JPH07111285B2 - 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 that uses both a compression refrigerator and an absorption refrigerator is used. This cold water generator drives a compressor of a compression refrigerator with 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 absorption 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. As described above, the cooling water deprived of such heat has a low temperature of about 40 ° C., and therefore cannot be used as a heat source for regeneration of the regenerator of the absorption refrigerating machine that is being used at the same time. It can be used for only a small part of the purpose.

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 object, the cold water generating apparatus of the present invention is a compression refrigerator using a compressor driven by an internal combustion engine, and exhaust heat recovery of the internal combustion engine. An absorption refrigerator using hot water of a hot water system as a heat source for regeneration is provided, and a second exhaust gas heat exchanger is provided in an exhaust gas path passing through an exhaust gas heat exchanger of the exhaust heat recovery hot water system. A second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger is configured, and an adsorption refrigerator that uses the hot water of the second exhaust heat recovery hot water system as a heat source for regeneration is provided. .

Next, the cold water generator of the present invention is provided with a compression refrigerator using a compressor driven by an internal combustion engine, and an absorption refrigerator using the hot water of the exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration. In the compression 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 of the exhaust heat recovery hot water system. A second exhaust gas heat exchanger is provided in the exhaust gas path passing through the gas heat exchanger to form a second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger, A heat recovery hot water system and an adsorption 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. Generate cold water in the evaporator of the absorption chiller used as the heat source for
This can be used 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 hot water of the second exhaust heat recovery hot water system is lower than the temperature of the hot water of the exhaust heat recovery hot water system, and therefore cannot be used as a heat source for regeneration of the absorption refrigerator.
The temperature can be raised to a temperature that can be used as a heat source for regeneration of the 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 the characteristics that the fluctuation of the capacity is small and that the operating range is wide with respect to the decrease of the heat source temperature, the hot water of the second waste heat recovery hot water system is guided to the regenerator of the adsorption refrigerator to By performing the regeneration, it is possible to sufficiently operate the adsorption refrigerator and generate cold water. And this cold water can be used in the same system as the cold water supply system generated in the compression type and absorption type refrigerators,
Or it 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, like the hot water of the second exhaust heat recovery hot water system, the hot water of the heat recovery hot water system can be guided to the regenerator of the second adsorption refrigerator to regenerate the adsorbent.

(Example) Next, the Example of this invention is described with reference to drawings. In this embodiment, the adsorption refrigerating machine is operated by simultaneously using the hot water of the heat recovery hot water system and the hot water of the second exhaust heat recovery hot water system as a heat source for regeneration.

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 configured by providing the heat exchanger 5 in the path from the compressor 1 to the condenser 2 as well as the evaporator 4 as a constituent element. The compressor 1 is 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 heat recovery hot water system Hb that sequentially passes through the exhaust gas heat exchanger 9 provided in the exhaust gas passage 8 and supplies this hot water as a heat source for regeneration of the absorption chiller B. The specific configuration of the absorption refrigerator B itself is appropriate. A second exhaust gas heat exchanger 10 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, and the second exhaust gas heat exchanger 10 is provided. A second exhaust heat recovery hot water system Hc passing through 10 is configured.

Reference numeral C indicates an adsorption refrigerator, and the adsorption refrigerator C has an adsorber 11, a regenerator 12, an evaporator 13 and a condenser 14 as constituent elements. The adsorber 11 and the regenerator 12 are alternately switched so that the adsorption and regeneration are continuously operated, or the rotating adsorbent is rotated over the adsorption unit and the regeneration unit to continuously operate the adsorption and regeneration. The specific configuration of the adsorption refrigerator C itself is appropriate.

Then, the hot water of the heat recovery hot water system Ha and the second waste heat recovery hot water system Hc are supplied to the regenerator 12 of the adsorption refrigerator C as a heat source for regeneration, and these systems are provided.
Ha and Hc are connected in parallel. The specific configuration of the routes of these systems is appropriate.

Reference numeral W indicates a cold water supply system generated by the compression refrigerator A and the absorption refrigerator B, and the cold water supply system W includes a path wa to the evaporator 4 of the compression refrigerator A, The path wb to the evaporator 15 of the absorption chiller B is configured in parallel. Reference numeral Wc indicates a cold water supply system generated in the adsorption refrigerator C. This cold water supply system Wc is configured as a system different from the cold water supply system W in the figure. However, it is possible to adopt a configuration in which they are merged and supplied. next,
Reference numeral R indicates a cooling water supply system for supplying the cooling water of the compression refrigerator A and the absorption refrigerator B, and the cooling water supply system R supplies the cooling water to the condenser 2 of the compression refrigerator A. Route
The ra and the route rb to the condenser 16 of the absorption refrigerator B are configured in parallel. Further, reference symbol Rc is the adsorber 11 of the adsorption refrigerator C.
And the cooling water supply system corresponding to the condenser 14, the cooling water supply system Rc is configured by connecting a route rc to the reduction well 17 and a route r to the cooling water supply system R in parallel. Cage,
An opening / closing valve 18 is provided in the latter route r. In addition, reference numerals in the figure
19a, 19b, 19c and 19d are pumps for supplying hot water or cooling water of each system. Reference numeral 20 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 20. 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 12 of the adsorption refrigerator C as a heat source for regeneration. On the other hand, due to this heat exchanger, the temperature of the refrigerant gas decreases from 85 ° C to 50 ° C as shown in the figure, and therefore the total amount of heat radiated in the condenser 2 when such heat exchange is not performed is performed. About 15% of the 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 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 to cool the cold water of 12 ° C. To 7 ° C
Can be cooled down to a cold water supply system in this case
The cold water of Wc can be used by being combined with the cold water of the cold water supply system W. Also, the reduction well 17 cannot be used,
When the cooling water or the like of the cooling water supply system R must be used, the cold water temperature of the cold water supply system Wc becomes 7 ° C. or higher. In this case, the cold water of the cold water supply system Wc is the cold water. It may be used in a system different from the chilled water of the supply system W, and can be used for precooling of air in air conditioning applications, for example.

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 21 of the absorption refrigerator B. In this way, the absorption chiller B uses the hot water of the exhaust heat recovery hot water system Hb as a heat source for regeneration, and operates with the cooling water of the cooling water supply system R as a cooling source to supply cold water of 7 ° C. to the cold water supply system W. Can be supplied, and 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 heated to 50 ° C. or higher, like the hot water of the heat recovery hot water system Ha described above. In this way, the hot water of the heat recovery hot water system Ha is merged and supplied to the regenerator 12 of the adsorption refrigerator C, and the adsorption refrigerator C can be operated. 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
The increment COPc 'of the primary energy equivalent COPc' by operating the adsorption refrigerator C with the hot water of Ha as the heat source for regeneration is
From FIG. 3, since the efficiency ηad of the adsorption refrigerator C is 0.5 and the heat dissipation coefficient COPh is 5.0, COPc ′ = 5.0 × 0.3 × 0.15 × 0.5 = 0.112.

In addition, the COPc increment COPc ″ of the primary energy conversion by operating the adsorption refrigerator C with the hot water of the second exhaust heat recovery hot water system Hc as the heat source for regeneration is 33% of the exhaust gas, the exhaust gas heat exchanger. Exhaust gas temperature decrease in 9 is 650 ° C → 200 ° C, exhaust gas temperature decrease in the second exhaust gas heat exchanger 10 is 200 ° C → 60
If the specific heat of the exhaust gas is approximately constant, COPc ″ = 0.33 x (200-60) / 650 x 0.5 = 0.035. Therefore, the hot water of the heat recovery hot water system Ha and the second exhaust heat recovery hot water system Hc is When the adsorption refrigerator C is operated by using both of the above as heat sources for regeneration, the increment of COPc in terms of primary energy 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, which is about the value compared to when the adsorption refrigerator C is not used.
The coefficient of performance is improved by 12%.

Then, as in the conventional case, the incremental COPc of the primary energy equivalent COPc by operating the absorption chiller C using the hot water of the exhaust heat recovery hot water system Hb as the heat source for regeneration is the total exhaust heat recovery rate.
COPc ^∧ = 0.52 × 0.7 = 0.364, assuming 52% and cold-heat conversion efficiency of 0.7. Therefore, the overall coefficient of performance COPc in the device of the example is COPc.
Becomes COPc ^∧ = 1.347 × 0.364 = 1.711.

As described above, in the present invention, the heat recovery hot water system Ha
And the second exhaust heat recovery hot water system Hc are both used as heat sources for regeneration to operate the adsorption refrigerator C, and in some cases, only one of them is used and the other uses heat by other means. It can also be configured to allow recovery. Further, in the present invention, the adsorption refrigerator C can be installed in a place apart from the compression refrigerator A and the absorption refrigerator B, for example, in a subway station, tunnel or underground redevelopment space. When the apparatus of the present invention is used for cooling or the like, the adsorption refrigerator C can be installed in an underground machine room or the like to easily use groundwater leakage as cooling water. The main body of the adsorption refrigerator C is vibration-free, noise-free, and the adsorbent such as silica gel or zeolite is non-toxic, non-polluting, and non-corrosive, so that environmental pollution is possible even in the event of a disaster. It is safe without causing

(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 absorption 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 type of exhaust heat recovery that exchanges heat with the exhaust gas from the exhaust gas heat exchanger of the exhaust heat recovery hot water system Since the hot water in the hot water system, or in addition to this, the hot water in the heat recovery hot water system that exchanges heat with the refrigerant gas that has passed through the compressor of the compression refrigerator is used as the heat source for regeneration, Part of the heat quantity of the exhaust gas that was discarded because it could not be sufficiently recovered, or in addition to this, part of the heat quantity of the refrigerant gas that was discarded in the condenser of the compression refrigerator is used effectively. And thus can significantly improve the efficiency of cold water generation. Has the effect of

[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 A: compression refrigerator, B ... absorption refrigerator, C ...
Adsorption refrigerator, 1 ... compressor, 2,14,16 ... condenser, 3
...... Expansion valve, 4,13,15 ...... Evaporator, 5 ...... Heat exchanger, 6
...... Internal combustion engine, 7 ... Jacket cooler, 8 ... Exhaust gas path, 9 ... Exhaust gas heat exchanger, 10 ... Second exhaust gas heat exchanger, 11 ... Adsorber, 12,21 ... … Regenerator, 17 ……
Reduction well, 18 ... open / close valve, 19a, 19b, 19c, 19d ... pump, 20 ... cooling tower, Ha ... heat recovery hot water system, Hb ... waste heat recovery hot water system, Hc ... second discharge Heat recovery hot water system, W, Wc ...
… Cold water supply system, R, Rc …… Cooling water supply system, wa, wb, ra, r
b, rc, rd ... 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, an absorption refrigerating machine using hot water from a hot water recovery hot water system of the internal combustion engine as a heat source for regeneration, and the exhaust heat recovery. A second exhaust gas heat exchanger is provided in the exhaust gas path passing through the exhaust gas heat exchanger of the hot water system to form a second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger, A chilled water generator characterized by being provided with an adsorption refrigerator that uses the hot water of the second exhaust heat recovery hot water system as a heat source for regeneration. 2. A compression type refrigerator using a compressor driven by an internal combustion engine, and an absorption type refrigerator using hot water of an exhaust heat recovery hot water system of the internal combustion engine as a heat source for regeneration, the compression type refrigerator. In the above, 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 the heat recovery hot water system passes through the exhaust gas heat exchanger. Provide a second exhaust gas heat exchanger in the exhaust gas path,
An adsorption refrigerator that constitutes a second exhaust heat recovery hot water system that passes through the second exhaust gas heat exchanger, and uses the second exhaust heat recovery hot water system and the hot water of the heat recovery hot water system as a heat source for regeneration. A cold water generator characterized in that