JPS62166272A - Double-effect 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 dual-effect absorption refrigerator having a control device for operating during shutdown.

[Conventional technology]

In conventional absorption refrigerators, in order to prevent solution crystallization when the operation is stopped, the solution pump continues to operate even after the control valve of the generator heating source is closed and the refrigerator operation is stopped.
The solution pump is stopped after performing dilution operation to equalize the concentration in the solution path, but the cooling water pump also continues to operate along with the solution pump, and stops when the solution pump stops. Ta.

[Problem that the invention seeks to solve]

However, usually the output of the solution pump (for example, 1 to 2 V
), the output of the cooling water pump is larger (e.g. 6 to 1
0kW), causing a loss of power because the cooling water pump was operated more than necessary.

Furthermore, if the cooling water is passed more than necessary, the internal pressure of the high temperature generator will drop and the solution will not be circulated, which may prevent the concentration from being sufficiently uniform and may lead to crystallization.

In order to avoid such problems, if you stop the cooling water pump immediately when the refrigerator stops, the spray remains at a high temperature and is not cooled down. Liquid B falls on the cooling water tube, and the temperature of the cooling water in the cooling water tube rises, and due to thermal expansion of the tube (the tube may be damaged due to excessive stress, or the plastic filling material in the cooling tower may be damaged during restart). This caused problems such as damage to the

The present invention solves the above-mentioned problems of the conventional ones, reduces power loss, promotes solution dilution, prevents damage to tubes due to thermal stress, and damages packing material in cooling tower during restart. The purpose of this invention is to provide a dual-effect absorption refrigerating machine that does not

[Means for solving problems]

The present invention is a means for solving the above problems.
generator, absorber, high temperature generator, low temperature generator, condenser, 78 liquid paths connecting these devices, refrigerant path, solution pumps provided in these paths, refrigerant pump, the absorber and condenser In a dual-effect absorption chiller comprising a cooling water path leading to the evaporator, a cooling water pump provided in the cooling water path, a cold water path leading to the evaporator, and a cold water pump provided in the cold water path. , a load detector that detects the load state before the operation is stopped; a timer mechanism that issues a signal to stop the operation of the cooling water pump after a predetermined set time after the operation is stopped; It is an object of the present invention to provide a dual-effect absorption refrigerating machine characterized by comprising a control mechanism that selects the predetermined set time according to a load state of the refrigerating machine.

[For production]

According to the present invention, when the absorption refrigerating machine is stopped, the cooling water pump is not immediately stopped, but is allowed to continue operating for a while depending on the load condition before stopping, thereby continuing to circulate the cooling water. The solution pump continues to operate for dilution, and the solution is circulated, but since heating in the generator has already been stopped, it is cooled by the cooling water, and the solution temperature gradually decreases, and the cooling water temperature also decreases. It gradually decreases.

The filling material used in cooling towers is, for example, hard vinyl chloride (PVC), and the practical heat resistance limit of these materials is approximately 60 to 80°C. Is the cooling water in the cooling water tube at a relatively high temperature as the temperature gradually decreases and the cooling water stops flowing and becomes stagnant? The cooling water pump can be stopped when the temperature drops to a level below (e.g. 25-30°C) that does not reach the above heat resistance limit even if the liquid 8 (the temperature has already dropped to a certain degree) falls on it. The state of decrease in cooling water temperature is related to the state of the load at or just before the stop.

That is, if the operation is under high load at the time of stopping, the pressure inside the generator will be high (and the solution temperature will also be high, so the temperature of the liquid 78 returning to the absorber will also be high, and the cooling after stopping the J1 rotation will be high). The rate at which the water temperature drops also slows down.

Therefore, the time required for the cooling water temperature to drop to a predetermined allowable temperature after the refrigerator stops operating is long after high-load operation, and short after low-load operation.

The load condition at the time of stopping operation or just before that (the average from the time immediately before or the time of stopping 10 molecules at 7 degrees until stopping) is detected by the temperature of the solution, etc., and on the other hand, cooling is performed after a predetermined set time from the time of stopping operation. A time limit mechanism is provided to stop the water pump, and the set time of this time limit mechanism is selected according to the pre-detected load condition, and the coolant pump is stopped after the point when the coolant temperature should fall below a predetermined allowable temperature. Make it.

In the present invention, the cooling water pump is stopped by selecting the set time of the timer mechanism according to the load condition at or before the stop time, so that the relatively high temperature ( Even if the solution (which has already cooled down to a certain degree) falls on the solution, it will remain in the tube and the cooling water will not reach the above-mentioned limit of 60-80℃, and the tube will not be damaged due to thermal expansion. Even if the chiller is restarted after the chiller is restarted, the cooling water will be sent to the cooling tower at a sufficiently low temperature and will not damage the filling material. It does not cause loss or reduce the pressure inside the high-temperature generator too much, thereby hindering the dilution operation.

In addition, when using a temperature detector that detects the temperature of the solution as a load detector that detects the load state, it is necessary to use a temperature sensor that detects the temperature of the solution as much as possible at a high temperature and high pressure part (a part where the pressure is equal to or higher than that of the low temperature generator GL, for example). Inside the hot generator GH, high temperature generator G
Preferably, the temperature at the H outlet, etc.) is detected. Other load detectors that detect the heating amount of the high-temperature generator GH include a flow rate detector for the heating source fluid (light black, hot water, or fuel gas or fuel oil in the case of a direct-fired type), or a flow rate control valve. An opening detector may also be used. Further, as the load detector, a pressure detector or a temperature detector that detects the pressure or saturation temperature within the high temperature generator GH may be used. Also,
A temperature detector that detects the cooling water temperature related to the above temperature and pressure may be used.

〔Example〕

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

In Figure 1, A is an absorber, E is an evaporator, GH is a high temperature generator, CL is a low temperature generator, C is a condenser, XH is a high temperature solution heat exchanger, XL is a low temperature solution heat exchanger, and SP is a The solution pump, RP is a refrigerant pump, and ■ is a pressure reducing valve.

A solution path 3.4.5 and a refrigerant path 6.
7.8 is connected and the absorption solution and refrigerant are circulated.

■ is the heating source path through which the heating source fluid such as steam flows;
The flow rate of the heating source fluid is controlled by the flow rate control valve 2; bll 1f
ft1 to control the capacity of the absorption refrigerator.

Reference numeral 9 denotes a cold water path, through which cold water is circulated between the load 10 and the evaporator E by a cold water pump 1.

12 is a cooling water path, in which cooling water is circulated through a cooling tower 14, an absorber A, and a condenser C by a cooling water pump 13.

Reference numeral 15 denotes a capacity control device, which receives a cold water temperature signal from a temperature detector 1G that detects the cold water outlet temperature and operates the flow rate control valve 2 so that the cold water temperature is constant.

(2) 8 is a control device which is configured to issue a signal to stop the cooling water pump 13 after a set time iM given by the timer mechanism 22 has elapsed since the operation of the freezing chamber is stopped. Thus, the set time in the timer mechanism 22 is selected depending on the solution temperature at or just before the stoppage of operation detected by the temperature detector 23 which is a load detector that detects the solution temperature in the high temperature generator GH.

As the load detector, a temperature detector 21 that detects the solution temperature at the outlet of the high temperature generator GH may be used, and a flow rate detector that detects meteors in the heating source fluid to detect the load based on the amount of heating. Alternatively, an opening detector 24 that detects the opening of the flow rate control valve 2 may be used, and the high temperature generator G)
A pressure detector 25 may be used to detect the internal pressure of I, or a degree detector may be used to detect the cooling water temperature related to these temperatures and pressures.

FIG. 2 is a flowchart when the operation is stopped.

〔Effect of the invention〕

The present invention prevents wasted power loss when shutting down an absorption chiller, promotes solution dilution, prevents damage to the chilled water tube of the absorber due to thermal stress, and prevents damage to the cooling tower when restarting the absorption chiller. It is possible to provide a dual-effect absorption refrigerator that does not cause damage to the filling material, which is extremely effective in practice.

[Brief explanation of drawings]

FIG. 1 is a flowchart of an embodiment of the present invention, and FIG. 2 is a flowchart thereof. l... Heat source path, 2... Flow rate control valve, 3... Solution path, 4... Solution path, 5... Solution path, 6...
- Refrigerant route, 7... Refrigerant route, 8... Refrigerant route, 9
...Cold water route, 10...Load, 11...Cold water pump, 12...Cooling water route, 13...Cooling water pump,
14... Cooling tower, 15... Capacity control AA position, 16.
...Temperature detector, 1 day...Control device, 21...Temperature detector, 22...Time limit mechanism, 23...Temperature detector,
24...Opening degree detector, 25...Pressure detector, A...
・Absorber, E... Evaporator, GH... High temperature generator, G
L...Low temperature generator, C...Condenser, XH...High temperature heat exchanger, XL...Low temperature heat exchanger, SP...Solution pump, RP...Refrigerant pump, ■... ·Pressure reducing valve. Figure 1

Claims (1)

[Claims] 1. An evaporator, an absorber, a high-temperature generator, a low-temperature generator, a condenser, a solution path connecting these devices, a refrigerant path, a solution pump provided in these paths, a refrigerant pump, A cooling water path communicating with the absorber and the condenser, a cooling water pump provided in the cooling water path, a cold water path communicating with the evaporator, and a cold water pump provided in the cold water path. In a heavy-effect absorption chiller, the load detector detects the load state before the operation is stopped, a timer mechanism that issues a signal to stop the operation of the cooling water pump after a predetermined set time after the operation is stopped, and the load detector. A dual-effect absorption refrigerating machine comprising: a control mechanism that selects the predetermined set time according to a detected load state before stopping operation. 2. The refrigerator according to claim 1, wherein the load detector is a temperature detector that detects a solution temperature in a high temperature section. 3. The refrigerator according to claim 1, wherein the load detector is a flow rate detector of the heating source fluid in the generator. 4. The refrigerator according to claim 1, wherein the load detector is a valve opening degree detector of a flow rate control valve for the heating source fluid of the generator. 5. The refrigerator according to claim 1, wherein the load detector is a pressure detector that detects the pressure within the high temperature generator.