JPH0480312B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an engine exhaust heat recovery absorption type refrigerating machine, and in particular, when the refrigeration load is reduced, heat radiation of the engine cooling water is performed preferentially. This invention relates to an economical engine exhaust heat recovery and absorption chiller/heater that does not require an auxiliary heat exchanger.

[Background of the invention]

First, a general refrigeration method of an absorption refrigerator will be explained with reference to FIG. Water, which is a refrigerant, is heated and evaporated by cold water 2 flowing through the tubes of the evaporator 1. At this time, heat of evaporation is removed from the cold water, so the cooled water is used for cooling purposes. The evaporated refrigerant gas 3 flows into the absorber 4 and is absorbed by the absorption solution 6 which has been appropriately cooled by the cooling water 5 flowing inside the tube, thereby diluting the solution. The diluted solution is delivered to a regenerator 9 via a heat exchanger 8 by a solution pump 7, where it is heated and concentrated by a heat source 10 such as steam flowing inside a pipe, and separated into a concentrated solution 11 and generated steam 12. . After the concentrated solution passes through the heat exchanger 8 again and exchanges heat with the diluted solution, it returns to the absorber 4 and is spread over the tube group to continue absorbing refrigerant vapor.
Steam 12 generated in the regenerator 9 reaches the condenser 13, is cooled and liquefied by the cooling water flowing in the pipe, and returns to the evaporator 1. The refrigerant liquid accumulated in the evaporator is spread over the evaporator tube group by the refrigerant pump 14 to promote evaporation. The above is the operating principle of a general single absorption refrigerating machine. Next, a general refrigeration system of a double absorption refrigerating machine will be explained with reference to FIG.
In FIG. 2, components given the same reference numerals as in FIG. 1 have the same functions. There are two main ways to flow the solution in a dual-effect absorption refrigerator, one of which is the second method.
This is the method shown in the figure. This method divides the solution discharged from the solution pump 7 into two parts, sends one part to the high temperature regenerator 15, and sends the remaining part to the low temperature regenerator 9 in parallel. The solution is recombined and returned to the absorber, and this is tentatively named parallel flow. The other is to send the entire amount of the solution discharged from the solution pump 7 to the high temperature regenerator 15, where it is concentrated to an intermediate concentration, and then send the entire amount to the low temperature regenerator 9, where it is further concentrated and absorbed. This method is based on the container, and is tentatively named series flow. Compared to single-effect absorption refrigerators, dual-effect absorption refrigerators have a clear advantage in that the steam obtained during the concentration process in the high-temperature regenerator is used again to heat the low-temperature regenerator. It is a well-known fact that energy efficiency can be improved by nearly twice as much. However, in a dual-effect absorption refrigerator, the refrigerant vapor generated in the high-temperature regenerator 15 must have a saturation temperature sufficient to heat and concentrate the solution in the low-temperature regenerator 9, so the temperature of the heating source must be constant. The efficiency must be higher than that of an absorption chiller. Therefore, in an absorption chiller that uses engine exhaust heat, engine jacket cooling water (70 to 80°C) is passed through a single-effect regenerator, and engine exhaust gas (approximately 400°C) is
A common method was to flow the gas into a high-temperature regenerator on the dual-effect side.

Next, the capacity control method of these absorption chillers will be explained. Engines are generally used to drive generators, and are usually operated at a constant load. On the other hand, since the cooling load changes depending on the outside temperature and the amount of heat generated indoors, the heat input of these exhaust heat recovery absorption refrigerators and the refrigeration capacity do not match.

Therefore, conventionally, in order to control the capacity of an absorption chiller, a method has been adopted in which the amount of heat input to the regenerator is controlled and the amount of refrigerant vapor generated in the regenerator is increased or decreased to adjust the refrigeration capacity. As a method for adjusting the amount of heat input to the regenerator, the single effect side uses a three-way valve 18 to increase or decrease the amount of heat source (hot water) flowing into the heat transfer tube of the regenerator 9 into the regenerator, and the double effect side uses a method to increase or decrease the amount of heat input to the regenerator. The engine exhaust gas 16 flowing into the high temperature regenerator 15 is passed through the two-way valve 19.
A method has been adopted in which the amount is increased or decreased by a combination of two or three of the following. In these adjustment methods, the regenerator 9 on the single-effect side cannot completely absorb the heat generated on the engine side at all times, so an auxiliary heat exchanger 20 for engine cooling water heat radiation is provided to exchange heat with the cooling water 5, It was necessary to provide a control device 21 that radiates only the amount of heat that could not be absorbed in the heat exchanger 9. The heat exchanger 20 generally has a large range of variation in cooling load, so it must have an electric heating area that can radiate the entire amount of heat generated by the engine. In other words, in order to dissipate heat from the engine cooling water, in addition to a single-effect absorption refrigerator, a heat exchanger that dissipates the entire amount of heat generated by the engine and its control equipment are required, making the equipment expensive.

[Purpose of the invention]

The present invention solves the above-mentioned drawbacks, and even when the cooling load changes, the required heat dissipation amount of engine cooling water is always absorbed by a single-effect absorption chiller, and an inexpensive engine exhaust system that does not require any other heat exchanger. The present invention provides a heat recovery and absorption type water chiller/heater.

[Summary of the invention]

In order to achieve the above object, the present invention provides a first evaporator, a first absorber, a first regenerator, a first condenser, a first
A first absorption chiller/heater including a heat exchanger, first pumps, and first piping connecting these, a second evaporator, a second absorber, a second low-temperature regenerator, a second high-temperature regenerator, In an engine exhaust heat recovery absorption type water chiller/heater comprising a second condenser, a second heat exchanger, a second pump, and a second piping that connects these, 1 evaporator, 1st absorber, 2nd evaporator, 2nd absorber, 2nd low temperature regenerator,
A second condenser is housed in the same shell, engine cooling water is used as a heating source for the first regenerator, engine exhaust gas is used as a heating source for the second high temperature regenerator, and the refrigerant of the second evaporator is used as a heating source for the second high temperature regenerator. 2nd to blow
A pipe is provided that communicates from the discharge part of the refrigerant spray pump to the first absorber via a refrigerant blow control valve, and a temperature controller that adjusts the opening and closing of the refrigerant blow control valve according to the chilled water outlet temperature. .

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 to 5.

Reference numeral 1 designates a first evaporator, and inside this evaporator 1, water, which is a refrigerant, takes heat from the cold water 2 and evaporates, thereby cooling the cold water 2 to an intermediate temperature. The evaporated refrigerant gas 3 flows into the first absorber 4 and is absorbed by the absorption liquid cooled by the cooling water 5 flowing inside the pipe.
Dilute the solution. The temperature of the cooling water 5 increases as it cools the solution, enters the second absorber 4, and cools the solution again. The diluted solution is delivered to the regenerator 9 via the first heat exchanger 8 by the solution pump 7, where it is heated and concentrated by the engine cooling water 10 flowing in the pipe and separated into a concentrated solution 11 and generated steam 12. Ru. The concentrated solution returns to the first absorber 4 via the heat exchanger 8 and absorbs refrigerant vapor again. 1' is a second evaporator, and in the same manner as the first evaporator, the cold water 2 that has been cooled to an intermediate temperature in the first evaporator is further cooled, the refrigerant is evaporated, and it becomes refrigerant gas 3', which is then transferred to the second evaporator. It is absorbed into the solution in the absorber 4'. The solution in the second absorber 4' is mixed with the cooling water 5 which has been raised to an intermediate temperature in the first absorber.
cooled down. The diluted solution 6' is sent to the second high temperature regenerator 15 and the second low temperature regenerator 9' via the second heat exchangers 8' and 18 by the solution pump 7'. The diluted solution is transferred to the second high temperature regenerator 15.
At this time, the refrigerant is heated and concentrated by engine exhaust gas 16 and separated into a concentrated solution 11' and generated refrigerant vapor 17. The generated refrigerant vapor 17 is transferred to the second low temperature regenerator 9'
The diluted solution is heated and concentrated to separate it into a concentrated solution 11' and the generated refrigerant vapor 12', which is condensed and liquefied and flows into the second condenser 13', where the generated refrigerant vapor 12' becomes the cooling water 5. It mixes with the cooled and liquefied refrigerant liquid and flows into the second evaporator 1'. The concentrated solution 19 is the concentrated solution 1 concentrated in the low temperature regenerator 9'.
1' and returns to the second absorber 4' to absorb refrigerant vapor again.

Refrigeration capacity is adjusted so that the outlet temperature of the chilled water 2 is constant.The outlet temperature is detected and the temperature controller 22 causes the refrigerant liquid blow control valve 23 to close if the chilled water outlet temperature is higher than the set value, and open if it is lower. The operation is performed by sending a signal. A communication pipe 25 is provided between the first evaporator 1 and the second evaporator 1' to seal the difference in the two evaporation pressures, and the pressure of the first evaporator disposed on the cold water inlet side is adjusted to the cold water outlet. Since the pressure is higher than that of the second evaporator disposed on the side, the refrigerant liquid of the first evaporator is also blown through the communication pipe 25 via the second evaporator refrigerant spray pump 14 . Also, the solution is passed through the communication pipe 2 between the first absorber 4 and the second absorber 4'.
4, the solution diluted by the refrigerant liquid blow flows from the first absorber to the second absorber to maintain balance.

With the above configuration, when a partial load is applied, the concentration of the solution in the first absorber 1 on the single-effect side first decreases, and the ability to absorb sufficient heat from the engine cooling water is maintained preferentially, further reducing the refrigeration load. At the same time, the solution concentration also decreases on the dual-effect side via the communication pipe 24, and the total solution concentration decreases to perform volume adjustment and achieve the desired purpose.

Another embodiment of the invention is shown in FIG. In this embodiment, the refrigerant liquid is blown to the regenerator 9 to adjust the refrigerating capacity, diluting the solution in the regenerator 9, and lowering the concentration of the solution returned to the first absorber 4, thereby adjusting the refrigerating capacity. I do. Since the solution in the regenerator 9 is diluted by blowing the refrigerant, the engine cooling water 10 flowing into the regenerator 9 absorbs heat well and sufficiently lowers the temperature to a predetermined temperature. The other parts have the same configuration as in FIG. 3, and their explanation will be omitted.

Another embodiment of the invention is shown in FIG. When the engine cooling water temperature is relatively high, the evaporator and absorber each consist of one piece, as shown in FIG. Even in such a configuration, by blowing refrigerant liquid to the regenerator 9, the refrigerating capacity can be adjusted,
The heat of the engine cooling water 10 can be absorbed preferentially.

〔Effect of the invention〕

According to the present invention, heat absorption of engine cooling water is performed preferentially regardless of refrigeration load conditions, and a heat exchanger for dissipating engine cooling water heat is not required in addition to an absorption chiller, eliminating the need for engine waste heat. A recovered cold/hot water system can be constructed at low cost.

[Brief explanation of the drawing]

Fig. 1 is a flow diagram of a single-effect absorption refrigerating machine, Fig. 2 is a flow diagram of a double-effect absorption refrigerating machine, and Fig. 3 is a flow diagram of an embodiment in which the present invention is applied to an exhaust heat recovery absorption type water chiller/heater. FIG. 4 is a flow diagram of another embodiment of the present invention, and FIG. 5 is a flow diagram of still another embodiment of the present invention. 1... Evaporator or first evaporator, 1'... Second evaporator,
2...Cold water, 3,3'...Evaporative refrigerant vapor, 4...Absorber or first absorber, 4'...Second absorber, 5...Cooling water,
6, 6'... dilution solution, 7, 7'... solution pump, 8,
8'... Heat exchanger, 9... Regenerator, 9'... Second low temperature regenerator, 10... Engine cooling water, 11, 11'... Concentrated solution, 12, 12'... Generated refrigerant vapor, 13... Condenser or 1 condenser, 13'...2nd condenser, 14,1
4'... Refrigerant pump, 15... Second high temperature regenerator, 16
...Engine exhaust gas, 17...High temperature regenerator generated steam, 18...Heat exchanger, 19...Concentrated solution, 22...Temperature regulator, 23...Refrigerant blow control valve, 24...Absorber communication pipe, 25...Evaporator communication tube.

Claims (1)

[Claims] 1 First evaporator, first absorber, first regenerator, first
A first absorption chiller/heater including a condenser, a first heat exchanger, a first pump, and first piping connecting these; a second evaporator; a second absorber; a second low-temperature regenerator; 2 high temperature regenerator, 2nd condenser, 2nd heat exchanger, 2nd pumps, and 2nd
In an engine exhaust heat recovery absorption type chilled/hot water machine equipped with a second absorption type chilled/heated water machine consisting of piping, a first evaporator, a first absorber, a second evaporator, a second absorber, a second
A low temperature regenerator and a second condenser are housed in the same shell, engine cooling water is used as a heating source for the first regenerator, engine exhaust gas is used as a heating source for the second high temperature regenerator, and the second evaporator is used as a heating source for the second evaporator. a pipe that communicates from the discharge part of a second refrigerant spray pump that blows refrigerant from the refrigerant to the first absorber via a refrigerant blow control valve, and a temperature controller that adjusts the opening and closing of the refrigerant blow control valve depending on the chilled water outlet temperature. An engine exhaust heat recovery and absorption type cold/hot water machine characterized by being equipped with a container.