JPH0447567Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to absorption refrigeration equipment, and particularly to absorption refrigeration equipment suitable for reducing operating costs during refrigeration operation.

[Conventional technology]

This type of absorption refrigeration equipment separates the heated solution in a high-temperature regenerator into concentrated solubility and water vapor in a separator.
The water vapor is converted into a liquid refrigerant in a condenser, this liquid refrigerant is evaporated in an evaporator, the refrigerant vapor is absorbed into a concentrated solution in an absorber to form a dilute solution, this liquid refrigerant is evaporated in an evaporator, and the refrigerant is The vapor is absorbed into a concentrated solution in an absorber to form a diluted solution, and the diluted solution is passed through a solution circulation circuit including a circulation pump and a heat exchanger for heat exchange between the diluted solution and the concentrated solution to a high-temperature regenerator. an absorption type water chiller/heater that can control the amount of heating given to the solution in the high-temperature regenerator according to the load size, and a cooling tower that converts high-temperature cooling water into low-temperature cooling water. , the water vapor in the condenser of the refrigerator is cooled and the cooled water with increased temperature is guided to the cooling tower, and the cooled water lowered to a lower temperature in the cooling tower can be pressurized by a cooling water pump and supplied to the condenser. Cooling water piping, Cold/hot water piping capable of guiding the cold water cooled by the evaporator of the refrigerator to the load, and pressurizing the cold water which cools the load and becomes high temperature with a cold/hot water pump to supply it to the evaporator; The refrigeration system is configured to include a control device that detects the state of the load and controls the refrigeration operation to a set state.

According to such absorption refrigerating equipment, when controlling the operation of this equipment, the control device receives a refrigerating operation signal of the absorption refrigerating machine, and when the refrigerating operation is in progress, the control device operates the cooling water pump and the cold/hot water pump. When the refrigerator is in operation and the refrigeration operation is stopped, the cooling water pump or cold/hot water pump is stopped to reduce power consumption. In addition, the temperature of the cooling water at the outlet of the cooling tower is detected by a detector, this is taken into the control device, and when the temperature detected by the detector falls below a set value, the control device detects the The power consumption of the fans was reduced by stopping the fans installed in the system.

[Problems solved by invention]

However, in such conventional technology, load fluctuations are made to correspond to changes in the temperature of cold and hot water, the temperature of this cold and hot water is detected by a detector, and the amount of heat input to the refrigerator is calculated based on the temperature of this cold and hot water. By controlling and thereby changing the amount of refrigerant generated,
Although the refrigeration capacity is matched to the load, auxiliary equipment such as cooling pumps and cold/hot water pumps are always operating at 100% output regardless of load fluctuations. Furthermore, in general, the air conditioning load of buildings, etc.
As shown in the figure, the percentage of full load operation is small in both summer and winter, and most of the heat source equipment and air conditioning equipment are operated at partial load.

This resulted in the following problems:

(1) The operating time of the auxiliary equipment becomes longer than the operating time of the refrigerator, and the proportion of energy consumed by the auxiliary equipment increases.

(2) During low-load operation, the amount of energy supplied to the load and the amount of heat input to the refrigerator decreases, so the amount of heat released from the cooling water side decreases. Therefore, there is no need to flow the rated amount of cooling water into the condenser.

(3) During operation during the intermediate period when the cooling water temperature drops, if the rated amount of cooling water is flowed into the condenser, the refrigerant will freeze or the solution will crystallize.

The purpose of this invention is to provide absorption refrigeration equipment that can save energy by operating auxiliary equipment in accordance with the refrigeration load.

[Means to solve the problem]

This idea consists of an absorption chiller that can supply thermal energy according to the size of the load, and whose capacity can be controlled in stages, and an absorption chiller that is connected to the chiller's condenser via a cooling water piping to provide cooling from the chiller. In absorption refrigeration equipment that has a cooling tower that exchanges heat between water and the atmosphere, a cooling water pump that can change the number of poles and adjust the flow rate of cooling water is installed in the cooling water piping, and the load on the chiller changes. and a sensor that detects a change in the temperature of the return cooling water from the cooling tower;
The present invention is characterized by comprising a control device that receives a detection signal from the sensor and outputs a control signal for switching the number of poles of the cooling water pump based on the detection signal and the set capacity of the refrigerator.

Preferably, the cooling water pump is a 2-pole-4-pole switching type pump.

[Effect]

The operation of the above device will be explained below.

When the absorption chiller is in cooling operation, if the load changes and falls below a certain set value, a sensor installed in the cold/hot water return pipe detects the decrease in load as a temperature drop, and the absorption chiller Reduces the amount of heat input into the machine and performs low output operation. At the same time, the controller turns the pump to low speed. As a result, the rotational speed of the pump decreases, so the flow rate of the cooling water decreases. In addition, if the outside air temperature or external temperature decreases, the cooling efficiency of the cooling tower increases and the cooling water return temperature decreases, or the load factor decreases and the cooling tower inlet temperature decreases, the above-mentioned The sensor detects the cooling water return temperature of the cooling tower, and this detection signal is input to the control device. When the temperature falls below a set value, the control device reduces the cooling pump cooling water flow rate.

〔Example〕

Examples of this invention will be described below.

Reference numeral 1 designates an absorption chiller. During cooling, this absorption chiller 1 supplies chilled water to a load 4 via a chilled/hot water pipe 2 with a chilled/hot water pump 3, and during heating, it supplies chilled water to the load 4 through the chilled/hot water pipe 2. Supply hot water to load 4. This absorption refrigerator 1 separates a solution heated in a high-temperature regenerator into a concentrated solution and water vapor in a separator, converts the water vapor into liquid refrigerant in a condenser, evaporates the liquid refrigerant in an evaporator, and evaporates the refrigerant vapor. is absorbed into a concentrated solution in an absorber, and the diluted solution is supplied to a high-temperature regenerator via a solution circulation circuit including a circulation pump and a heat exchanger that exchanges heat between the diluted solution and the concentrated solution. It has a configuration that allows it. 5 is a cooling tower, and this cooling tower 5 extracts the amount of heat from the load 4 and the amount of heat required to drive the refrigerator 1 using cooling water when the absorption refrigerator 1 performs cooling operation. Heat is exchanged between the cooling water and the air in the atmosphere, and the heat is radiated to the atmosphere to cool the cooling water to a predetermined temperature. 6 is a cooling pump, and this cooling pump supplies cooling water to the absorption refrigerator 1 and the cooling tower 5. Moreover, this cooling water pump 6 has a structure in which the flow rate of cooling water is varied by changing its rotation speed. Reference numeral 7 denotes a cold/hot water temperature sensor, which senses the return temperature of the cold/hot water on the load side and measures the amount of load. 8 is a cooling water temperature sensor, and this sensor 8 detects the temperature of the cooling water returned from the cooling tower 5. 9 is a control device;
A control device 9 receives detection signals from the sensors 7 and 8 and controls the rotation speed of a motor 10 that drives the cooling pump 6. These sensors 7 and 8 and the control device 9 are built into the absorption refrigerator 1, and the cooling water pump 6 is built into the cooling tower 5. The absorption refrigerator 1 and the cooling tower 5 are connected by a cooling water pipe 11.

FIG. 2 is a circuit diagram showing an example of a rotation speed control method for the motor 10. The circuit example shown in FIG. 2 changes the motor rotational speed by switching the motor's pole number ratio, for example, between two and four poles.

The motor 10 is connected to the control device 9 via wiring for switching the number of poles. The control device 9 switches the polarity of the motor 10 according to the temperature detected by the sensor 8. Although a method of switching the polarity of the motor was adopted here, the method is not limited to this, and various speed control methods for induction motors may be used, such as the secondary resistance method, Ward Leonard method, variable frequency method, etc. It goes without saying that this method can be adopted.

The operation of the embodiment configured in this way will be explained.

When the absorption chiller 1 is in cooling operation, if the load amount of the load 4 changes and becomes less than a certain set value, the sensor 8 detects the decrease in the load amount as a temperature drop, thereby reducing the heat input to the absorption chiller 1. Reduce the power and perform low output operation. At the same time, the control device 9 causes the motor 10 to rotate at low speed. That is, the induction motor 10
By switching from two-pole operation to four-pole operation, the rotational speed of the pump 6 is reduced, and the cooling water flow rate is reduced. In addition, when the outside air temperature or the outside temperature decreases, the cooling efficiency of the cooling tower 5 increases and the cooling water return temperature decreases, or the load factor decreases and the inlet temperature of the cooling tower 5 decreases. The sensor 8 detects the cooling water return temperature of the cooling tower 5, and this detection signal is taken into the control device 9. When this becomes less than a set value, the control device 9 switches the number of poles of the motor 10 that drives the cooling pump 6. control to reduce the cooling water flow rate. Conversely, when the load factor increases or the cooling water temperature rises, the control device 9 switches the number of poles for driving the cooling water pump to increase the flow rate of the cooling water.

[Effect of idea]

As explained above, according to this idea,
During partial load operation, the power consumption of the cooling water pump is reduced, resulting in approximately 18% power savings over the entire cycle compared to conventional constant flow systems. In addition, according to this invention, since the amount of cooling water is reduced when the cooling water is low, the heat exchange rate is reduced and the temperature inside the refrigerator can be prevented from dropping more than necessary, and freezing of the refrigerant and crystallization of the solution can be prevented. .

[Brief explanation of the drawing]

Figure 1 is a system diagram showing an embodiment of this invention;
The figure is a circuit diagram showing the rotation speed control system of the cooling water pump used in this invention, and FIG. 3 is a diagram showing the load frequency distribution in summer and winter in a typical building. 1...Absorption chiller, 2...Cold/hot water circuit, 3...
...Cold/hot water pump, 4...Load, 5...Cooling tower, 6
...Cooling water pump, 7...Cold and hot water temperature sensor,
8...Cooling water temperature sensor, 9...Control device, 1
0...Motor, 11...Cooling water piping.

Claims (1)

[Scope of claim for utility model registration] (1) An absorption chiller that can supply thermal energy according to the size of the load and whose capacity can be controlled in stages;
In absorption refrigeration equipment having a cooling tower that is connected to a condenser of the refrigerator via a cooling water piping and exchanges heat with the cooling water from the refrigerator with the atmosphere, the cooling water piping is configured to switch the number of poles. A cooling water pump that is possible and that adjusts the flow rate of the cooling water is provided, and a sensor that detects changes in the load on the refrigerator and changes in the temperature of the cooling water returned from the cooling tower, and a detection signal from the sensor. absorption refrigeration equipment, comprising: a control device that receives the detection signal and outputs a control signal for switching the number of poles of the cooling water pump based on the detection signal and the set capacity of the refrigerator. (2) The absorption refrigeration equipment according to claim 1, wherein the cooling water pump is a 2-pole-4-pole switching type pump.