JPH07218024A - Absorption type chilled and warm water generator - Google Patents

Abstract

PURPOSE:To hold a supply amount and a return amount in balance by providing a control valve in series with a float valve in a solution distribution conduit, installing a bypass valve for bypassing them, switching the control vale by a liquid level of an absorber or a pressure of a high temperature regenerator, and supplying solution to the regenerator. CONSTITUTION:A dropped liquid level of an absorber 5 is detected by a liquid level switch 16, and a pressure of a high temperature regenerator 9 is detected by a pressure switch 17. When two conditions are satisfied, a control valve 13 provide din series with a float valve 15 in a solution distribution conduit is fully closed by an electric signal, and a control valve 14 is fully opened. A dropped liquid level of the absorber 5 is controlled by a flow rate regulating valve 18 as a bypass valve provided at a secondary side of the valve 14, a concentrated solution liquid level is raised, the valve 15 is fully closed, and dilute solution passed through a valve gap at the time of fully closing the valve 15 is supplied to the regenerator 9. Thus, at the time of starting and stopping a circulating malfunction due to a liquid level drop of the absorber 5 can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller / hot water generator, and more particularly to a chiller / hot water generator for performing on / off control of a small absorption type direct-fired chilled / hot water generator.

[0002]

2. Description of the Related Art Conventionally, a method of controlling the liquid supply amount of a high temperature regenerator is to install a float valve in the liquid supply piping system, guide the concentrated solution return amount of the high temperature regenerator to a float box, and Float valve control in which the float is floated at a level and the supply amount is controlled is common.

[0003]

In the float valve control of the prior art, since the control circulation amount is small in the small capacity hot and cold water generator, the operating state of the valve and the leaf amount of the valve form a cycle. Is a very important part. Therefore, the manufacturing accuracy and reliability of the float valve determine the reliability of the cold / hot water generator.

However, the float valve has a defect factor that may cause unstable operation or may not operate. In particular, it is difficult to control a small amount of circulation depending on the operation of the float valve and the processing accuracy of the valve.Therefore, in a small capacity machine, the leak amount when the float valve is fully closed has a great effect on the relationship between the supply amount and the return amount. give.

An object of the present invention is to always perform a constant liquid supply method regardless of the accuracy of the fully closed leak amount of the float valve, maintain a balance between the supply amount and the return amount, and improve the reliability of the cold / hot water generator. It is in.

[0006]

In order to achieve the above object, the present invention provides a float valve and a series control valve in a lithium bromide aqueous solution (hereinafter simply referred to as solution) pipe line to be supplied to a high temperature regenerator. Bypass valve is installed to bypass the liquid level of the absorber and the pressure of the high temperature regenerator.
By opening and closing each control valve, the solution is supplied to the high temperature regenerator.

[0007]

There are various methods for controlling the heat input to the high temperature regenerator, such as proportional expression, four-position, three-position and on-off control.
As for the control signal, the temperature of cold / hot water that generally changes depending on the load is detected by a sensor, etc., that signal is input to the temperature controller, the deviation amount for the set temperature is arithmetically processed, and the result is used as an output signal of the high temperature regenerator. The heat input is output to a control device that controls the heat input to control the heat input. In the high temperature regenerator, the diluted solution is heated by the heat input, the refrigerant in the diluted solution is taken out as a refrigerant vapor, the solution is concentrated, and the amount of solution retained in the high temperature regenerator is reduced. Therefore, the diluted solution is supplied again,
Since the concentrated solution returns to the absorber for dilution, a control mechanism for maintaining the balance between the amount of concentrated solution returning to the absorber and the amount of solution supplied to the high temperature regenerator is necessary.

The balance between the supply of the solution and the amount of the returned liquid is carried out by the float valve control in which the amount of the liquid returned from the high temperature regenerator is detected by the liquid level and as a result, the liquid supply control valve on the supply side is interlocked with and controlled. . This float valve is housed in the float chamber, which is the same pressure chamber as the inside of the high temperature regenerator.
The feed liquid is supplied to the high temperature regenerator by the pushing pressure of the floating liquid circulation pump, and the return solution returns to the absorber by the driving force of the pressure head and the position head of the high temperature regenerator and the liquid ejector returning to the absorber. The relationship between the supply liquid and the return liquid becomes unbalanced as the pressure difference between the absorber and the high temperature regenerator becomes smaller.

In the present invention, when the supply amount and the return amount are unbalanced, the liquid level of the absorber lowers, the solution circulation pump enters cavitation, and the operation becomes unstable. When the pressure of the high temperature regenerator is detected and the liquid level of the absorber reaches the pump cavitation level, or when the high temperature regenerator pressure falls below a certain reference pressure, the supply amount will not depend on the float valve control. To a constant
Create a control system to prevent pump cavitation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 illustrates a cycle of a direct-burning absorption double-effect cold / hot water generator of the present invention.

The inside of the evaporator 1 is maintained at about one-hundredth atmospheric pressure, in which the refrigerant 2 (water) takes heat of the cold water by the refrigerant pump 3 and evaporates, thereby producing a cooling effect. The evaporated refrigerant vapor is kept at a low pressure by the cooling water and flows into the absorber 5, where it is absorbed by the solution sprayed on the absorber heat transfer tube 6 and the solution is diluted. This diluted solution is sent to the high temperature regenerator 9 and the rest to the low temperature regenerator 10 through the heat exchanger 8 by the solution pump 7,
In the high temperature regenerator 9, it is directly heated by the heat source 11 and separated into vapor and concentrated solution.

On the other hand, in the low temperature regenerator 10, the diluted solution is heated by the steam generated in the high temperature regenerator 9 to form steam.
Separated into a concentrated solution. The solution thus concentrated is
It is sprayed again into the absorber 5 via the heat exchanger 8.

Further, the drainage obtained by heating the solution in the low temperature regenerator 10 and condensing is introduced into the condenser 12.

On the other hand, the steam generated in the low temperature regenerator 10 is
It is condensed in the condenser 12. The condensed refrigerant thus produced is guided to the evaporator, sprayed, and cycled once.

The control method of the amount of solution supplied to the high temperature regenerator 9 will be described with reference to FIG.

FIG. 2 illustrates the function of controlling the solution supply system to the high temperature regenerator 9 and the control valves 13 and 14 for adjusting the supply amount according to the present invention.

The diluted solution supplied to the high temperature regenerator 9 is controlled by the float valve 15 to detect the liquid level of the concentrated solution in the float box 16 of the concentrated solution returned from the high temperature regenerator 9 during operation.

The liquid level of the concentrated solution rises, and the float valve 1
When 5 is fully closed, the diluted solution that subsequently passes through the valve gap when the float valve 15 is fully closed is supplied to the high temperature regenerator 9. When the pressure of the high temperature regenerator 9 is high, the solution balance between the supply side and the return side is maintained and the liquid level of the absorber 5 is maintained above the cavitation liquid level of the solution pump 7. Is low, it becomes difficult for the liquid to return due to the pressure loss of the flow path on the return side, and the liquid level of the absorber 5 drops.
This falling liquid level is detected by the liquid level switch 16, and the pressure condition of the high temperature regenerator 9 is also necessary. Therefore, the pressure of the high temperature regenerator 9 is detected by the pressure switch 17, and when two conditions are provided, an electrical condition is set. The signal causes the control valve 13 to be fully closed and the control valve 14 to be fully open. As a result, the flow rate control valve 18 provided on the secondary side of the control valve 14 restricts the flow rate to a constant flow rate, controls the liquid supply amount, and controls the descending liquid level of the absorber 5.

[0020]

EFFECTS OF THE INVENTION According to the present invention, the circulation problem due to the drop in the liquid level of the absorber at the time of starting and stopping the small cold / hot water generator is solved, the valve processing accuracy of the float valve is relaxed, and the minimum circulation amount is reduced. The operational reliability of the equipment, such as securing it, is improved.

[Brief description of drawings]

FIG. 1 is a system diagram of cycle circulation of a cold / hot water generator.

FIG. 2 is a system diagram of a solution supply control mechanism of the high temperature regenerator of the present invention.

[Explanation of symbols]

5 ... Absorber, 9 ... High temperature regenerator, 11 ... Heat source, 13 ... Control valve, 14 ... Control valve, 15 ... Float valve, 16 ... Liquid level switch, 17 ... Pressure switch, 18 ... Flow control valve, 19 ...
Bypass piping.

Claims (1)

[Claims] 1. An absorption-type cold / hot water generator including an evaporator, an absorber, a condenser, a low-temperature and high-temperature regenerator, a heat exchanger, a refrigerant pump for operating these components continuously to maintain a cycle, and a solution pump. , A method of controlling the supply amount of the lithium bromide aqueous solution to the high temperature regenerator, a float type control valve controlled by the liquid level of the lithium bromide aqueous solution returning from the high temperature regenerator, and the odor in series and in parallel. A valve is provided in the supply line of the lithium bromide aqueous solution, and a control mechanism for controlling the opening / closing command of the valve to control the supply amount of the lithium bromide aqueous solution by the liquid level of the absorber or the pressure of the high temperature regenerator. An absorption type cold / hot water generator characterized by.