JPS6117319Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an absorption refrigerator in which the amount of heat input and the amount of solution circulation are controlled depending on the state of the cooling load.

A water-lithium salt absorption refrigerator using water as a refrigerant and a salt solution such as a lithium bromide solution as an absorption solution is known. Conventionally, in this type of absorption refrigerator, in order to balance the refrigeration output with the cooling load, the temperature of the cold water flowing to the load is detected, and the amount of heat input to the refrigerator and the amount of solution circulation are adjusted according to this temperature.
It was controlled in stages such as "strong,""weak," and "stop." Since both the heat input amount and the solution circulation amount are controlled simultaneously, especially when switching from "strong" to "weak", if you throttle both at the same time, the flow rate of the absorption solution flowing to the absorber will immediately decrease. The amount of liquid refrigerant flowing to the evaporator does not decrease easily, and a "strong" amount of liquid refrigerant continues to flow for a while.
Therefore, the refrigerant vapor generated in the evaporator cannot be sufficiently absorbed by the absorber, resulting in a large amount of ineffective refrigerant, resulting in a reduction in operating efficiency.

The present invention has been made with the aim of eliminating the drawbacks of the conventional ones as described above. An embodiment of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a system diagram of an embodiment of an absorption refrigerator according to the present invention.

In the figure, 1 is a high-temperature regenerator that heats a dilute solution in which refrigerant has been absorbed by an absorption solution using a heat source such as a burner or hot water, and separates it into refrigerant vapor and an intermediate concentrated solution. The intermediate concentrated solution is cooled down through the high-temperature heat exchanger 6, and then introduced into the low-temperature regenerator, where it is heated and concentrated again with high-temperature refrigerant vapor from the high-temperature regenerator 1, 3 is the low-temperature regenerator 2.
A condenser 4 condenses the refrigerant introduced from the condenser 3, an evaporator 4 evaporates the liquid refrigerant condensed in the condenser 3, and cools cold water from a load (not shown); The absorber 8 is introduced after the temperature has been lowered through the exchanger 7 and absorbs the refrigerant vapor evaporated in the evaporator 4 to form a dilute solution.The absorber 8 converts the dilute solution from the absorber 5 through the heat exchangers 7 and 6 to a high temperature. The solution pump 9 that sends to the regenerator 1 controls the flow rate of the dilute solution to “strong” and “weak”.
Two-stage switching solution flow rate adjustment valve, 10a, 10
b is a heat input adjustment valve that turns on and off a supply heat source such as fuel or hot water to the high-temperature regenerator 1; 11 is a chilled water coil into which chilled water from a load (not shown) is introduced;
12 is a cooling water coil for removing the heat absorbed by the absorber 5; 13 is a temperature measuring device for measuring the temperature of the cold water flowing through the cold water coil 11; and 14 is a temperature measuring device 1.
This is a controller that sends a control signal to the solution flow rate adjustment valve 9 and the heat input amount adjustment valves 10a and 10b based on the cold water temperature measured in step 3.

In addition, FIG. 2 shows the adjustment valves 9, 10a, 10 controlled by the controller 14 based on the detection signal of the temperature measuring device 13.
Fig. 3 shows the control system of Fig. b.

Next, the operation of the absorption refrigerator of the present invention configured as described above will be explained.

The dilute solution in the absorber 5 is sent by a solution pump 8 to the high temperature regenerator 1 via a solution flow rate adjustment valve 9 and heat exchangers 7 and 6, where it is heated. Therefore, the refrigerant in the dilute solution evaporates and is separated into refrigerant vapor and an intermediate concentrated solution. The temperature of the separated intermediate concentrated solution is lowered by heat exchange with the dilute solution in the high temperature heat exchanger 6, and then heated again by high temperature refrigerant vapor in the low temperature regenerator 2 to form a concentrated solution. The refrigerant vapor generated in the low-temperature regenerator 2 and the refrigerant that heated the intermediate concentrated solution are condensed in the condenser 3 to become liquid refrigerant, and introduced into the evaporator 4. The evaporator 4 has a chilled water coil 1 through which chilled water from the load flows.
1 is provided, and the liquid refrigerant removes heat from the cold water flowing through the coil 11 and evaporates, so that the temperature of the cold water flowing through the cold water coil 11 decreases. On the other hand, the concentrated solution flows from the low-temperature regenerator 2 due to the pressure difference and gravity.
After being cooled down through the low-temperature heat exchanger 7, it is introduced into the absorber 5, where it absorbs the refrigerant vapor evaporated in the evaporator 4 and becomes a dilute solution. The same operation is repeated thereafter.

By the way, the temperature of the cold water from the load is measured by the temperature measuring device 13, and the measurement result is sent to the controller 14.
sent to. In the illustrated embodiment, the cold water temperature is measured at the outlet of the cold water coil 11, but the temperature at the inlet may also be measured. Controller 1
In step 4, the suitability of the refrigeration output for the load is determined based on the chilled water temperature, and if the chilled water temperature is high, the refrigeration output is increased, and the solution flow rate adjustment valve 9 is sufficiently opened to create a "strong" state where the solution flow is sufficiently flowing. At the same time, both heat input adjustment valves 10a and 10b are opened to ensure that sufficient fuel or hot water is supplied to the high temperature regenerator 1.

On the other hand, if the controller 14 determines that the chilled water temperature is lower than the predetermined temperature, the opening degree of the solution flow rate adjustment valve 9 is narrowed to reduce the solution flow rate to reduce the refrigeration output to a "weak" state. In addition to controlling
One heat input amount adjusting valve 10a is closed, and fuel or hot water is supplied to the high temperature regenerator 1 through the other heat input amount adjusting valve 10b. However, at this time, after the control valve 14 sends out a signal to close the heat input amount adjustment valve 10a, it sends out a signal to switch the solution flow rate adjustment valve 9 to the "weak" state after a predetermined delay. Note that this delay time is such that the amount of liquid refrigerant introduced into the evaporator 4 after reducing the amount of heat input to the high-temperature regenerator 1 is "weak".
For example, a timer or the like is set to correspond to the time required for the state to decrease.

In this way, when the operating state of the refrigerator changes from the "strong" state to the "weak" state, the solution circulation amount remains in the "strong" state for a while, and the remaining liquid It is possible to absorb refrigerant and turn it into effective refrigerant, prevent generation of ineffective refrigerant, and improve operating efficiency at partial loads.

As mentioned above, according to the present invention, when switching the operating state from "strong" to "weak", the solution flow rate is reduced later than the action to reduce the heat input, thereby eliminating the drawbacks of the conventional method. An absorption refrigerator having the above effects is provided.

Although the present invention has been described for a case where it is applied to a double-effect absorption refrigerator, it is of course possible to apply it to a single-effect absorption refrigerator as well, and the present invention can be modified in various ways without departing from the gist. Needless to say, it can be implemented by

Moreover, when stopping the operation of the refrigerator, the controller 14 sends a signal to close both the heat input amount adjusting valves 10a and 10b.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of an absorption refrigerator according to the present invention, and FIG. 2 is a diagram showing an extracted control system shown in FIG. 1. 1...High temperature regenerator, 2...Low temperature regenerator, 3...
Condenser, 4...Evaporator, 5...Absorber, 9...Solution flow rate adjustment valve, 10a, 10b...Heat input amount adjustment valve, 11...Cold water coil, 13...Temperature measuring device,
14...Controller.

Claims (1)

[Scope of utility model registration request] A regenerator that regenerates refrigerant vapor and absorption solution by heating a dilute solution in which refrigerant has been absorbed into an absorption solution, a condenser that condenses the refrigerant vapor regenerated by this regenerator into liquid refrigerant, and this condenser. An absorber comprising an evaporator that evaporates liquid refrigerant from the evaporator to lower the temperature of the chilled water in the load, and an absorber that absorbs the refrigerant evaporated in the evaporator into the absorption solution regenerated by the regenerator to form a dilute solution. In the refrigerator, a flow rate regulator that adjusts the flow rate of dilute solution from the absorber to the regenerator, a heat input amount regulator that adjusts the amount of heating heat input to the regenerator, and a temperature of the chilled water of the load is measured. It is equipped with a temperature measuring device, and a controller that controls the flow rate regulator and the heat input amount regulator based on the temperature measured by the temperature measuring device to control the operating state of the absorption chiller, and the controller is configured to control the operation state of the absorption chiller. An absorption refrigerating machine characterized in that the flow rate regulator is operated a predetermined time later than the heat input amount regulator when switching the operating state of the machine from strong to weak.