JP3205094B2 - How to control the number of absorption chillers and water heaters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently controlling the number of absorption chillers and chiller / heater units in which a plurality of absorption chiller modules or absorption chiller / heater modules are installed.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a plurality of absorption chiller modules or chiller / heater modules 10 are installed as absorption chillers and chiller / heater modules, and each module 10
A configuration in which a cold / hot water supply pipe 12 and a cold / hot water supply pipe 14 are connected in parallel is known. 16 is a cold / hot water pump, 18 is a cooling water pump, 20 is a cooling water supply pipe, and 22 is a cooling water discharge pipe. To calculate the load factor, the calorific value and the temperature difference between the entrance and exit (in the case of a constant flow rate system) are separately measured.

[0003]

In the system as shown in FIG. 5, the control has been conventionally made based on the inlet / outlet water temperature. For example, in the case of the chilled water mode, as shown in FIG. 6, the chilled water inlet temperature is controlled to be constant (for example, 12 ° C.). In this case, when the load becomes low, there is a problem that the temperature of the chilled water outlet increases, and it becomes difficult to perform cooling. An object of the present invention is to solve the above-mentioned problem, and it is possible to control the chilled / hot water outlet temperature until the unit number control is started, to reduce the number of units at low load operation, and to set the chilled / hot water outlet temperature to the chilled water mode. The object of the present invention is to provide a method for controlling the number of vehicles, which is increased in the heating mode and lowered in the heating mode.

[0004]

In order to achieve the above object, a method for controlling the number of absorption chillers and chilled and heated water heaters according to the present invention, as shown in FIGS. In the absorption chiller / cooled / hot water machine where multiple machine modules are installed and the chilled / hot water piping is connected in parallel to each module,
When the cooling load or the heating load decreases to a predetermined ratio, the number of operating modules is reduced by one, and the cooling / heating water outlet control temperature setting value is set to an initial setting value + α ° C. in the cooling mode, and to an initial setting value−α in the heating mode. The temperature is automatically changed stepwise within this temperature range so that β ° C. becomes a set value for only one final module.
As shown in FIG. 1, the temperature detector 2
4 are connected, and the temperature detector 24 and each module 10 are connected.
Are connected via a number control device 26 so that the number of operating modules is controlled by the cold / hot water outlet temperature. Further, each time the number of operating modules is increased or decreased, the cold / hot water outlet temperature control set value is automatically changed. Therefore, it is not necessary to provide a stop valve in the cold / hot water / cooling water system of each module.

In the cooling mode, α ° C. is 1.5 to 4 ° C.
Desirably from 2 to 3 ° C., beta ° C. is 1.5 to 8 ° C. in the heating mode, and desirably 2 to 3 ° C.. Α ℃ above
If the value of 4 ° C exceeds 4 ° C or the value of β ° C exceeds 8 ° C, during low-load operation, in cooling operation, the chilled water outlet temperature is too high, and sufficient cooling cannot be performed, or in heating operation Has the disadvantage that the hot water outlet temperature is too low and heating cannot be performed sufficiently.On the other hand, if the temperature is lower than 1.5 ° C, when the number decreases during low load operation, when cooling operation, The chilled water outlet temperature of the operation module is too low, the capacity is reduced, the COP is reduced, and the safety device operates. Further, in the case of the heating operation, there is a disadvantage that the temperature of the hot water outlet of the operation module is too high, and the safety device operates.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. However, the shapes of the components described in this embodiment, the relative arrangement thereof, and the like are not intended to limit the scope of the present invention to them only, unless otherwise specified, and are merely illustrative examples. It's just In FIG. 1, the temperature is detected by a temperature detector 24 provided in the cold / hot water discharge pipe 14, and the total number of modules is controlled by the number controller 26 so that the temperature can be maintained at a set point.

The load factor is counted by the ratio between the total value of the combustion amount (fuel control valve opening) of each module 10 (the load factor is 0 for a stopped module) and the total rated combustion amount. In the control of changing the number of operating modules, if the average load factor of the operating modules decreases to, for example, 40%, one module is stopped. Conversely, if the average load factor of the operating modules exceeds, for example, 90%, one additional module is operated.
The set value of the hot / cold water outlet temperature is, for example, an initial set value (for example, 7 ° C.) + 3 ° C. for cooling, and an initial set value (for example, 60 ° C.)-3 ° C. for one example of heating, and one final module. Set values only for minutes and automatically change in stages.

FIG. 2 shows a cooling operation in the case of two modules. A cooling water outlet control temperature of 7 ° C. and a cooling water inlet temperature of 12 ° C. at a cooling load of 100%, and a cooling load of 40%
Shows the case of switching to the state of the chilled water outlet control temperature of 10 ° C. In this case, the chilled water outlet temperature of the operation module changes as shown by the broken line.

FIG. 3 shows a cooling operation in the case of four modules. FIG. 4 shows the cooling operation when the number of modules is six. Each time the cooling load becomes 40% and the module stops, the chilled water outlet control temperature is set to 7 ° C.
Control is performed so as to increase stepwise between + 3 ° C. = 10 ° C. The chilled water outlet temperature of the operating module rises as shown by the dashed line.

[0010]

As described above, the present invention has the following effects. (1) Even if the load becomes low, the temperature of the cold and hot water does not greatly change and cooling or heating can be performed efficiently. (2) As compared with the conventional chilled water inlet temperature control, the chilled water outlet control temperature does not need to be raised, so that the usability is improved and the number of units can be controlled more efficiently.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of an apparatus for implementing a method of controlling the number of absorption refrigerators / cooled / hot water heaters according to the present invention.

FIG. 2 is a graph showing a cooling operation control state when the number of modules is two in the embodiment of the present invention.

FIG. 3 is a graph showing a cooling operation control state when four modules are used in another embodiment of the present invention.

FIG. 4 is a graph showing a cooling operation control state in a case where the number of modules is six in still another embodiment of the present invention.

FIG. 5 is an explanatory view showing an example of a conventional absorption refrigerator / cooled / hot water machine.

FIG. 6 is a graph showing a case where control is performed at a cold / hot water inlet temperature in the system shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Absorption chiller / cooling / hot / water machine module 12 Cooling / heating water supply pipe 14 Cooling / heating water extraction pipe 16 Cooling / heating water pump 18 Cooling water pump 20 Cooling water supply pipe 22 Cooling water extraction pipe 24 Temperature detector 26 Number control device

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 15/00 306

Claims (2)

(57) [Claims] 1. A cooling load or a heating load is previously determined in an absorption refrigerator / cooler / heater in which a plurality of absorption / chiller / cooler / heater modules are installed, and a cooler / heater pipe is connected to each module in parallel. When the ratio decreases to one, the number of operating modules is reduced by one, and the chilled / hot water outlet control temperature set value is set to the initial set value + α ° C in the cooling mode and the initial set value -β ° C in the heating mode for only the last module. A method for controlling the number of absorption chillers and water heaters and chillers, which is automatically changed stepwise within this temperature range so as to reach the set value of 2. α ° C. is 1.5 to 4 ° C., β ° C. is 1.5 to 8 ° C.
2. The absorption refrigerator according to claim 1, wherein
How to control the number of hot and cold water heaters .