JPS6269074A - 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 control method for an absorption refrigerator, and more particularly, to a control method for adjusting the opening of an opening adjustment valve provided at a steam outlet of a regenerator. .

[Prior art]

BACKGROUND ART Among absorption refrigerators that can obtain cold water or hot water by receiving and receiving heat generated during repeated evaporation and condensation of a lithium bromide aqueous solution, some have a regenerator equipped with a heating source. In such an absorption refrigerator, a large amount of vapor and a highly concentrated absorption liquid can be obtained from a dilute absorption liquid of lithium bromide, so that 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 1% by weight of sulfur will condense at approximately 140°C, and if the content is lower than that, condensation will occur. The dew point temperature also becomes lower. Therefore, if a fuel with a high sulfur content is used, dew condensation is likely to occur on the heat absorption surface of the regenerator when the load is low and the temperature of the heat absorption surface of the regenerator and the exhaust gas decrease. When the sulfur dioxide gas melts in the dew, it becomes dilute sulfuric acid, which causes the problem that regenerators made of iron-based metals corrode in a short period of time. In addition, unburned carbon and other substances adhere to the condensation, narrowing the exhaust gas passage, forcing the performance of the blower for heating to deteriorate, causing combustion abnormalities, and causing problems such as a rapid increase in the generation 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 high-temperature regenerators.
There is a problem of rising fuel costs, and improvement 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 characteristics of the absorption chiller control method of the present invention are as follows:
By increasing or decreasing the opening degree of the opening adjustment valve at the steam outlet of the regenerator, the pressure inside the regenerator is increased, the temperature of the absorption liquid and the heat absorption surface is increased, and combustion occurs on the heat absorption surface through which the exhaust gas flows. This prevents problems caused by gas condensation.

[For production]

When a pressure sensor, a temperature sensor, or the like detects that the exhaust gas has reached the dew point temperature, the opening of the opening adjustment valve provided at the steam outlet of the regenerator is reduced. The burnup at the heating source is maintained as long as the temperature at which cold water or hot water is taken out remains unchanged, so as the steam pressure in the gas-liquid separator increases, the temperature of the absorption liquid increases, which also increases the temperature of the heat absorption surface. However, the exhaust gas temperature of the regenerator is increased. Therefore, the temperature of the heat absorption surface in the regenerator is maintained above the dew point temperature of the exhaust gas, and problems such as corrosion on the heat absorption surface and increased adhesion of unburned carbon are avoided.

〔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 can be 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.

In addition to the above-mentioned configuration, in order to prevent dew condensation in the high-temperature regenerator 7, an opening adjustment valve 19 is installed at the steam outlet of the gas-liquid separator 8. The pressure in the regenerator 7 is increased or decreased.

Note that a pressure sensor 17 is installed in the gas-liquid separator 8 or the steam pipe 16.
is provided. The above-mentioned opening adjustment valve 19 changes its opening according to the signal from the pressure sensor 17, and since this vapor pressure is proportional to the solution temperature, it is used instead of detecting the temperature. However, as shown in the figure, a temperature sensor I2 may be provided, and the opening degree of the opening adjustment valve 19 may be adjusted in response to a signal from the temperature sensor I2.

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 and 29 are absorption liquid pumps, and 30 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, when the load on the absorption chiller/heater is large, even if oil with a high sulfur content is used as fuel, the burnup in the heating source 6 is high, so that the exhaust gas flows into the heat absorption surface of the high temperature regenerator 7. There will be no condensation. 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 exhaust gas temperature is also reduced. When the temperature sensor 12 installed in the high-temperature regenerator 7 detects that the dew point temperature has been reached, the opening adjustment valve 19 installed at the steam inlet of the low-temperature regenerator 3 is opened in response to the detection signal. degree is reduced. As a result, the vapor pressure in the gas-liquid separator 8 is maintained, and the solution temperature corresponding to the pressure is, for example, 1
40° C. is maintained on the heat absorption surface, and dew condensation on the heat absorption surface of the high temperature regenerator 7 is prevented.

If such control is carried out appropriately when the load is reduced, condensation of the exhaust gas flowing through the high-temperature regenerator will be avoided even when using fuel with a high sulfur content, and even when using cheap fuel, corrosion will not occur. It is possible to prevent troubles caused by such problems. Note that the absorption chiller/heater is not limited to the illustrated example, but may also include absorption chiller/heater including an absorption heat pump other than the illustrated one, as long as it is equipped with a regenerator that has a heating source that burns fuel. It goes without saying that the present invention can be applied.

〔Effect of the invention〕

As described in detail above, the present invention adjusts the steam pressure or solution temperature of the regenerator in accordance with the exhaust gas temperature of the regenerator, etc. by applying a pressure difference to the steam led out from the steam outlet of the regenerator, Since the pressure or temperature is maintained above the set value, 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--heat source, 7--high temperature regenerator, 12--temperature sensor, 17-pressure sensor, 19--opening adjustment valve.

Claims (1)

[Claims] (1) In an absorption refrigerator including an absorption heat pump that has a regenerator equipped with a heat source in addition to an absorber, a condenser, and an evaporator, increasing or decreasing the opening of the opening adjustment valve at the steam outlet of the regenerator. By doing so, the pressure within the regenerator is increased to increase the temperature of the absorbing liquid and the heat absorption surface, thereby making it possible to prevent problems due to condensation of combustion gas on the heat absorption surface through which exhaust gas flows. How to control an absorption refrigerator.