JPS6269073A - Method of controlling absorption refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method of controlling an absorption refrigerator, and more particularly, to a method of controlling an absorption refrigerator that increases or decreases the amount of absorption liquid introduced into a regenerator. .

[Prior art]

Some absorption refrigerators have a regenerator equipped with a heating source, in which cold water or hot water can be obtained by receiving and receiving heat generated during repeated evaporation and condensation of an aqueous lithium bromide solution. In such an absorption refrigerator, 1 is
Since an absorption liquid with a large amount of vapor and a high concentration can be obtained from a dilute absorption liquid of lithium bromide, the performance of the absorption refrigerator can be improved.

By the way, the burnup in the heater is controlled according to the temperature of the obtained cold water or hot water, and if the load is high, the heating in the regenerator is increased, and the exhaust gas exhausted through the regenerator is The temperature increases. On the other hand, when the load is low, the burn-up in the heater is weakened, so the temperature of the exhaust gas flowing through the regenerator also decreases. This is not a problem if the sulfur content contained in the fuel used in the heating source is small, but if it contains a considerable amount of sulfur content, exhaust gas containing sulfur dioxide gas and unburned substances may be regenerated. It will flow through the vessel. It is well known that the dew point temperature of combustion gas varies depending on the amount of sulfur contained in the fuel. For example, a fuel containing IM% sulfur will condense at about 140°C, and if the content is lower than that, condensation will occur. The dew point temperature also becomes lower. Therefore, if fuel with a high sulfur content is used, when the load is low (and the temperature of the heat absorption surface of the regenerator and exhaust gas decreases), condensation will easily occur on the heat absorption surface of the regenerator.The dew will contain sulfur dioxide gas. When melted, it becomes dilute sulfuric acid, which corrodes regenerators made of iron-based metals in a short period of time.Furthermore, unburned carbon and other substances adhere to the condensation, narrowing the exhaust gas passage and causing heating. The performance of the air blower is forced to deteriorate, leading to problems such as combustion abnormalities and a rapid increase in the amount of unburned carbon.

To avoid this situation, conventionally, high-quality heavy oil with low sulfur content, kerosene, or even city gas have been used as heating fuel in the regenerator, but this has led to high fuel costs, and improvements are being made. is desired.

[Purpose of the invention]

The present invention was made in view of the above-mentioned problems, and its purpose is to prevent corrosion and unburned fuel from condensation in the regenerator even if a fuel containing a large amount of components such as sulfur that lowers the dew point of exhaust gas is used in the heating source. It is an object of the present invention to provide a control method for an absorption refrigerating machine that can avoid adhesion of carbon components and the like and can be operated with inexpensive fuel.

[Structure of the Invention] The absorption chiller control method of the present invention is characterized by the following:
The amount of absorption liquid introduced into the regenerator can be increased or decreased to increase the pressure inside the regenerator and raise the temperature of the absorption liquid and heat absorption surface to prevent problems caused by condensation on the heat absorption surface of the regenerator. That's what I did.

[For production]

When a pressure or temperature sensor detects that the exhaust gas temperature has reached the dew point temperature, the amount of absorption liquid supplied to the regenerator is reduced. Since the burnup at the heating source is maintained as long as the withdrawal temperature of cold or hot water remains unchanged, the heating of the absorption liquid in the regenerator is relatively strengthened, and the concentration, temperature and pressure of the absorption liquid in the regenerator are high. Become. The temperature of the heat absorption surface increases according to its concentration, temperature, and pressure, and the temperature of the heat absorption surface is maintained above the dew point temperature of the exhaust gas, leading to corrosion on the heat absorption surface and an increase in the amount of unburned carbon attached. This avoids problems caused by

〔Example〕

The present invention will be described in detail below based on an embodiment of an absorption chiller/heater that performs absorption refrigeration.

FIG. 1 is an overall system diagram of an example of an absorption chiller/heater to which the control method of the present invention is applied.
A low-temperature regenerator 3, a condenser 4, and an evaporator 5 are each formed, and in addition to these, a high-temperature regenerator 7 equipped with a heating source 6 is provided. Furthermore, a gas-liquid separator 8 is provided between the low-temperature regenerator 3 and the low-temperature regenerator 3, which separates vapor and concentrated absorption liquid from the gas-liquid mixed absorption liquid heated by the high-temperature regenerator. In the high-temperature regenerator 7, the heating source 6 burns the fuel, and the exhaust gas is discharged from the exhaust pipe 9.

A temperature sensor 12 (attached to such a high-temperature regenerator 7) can detect when the temperature of the exhaust gas or the heat absorption surface has reached the dew point temperature based on the sulfur content of the fuel used. An absorption liquid pump 14 for transferring the absorption liquid and a flow rate adjustment valve 15 are interposed in the pipe line 13 that introduces the absorption liquid into the high temperature regenerator 7. This flow rate adjustment valve receives a temperature signal from the temperature sensor 12. The opening degree is changed according to the temperature, and by reducing the amount of absorption liquid introduced into the high-temperature regenerator 7, the concentration, temperature, and pressure of the absorption liquid in the high-temperature regenerator 7 can be increased. If the absorption liquid pump 14 is a variable displacement type,
The discharge amount can be changed by the signal from the temperature sensor 12 without providing the flow rate adjustment valve 15. By the way,
Instead of such a method based on temperature detection, the amount of absorption liquid may be adjusted using a signal from the pressure sensor 17.

In this example, 25 in the figure is the dilute absorption liquid 2 in the absorber 2.
A heat exchanger 27 heats the absorption liquid flowing through the pipe line 13. The absorption liquid from the low-temperature regenerator 3 and the concentrated absorption liquid from the gas-liquid separator 8 are supplied to the heating side of each heat exchanger. It is designed to be distributed within 2. 28 is an absorption liquid pump, and 29 is a refrigerant pump.

In the absorption chiller/heater having such a configuration, predetermined control is performed in the following operating conditions to prevent dew condensation on the heat absorption surface of the high temperature regenerator 7.

In the cooling and heating cycles, if the load on the absorption water cooler/heater is large, even if oil with a high sulfur content is used as fuel, the burnup in the heating source 6 will be high, so the temperature of the heat absorption surface will be high, and the exhaust gas will be at a high temperature. There is no condensation on the heat absorption surface of the regenerator 7. On the other hand, when the load becomes smaller, the burnup of the heating source 6 in the high-temperature regenerator 7 is reduced, and the heat absorption surface and exhaust gas temperature are also reduced. When the temperature sensor 12 provided in the high temperature regenerator 7 etc. detects that the dew point temperature has been reached, the opening degree of the flow rate regulating valve 15 provided in the pipe line 13 is reduced in accordance with the detection signal. The amount of absorption liquid introduced into the high temperature regenerator 7 is reduced. Therefore, the concentration, temperature, and pressure of the absorption liquid introduced from the high-temperature regenerator 7 to the gas-liquid separator 8 are increased, so the temperature of the heat absorption surface is increased and the exhaust gas temperature is also increased, so that the exhaust gas does not condense, for example, 140° C. or higher. maintained at a temperature of

If such control is performed appropriately when the load decreases, condensation in the exhaust gas flowing through the high-temperature regenerator can be avoided even when fuel with a high sulfur content is used, and even when cheap fuel is used, condensation can be avoided. It is possible to prevent problems such as corrosion due to Note that the absorption chiller/heater is not limited to the illustrated example, and the present invention is also applicable to absorption chiller/heater other than the illustrated one as long as it is equipped with a regenerator having a heating source that burns fuel. Needless to say, it can be done.

Of course, since control of the amount of absorption liquid introduced into the high-temperature regenerator is applied in the refrigeration cycle, it is sufficient that it has at least an absorption refrigeration function, and is not limited to the above-mentioned absorption chiller/heater. It can be applied to absorption refrigerators including absorption heat pumps.

〔Effect of the invention〕

As explained in detail above, the present invention maintains the pressure or temperature above a set value by increasing or decreasing the amount of absorption liquid introduced into the regenerator according to the exhaust gas temperature within the regenerator. Therefore, it is possible to prevent the exhaust gas of the heating source and the heat absorption surface of the regenerator from dropping below the dew point temperature. Therefore, dew condensation of the exhaust gas flowing through the regenerator is avoided, and the effect of preventing damage caused by corrosion on the heat absorption surface and adhesion of unburned carbon components due to dew condensation is exhibited.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an embodiment of an absorption chiller/heater to which the present invention is applied. 2--Absorber, 4-Condenser, 5--Evaporator, 6--
・Heating source, 7...-high temperature regenerator, 12.-1 temperature sensor,
14... Absorption liquid pump, 15... Flow rate adjustment valve, l'
l - Pressure sensor.

Claims (1)

[Claims] (1) In an absorption refrigerator including an absorption heat pump that has a regenerator equipped with a heating source in addition to an absorber, a condenser, and an evaporator, the amount of absorption liquid introduced into the regenerator is increased or decreased, and A control for an absorption chiller characterized by increasing the pressure in the regenerator and increasing the temperature of the absorption liquid and the heat absorption surface to increase the temperature of the exhaust gas, thereby preventing troubles due to condensation on the heat absorption surface. Method.