JPS61231360A - 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 for controlling a dual-effect absorption refrigerator.

[Conventional technology]

A conventional dual-effect absorption refrigerator includes, for example, an absorber A, an evaporator E11, a light generator GH1, a low-temperature generator O
L, condenser C1 solution heat exchanger XH1XL, solution pump S
P, a refrigerant pump RP is provided, and as a solution path, 21
．． 22, 23, 24, 25, 26, 27, 1O111, 12, 13 as a refrigerant path, and an overflow pipe 20 connect the above-mentioned devices to form a refrigeration cycle. Note that 1 is a cold water pipe, 2.3 is a cooling water pipe, 4 is a heat source supply pipe, 5 is a cold water measuring device, 6 is a temperature regulator, H is a heat source control valve, 30.
31 is an electrode rod of a level switch for starting and stopping the solution pump.

In such a refrigeration cycle, at the start of operation, the pressure in the high temperature generator GH is low and the circulation of the solution from the high temperature generator GH to the low temperature generator GL is poor, so the solution accumulates in the high temperature generator 0M and the absorber A Cavitation may occur in the solution pump SP due to insufficient amount of solution in the tank, or high temperature nGH
There was a risk that the solution inside would mix into the refrigerant side. Therefore, a level switch for starting and stopping the solution pump 8P, for example, two electrode rods 30 and 31, is attached to the high temperature generator GH, and when the solution level rises to one of the upper limit electrode rods 30 and comes into contact, the conduction causes the solution to Pump SP is stopped, the liquid level is lowered to below the level of the other lower limit electrode rod 31, and electrode rod 31. When there is no continuity with the solution pump S
I was trying to restart P.

FIG. 6 shows an example of a level switch for starting and stopping one solution pump, which is attached to a suitable position of the high temperature generator GH, and the electrode rod 30 is for detecting (stopping) the upper liquid level;
It is attached to the casing via an insulating airtight packing 32. The electrode rod 31 is for detecting the lower liquid level (for restarting) 1 and is attached to the casing via an insulating airtight packing 32.

Fig. 7 shows a sequence circuit, where 883P is an electromagnetic switch for the solution pump, El is turned on when the electrode rod 30 is electrically connected to the liquid surface, and Ef is turned on when the electrode rod 31 is electrically connected to the liquid surface. It is a switch.

[Problem that the invention seeks to solve]

However, in a device using such a conventional level switch for starting and stopping a solution pump, the electrode rods 30 and 31 are attached to the housing via an insulating and airtight gasket 32.
However, insulation failures often occurred. For this reason, for example, when the liquid level reaches the upper limit during refrigerator operation, the electrode rod 3
When the solution pump SP stops due to conduction of 0 and the liquid level gradually falls, if the electrode rod 31 has poor insulation, the switch E8 remains on even if the liquid level leaves the electrode rod 31 and falls. Therefore, since relay RYz and relay RY also remain on, solution pump SP remains in a stopped state. Furthermore, even if there is an insulation failure in the electrode rod 30, the solution pump SP remains stopped, resulting in an abnormal drop in the liquid level, which leads to abnormal concentration of the solution in the high temperature generator OH, which poses a risk of crystal formation. was there.

The present invention aims to provide a control method for an absorption refrigerator that prevents the risk of solution crystallization even when a conventional level switch for starting and stopping a solution pump becomes short-circuited due to poor insulation and solves the above-mentioned problems. The purpose is to

In other words, we focused on the fact that when the solution pump stops, the liquid level that is at the stop level usually drops below that level after a predetermined period of time, and we also use a timer to monitor the insulation of the electrode rod and detect any insulation failure. If this occurs, an alarm is issued and the refrigerator is stopped.

(Means for Solving the Problems) The present invention provides an absorber, a high temperature generator, a low temperature generator, a condenser, an evaporator, a solution heat exchanger, a solution pump; In a method for controlling an absorption refrigerator, which has a refrigerant pump, a solution path and a refrigerant path that connect these devices, and includes a level switch for starting and stopping the solution pump in a high temperature generator to start and stop the solution pump. ,
A predetermined period of time after the solution level in the high temperature generator reaches an upper limit and the solution pump stop level switch is turned on and the solution pump is stopped, the switch is still on. An object of the present invention is to provide a control method for an absorption chiller, which is characterized in that, when the absorption chiller is activated, an alarm is issued or the operation of the chiller is stopped.

Further, the pressure inside the high temperature generator is detected, and when the pressure exceeds a certain predetermined value, the refrigerator is stopped after a predetermined period of time has elapsed. Furthermore, the set time of the timer is changed depending on the pressure inside the high temperature generator when the solution pump is stopped.

The present invention was made based on the fact that when a solution pump stops, the liquid level at the stop level will always fall below the stop level after a predetermined period of time has passed. Monitor the rod for poor insulation, and if continuity is still observed after a predetermined period of time has passed after the solution pump has stopped, if the level switch is the electrode rod, it is determined that the insulation is poor, and the level switch is connected to the float 2. In this case, it is determined that the float is malfunctioning, and an alarm is issued or the refrigerator is stopped to ensure safe operation.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, 35 is a pressure detector that detects the internal pressure of the high temperature generator GM, and 36 is a temperature detector that detects the condensation temperature of the refrigerant generated in the high temperature generator GH. 37 is equipped with a timer 38, and conductive signals from electrode rods 30 and 31;
Upon receiving the pressure signal from the pressure detector 35 or the temperature signal from the temperature detector 36, the alarm 39 is activated to issue an alarm (
emit light or sound) or send a signal to the start/stop command device 40, close the heat source control valve H of the high temperature generator GH at an appropriate time, and stop the solution pump SP and refrigerant pump RP. This is a control device that has the function of stopping the refrigerator.

Figure 2 shows a sequence example, 3X is an auxiliary relay, FB
I is the stop button, PB2 is the run button, T is the timer,
L is a warning lamp, and B2 is a warning buzzer.

The liquid level in the high temperature generator GH has reached the upper limit, and the electrode rod 30
When contacted, switch E is turned on, solution pump SP is stopped, and at the same time, timer 38 (T) is activated. When the i-liquid pump SP stops, the liquid level will drop, so it should move away from the electrode rod 30 and turn off the switch EI, but the electrode rod 30
If the insulation fails, the switch E remains on even though there is no contact with the liquid surface.

In this state, even if the liquid level further falls below the lower limit and falls below the lower end of the electrode rod 31 and the switch E8 is turned off, the switch E1 remains on, so the solution pump SP
remains stopped.

However, in the unimplemented example, the timer 38 (T) is
It operates after a predetermined time T, turns off the auxiliary relay 3X (included in the start/stop command 40 in Figure 1), and stops the heat source supply, solution pump SP, refrigerant pump RP, etc. in a timely manner. This allows the refrigerator to be stopped before it becomes abnormal.

The rate of drop of the liquid level after stopping the solution pump SP is determined by the high pressure generator O.
It is related to the pressure P in H. If the pressure is below a certain level p0, the pressure difference with the low temperature generator GL will be small and the solution will not be transferred, so the rate of drop of the liquid level will also be small. Therefore, when the pressure p is low, the timer 38 operates and the solution pump SP is restarted more frequently than necessary before the liquid level has sufficiently fallen to the lower limit.

In order to prevent this, in the control device 37, the timer 3
8, the time is counted only during the period when the internal pressure p of the high temperature generator GH is p>Pa, and when the tally reaches a predetermined time T, if the switch El is still on, the timer is activated. 38 to issue an alarm and stop the refrigerator.

Further, the predetermined time T3 may be set depending on the pressure of the high pressure generator GH at the time when the solution pump SP is stopped, for example, as shown in FIG.

Moreover, instead of directly detecting the pressure of the high pressure generator GH with the pressure detector 35, a state quantity correlated with this pressure,
For example, the temperature may be detected indirectly by detecting the refrigerant condensation temperature using the temperature detector 36.

Furthermore, focusing on the fact that the time from when the timer 38 is activated until the liquid level reaches the lower limit is related to the momentary pressure of the high pressure generator OH, as shown in FIG. The time Ts when the sum of the areas of reaches a certain predetermined value A,
That is, the timer 38 may be activated when the time T such that T is reached.

In the above embodiment, the timer 38 operates when the liquid level of T+, Ta, and Ta falls further to 9 below the lower limit (the lower end of the electrode rod 31), and when it does not fall too much. It is preferable to determine the goal experimentally, empirically, or by calculation.

Note that the above embodiment has the same effect even when insulation failure occurs in the electrode rod 31.

In addition, when the liquid level switch is a float type, the present invention can be applied even when the normal inertia cannot be obtained due to a malfunction in the operation of the float.

〔Effect of the invention〕

According to the present invention, even in the case of malfunction of the level switch such as malfunction of the non-insulated float of the electrode rod, the solution and pump can be reliably restarted and dangers due to insufficient solution volume can be prevented. It is possible to provide a method for controlling a refrigerator and refrigerator, and it has an extremely large practical effect.

[Brief explanation of the drawing]

Figures 1 to 4 relate to an embodiment of the present invention; Figure 1 is a flow diagram, Figure 2 is a sequence diagram thereof, and Figure 3 is a diagram showing the relationship between timer setting time and high temperature generator internal pressure in another embodiment. 4 is a relationship graph between the timer setting time and the internal pressure of the high temperature generator in another embodiment, 5 to 7 are related to the conventional example, 5 is a flow diagram, and 6 is a relationship graph. is a detailed diagram of the level switch, and FIG. 7 is its sequence diagram. 1... Cold water pipe, 2, 3... Cooling water pipe, 4... Heat source supply pipe, 5... Cold water thermometer, 6... Temperature controller, 1
0,11゜12.13... Refrigerant path, 20... Overflow, -pipe, 21.22, 23, 24, 25, 26
．． 27...Solution route, 30.31...Electrode rod, 32
...Packskin, 35...Pressure detector, 36.2.Temperature detector, 37...Control device, 38...Timer,
39...Alarm device, 40...Start/stop command device. Patent applicant: EBARA CORPORATION Representative Patent Attorney: Masayuki Takagi Representative Patent Attorney: Yakushi Minoru Representative Patent Attorney: Yori 1) Takaji
Department supplementary Hrigada

Claims (1)

[Claims] 1. An absorber, a high temperature generator, a low temperature generator, a condenser, an evaporator, a solution heat exchanger, a solution pump, a refrigerant pump, and a solution path and a refrigerant path connecting these devices. , in a control method for an absorption refrigerator, in which a level switch for starting and stopping a solution pump is provided in a high temperature generator to start and stop the solution pump, when the solution level in the high temperature generator reaches an upper limit, the solution pump After the stop level switch is turned on and the solution pump is stopped, if the switch is still on after a predetermined time T_1 has elapsed, an alarm is issued or the operation of the refrigerator is stopped. A method for controlling an absorption chiller, characterized in that: 2. It has an absorber, a high temperature generator, a low temperature generator, a condenser, an evaporator, a solution heat exchanger, a solution pump, a refrigerant pump, and a solution path and a refrigerant path that connect these devices. In the method for controlling an absorption refrigerator including a level switch for starting and stopping the solution pump, the level switch for stopping the solution pump is turned on when the solution level in the high temperature generator reaches an upper limit. After the solution pump stops and the total time during which the pressure inside the high-temperature generator exceeds a predetermined value reaches a predetermined time T_2, if the switch is still on, an alarm is issued. 1. A method for controlling an absorption chiller, characterized in that the operation of the chiller is stopped. 3. Claim 2, wherein the predetermined time T_2 is set in direct or indirect correspondence to the pressure within the high temperature generator at the time when the solution pump is stopped.
The method described in section. 4. It has an absorber, a high temperature generator, a low temperature generator, a condenser, an evaporator, a solution heat exchanger, a solution pump, a refrigerant pump, and a solution path and a refrigerant path that connect these devices. In the method for controlling an absorption refrigerator including a level switch for starting and stopping the solution pump, the level switch for stopping the solution pump is turned on when the solution level in the high temperature generator reaches an upper limit. and after the solution pump has stopped, the pressure p in the high temperature generator after that time is a function of time t, and p_0 can be forced from the high temperature generator to the low temperature generator, or When the predetermined reference pressure is set to a certain predetermined value, and A is set to a certain predetermined value, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ If the switch is still on even after the time T_3 has been reached, should an alarm be issued? , a method for controlling an absorption chiller, characterized by stopping operation of the chiller.