JPH06294555A - Cooling operation of absorption water cooling/heating apparatus - Google Patents

Abstract

PURPOSE:To provide a cooling operation of an absorption water cooling/heating apparatus which is free from danger of freezing by allowing adaptation to a sudden change in the temperature of chilled water associated with a change in the flow rate of the chilled water. CONSTITUTION:In an operation method of an absorption water cooling/heating apparatus which has a water cooling/heating apparatus, an air-conditioner 27, a water cooling/heating piping 20 connected thereto, a bypass piping 23 having bypass valve 24 to link a water cooling/heating inlet piping and a water cooling/ heating outlet piping of the piping 20 and a water cooling/heating pump 21 for circulating chilled or heated water as provided in the water cooling/heating piping on the side of a water cooling/heating device from the bypass piping 23, the bypass valve 24 is opened when the amount 18 of chilled or heated water circulating through the water chilling/heating machine, the number of operating units on the side of the air conditioner or a load 19 falls below a set value. The water chilling/heating pump 21 and a bypass piping 23 may be set within the water chilling/heating apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling operation of an absorption chilled / hot water device, and more particularly, to a cooling system capable of preventing freezing when the chilled water temperature suddenly changes when the chilled water temperature changes suddenly. Regarding driving method.

[0002]

2. Description of the Related Art In a conventional absorption chiller-heater, a change in the flow rate of chilled-heated water flowing through the absorption chiller-heater is regulated within half of the rated flow rate, and when it falls below half, the absorption chiller-heater is stopped urgently. I was trying to be safe. A conventional absorption refrigerator is shown in FIG. In FIG. 3, 1 is an evaporator, 2 is an absorber, 3 is a regenerator, and 4 is a condenser. And the hot and cold water piping 2 on the load side
0 is a cold / hot water pump (primary pump) for absorption cold / hot water machine 21
, And an air conditioner cold / hot water pump (secondary pump) 22 are separately provided, and a bypass control valve 26 is further provided between the cold / hot water feed header 28 and the cold / hot water return header 29 so that the differential pressure between these headers becomes constant. In this way, the flow rate of the absorption / cooling water heater cold / hot water pump 21 is prevented from decreasing. Therefore, the equipment is complicated and expensive.

Further, even if the load on the air conditioner 27 side is reduced, the flow rate of cold / hot water on the cold / hot water machine side is kept substantially constant, so that the power of the primary pump 21 does not decrease, and also from the viewpoint of energy saving operation. There was a problem. Furthermore, the bypass control circuit between the headers and the safety circuit of the chiller / heater (a circuit that detects a decrease in the flow rate of chilled / hot water and performs an emergency stop) are completely separate circuits. There was also a problem in operation control that the chiller-heater stopped urgently due to the delay.

[0004]

[Problems to be Solved by the Invention] Cold / hot water pump 2 for air conditioning
2 without the bypass control valve 26 and only by the cold / hot water pump 21 for the absorption cold / hot water machine, as it is, the air conditioner 2
When a system for supplying cold / hot water to 7 is used, the flow rate of cold / hot water greatly varies depending on the operating state of the air conditioner side. An air conditioner, for example, an air handling unit having a relatively large capacity, adjusts the cold / hot water valve to change the cold / hot water flow rate in order to control the supply air temperature. Further, for a fan coil unit or the like having a relatively small capacity, the cold / hot water valve is turned on / off depending on use / non-use to change the cold / hot water flow rate.

On the air-conditioned side, a large number of air handling units and fan coil units are usually used. Therefore, the circulating flow rate of cold / hot water greatly changes depending on the use condition or load condition. In extreme cases, the amount of cold and hot water becomes zero. The absorption chiller-heater has concentration energy stored in the absorption solution, and normally does not suddenly lose its capacity even when the operation is stopped.

[0006] Assume that stable operation was performed at a certain cold water flow rate. At this time, if the cold water flow rate drastically decreases, the capacity of the absorber exceeds the heat capacity of the cold water, and the cold water temperature drops sharply. With this, control is performed so as to reduce the amount of heat supplied to the regenerator, but the absorber capacity does not decrease sharply due to the amount of solution retained, and the cold water temperature continues to decrease and there is a risk of freezing. Therefore, it is an object of the present invention to provide a cooling operation method of an absorption chilled / hot water apparatus which can appropriately cope with a sudden change in cold water temperature due to a change in cold water flow rate as described above and which does not pose a risk of freezing.

[0007]

In order to solve the above problems, in the present invention, a hot and cold water machine, an air conditioner, cold and hot water pipes connecting them, cold and hot water inlet pipes and cold and hot water outlet pipes of the pipes are provided. In a method for operating an absorption chilled / hot water device having a bypass pipe having a bypass valve for connecting the hot and cold water pumps for circulating cold and hot water provided in the hot and cold water pipes on the hot and cold water machine side of the bypass pipe, The method for operating an absorption chilled / hot water device is characterized in that the bypass valve is opened when the amount of chilled / hot water circulating in the chilled / hot water machine, the number of operating units on the air conditioner side, or the load falls below a set value.

In the cooling / heating device of the cooling operation method,
The cold / hot water pump and the bypass pipe may be installed inside the cold / hot water machine. As the absorption cold / hot water device to which the operation method of the present invention can be applied, a regenerator, an absorber, an evaporator, a condenser,
It can be applied to all known absorption cooling and hot water devices having a cooling water pump, a refrigerant pump, and a heating valve, for example, a type in which a high temperature regenerator is separately provided as a regenerator, and the refrigerant vapor from the regenerator can be used. A pipe having a valve leading to the absorber / evaporator may be provided, and in such a type, the cooling water pump may be stopped and the valve may be opened to directly introduce the heated steam into the evaporator. This helps to quickly raise the temperature of the circulating cold water.

[0009]

According to the present invention, in the cooling operation of the absorption chilled / hot water device, when the chilled water flow rate becomes equal to or less than the set value, the bypass valve connecting the chilled / hot water inlet pipe and the chilled / hot water outlet pipe is opened,
The minimum required amount of cold water can be circulated inside the absorption chiller / hot water generator by the discharge pressure of the cold / hot water pump to prevent the cold water temperature from excessively decreasing. The same effect can be obtained even if the above-mentioned operation is controlled by the number of operating air conditioners or the load instead of the flow rate of cold water. In this way, it is possible to prevent freezing due to a sudden change in the cold water outlet temperature when the flow rate of cold water changes.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings, but the present invention is not limited thereto. Example 1 FIG. 1 is a schematic configuration diagram showing an example of an absorption chiller-heater to which the present invention is applied. In FIG. 1, 1 is an evaporator, 2 is an absorber, 3 is a regenerator, 4 is a condenser, 5 is a cooling water pump, 7 is a refrigerant pump, 8 is a heating valve, and 10 is a solution pump, 1
1, 12 are solution passages, 13, 14, 17 are refrigerant passages, 1
5 is a refrigerant bypass passage, 16 is a bypass valve, and 2
Reference numeral 0 is a cold / hot water pipe, 21 is a cold / hot water pump, 18 is a cold / hot water amount detecting device provided in the cold / hot water pipe, 19 is an air conditioner side load detecting device, 23 is a bypass pipe provided in the cold / hot water pipe, and 24 is a bypass valve. is there.

In the cooling operation of this apparatus, the dilute solution that has absorbed the refrigerant passes from the absorber 2 through the passage 11,
It is introduced into the regenerator 3 by the pump 10. In the regenerator 3, the solution heated by the heating pipe 9 whose heating amount is controlled by the heating valve 8 and concentrated by evaporating the refrigerant from the dilute solution is passed through the passage 1
It is returned to the absorber 2 through 2 and absorbs the refrigerant. on the other hand,
The evaporated refrigerant enters the condenser 4 through the passage 13, is cooled by the cooling water, is condensed, and enters the evaporator 1 through the passage 14. In the evaporator 1, the refrigerant is circulated and evaporated by the refrigerant pump 7, and at that time, the heat of evaporation is taken from the cold water on the load side, the cold water is cooled, and the cold water is provided for cooling.

In the cooling operation of such an absorption chiller-heater, the flow rate of cold water flowing through the cold-hot water pipe 20 is detected, and when the flow rate of cold water becomes less than a set value, the bypass provided in the feed cold-water pipe and the return cold-hot water pipe. The bypass valve 24 of the pipe 23 is opened, and then the bypass valve 24 is closed as the flow rate of cold water flowing to the air conditioner side increases. The above control can be controlled by the number of air conditioners operating the air conditioner 27 or the air conditioner load by the air conditioner side load detection device 19, and when these are below the design value, the bypass valve 24 is opened, After that, the bypass valve 24 is closed when the number of operating air conditioners or the load of the air conditioners exceeds a set value.

FIG. 4 is a flow rate characteristic diagram showing the relationship between the load and the flow rate. From FIG. 4, the air conditioner 27 changes depending on the change of the air conditioning load.
The amount of cold and warm water flowing through the side changes to-(area A). At this time, the flow rate of the cold / hot water pump in the conventional system that performs header bypass control changes to-and becomes constant regardless of the load.

In the case of the bypass control according to the present invention, when the bypass valve 24 is the proportional control valve, it changes to-, and the region B becomes the bypass flow rate, and when it is the ON-OFF valve, it becomes -'- ', and the control characteristic is Will be different. In any case, as compared with the conventional header bypass method, the amount of energy saved is equivalent to the area C. The point at which the bypass valve is operated can be set arbitrarily. Further, the point at which the bypass valve is returned from the open state to the closed state is naturally or when the amount of cold / hot water increases more than ′.

Embodiment 2 FIG. 2 is a flow diagram showing another example of an absorption chiller-heater to which the present invention is applied. 2, the same symbols as those in FIG. 1 have the same meaning. In FIG. 2, the dilute solution from the absorber 2 enters the heat exchanger by the solution pump 10, where it is branched and part of it enters the high temperature regenerator 3'through the passage 11 'and is heated to evaporate the refrigerant. Then, the concentrated concentrated solution is introduced into the absorber 2 after being heat-exchanged by the heat exchanger through the passage 12 '.

On the other hand, the evaporated refrigerant gas passes through the passage 13 ', is used as a heat source of the regenerator 3, and is then introduced into the condenser 4. Further, a bypass passage 15 'provided with a bypass valve 16' is provided in the passage 13 'so that the refrigerant gas can be directly introduced into the absorber. Each of the other devices has the same operation as in FIG. 1 and is similarly cooled. Then, as in the case of FIG. 1, the bypass valve can control the flow rate of cold water on the load side, the number of operating air conditioners, or the load.

[0017]

According to the present invention, during the cooling operation of the absorption chilled / hot water apparatus, the risk of freezing can be prevented even when the flow rate of the cold water flowing through the apparatus is drastically reduced and the cold water temperature is suddenly changed. It is not necessary to use a hot and cold water pipe header, which simplifies the equipment, and at the same time saves energy without unnecessary heat escaping to the air conditioner side.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an absorption cold / hot water device to which the present invention is applied.

FIG. 2 is a flow configuration diagram showing another example of the absorption cold / hot water device to which the present invention is applied.

FIG. 3 is a schematic configuration diagram of a conventional absorption cold / hot water device.

FIG. 4 is a flow rate characteristic diagram showing the relationship between load and flow rate.

[Explanation of symbols]

1: Evaporator, 2: Absorber, 3: Regenerator, 3 ': High temperature regenerator, 4: Condenser, 5: Cooling water pump, 6: Cooling water pipe,
7: Refrigerant pump, 8, 8 ': Heating valve, 9: Heating pipe, 1
0: solution pump, 11, 11 ', 12, 12': solution passage, 13, 13 ', 14, 15, 15', 17: refrigerant passage, 16, 16 ': refrigerant bypass valve, 18: cold / hot water flow rate detection Device, 19: Air conditioner side load detection device, 20: Cold / hot water pipe, 21: Cold / hot water pump (primary pump), 22: Cold / hot water pump (secondary pump), 23: Bypass pipe, 24: Bypass valve, 25: Difference Pressure detector, 26: header bypass valve,
27: Air conditioner (plural units), 28: Hot and cold water feed header, 2
9: Cold / hot water return header

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Matsubara 11-1 Haneda-Asahicho, Ota-ku, Tokyo Inside EBARA CORPORATION

Claims (2)

[Claims] 1. A cold / hot water machine and an air conditioner, cold / hot water pipes connecting them, a bypass pipe having a bypass valve connecting the cold / hot water inlet pipe and the cold / hot water outlet pipe of the pipe, and a temperature lower than the bypass pipe In an operating method of an absorption chilled / hot water device having a chilled / hot water pump for circulating chilled / hot water provided in a chilled / hot water pipe on the water machine side, the amount of chilled / hot water circulating in the chilled / hot water machine, the number of operating units on the air conditioner side, or A method for operating an absorption chilled / hot water device, wherein the bypass valve is opened when the load becomes equal to or lower than a set value. 2. The method for operating an absorption chilled / hot water apparatus according to claim 1, wherein the cold / hot water pump and the bypass pipe are installed inside a cold / hot water machine.