaporator 6. The water refrigerant supplied to the refrigerant distributor 6B via the water refrigerant proportional valve 11 is excess water refrigerant, and most of the water refrigerant flows down to the bottom of the evaporator 6 without evaporating, and is absorbed by the absorber 5 by absorbing the refrigerant vapor. It is mixed with the solution to form a dilute solution. That is, the concentration of the absorbing solution is reduced by returning the water refrigerant which has been outside the circulation cycle to the circulation cycle, and the absorption capacity of the absorber 5 is reduced. Due to the decrease in the absorption capacity, the cooling capacity of the evaporator is reduced, the imbalance of the load supplied to the evaporator 6 is reduced, and the rapid decrease in the evaporator temperature at the start of the cooling operation is reduced. Since it is prevented that the temperature drop of the evaporator decreases and the operating temperature of the antifreeze valve decreases, the LT1 operation (opening of the antifreeze valve) at the start of the cooling operation can be avoided.

When the cooling water inlet temperature is 22 ° C. or higher, the controller 59 controls the opening degree of the water refrigerant proportional valve based on the input evaporator temperature.
In the above case, the excessive cooling capacity of the evaporator due to the cooling water temperature is not large, and the risk of LT1 operation is relatively small as compared with the case where the cooling water inlet temperature is lower than 22 ° C.

As described above, the cooling water inlet temperature is 22 ° C.
Since the increase in the absorption capacity of the absorber that occurs when the temperature is lower than that is suppressed by opening the water refrigerant proportional valve and lowering the concentration of the absorbing solution, at the time of starting the cooling operation due to the low cooling water temperature The LT1 operation (freezing prevention valve opening) can be avoided, and as a result, the time required for recovering the cooling capacity of the evaporator and forming the liquid head required for the natural circulation of the refrigerant, that is,
It is possible to prevent the time required for starting the cooling operation from increasing.

In the above embodiment, the temperature (first temperature) of the cooling water at which the blower 42A of the cooling tower 42 is stopped.
And the second temperature is set such that the difference between the temperature of the cooling water (the second temperature) at which the water refrigerant proportional valve 11 is fully opened is 2 ° C. In setting the second temperature, the difference is set. Is 2 ° C ~
It is desirable that the temperature be about 5.5 ° C. 2 ° C difference
If it is less than this, there is a possibility that the absorption capacity is uselessly reduced and the margin of the cooling capacity is lost, and if it is more than 5.5 ° C., the effect of suppressing the LT1 operation decreases.

[0029]

According to the present invention, when a phase-changing fluid is naturally circulated as a secondary refrigerant cooled by an evaporator,
Even when the cooling water temperature is lower than the planned temperature, an excessive drop in the temperature of the evaporator is suppressed at the time of starting the cooling operation, and the mixture of the concentrated solution into the water refrigerant supplied to the evaporator is prevented.
It is possible to avoid an increase in the time required for the rise of cooling.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a main configuration of an embodiment of the present invention.

FIG. 2 is a graph showing an example of the relationship among the opening degree of the water refrigerant proportional valve, the evaporator temperature, and the cooling water inlet temperature of the embodiment shown in FIG.

FIG. 3 is a conceptual diagram illustrating an example of protection control based on an evaporator temperature.

FIG. 4 is a system diagram showing an example of the related art.

FIG. 5 is a system diagram showing another example of the related art.

FIG. 6 is a graph showing an example of a relationship between an evaporator temperature and a water refrigerant proportional valve opening.

FIG. 7 is a graph showing an example of a correlation between an evaporator temperature and a cooling water inlet temperature.

[Description of Signs] 1 High temperature regenerator 2 Separator 3 Low temperature regenerator 4 Condenser 5 Absorber 6 Evaporator 6B Refrigerant distributor 7 High temperature solution heat exchanger 8 Low temperature solution heat exchanger 8A Concentrated solution pipe 9 Solution circulation pump 10 Cooling / heating switching valve 10A Line 11 Water refrigerant proportional valve 11A Line 11B Water refrigerant pipe 12 Freezing prevention valve 12A Line 13 Solution bypass valve 13A Line 14 Cooling water circulation pump 15 Cold and hot water circulation pump 16 Cold water outlet temperature sensor 17 Evaporator temperature sensor DESCRIPTION OF SYMBOLS 21 Refrigerant liquid temperature sensor 22 Solution bypass valve 25 Cooling water inlet temperature sensor 40, 41 Cooling water pipe 42 Cooling tower 42A Blower 43, 44 Cooling / heating water pipe 50 Refrigerant liquid pipe 51 Refrigerant vapor pipe 52, 53 Indoor unit 54, 55 Expansion valve 56 Cooling / heating switching Valve 57 Refrigerant pump 58 Check valve 59 Controller 60 Solenoid valve

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-247968 (JP, A) JP-A-6-257880 (JP, A) JP-A-56-155352 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F25B 15/00 306

Claims (3)

(57) [Claims] 1. A concentrated solution pipe for introducing a concentrated solution to an upper part of an absorber and a steam
A conduit which communicates the interior refrigerant distributor via the antifreeze valve Hatsuki, water refrigerant pipe for guiding the water coolant to said refrigerant distributor from the condenser, evaporator connected in parallel to the water refrigerant pipe a conduit <br/> was interposed water coolant proportional valve which is opening control based on the vessel temperature, and the cooling water pipe for supplying cooling water to the cooling water coil is decorated in the absorber, cooled to cooling water Blast to blow air
A cooling tower having a cooling device for cooling the cooling water, wherein the blower stops blowing when the temperature of the cooling water flowing into the cooling tower falls below a first temperature set in advance. Configured as above,
In an absorption-type cold heat generating apparatus in which a phase-change fluid is used as a secondary refrigerant circulating between an evaporator and a load,
The cooling water inlet temperature sensor detects and outputs the absorber cooling water inlet temperature in the vicinity of the inlet of the cooling water pipe is provided, the water
The refrigerant proportional valve is configured to be fully opened irrespective of an evaporator temperature when a cooling water temperature output by the cooling water inlet temperature sensor is lower than a second temperature set lower than the first temperature. An absorption type cold heat generator. 2. The absorption type cold heat generator according to claim 1, wherein a temperature difference between the second temperature and the first temperature is in a range of 2 to 5.5 ° C. 3. The absorption-type cold heat generator according to claim 1, wherein the second temperature is 22 ° C.