JPH03156259A - Absorption type cold/hot water producer - Google Patents

Abstract

PURPOSE:To interrupt the operation of load side instruments in diluting operation by connecting a refrigerant tank absorber of an evaporator and a solution lower header through opening/closing means which is closed upon power supply and opened upon interruption of the power supply. CONSTITUTION:There is installed, between a refrigerant tank 16 and a solution lower header 6, a piping 20 including opening/closing means which is closed upon power supply and close upon interruption of the power supply, say, a solenoid valve 19, one end of which piping 20 is opened to a proper height in the refrigerant tank 16 and the other end of which is opened to the lower header 6 of an absorber A. When the operation is interrupted and diluted operation is started, a refrigerant pump 3 and a heat source 10 are interrupted, with a solution pump 7 successively in operation. A refrigerant is thus prevented from being sprayed on a group of pipes of the evaporator, and although cooling water is immediately interrupted from its flowing there is no fear that cooling water in the evaporator pipes is excessively cooled and frozen. Thereupon, since the solenoid valve 19 is also opened simultaneously, a predetermined amount of the refrigerant remaining in the refrigerant tank 16 flows into the absorber lower header 6 and hence a diluted solution is fed by the solution pump 7 to both regenerators for dilution of the whole system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an absorption type water chiller/heater, particularly an absorption type water chiller/heater suitable for air-cooling.

[Conventional technology]

BACKGROUND ART Conventionally, among water-cooled absorption type water coolers and hot water machines, there is one type that uses a refrigerant blower.

Incidentally, related examples of this type include those described in Japanese Unexamined Patent Publication No. 63-65257.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, the refrigerant tank is provided above the evaporator, and the refrigerant pump for the evaporator is not provided. The heat transfer coefficient of the evaporator deteriorates, requiring a larger evaporator.

In addition, absorption type water cooler/heater uses a lithium bromide aqueous solution as a heat medium, and the concentration of this aqueous solution is .

At the highest concentration during operation, the concentration reaches about 65%, and if left as is, crystals will precipitate when stopped, so dilution operation is generally performed to prevent crystal precipitation when stopped.

In dilution operation, the solution and refrigerant pumps are operated without adding a heating source, and the residual absorption capacity of the concentrated solution is released to absorb the refrigerant.As a result, the concentration of the liquid is increased to such an extent that crystals do not precipitate even if left unattended. It is a dilution operation. Therefore, during dilution operation, although the capacity is reduced compared to full-load operation, some refrigeration capacity is generated, and for this reason, the chilled water pump,
It was necessary to continue operating load-side equipment such as air conditioners.

When a building is air-conditioned using a water cooler/heater left in the center, operation is stopped in advance by considering the time required for dilution, cooling is performed using the remaining capacity, and the equipment on the load side is stopped after dilution is completed. You can also take methods such as
In recent years, demands for air conditioning have become more diverse, and even within the same building, there are parts that require cooling and parts that do not need cooling, depending on the floor or room. This method is no longer necessarily convenient, and more and more distributed air conditioning systems are being used, in which a turn-on/off device is attached to a terminal in each room, and commands are sent from this device to cool the required number of rooms. This method has the disadvantage that it is not known when all the required cooling loads will reach zero, so the operation of the equipment on the load side during dilution operation becomes extremely turbulent.

In other words, if dilution operation continues even though there is no room that requires cooling, the refrigeration capacity will not be used to cool the room, but will be used exclusively to cool the small amount of cold water circulating in the cold water pipes. Therefore, there was a problem in that the temperature of the chilled water rapidly decreased, resulting in freezing, which caused serious failures such as rupture of the chilled water system heat transfer tubes due to volumetric expansion.

In other words, absorption type water chillers and hot water machines are said to produce chilled and hot water that is not suitable for distributed air conditioning systems due to their dilution operation. This was a major technological improvement for the use of water coolers and hot water machines in distributed air conditioning systems.

[Means to solve the problem]

In order to achieve the above object, the refrigerant tank of the evaporator and the absorber are connected by an opening/closing means that is closed when energized and opened when not energized. Then, when the operation is stopped and the dilution operation is about to start, this opening/closing means is opened,
A certain amount of the refrigerant held in the refrigerant tank was made to flow into the solution tank. Furthermore, at the same time, the refrigerant pump was stopped, thereby instantaneously stopping the refrigerant from being spread into the evaporator tube group and exerting its refrigerating ability.

In addition to this, only the solution pump continues to operate, dropping the refrigerant in the refrigerant tank and sending the diluted solution to the regenerator side, and circulating the liquid to make the entire cycle a uniform diluted solution. was determined by a timer or by sensing the temperature of the return solution from the regenerator.

Furthermore, even in the event of a power outage, the refrigerant in the refrigerant tank can be automatically sent to the solution side, which helps prevent crystal formation.

[Effect]

In an air-cooled absorption type water cooler/heater, the solution must be cooled with air, so the absorber flows the solution into a heat transfer tube,
Fins are attached to the outside of the heat transfer tube to improve heat transfer on the air side.

For this reason, the heat exchanger tube is installed vertically, and the structure is such that a concentrated solution flows down from the top along the inner surface of the heat exchanger tube, is cooled by the outside air, and absorbs the water vapor flowing inside the heat exchanger tube.

Due to these structural requirements, the solution tank is placed at the bottom of the vertical heat transfer tube, and the steam flowing in from the evaporator needs to be placed close to the top of the vertical heat transfer tube in order to reduce pressure drop, so it can evaporate by itself. The container and refrigerant tank are installed at the top of the water cooler/heater. Therefore, the refrigerant always flows in the direction toward the solution side, and conversely, the solution cannot flow into the refrigerant side. 6. Regardless of whether the amount of refrigerant in the refrigerant tank is large or small, the dilution amount required at any time. refrigerant overflows accurately. For example, when the solution concentration in the cycle is already sufficiently dilute before stopping, the amount of refrigerant in the refrigerant tank is small, so the amount of refrigerant flowing down is small, and unnecessary over-dilution is not caused.

Further, in the event of a power outage, the opening/closing means opens and the refrigerant flows into the solution tank. This alone does not mean that the solution on the regenerator side has been diluted, but if a power outage occurs, the solution pump that sends the solution from the absorber to the regenerator will also stop, so the pressure on the regenerator side will be close to atmospheric pressure.

Due to the pressure difference on the absorber side, which is close to vacuum, all of the concentrated solution in the heat exchanger is pushed back to the absorber side, mixes with the diluted solution in the solution tank, and returns to the valves. For example, the effect of preventing crystallization in the middle of piping can be achieved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

When the cold water 1 used for cooling flows through the pipe of the evaporator 2,
The refrigerant sprayed onto the tube group by the refrigerant pump 3 takes away the heat of evaporation and evaporates. This vapor flows into the upper header 4 of the absorber A, is absorbed by the sprayed concentrated solution in the tube bank 5, and becomes a dilute solution which accumulates in the lower header 6. The dilute solution is sent to a low temperature regenerator 8 and a high temperature regenerator 9 by a solution pump 7, and is heated and concentrated in each regenerator. In the high-temperature regenerator 9, a heat source 10 is supplied to a burner 11 and burned therein, and the generated steam is condensed in the pipes of the low-temperature regenerator 8 and is supplied to the upper part of the condenser C to the rudder 12. At this time, the steam generated outside the low temperature regenerator tube passes through the duct 13 and directly into the condenser 1.
The concentrated solution heated and concentrated in the regenerator 2 passes through the heat exchanger 14 and is sprayed onto the header 4 along with a portion of the diluted solution coming from the solution pump 7. On the other hand, the refrigerant condensed and liquefied in the condenser tube group 15 returns to the refrigerant tank 16 and is distributed together with the refrigerant in the refrigerant tank 16 onto the evaporator tube group by the refrigerant pump 3.A cooling fan 17 is installed at the top of the equipment. is motor 1
8, and discharges air that cools the air-cooled absorber A and the air-cooled condenser C.

Between the refrigerant tank 16 and the ladder 6 to the lower part of the solution, there is an opening/closing means, such as a solenoid valve 19, which is closed when energized and closed when de-energized.
One end of the pipe 20 is opened to an appropriate height inside the refrigerant tank 16, and the other end is connected to the absorber A.
It opens into the lower header 6 of.

When stopping operation and starting dilution operation, first the refrigerant pump 3. The heat source 10 is stopped, and the solution pump 7 continues to operate. Since the refrigerant pump 3 is stopped, refrigerant is no longer sprayed onto the evaporator tube bank, and even though the chilled water immediately stops flowing, the remaining chilled water in the evaporator C tubes is not over-cooled. There is no need to worry about freezing.

At this time, the solenoid valve 19 is also opened, so a certain amount of the refrigerant remaining in the refrigerant tank 16 flows into the ladder 6 into the lower part of the absorber, and the diluted solution is sent to both regenerators by the solution pump 7. , a dilution of the entire system is performed. During this time, the cooling fan 17 and motor 18 are also stopped, so the power required during dilution is:

Only a small amount of electric power is required to operate the solution pump 7, which is useful for energy saving.

The method of determining the time to operate the solution pump 7 is, for example, by simply operating it for a predetermined time using a timer, or by stopping the operation (if the solution concentration has already become rare to a certain extent,
Since dilution for a certain period of time is wasteful), operate until the liquid temperature at a position such as the high temperature regenerator return liquid temperature detector 21, the low temperature regenerator return liquid temperature detector 22, or the liquid temperature detector 23 after merging, becomes below a predetermined value. The controller 24 instructs the solution pump 7 to:

According to this embodiment, even if there is a power outage during operation, the refrigerant in the refrigerant tank 16 will flow down to the lower tank 6,
In addition, since the solution pump 7 is also stopped, the pressure from the high temperature regenerator 9 pushes the solution in the intermediate pipes and the liquid-liquid heat exchanger 14 back to the absorber side, and mixes it with the diluted solution in the lower tank 6. After the overall liquid concentration becomes diluted, as the pressure inside the high-temperature regenerator 9 decreases, semen fills the piping and the heat exchanger 14 again, making it difficult for crystals to occur.In this case, turn the pump 7. Compared to the dilution at It becomes very easy to do.

As mentioned above, this embodiment can stop the operation of the chilled water pump, cooling fan motor, etc. during dilution, so it is ideal as a water cooler/heater for cases where the chilled water pump cannot be operated during dilution, such as in distributed air conditioning. This makes it possible to perform absorption-type distributed air conditioning, which was previously considered difficult.

〔Effect of the invention〕

According to the present invention, during dilution operation, the refrigerant in the refrigerant tank is automatically transferred to the solution side, and dilution is completed by operating only the solution pump, so operations such as immediate stop of the cold water pump are possible.

In addition, in the event of a power outage, the solution in the absorber can be diluted without operating pumps, and the pipes between the high-temperature regenerator, low-temperature regenerator and absorber, and the liquid-liquid heat exchanger can be diluted. The solution can be diluted.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an absorption type water chiller/heater according to the present invention. 2... Evaporator, 3... Refrigerant pump, 7... Solution pump, 8... Low temperature regenerator, 9... High temperature regenerator, 19
... Solenoid valve, 21 ... High temperature regenerator return liquid temperature detector,
22... Low temperature regenerator return liquid temperature detector, 23... Return liquid temperature measurement after merging %l Figure C - Simulated ticket

Claims (1)

[Claims] 1. In an absorption type water chiller/heater comprising an evaporator, a regenerator, an absorber, a condensate liquid heat exchanger, and a pump, the refrigerant tank of the evaporator and the absorber are closed when energized; An absorption type water chiller/heater characterized by being connected by an opening/closing means that opens when power is not applied. 2. The water chiller/heater according to claim 1, wherein the absorber and the condenser are air-cooled. 3. In an absorption type water chiller/heater equipped with an evaporator, a regenerator, an absorber, a condenser, a liquid-liquid heat exchanger, and a pump, the refrigerant tank of the evaporator and the absorber are closed when energized and open when not energized. What is claimed is: 1. An absorption type water chiller/heater comprising: an opening/closing means, and a control device that operates a solution pump for a predetermined period of time after stopping operation of the chiller/heater and stopping a refrigerant pump. 4. The absorption type water chiller/heater according to claim 3, wherein the absorber and the condenser are air-cooled. 5. Evaporator, regenerator, absorber, condenser, liquid-liquid heat exchanger,
and an absorption type water chiller/heater equipped with a pump, an opening/closing means that closes the refrigerant tank of the evaporator and the absorber when energized and opens when not energized; 1. An absorption chiller/heater comprising: a control device that operates the solution pump after the solution pump is stopped until the temperature of the solution returned from the high-temperature regenerator reaches a predetermined value. 6. The absorption type water chiller/heater according to claim 5, wherein the absorber and the condenser are air-cooled. 7. The device according to claim 5, characterized in that a liquid temperature detector is provided to detect the temperature of the solution returned from the high temperature regenerator, and the control device is controlled by a signal from the liquid temperature detector. Absorption type water cooler/heater. 8. Evaporator, regenerator, absorber, condenser, liquid-liquid heat exchanger,
and an absorption type water chiller/heater equipped with a pump, an opening/closing means that closes the refrigerant tank of the evaporator and the absorber when energized and opens when not energized; 1. An absorption type cold/hot water machine characterized by being provided with a control device that operates the solution pump after the solution pump is stopped until the temperature of the solution returned from the low-temperature regenerator reaches a predetermined value. 9. The absorption type water chiller/heater according to claim 8, wherein the absorber and the condenser are air-cooled. 10. The device according to claim 8, characterized in that a liquid temperature detector is provided to detect the temperature of the solution returned from the low-temperature regenerator, and the control device is controlled by a signal from the liquid temperature detector. Absorption type water cooler/heater.