JPH1099256A - Heat exchange equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To always keep a tank for collecting waste water and a heat exchange pipe clean. SOLUTION: A pipe-shaped evaporator 27 which is a component of a heat pump 21 is spirally wound along an inner peripheral surface of a waste water recovery tank 30 for storing waste water of a dishwasher 1. Have been. A propeller-like agitator 36 driven by a motor 37 is provided at a substantially central height inside the evaporator 27, and a normally-open drain valve 40 is provided on the bottom surface of the tank 30. The heat exchange is performed by closing the drain valve 40 and driving the stirrer 36. The agitation of the entire hot water prevents the food residue mixed with the hot water from adhering to the inner surface of the tank 30 or the surface of the evaporator 27. When the heat exchange is completed, the drain valve 40 on the bottom surface of the tank 30 is opened to discharge the hot water, and the discharged hot water is discharged as a vortex due to the inertial force. There is no accumulation on the bottom of the.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanging apparatus for raising the temperature of a fluid such as water or a refrigerant using waste heat of domestic waste water.

[0002]

2. Description of the Related Art In the field of dishwashers, for example, in order to save energy and reduce running costs, the temperature of newly supplied rinsing water is increased by utilizing the heat of hot water after rinsing is completed. That is being done. Japanese Patent Application Laid-Open No. 8-15010 discloses an example of a heat exchange device for this purpose.
No. 7 is known. In this, as shown in FIG. 10, a feed pipe b for feeding raw water of rinsing water is provided in a tank a for collecting hot water from a dishwasher, and the raw water is fed to the feed pipe b. In the meantime, the raw water is preheated by exchanging heat with the hot water. On the other hand, the hot water discharged from the dishwasher contains food residues, and if it adheres to the feed pipe b, the heat exchange performance may be degraded, or it may settle at the bottom of the tank a and stick. It is necessary to wash appropriately. Therefore, in the conventional apparatus, after draining hot water, washing water is injected from the shower pipe c to be stored in the tank a, and the propeller fan d is turned to perform washing while generating a vortex.

[0003]

However, in the conventional apparatus, the propeller fan d must be provided at the bottom of the tank a due to the piping structure of the feed pipe b, and therefore, a vortex is generated in the entire tank a. And it is very difficult to remove the residue once stuck on the feed pipe b,
Further, since the outlet e is provided at the bottom of the side surface of the tank a, it is difficult to completely discharge the residue settled at the bottom of the tank a. In addition, propeller fan d during heat exchange
It is also attempted to prevent food residues from adhering to the feed pipe b by turning the tank a.
It was also insufficient because it was difficult to create a vortex in the entire interior. That is, in the related art, it is not always satisfactory to keep the tank a and the feed pipe b clean, and a new device has been eagerly desired. The present invention has been completed on the basis of the above-mentioned demands, and has a heat exchange device capable of always keeping a tank for collecting waste water and a feed pipe provided therein clean. The purpose is to provide.

[0004]

In order to achieve the above object, the present invention is directed to a heat exchanger in which a fluid supply pipe is provided in a tank for collecting domestic waste water so as to be able to exchange heat. In the apparatus, a rotatable stirrer is provided in the tank, and an openable / closable outlet is provided on the bottom surface of the tank. During heat exchange, the outlet is closed and the agitator is driven to drive the agitator into the tank. The feature is that it is configured to generate a vortex. A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the feeding pipe is configured to be bent and piped along the inner surface of the tank.
The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, when the heat exchange is completed, the drive of the stirrer is stopped to open the discharge port. A fourth aspect of the present invention is characterized in that, in the first, second or third aspect of the invention, the agitator is provided with a brush for wiping the surface of the feed pipe.

[0005]

Actions and effects of the present invention

<Invention of Claim 1> The heat exchange operation is performed by closing the discharge port of the tank, storing the domestic wastewater therein, and feeding the fluid to the feed pipe while rotating the stirrer. During this time, since the domestic waste water in the tank is agitated so as to generate a vortex over the whole, the heat exchange with the fluid is greatly promoted. At the same time, the dirt mixed with the domestic waste water tends to adhere to the inner surface of the tank and the surface of the feed pipe. Is prevented. In other words, eddy currents occur in the domestic wastewater during heat exchange, thereby preventing dirt mixed therein from adhering to the feed pipe or the tank inner surface,
It is possible to secure a clean and efficient heat exchange, and to realize a clean device that does not emit an odor or the like. <Invention of Claim 2> When the stirrer is driven, a vortex is more likely to be generated, which is more effective in preventing adhesion of dirt. <Invention of claim 3> When the liquid level drops to the position of the stirrer with the discharge of the hot water, since the stirrer has already stopped, there is no danger that the hot water will scatter. <Invention of Claim 4> Since the brush provided on the stirring tool wipes the feed pipe, it is possible to more reliably prevent the attachment of dirt to the feed pipe.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, the case where hot water for rinsing used in the dishwasher is generated by a hot water generator equipped with a heat pump, and the refrigerant flowing through the evaporator portion of the refrigeration cycle constituting the heat pump and the dishwasher, 1 shows an example in which the present invention is applied to a part that exchanges heat with hot water. <First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a dishwasher, on the side of which a hot water generator 20 equipped with a heat pump 21 is installed. First, the structure of the dishwasher 1 will be described.
A washing chamber 2 in which tableware is removably stored via a rack (not shown) is formed. A pair of washing nozzles 3 and rinsing nozzles 4 are arranged on the upper and lower sides of the washing chamber 2. I have. On one side of the bottom surface of the cleaning chamber 2, a cleaning tank 6 for storing cleaning water mixed with an alkaline detergent is formed, and the cleaning water stored therein is pumped up by a cleaning pump 7 and the cleaning nozzle 3 described above. Are sprayed toward tableware, and then circulated and supplied to the washing tank 6.

Below the washing tank 6, a hot water storage tank 8 for storing hot water for rinsing is provided. In the hot water storage tank 8, the hot water generator 2
0 is supplied to the hot water supply pipe 1 provided with the hot water supply valve 9.
0 and stored. The stored hot water is pumped up by the rinsing pump 11, is jetted from the rinsing nozzle 4 toward the tableware, and is collected in the washing tank 6. The washing tank 6 is provided with an overflow pipe 13. The overflow pipe 13 takes in the overflowed hot water from the washing tank 6,
The hot water is discharged through a drain pipe 14 into a waste water recovery tank 30 provided in the hot water generator 20. In addition,
The heater 1 is provided in the cleaning tank 6 and the hot water storage tank 8, respectively.
Thermostats 5 and 16 and a thermostat (not shown) are provided so that the temperature of the washing water is maintained at about 60 ° C. and the temperature of the rinsing water is maintained at about 80 ° C.

That is, when the dishes are stored in the washing room 2,
The washing water is sprayed from the washing nozzle 3 to wash the dishes,
Subsequently, hot water is sprayed from the rinsing nozzle 4 to perform rinsing. The waste water that has overflowed without being collected in the washing tank 6 is discharged to the hot water generator 20 to recover waste heat, and the recovered heat is supplied to the raw water such as tap water supplied to the water supply pipe 10. The hot water is generated by the heat exchange with the hot water storage tank 8.

Next, the hot water generator 20 will be described in detail. The hot water generator 20 includes a heat pump 21 and is housed in a box-shaped casing 22. As shown in FIG. 6, in the heat pump 21, a compressor 24, a condenser 25, an expansion valve 26, and an evaporator 27 are connected in a circulating manner, and Freon gas (R-22) as a refrigerant is sealed therein so that the refrigerant can flow therethrough. This constitutes a refrigeration cycle.

[0010] The compressor 24 is relatively large,
As shown in FIGS. 2 and 3, it is installed on the bottom surface in the casing 22. A hot water recovery tank 30 with a cover plate 31 is provided on a side of the compressor 24. As shown in FIGS. 4 and 5, a pipe-shaped evaporator 27, which is a component of the refrigeration cycle, is spirally wound around the wastewater recovery tank 30 along the inner peripheral surface thereof. , Its entrance 2
The outlet 7b and the outlet 27b protrude from the upper surface of the cover plate 31 and are connected to the refrigerant pipe 21a. A drainage inlet 32 is provided on one side of the drainage recovery tank 30 and is connected to a drainage pipe 14 drawn from an overflow pipe 13 of a washing tank 6 in the dishwasher 1. The hot water overflowing from 6 can be introduced. On the other side, there is provided a discharge port 33 for discharging overflow water from the hot water recovery tank 30 itself, and a drain pipe 3 is provided.
4 are connected.

As shown in FIG. 5, a propeller-like agitator 36 is provided in the hot water recovery tank 30 so as to be located at a substantially central height inside the evaporator 27. The drive motor 37 provided on the cover plate 31 is driven to rotate via a shaft 38. A drain valve 40 is provided on the bottom surface of the waste water recovery tank 30. The drain valve 40 is a normally-open type, and opens and closes at the tip of a rod 41 that is freely movable up and down through the cover plate 31, and contacts and separates from the upper surface side of a valve port 42 opened at the bottom surface. A valve element 43 is provided, and the rod 41 is always
Is upwardly urged by the spring member 44, and the valve body 43 is pulled up as shown by a chain line in FIG. 5, so that the valve port 42 is opened, and the solenoid mounted on the cover plate 31 via the bracket 45 The valve port 42 is closed by pushing down the rod 41 and the valve element 43 against the urging force as shown by the solid line in FIG. The drain valve 40 is connected to the above-mentioned drain pipe 34 so as to be joined therewith. The lid plate 31 of the hot water recovery tank 30 is provided with two watering nozzles 48 for spraying hot water toward the evaporator 27 to wash it.

The condenser 25 is formed in the shape of a large-diameter pipe, into which a water supply pipe 10 for supplying raw water for rinsing water is provided.
Double tube part 2 through which the middle part is inserted to enable heat exchange
8 are formed. As shown in FIGS. 2 and 3, the double pipe portion 28 is stretched while turning around the inside of the two side surfaces of the casing 22. The outlet side of the water supply pipe 10 is connected to the hot water storage tank 8 of the dishwasher 1 as described above. The expansion valve 26 is of a temperature type having a temperature-sensitive cylinder 26a (see FIG. 6). A control box 49 containing a device for controlling the refrigeration cycle of the heat pump 21 and water supply and drainage is provided in the casing 22.
Is provided.

Referring to FIG. 6, the refrigeration cycle will be described. A bypass pipe 51 is provided between the high pressure side and the low pressure side of the compressor 24, and a capacity adjusting valve 52 is provided therein. The capacity adjusting valve 52 functions to open when the pressure difference between the high-pressure side and the low-pressure side increases and to allow the high-pressure side hot gas to flow into the low-pressure side. Water pipe 1
An automatic water supply valve 53 is provided at a position exiting the double pipe section 28 at 0. The automatic water supply valve 53 functions to detect the pressure on the high pressure side, adjust the water supply amount accordingly, and keep the pressure on the high pressure side constant. Along with this, it is possible to take out hot water having a substantially constant temperature. On the upstream side of the automatic water supply valve 53 in the water supply pipe 10, a watering hose 55 provided with a flow dividing valve 54 is connected in a branched manner, and the watering hose 55 is provided on the cover plate 31 of the above-described wastewater recovery tank 30. Connected to the sprinkling nozzle 48. The flow dividing valve 54 is opened when the operation is stopped, so that the double pipe section 28 is opened.
The hot water remaining inside is discharged and used for cleaning the evaporator 27, and also functions to prevent transient shortage of condensation capacity at the start of operation.

A refrigerant pipe 21a on the outlet side of the condenser 25;
A first auxiliary heat exchange unit 57 is configured by closely connecting a portion of the raw water supply pipe 10 on the near side that enters the double pipe section 28 in parallel. The first auxiliary heat exchange unit 57 functions to preheat the raw water by causing heat exchange between the liquid refrigerant discharged from the condenser 25 and the raw water of the rinse water. In addition, the refrigerant pipe 21a on the downstream side of the portion forming the first auxiliary heat exchange unit 57 and the refrigerant pipe 21a on the outlet side of the evaporator 27 are similarly closely connected in parallel to form the second refrigerant pipe. An auxiliary heat exchange section 58 is configured. The second auxiliary heat exchange section 58 heats the low-temperature refrigerant that has passed through the evaporator 27 with the high-temperature liquid refrigerant that has flowed out of the condenser 25 to prevent a liquid return phenomenon to the compressor 24 particularly in the latter half of operation. It functions to suppress and increase the heat utilization efficiency.

A receiver 59 is provided in the refrigerant pipe 21a between the portion constituting the second auxiliary heat exchange section 58 and the expansion valve 26. The receiver 59 serves to store the liquid refrigerant when the refrigerant is overfilled or when the internal balance is lost and the liquid refrigerant becomes excessive, thereby preventing the liquid refrigerant from staying in the condenser 25. . A refrigerant solenoid valve 60 is interposed between the receiver 59 and the expansion valve 26. The refrigerant solenoid valve 60 functions to prevent high-pressure gas from leaking from the expansion valve 26 to the low-pressure side when the operation is stopped, and to maintain high pressure.

The first embodiment has the above-described structure, and its operation will be described with reference to the timing chart of FIG. The washing operation is performed when the washing tank 6 and the hot water storage tank 8 of the dishwasher 1 are full. First, dishes to be washed are stored in a rack and accommodated in the washing room 2 (rack operation). When the rack operation is completed, a cleaning cycle is started, and the cleaning water in the cleaning tank 6 is supplied to the cleaning pump 7.
The washing operation such as being pumped up and ejected from the washing nozzle 3 is performed for several tens of seconds. After a stop time (draining time) of about 5 seconds, a rinsing cycle is subsequently started, and a rinsing operation in which warm water in the hot water storage tank 8 is pumped up by the rinsing pump 11 and jetted out of the rinsing nozzle 4 is performed for 7 seconds. Done to the extent. Then 5
A stop time of about seconds (similarly, a draining time) is set, whereby one washing step is completed.

In the above, when the rinsing cycle is started, the hot water supply valve 9 is opened by turning off the float switch provided in the hot water storage tank 8, and the compressor 24 is turned on to start the heat pump 21. Get up and running. At the same time, the refrigerant solenoid valve 60 is also opened. In addition, the solenoid 46 provided in the waste water recovery tank 30 is excited to close the normally open drain valve 40, and the agitator 36 is driven to rotate. The hot water overflowing from the washing tank 6 after the start of the rinsing cycle flows into the hot water recovery tank 30 with a slight delay, and the evaporator 27 actually starts absorbing heat only a few seconds later.

In the hot water recovery tank 30, the hot water overflowing from the washing tank 6 of the dishwasher 1 is taken in little by little (taking several tens of seconds). While the waste water is being taken in, the heat pump 21 is fully operated to supply the liquid refrigerant to the evaporator 27, and the waste water is agitated by the stirrer 36 to promote heat exchange and start absorbing heat. Since the time that can be actually absorbed is several tens of seconds, the expansion valve 26 having a relatively large flow rate (refrigeration capacity) is used, and a large amount of refrigerant is supplied immediately after the rise. During the heat absorption, the overflow from the washing tank 6 ends first,
The waste water recovery tank 30 becomes full. Although the heat absorption is further continued, when the refrigerant reaches the evaporator 27 sufficiently, the temperature detected by the temperature-sensitive cylinder 26a decreases and the expansion valve 26 starts to close. However, since the timing of the flow control of the expansion valve 26 is necessarily delayed, the liquid returns slightly. Therefore, the liquid is prevented from returning by being heated in the second auxiliary heat exchange section 58, and the heat utilization efficiency is also improved. In addition, during this heat absorbing operation, the agitator 36 rotates as described above to generate a vortex in the discharged hot water.
The residue of the food mixed with the waste water tends to adhere to the inner surface of the waste water recovery tank 30 and the surface of the evaporator 27. It is prevented beforehand.

During this time, the raw water of the rinsing water supplied to the water supply pipe 10 is preheated by the first auxiliary heat exchange section 57, and then heat-exchanged with the refrigerant in the double pipe section 28 to increase the temperature, thereby increasing the temperature of the hot water. Hot water storage tank 8 of dishwasher 1 through hot water supply valve 9
Will be supplied gradually. When a predetermined amount of hot water is accumulated in the hot water storage tank 8 and the float switch is turned on, the compressor 24 is turned off, the refrigerant solenoid valve 60 is closed, and the operation of the heat pump 21 is stopped. In addition, the drain valve 40 of the hot water recovery tank 30 is opened, and the agitator 36 is stopped. As a result, the hot water in the hot water recovery tank 30 is discharged. However, since the hot water is discharged as a vortex due to the inertial force, all the food residues mixed in the hot water are also discharged together with the vortex, and the residue is discharged. Does not remain settled on the bottom surface of the tank 30. When the float switch is turned on, the flow dividing valve 54 is opened for 10 to 15 seconds, and the warm water remaining in the double pipe portion 28 is divided into the watering hose 55 side. The hot water is sprinkled from the sprinkling nozzle 48 of the hot water recovery tank 30 toward the evaporator 27,
7 is cleaned. After that, the hot water recovery tank 30
Is completely discharged, and the dishwasher 1 can be rinsed. As described above, the cleaning operation and the generation of warm water are repeatedly performed.

As described above, according to the present embodiment, when the refrigerant flowing through the evaporator 27 of the heat pump 21 and the waste water stored in the waste water recovery tank 30 undergo heat exchange, the waste water recovery tank The stirrer 3 provided at a substantially central portion in the inside 30
6 is rotated, heat exchange is promoted by agitating the entire hot water, and in addition, a vortex is generated in the entire hot water, and food residues mixed with the hot water are discharged into the hot water recovery tank 30. Attempts to adhere to the inner surface of the evaporator 27 and the surface of the evaporator 27 are stripped off by the centrifugal force caused by the vortex, thereby preventing the residue from adhering. When the heat exchange is completed, the drain valve 40 provided on the bottom of the waste water recovery tank 30 is opened to discharge the waste water. At this time, the discharged hot water is discharged as a vortex due to inertial force. All the food residues mixed therein are also discharged together with the vortex, so that the residues do not remain settled on the bottom surface of the tank 30. That is, the residue of food mixed with the waste water is prevented from adhering to the evaporator 27 and settling in the waste water recovery tank 30, and is always kept clean, efficiently recovering the waste heat, and thus, Hot water can be satisfactorily generated, and a clean device that does not emit off-flavors or the like can be realized.

<Second Embodiment> FIGS. 8 and 9 show a second embodiment of the present invention. In the second embodiment, the structure of the waste water recovery tank is improved. here,
A pipe-shaped evaporator 27, which is a component of the refrigeration cycle of the heat pump 21, is provided spirally wound at a position separated from the inner surface of the waste water recovery tank 30. A circular opening 62 is formed at the center of the cover plate 31, and a drive motor 37 for driving a stirring rod 64 is installed on a bracket 63 attached so as to straddle the opening 62. The stirring rod 64 is formed in a hairpin shape so as to sandwich both inner and outer sides of the evaporator 27 having a spiral lower end side. A brush 66 for wiping the surface of the evaporator 27 is provided on the inner surface of the hairpin portion 65. ing. This stirring rod 64
The upper end of the drive motor 3 projects through the opening 62 of the cover plate 31 to the upper surface thereof, and the connection portion 67 bent at a right angle is connected to the drive motor 3.
7 is connected to the output shaft 37a. Therefore, when the drive motor 37 is driven, the hairpin 6
As shown by the arrow in FIG. 8, 5 moves circularly along the evaporator 27, and at the same time, the brush 66 wipes the surface of the evaporator 27. A normally-open drain valve 40 similar to that of the first embodiment is provided at the center of the bottom surface of the waste water recovery tank 30. Other structures are the same as those of the first embodiment, and components having the same function are denoted by the same reference numerals, and redundant description is omitted.

The operation of the second embodiment is as follows. The waste heat recovery operation is performed by closing the drain valve 40 to store the waste water in the waste water recovery tank 30, and rotating the stirring rod 64. During this time, the entire hot water is stirred by rotating the stirring rod 64, and heat exchange with the refrigerant in the evaporator 27 is promoted. In addition, a vortex is generated in the entire hot water, and food residues mixed in the hot water are discharged into the hot water recovery tank 3.
To adhere to the inner surface of the evaporator 27 or the surface of the evaporator 27,
It is stripped off by the centrifugal force caused by the eddy current.
As the surface of 7 is sequentially wiped with the brush 66,
The residue is prevented from adhering. When the heat exchange is completed, the drain valve 40 provided on the bottom surface of the hot water recovery tank 30 is opened to discharge the hot water. At this time, the hot water is discharged as a vortex due to inertial force. The residue mixed with the water is all discharged together with the vortex, and the residue does not remain settled on the bottom surface of the tank 30. As described above, also in the second embodiment, the residue of the food mixed with the waste water is prevented from adhering to the evaporator 27 and settling in the waste water recovery tank 30, and is always kept clean. When the surface of the evaporator 27 is wiped with a brush,
7 is more reliably prevented from adhering to the residue.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition, various changes can be made without departing from the scope of the invention. (1) As a modification of the first embodiment, as shown by a chain line in FIG. 5, if a water splash prevention plate 70 is provided above the stirrer 36, for example, the amount of hot water is small and the liquid surface rotates. The water splash prevention plate 70
This can prevent the hot water from scattering. (2) In the present invention, a feed pipe for feeding raw water of rinsing water is provided in a tank for collecting hot water from a dishwasher, and hot water and heat are supplied during feeding of the raw water to the feed pipe. The present invention can be similarly applied to a heat exchange device used for preheating raw water by exchanging. (3) Further, the present invention is not limited to the drainage of the dishwasher, but also relates to a general device for heat exchange using household wastewater containing waste, such as remaining water from a bath, drainage from a sink, and the like. It can be widely applied.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall structure of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the hot water generator as viewed from above.

FIG. 3 is a sectional view seen from the front.

FIG. 4 is a cross-sectional view of the waste water recovery tank as viewed from above.

FIG. 5 is a sectional view seen from the front.

FIG. 6 is a refrigeration cycle diagram of a heat pump.

FIG. 7 is a timing chart during a cleaning operation.

FIG. 8 is a plan view of a hot water recovery tank according to a second embodiment.

FIG. 9 is a sectional view seen from the front.

FIG. 10 is a sectional view of a conventional example.

[Explanation of symbols]

1 ... Dishwasher 21 ... Heat pump 27 ... Evaporator
30 ... Hot water recovery tank 36 ... Stirrer 37 ... Drive motor 40 ... Drain valve 64
… Stir bar 66… brush

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F28G 9/00 F24H 1/00 631G

Claims (4)

[Claims] 1. A heat exchanger in which a fluid supply pipe is provided in a tank for collecting domestic waste water so as to be capable of exchanging heat, wherein a rotatable stirring tool is provided in the tank and a bottom surface of the tank is provided. A heat exchange device comprising a discharge port that can be opened and closed, and a configuration in which a vortex is generated in the tank by closing the discharge port and driving a stirrer during heat exchange. 2. The heat exchange apparatus according to claim 1, wherein the feed pipe is bent so as to extend along the inner surface of the tank. 3. The heat exchange apparatus according to claim 1, wherein when the heat exchange is completed, the drive of the stirrer is stopped to open the discharge port. 4. The heat exchanging device according to claim 1, wherein the stirrer is provided with a brush for wiping the surface of the feed pipe.