JPH07111286B2 - Cold water generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cold water generator for generating cold water for cooling or the like.

(Prior Art) Recently, as one of the cold water generators, a cold water generator using both a compression refrigerator and an adsorption refrigerator is used. This cold water generator drives a compressor of a compression refrigerator by an internal combustion engine such as a gas engine, and uses hot water of an exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration of a regenerator of an adsorption refrigerator. By doing so, the efficiency of generation of cold water is increased.

(Problems to be Solved by the Invention) In an exhaust heat recovery hot water system of an internal combustion engine, the hot water of the internal combustion engine is used in order to use the hot water in the system as a heat source for regeneration of a regenerator of an adsorption refrigerator. Exhaust heat is recovered at a temperature of, for example, 85 ° C or higher through the jacket and the exhaust gas heat exchanger, and therefore exhaust heat of exhaust gas is not sufficiently recovered. That is, even if exhaust heat is recovered as hot water of 85 ° C or higher in the exhaust gas heat exchanger, the temperature of the exhaust gas is, for example, 650
It decreases only from about ℃ to about 200 ℃, and the sensible heat below this temperature and the latent heat of water vapor contained in the exhaust gas are not effectively recovered.

In addition, in a compression refrigerator, in order to improve efficiency,
It is required to operate by reducing the condensation temperature of the refrigerant gas in the condenser as much as possible, and is usually set to about 40 ° C. depending on the conditions such as the temperature of the cooling water supplied to the condenser. However, the temperature of the refrigerant gas discharged from the compressor is usually relatively high at about 90 ° C., and conventionally, the refrigerant gas is radiated to the cooling water as it is and discarded. That is, conventionally
In the condenser, the total heat of the compressor's cooling capacity and shaft power is wasted into the cooling water. And, as described above, the cooling water that has deprived the amount of heat has a low temperature of about 40 ° C., so that it is used only for a part of heating.

An object of the present invention is to solve the above problems and further improve the efficiency of cold water generation.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the cold water generating device of the present invention first comprises a compression refrigerator using a compressor driven by an internal combustion engine, and exhaust heat of the internal combustion engine. A first adsorption refrigerator that uses the hot water of the recovered hot water system as a heat source for regeneration is provided, and a second exhaust gas heat exchanger is provided in the exhaust gas path that passes through the exhaust gas heat exchanger of the exhaust heat recovered hot water system. A second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger,
A second adsorption type refrigerator using the hot water of the second exhaust heat recovery hot water system as a heat source for regeneration is provided.

Further, the cold water generating device of the present invention is a compression refrigerating machine using a compressor driven by an internal combustion engine, and a first adsorption refrigerating machine using hot water of an exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration. In the compression type refrigerator, a heat exchanger is provided in the path from the compressor to the condenser to configure a heat recovery hot water system passing through the heat exchanger, and the exhaust heat recovery hot water system. A second exhaust gas heat exchanger is provided in an exhaust gas path passing through the exhaust gas heat exchanger, and a second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger is constituted, The exhaust heat recovery hot water system and the second adsorption type refrigerator using the hot water of the heat recovery hot water system as a heat source for regeneration are provided.

(Operation) In the above configuration, the cold water generator of the present invention regenerates the hot water of the evaporator of the compression refrigerator using the compressor driven by the internal combustion engine and the exhaust heat recovery hot water system of the internal combustion engine. It is possible to generate cold water in the evaporator of the first adsorption type refrigerating machine which is a heat source for use, and use it for cooling or the like.

In such an operation, in the second exhaust gas heat exchanger, by exchanging heat between the exhaust gas that has passed through the exhaust gas heat exchanger of the exhaust heat recovery hot water system and the hot water of the second exhaust heat recovery hot water system, The temperature of the hot water of the second exhaust heat recovery hot water system can be raised to a temperature lower than the temperature of the hot water of the exhaust heat recovery hot water system but usable as a heat source for regeneration of the second adsorption refrigerator. . That is, in general, the adsorption type refrigerating machine does not have the inconvenience of crystal precipitation of the absorbent in the absorption type refrigerating machine, and in addition, it produces cold water against the fluctuation of the heat quantity of the heat source for regeneration in the regenerator. Since it has a characteristic that the fluctuation of the capacity is small and the operating range is wide with respect to the decrease of the heat source temperature, the hot water of the second exhaust heat recovery hot water system is guided to the regenerator of the second adsorption refrigerator, By regenerating the adsorbent, it is possible to sufficiently operate the second adsorption refrigerator and generate cold water. This cold water can be used in the same system as the supply system of the cold water generated in the compression type and the first adsorption type refrigerator, or can be used in another system.

Further, in the above operation, in addition to the above, in the heat exchanger provided in the path from the compressor to the condenser, by exchanging heat between the refrigerant gas and the hot water of the heat recovery hot water system, Can be heated to a temperature lower than the hot water temperature of the exhaust heat recovery hot water system of the internal combustion engine, but higher than the condensation temperature in the condenser. Therefore, the hot water of the heat recovery hot water system can be guided to the regenerator of the second adsorption refrigerating machine to regenerate the adsorbent, like the hot water of the second exhaust heat recovery hot water system.

(Example) Next, the Example of this invention is described with reference to drawings. In this embodiment, the hot water of the heat recovery hot water system and the hot water of the second exhaust heat recovery hot water system are simultaneously used as a heat source for regeneration to operate the second adsorption refrigerator.

In FIG. 1, reference numeral A indicates a compression refrigerator.
This compression refrigerator A includes a compressor 1, a condenser 2, and an expansion valve 3.
Further, the heat recovery hot water system Ha passing through the heat exchanger 5 is constructed by providing the heat exchanger 5 in the path from the compressor 1 to the condenser 2 while having the evaporator 4 as a constituent element. The compressor 1 is configured to be driven by an internal combustion engine 6 such as a gas engine. The internal combustion engine 6 includes a jacket cooler 7 and an exhaust gas heat exchanger 9 provided in an exhaust gas passage 8.
A waste heat recovery hot water system Hb that sequentially passes through is configured. Also,
A second exhaust gas heat exchanger is provided in the exhaust gas passage 8 at a position after passing through the exhaust gas heat exchanger 9 of the exhaust heat recovery hot water system Hb.
A second exhaust heat recovery hot water system Hc that passes through the second exhaust gas heat exchanger 10 is configured by providing 10.

Reference numerals B and C indicate the first and second adsorption type refrigerators, respectively, and these first and second adsorption type refrigerators B and C are the adsorber 1 respectively.
1b, 11c, regenerators 12b, 12c, evaporators 13b, 13c and condenser 14b,
It is composed of 14c. Adsorbers 11b, 11c and regenerator 12b,
12c is configured to continuously operate adsorption and regeneration by switching alternately, or configured to continuously operate adsorption and regeneration by rotating the rotating adsorbent across the adsorption unit and regeneration unit, etc. The specific configuration of the adsorption refrigerators B and C themselves is appropriate.

Then, the hot water of the exhaust heat recovery hot water system Hb is supplied to the regenerator 12b of the first adsorption refrigerator B as a heat source for regeneration, and the heat recovery hot water system Ha and the second exhaust heat The hot water of the recovered hot water system Hc is supplied to the second adsorption refrigerator C
It is configured to be supplied to the regenerator 12c as a heat source for regeneration. The latter systems Ha and Hc are connected in parallel. The specific configuration of the routes of the above system is appropriate.

The symbol W indicates the compression refrigerator A and the first adsorption refrigerator B.
The chilled water supply system W includes a path wa to the evaporator 4 of the compression refrigerator A,
The path wb to the evaporator 13b of the first adsorption refrigerator B is configured in parallel. Reference numeral Wc is the second adsorption refrigerator C
In the figure, the cold water supply system Wc is configured separately from the cold water supply system W in FIG. You can also Next, reference symbol R indicates a cooling water supply system for supplying the cooling water for the compression refrigerator A and the first adsorption refrigerator B, and the cooling water supply system R is for the compression refrigerator A. Path ra to the condenser 2 and the first adsorption type refrigerator B
The adsorber 11b and the path rb to the condenser 14b are configured in parallel. Further, reference symbol Rc is the adsorber 11c of the second adsorption type refrigerator C.
And showing the cooling water supply system corresponding to the condenser 14c,
In this cooling water supply system Rc, a route rc to the reduction well 15 and a route r to the cooling water supply system R are arranged in parallel, and an opening / closing valve 16 is provided in the latter route r. Reference numerals 17a, 17b, 17c, 17d in the figure are pumps for supplying hot water or cooling water of each system. Further, reference numeral 18 is a cooling tower.

The operation of the configuration of the above embodiment will be described based on specific numerical examples. In this specific example, the cold water supply system W
The cold water temperature on the cold water supply side is 7 ° C, the cooling water temperature on the cooling water supply side of the cooling water supply system R is 32 ° C, and the cooling water temperature on the cooling water supply system Rc is around 20 ° C. To do.

First, the operation of the compression refrigerator A will be described with reference to the Mollier diagram shown in FIG. The refrigerant gas compressed by the compressor 1 (point a in the figure) exchanges heat with the hot water of the heat recovery hot water system Ha in the heat exchanger 5 until it reaches the condenser 2, and a part of its heat amount. Radiates heat and lowers the temperature. (Point a → b in the figure) The refrigerant gas whose temperature has decreased in this way is condensed while radiating heat to the cooling water in the condenser 2 and then supercooled (point b → c in the figure), and then evaporated through the expansion valve 3. It reaches the vessel 4 (point c → d in the figure) where it evaporates while taking heat from the cold water, and is overheated (point d → e in the figure) to recirculate to the suction side of the compressor 1 Compressed again with (point e → a in the figure)
The above operation is repeated.

As described above, the refrigerant gas in the condenser 2 is 32 ° C.
At this temperature, the cooling water of the cooling water supply system R introduced into the condenser 2 condenses and radiates heat at a temperature of 40 ° C., so that the cooling water becomes hot water of 40 ° C. and exits from the condenser 2 and is cooled. Reflux to tower 18. Also, in the evaporator 4, the refrigerant gas evaporates at a temperature of 0 ° C., and thus cold water of 7 ° C. can be obtained.

In the above operation, the hot water of the heat recovery hot water system Ha that has exchanged heat with the refrigerant gas in the heat exchanger 5 becomes 50 ° C. or higher,
It joins with the hot water of the second exhaust heat recovery hot water system Hc and is supplied to the regenerator 12c of the second adsorption refrigerator C as a heat source for regeneration. On the other hand, due to this heat exchange, the temperature of the refrigerant gas decreases from 85 ° C to 50 ° C as shown in the figure, and therefore, when such heat exchange is not performed, the total amount of heat radiated in the condenser 2 is About 15% of heat can be recovered by the heat recovery hot water system Ha. At this time, depending on the operating conditions, if the condensing temperature becomes higher than the above temperature, the latent latent heat of condensation is added to the sensible heat, and the above-mentioned heat recovery rate also increases.

As shown in FIG. 3 showing the performance of the second adsorption type refrigerator C, when the temperature of the cooling water is 20 ° C., the hot water of 50 ° C. is used as a heat source for regeneration. Chilled water of ℃ can be cooled to 7 ° C. In this case, the chilled water of the chilled water supply system Wc can be used by being combined with the chilled water of the chilled water supply system W. When the reduction well 15 cannot be used and the cooling water of the cooling water supply system R or the like has to be used, the cold water temperature of the cold water supply system Wc is 7
Since the temperature is higher than or equal to ℃, for example, about 15 ℃, in this case, the cold water of the cold water supply system Wc may be used in a system different from the cold water of the cold water supply system W. For example, in the air conditioning application, precooling of air is performed. It can be used for etc.

On the other hand, in the internal combustion engine 6 driving the compressor 1 of the compression refrigerator A, the hot water of the exhaust heat recovery hot water system Hb first flows through the jacket cooler 7 and then the exhaust gas heat exchanger 9. Then, the temperature is raised to 85 ° C. or higher and is supplied to the regenerator 12b of the first adsorption refrigerator B. Thus, the first adsorption refrigerator B
Can supply the cold water of 7 ° C. to the cold water supply system W by using the hot water of the exhaust heat recovery hot water system Hb as a heat source for regeneration and operating the cooling water of the cooling water supply system R as a cooling source. Thus, this cold water can be used by being combined with the cold water generated in the compression refrigerator A described above.

In the above operation, the exhaust gas flowing through the exhaust gas passage 8 is first exhausted in the exhaust gas heat exchanger 9 into the exhaust heat recovery hot water system.
After heat exchange with the hot water of Hb, the temperature drops from about 650 ° C to about 200 ° C, after which the heat of the second exhaust gas heat exchanger 10 is exchanged with the hot water of the second exhaust heat recovery hot water system Hc. Then, the temperature is further lowered, and then it is discharged. On the other hand, by such heat exchange, the hot water of the second exhaust heat recovery hot water system Hc can be set to 50 ° C. or higher like the hot water of the heat recovery hot water system Ha described above, and thus, the hot water of the heat recovery hot water system Ha The second adsorption type refrigerator C can be operated by merging and supplying to the regenerator 12c of the second adsorption type refrigerator C. By the above heat exchange, the temperature of the exhaust gas is lowered from the above-mentioned 200 ° C. to about 60 ° C., and the heat quantity corresponding to the reduced amount can be recovered by the second exhaust heat recovery hot water system Hc.

Next, the coefficient of performance in the operation of the above embodiment will be described.

First, as described above, when the cold water temperature on the cold water supply side of the cold water supply system W is 7 ° C. and the cooling water temperature on the cooling water supply side of the cooling water supply system R is 32 ° C., compression refrigeration is performed. If COPc is the coefficient of performance of the compressor shaft power standard in machine A, for example, COPc = 4.0 for medium and small capacity machines around 100 USRT,
COPc is around 4.8 for a large-capacity machine of 500 USRT or more, so the coefficient of performance of the device of the present invention using a small-medium capacity machine is as follows. If the heat dissipation coefficient is COPh, COPh = COPc
It is +1.

Gas engine efficiency ηe is ηe = 0.
If it is set to 3, the coefficient of performance COPc of the compression chiller A converted into primary energy is COPc = COPc × engine efficiency = 4.0 × 0.3 = 1.2. Further, as described above, when the temperature of the cooling water in the cooling water system Rc is 20 ° C. and the temperature of the cold water on the cold water supply side of the cold water supply system Wc is 7 ° C., the heat recovery hot water system
Incremental COP of primary energy equivalent COPc by operating the second adsorption refrigerator C with hot water of Ha as heat source for regeneration
c ′ is the efficiency ηad = of the second adsorption refrigerator C from FIG.
Since it is 0.5 and the heat dissipation coefficient COPh = 5.0, COPc '= 5.0 x 0.3 x 0.13b x 0.5 = 0.112.

The COPc increment COPc ″ of the primary energy conversion by operating the second adsorption refrigerator C using the hot water of the second exhaust heat recovery hot water system Hc as the heat source for regeneration is the exhaust gas ratio 33
%, Temperature decrease of exhaust gas in exhaust gas heat exchanger 9 65
0 ° C → 200 ° C, the temperature of the exhaust gas in the second exhaust gas heat exchanger 10 drops 200 ° C → 60 ° C, and the specific heat of the exhaust gas is approximately constant, COPc ″ = 0.33 × (200-60) / 650 × 0.5 = 0.035 Therefore, the primary energy conversion by operating the second adsorption refrigerator C with both the hot water of the heat recovery hot water system Ha and the hot water of the second exhaust heat recovery hot water system Hc as heat sources for regeneration CO
The increment of Pc is COPc '+ COPc "= 0.112 + 0.035 = 0.147.

The overall coefficient of performance COPc, which is a combination of the above, is COPc = COPc + COPc ′ + COPc ″ = 1.2 + 0.112 + 0.035 = 1.3
47, the coefficient of performance is improved by about 12% compared to the case where the second adsorption refrigerator C is not used.

Then, as in the conventional case, the incremental COPc of the primary energy equivalent COPc by operating the first adsorption refrigerator C using the hot water of the exhaust heat recovery hot water system Hb as the heat source for regeneration is the exhaust heat total recovery rate 52. %, And the heat-to-heat conversion efficiency is 0.59, COPc ^∧ = 0.52 × 0.59 = 0.307, and therefore the overall coefficient of performance COPc
Becomes COPc = 1.347 × 0.307 = 1.654.

As described above, in the present invention, the heat recovery hot water system Ha
And using the hot water of the second exhaust heat recovery hot water system Hc as heat sources for regeneration, the second adsorption refrigerator C is operated,
In some cases, only one of them may be used, and the other may be configured to recover heat by other means. Further, in the present invention, at least one side of the adsorption type refrigerators B and C can be installed in a place apart from the compression type refrigerator A, for example, in a subway station, tunnel or underground redevelopment space. When the device of the present invention is used for cooling or the like, by installing the adsorption refrigerators B and C in an underground machine room or the like, leakage of groundwater can be easily used as cooling water. The main body of the adsorption type refrigerator B, C is vibration-free and noise-free, and the adsorbents such as silica gel and zeolite are non-toxic, non-polluting and non-corrosive, so even in the event of a disaster, etc. It is safe without causing pollution.

(Effects of the Invention) As described above, the present invention provides a compression refrigerator that uses a compressor driven by an internal combustion engine, and an adsorption refrigerator that uses hot water of an exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration. A second cold water generator that is used in combination with another adsorption refrigerating machine and exchanges the operation of this other adsorption refrigerating machine with the exhaust gas that has passed through the exhaust gas heat exchanger of the exhaust heat recovery hot water system. Since it is performed by using the hot water of the exhaust heat recovery hot water system or the hot water of the heat recovery hot water system that exchanges heat with the refrigerant gas that has passed through the compressor of the compression refrigerator in addition to this, as a heat source for regeneration, Recovers part of the heat quantity of the exhaust gas that was discarded because exhaust heat could not be sufficiently recovered, or part of the heat quantity of the refrigerant gas that was discarded in the condenser of the compression refrigerator. Can be used effectively, and thus the efficiency of cold water generation can be significantly improved. The effect is that you can

[Brief description of drawings]

FIG. 1 is a system explanatory view showing the configuration and operation of an embodiment of the device of the present invention, FIG. 2 is a Mollier diagram showing an operation example of a compression refrigerator applied to the device of the present invention, and FIG. It is a characteristic view showing an operation example of an adsorption type refrigerator applied to an invention device. Reference symbol A ... compression refrigerator, B ... first adsorption refrigerator,
C: second adsorption refrigerator, 1 ... compressor, 2 ... condenser, 3 ... expansion valve, 4 ... evaporator, 5 ... heat exchanger, 6
...... Internal combustion engine, 7 ...... Jacket cooler, 8 ...... Exhaust gas passage, 9 ...... Exhaust gas heat exchanger, 10 ...... Second exhaust gas heat exchanger, 11b, 11c …… Adsorber, 12b, 12c ... regenerator,
13b, 13c ... Evaporator, 14b, 14c ... Condenser, 15 ... Reduction well, 16 ... Open / close valve, 17a, 17b, 17c, 17d ... Pump, 18 ...
… Cooling tower, Ha… Heat recovery hot water system, Hb… Exhaust heat recovery hot water system, Hc… Second heat recovery hot water system, W, Wc… Cold water supply system, R, Rc… Cooling water supply System, wa, wb, ra, rb, rc ……
Route.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Nobuumi Ino 1-5-15-204 Shimizuguchi, Usui-cho, Inba-gun, Chiba Prefecture (72) Hideji Yanagi 3600-80, Nakane, Katsuta-shi, Ibaraki (56) References Special Kai 63-143468 (JP, A)

Claims (2)

[Claims] 1. A compression refrigerating machine using a compressor driven by an internal combustion engine, and a first adsorption refrigerating machine using hot water of an exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration.
A second exhaust gas heat exchanger is provided in the exhaust gas passage passing through the exhaust gas heat exchanger of the exhaust heat recovery hot water system, and a second exhaust heat recovery hot water system passing through the second exhaust gas heat exchanger is provided. A chilled water generator comprising a second adsorption type refrigerator configured to use the hot water of the second exhaust heat recovery hot water system as a heat source for regeneration. 2. A compression refrigerating machine using a compressor driven by an internal combustion engine, and a first adsorption refrigerating machine using hot water of an exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration are provided. In a refrigerator, a heat exchanger is provided in the path from the compressor to the condenser to form a heat recovery hot water system passing through the heat exchanger, and exhaust gas heat exchange of the exhaust heat recovery hot water system. A second exhaust gas heat exchanger is provided in the exhaust gas path passing through the reactor to form a second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger, and the second exhaust heat recovery hot water is provided. System and a second adsorption type refrigerator using the hot water of the heat recovery hot water system as a heat source for regeneration