JP3383898B2 - 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 chiller-heater, and more particularly to an absorption-type cold heat generator using a secondary refrigerant that changes phase.

[0002]

2. Description of the Related Art Conventionally, an air conditioner using an absorption chiller-heater shown in FIG. 2 is known as an absorption type cold heat generator. The illustrated apparatus includes an absorption chiller-heater 100 that generates cold heat, and a cooling tower (cooling tower water tank) 42 that is connected to the absorption chiller-heater 100 by cooling water pipes 40 and 41 to cool the cooling water.
And an unillustrated air conditioning indoor unit that is connected to the absorption chiller / heater 100 by cold / hot water pipes 43 and 44 and is arranged in the air-conditioned space to exchange heat with the air in the space, and is installed in the cooling water pipe 41. A cooling water circulation pump 14 that circulates the cooling water from the cooling tower 42 to the absorption chiller-heater 100, and an absorption chiller-heater 100 and an air-conditioning room that absorbs the secondary refrigerant that is interposed in the cold-hot water pipe 43 and filled in the cold-hot water pipes 43 and 44. It is configured to include a cold / hot water circulation pump 15 that circulates between the machine and the machine.

In contrast to the indoor unit, the absorption chiller / heater 100
Is usually called an outdoor unit, and is a high temperature regenerator 1 that burns fuel and heats the dilute solution with the heat, and a separation that separates the refrigerant vapor and the intermediate concentrated solution from the dilute solution heated by the high temperature regenerator 1. 2, a low-temperature regenerator 3 that heats the intermediate concentrated solution using the separated refrigerant vapor as a heat source to further generate refrigerant vapor, a refrigerant vapor that has passed through the low-temperature regenerator 3 and a refrigerant generated in the low-temperature regenerator 3. A condenser 4 that cools and condenses and liquefies the vapor to produce a liquid refrigerant, and a liquid refrigerant produced in the condenser 4 is dropped and evaporated from the refrigerant distributor 6B in which it is installed onto an evaporation coil that is also installed, and An evaporator 6 for cooling the next refrigerant, an absorber 5 for absorbing the refrigerant vapor evaporated in the evaporator 6 into a concentrated solution to produce a dilute solution, a low temperature solution heat exchanger 8 and a high temperature solution heat exchange by pressurizing the dilute solution. High-temperature regenerator 1 through the heated fluid side of vessel 7. A solution circulation pump 9 for feeding in, a pipe 10A for communicating the bottom of the separator 2 and the bottom of the evaporator 6 via a cooling / heating switching valve 10, and a heating fluid outlet side of the low temperature solution heat exchanger 8 at an upper part of the absorber 5. A concentrated solution pipe 8A, a conduit 13A connecting the concentrated solution pipe 8A and the lower part of the absorber 5 via the solution bypass valve 13, and a concentrated solution pipe 8A and a refrigerant distributor installed in the evaporator 5. A pipeline 12A communicating through the antifreezing valve 12, an evaporator temperature sensor 17 mounted on the refrigerant distributor to detect the temperature of the refrigerant in the refrigerant distributor 6B, and a liquid refrigerant from the condenser 4 to the refrigerant distributor 6B. And a pipe line 11A that is connected in parallel to the pipe line that guides the water refrigerant and that has the water-refrigerant proportional valve 11 interposed therebetween.

The intermediate concentrated solution separated in the separator 2 is introduced into the low temperature regenerator 3 via the heating fluid side of the high temperature solution heat exchanger 7, and the refrigerant is evaporated in the low temperature regenerator 3 to form a concentrated solution. After that, the pipe line is configured so as to be guided to the concentrated solution pipe 8A via the heating fluid side of the low temperature solution heat exchanger 8. A cooling water coil is installed in each of the absorber 5 and the condenser 4, the outlet of the cooling water coil of the absorber 5 is connected to the inlet of the cooling water coil of the condenser 4, and the cooling water coil of the absorber 5 is The inlet is connected to the cooling water pipe 41, and the outlet of the cooling water coil of the condenser 4 is connected to the cooling water pipe 40.
The cold / hot water pipe 43 is connected to the inlet side of the evaporator coil of the evaporator 6, and the cold / hot water pipe 44 is connected to the outlet side of the evaporator coil of the evaporator 6, respectively, and the temperature of the secondary refrigerant is provided near the outlet of the evaporator coil of the cold / hot water pipe 44. A cold water outlet temperature sensor 16 for detecting is mounted.

In recent years, there has been devised a method of increasing the amount of heat transfer per unit flow rate by causing a secondary refrigerant to undergo a phase change. FIG. 3 shows an example of such a configuration. In the configuration shown in FIG. 2, instead of the cold / hot water pipes 43 and 44, a refrigerant liquid pipe 50 and a refrigerant vapor pipe 51 are the lower end of the evaporation coil.
Each is connected to the top. The other ends of the refrigerant liquid pipe 50 and the refrigerant vapor pipe 51 forming the refrigerant circuit are branched by the number of the indoor units 52 and 53 arranged below the evaporation coil, and the branched end of the refrigerant liquid pipe 50 is It is connected to the lower inlets of the heat exchangers respectively installed in the indoor units via expansion valves 54 and 55, and the branch ends of the refrigerant vapor pipes 51 are respectively connected to the upper inlets of the heat exchangers. A refrigerant liquid temperature sensor 21 that detects the temperature of the secondary refrigerant and outputs it as an electric signal to a controller (control means) 59 is mounted near the connection portion of the refrigerant liquid pipe 50 with the evaporation coil.

The refrigerant liquid pipe 50 is connected to the indoor units 52 and 53 on the way.
There is a portion arranged at a lower position than that, and a refrigerant pump 57 that pressurizes the refrigerant liquid and sends it to the evaporation coil is attached thereto. A check valve 58 is provided on the discharge side of the refrigerant circulation pump 57, and the outlet side of the check valve 58 and the suction side of the refrigerant circulation pump 57 are connected via a cooling / heating switching valve 56. For example, HFC-134a is filled in the refrigerant liquid pipe as a secondary refrigerant (hereinafter also simply referred to as a refrigerant) that undergoes a phase change. Other configurations are the same as those described with reference to FIG.

The operation of the air conditioner shown in FIG. 3 during cooling is as follows. The cooling / heating switching valve 56 is opened during cooling. Refrigerant vapor (HFC-134a, R404A, etc.)
It is cooled and condensed by the evaporation coil of the evaporator 6 to become a refrigerant liquid,
Due to gravity, the refrigerant liquid pipe 50 flows downward, and the expansion valve 54,
After passing through 55, it flows into the heat exchanger of each indoor unit 52, 53.
The refrigerant liquid that has flowed into the heat exchanger deprives the heat of the air in the air-conditioned space to evaporate, becomes refrigerant vapor, rises through the refrigerant vapor pipe 51, and flows into the evaporation coil of the evaporator 6. Since the outdoor unit (absorption cooling / heating machine) 100 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 (flowing into the evaporation coil ( HFC-134a, R404A, etc.) is condensed and liquefied. Due to this condensation and liquefaction, the pressure inside the evaporation coil is lowered, 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, R404A, etc.) naturally circulate, and it is not necessary to drive the refrigerant by a pump.

When the cooling operation is started, as described above,
The pressure inside the evaporation coil decreases, and the saturated refrigerant vapor in the refrigerant vapor pipe flows into the evaporation coil due to the pressure difference. The refrigerant liquid condensed and generated in the evaporation coil flows down in the refrigerant liquid pipe 50 by its own weight, and the head (liquid column) of the refrigerant liquid rises. In order to establish the natural circulation of the refrigerant described above,
It is sufficient that (refrigerant liquid head-refrigerant gas head) is equal to or greater than the total pressure loss of the refrigerant circulation path. That is, the natural circulation of the refrigerant is not started until the liquid head satisfying this relationship is formed. This means that the heat load supplied to the evaporator 6 at the start of the cooling operation is small.

In the apparatus having the above-mentioned structure, generally, when the cooling / heating operation mode is switched at a distant place (on the side of the secondary refrigerant), the cooling / heating switching valve 10 for the solution is automatically opened and closed, and is closed during cooling. , It is opened during heating. When the cooling operation is started up, the control equipment (level switch and feed water pressure switch, etc.) 61 and 62 for detecting the water level in the cooling tower water tank 42 is used to confirm that the cooling water circulation pump 14 does not run idle due to the water level. Start driving. When the water level is at a drought level or when the water supply pressure falls below the usable range due to water interruption or the like, the operation of the absorption chiller-heater 100 is immediately stopped. However, in the natural circulation system, even if the cooling water circulation pump 14 is instantaneously stopped due to an abnormality in the water level signal in the conventional cooling water control shown in FIG. 4, even if the control devices 61 and 62 malfunction. In the system, once the expansion valves (electronic expansion valves) 54, 55 on the indoor unit side are fully closed, the expansion valves 54, 55 are activated after a certain period of time when the absorption-type cold heat generator is restarted. Had a problem that could not maintain the cooling cycle.

[0010]

In the conventional absorption type cold heat generator, when the cooling operation is started, the water level in the cooling tower water tank is at a drought level, or the water supply pressure falls below the usable range due to water interruption or the like. If so, the operation of the absorption chiller-heater is immediately stopped. However, when the operation of the absorption chiller / heater is stopped due to an abnormal water level due to malfunction of the control equipment, the controller controls the expansion valve on the indoor unit side to be fully closed, but once the expansion valve is fully closed, the absorption chiller There is a problem that the cooling cycle cannot be maintained because the generator operates after a certain period of time when it is restarted. Especially when supplying makeup water to the cooling tower water tank with a pressurizing pump, the fluctuation range of the pressure in the cooling tower water tank is large, the pressure drops instantly and it is easy to stop the operation of the absorption chiller-heater, and the cooling cycle is maintained. There was a problem that it was easy to occur when it was impossible.

An object of the present invention is to provide an absorption-type cold heat generating device that determines malfunction even if the water level in the cooling tower water tank is abnormal unless an abnormal signal continues for a set time.

[0012]

In order to achieve the above-mentioned object, an absorption type cold heat generator according to the present invention is an absorption type cold and hot water machine in which devices including a regenerator, a condenser, an evaporator and an absorber are connected. When, water was cooling water and cooling tower water bath that circulates to the condenser through the absorber in the cooling water circulation pump, an evaporator and at least one refrigerant phase change to a refrigerant circulates between the indoor unit
In an absorption type cold heat generating device comprising a refrigerant circuit including a liquid pipe and a refrigerant vapor pipe, and a control means for suppressing a cooling operation when the water level of a cooling tower water tank is abnormal, the refrigerant liquid pipe is an indoor unit.
Is connected to a heat exchanger installed in the engine via an expansion valve, and the control means controls the operation of the cooling water circulation pump when the water level is abnormal.
When the operation of the cooling water circulation pump is suppressed and the operation of the cooling water circulation pump is continued for a set time or longer, a cooling switching abnormality signal for stopping the operation of the device is output .

The control means inhibits the operation of the cooling water circulation pump based on the water level signal abnormality of the cooling tower water tank, and
When the water level in the cooling tower water tank is abnormal,
When the cooling preparation completion signal is abnormal, and the abnormality of the cooling preparation completion signal exceeds the set time continuously for the cooling preparation start set time, the cooling switching abnormality signal is output and the abnormality of the cooling preparation completion signal is output. When the continuation of is within the set time, the control may be shifted to the normal control.

According to the present invention, even if the cooling preparation completion signal becomes abnormal due to the water level abnormality in the cooling tower water tank, the cooling switching abnormality signal is not output unless it continues for the set time or more, so that the control device malfunctions. Momentary outages are avoided.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 3, an absorption chiller-heater 100 to which equipment including a high temperature regenerator 1, a separator 2, a low temperature regenerator 3, a condenser 4, an evaporator 6 and an absorber 5 is connected, and water storage A cooling tower water tank (cooling tower) 42 in which the cooling water is circulated by the cooling water circulation pump 14 to the condenser 4 via the absorber 5, and a refrigerant that changes phases between the evaporator 6 and one or more indoor units 52, 53. refrigerant but circulating
An absorption type cold heat generating device comprising: a refrigerant circuit including a liquid pipe 50 and a refrigerant vapor pipe 51; and a control means (controller) 59 for suppressing a cooling operation when the water level in the cooling tower water tank 42 is abnormal, control means 59, the water level abnormally suppressed more operation of the cooling water circulation pump 14 of the cooling tower water tank 42, when the operation inhibiting retention of the cooling water circulation pump 14 are continuously set time or more, stops the operation of the apparatus, the expansion valve Is configured to output a cooling switching abnormality signal that completely closes . That is, the control means 59 inputs the water level signal of the cooling tower water tank 42 detected by the control devices 61 and 62, and the water level signal is abnormal (O
FF) based on the operation of the cooling water circulation pump 14 (OF)
At the same time as F), the cooling preparation (CIR) completion signal is set to abnormal (OFF) . When the abnormality of the CIR completion signal continues for the set time or more and the CIR start set time elapses, the cooling switching abnormality signal is output. If the signal abnormality does not continue for the set time, the normal control flow is entered. Cooling ready (CIR) completion signal is cooling
When the water level in the tower water tank 42 is abnormal (OFF),
It is a signal that is abnormal (OFF) and this signal is set
Abnormality of air-conditioning switching when it is abnormal for more than 1 consecutive period
The signal is output.

As described above, the control means for detecting the cooling water level in the cooling tower water tank is provided with a timer, a judging device, etc., and the apparatus is not stopped instantaneously when the water level signal is abnormal (OFF). Rise when keeping a certain time signal abnormality set, by stopping <br/> the device outputs a cooling switch abnormality signal, the apparatus stops due to malfunction of the control device to the
It is intended to prevent the tension valve from fully closing . Especially when sending makeup water to the cooling tower water tank with a pressurizing pump, the pressure fluctuation range is large, and the pressure is instantly lowered, and the operation is likely to be stopped.
Even if the cooling water level is abnormal and the cooling preparation (CIR) completion signal becomes abnormal, the elapsed time is compared with the set time and the cooling preparation (CIR) completion signal error (OFF) is maintained continuously for the set time or longer. If it is not, the control device for detecting the water level is judged to be malfunctioning by a judging device or the like, and the process is shifted to the normal control flow.

According to the present invention, malfunctions can be prevented, the refrigerating capacity down time in the system can be shortened, and instantaneous stoppage of operation of the device due to the cooling water level (OFF) of the outdoor unit can be prevented.

[0018]

According to the present invention, when an abnormality in the cooling preparation completion signal continues for a set time or longer due to an abnormality in the water level of the cooling tower water tank, a cooling switching abnormality signal is output. The operation stop is avoided and the refrigerating capacity down time is shortened.

[Brief description of drawings]

FIG. 1 is a control flow diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional outdoor unit.

FIG. 3 is a diagram showing a recent device.

FIG. 4 is a diagram showing a control flow of a conventional technique.

[Explanation of symbols]

1 High temperature regenerator 2 separator 3 low temperature regenerator 4 condenser 5 absorber 6 evaporator 7 High temperature solution heat exchanger 8 Low temperature solution heat exchanger 9 Solution circulation pump 14 Cooling water circulation pump 52,53 Indoor unit 59 controller 100 absorption cold water heater

Continuation of front page (56) Reference JP-A-8-121894 (JP, A) JP-A-7-229658 (JP, A) JP-A-5-302770 (JP, A) JP-A-8-247571 (JP , A) JP-A-3-134441 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 15/00 306

Claims (2)

(57) [Claims] 1. An absorption chiller-heater connected to equipment including a regenerator, a condenser, an evaporator, and an absorber, and cooling in which stored cooling water is circulated to the condenser via a absorber by a cooling water circulation pump. and towers water tank, the evaporator and at least a refrigerant liquid pipe of one phase change refrigerant between the indoor unit circulates the refrigerant vapor
In an absorption type cold heat generating device provided with a refrigerant circuit including a trachea, and a control means for suppressing cooling operation when the water level of the cooling tower water tank is abnormal, the refrigerant liquid pipe is installed in an indoor unit.
Connected to the heat exchanger via an expansion valve, and the control means operates the cooling water circulation pump when the water level is abnormal.
Arresting, the when the cooling water circulation pump operation inhibiting retention successive set time or more, absorption cold generating apparatus, characterized in that outputs a cooling switch abnormality signal for stopping the operation of the apparatus. Wherein the control means is cooled while operating deter water level signal abnormally based coolant circulation pump of the cooling tower water tank
If the water level in the tower tank is abnormal, it will be
The cooling preparation completion signal is abnormal, and when the abnormality of the cooling preparation completion signal exceeds the set time continuously for the cooling preparation start set time, the cooling switching abnormality signal is output, and the abnormality of the cooling preparation completion signal is output. The absorption cold heat generator according to claim 1, wherein when the continuation is within a set time, the control is shifted to a normal control.