JP6942352B2 - Hot water generation hot water storage device for dishwasher - Google Patents

Description

The present invention relates to an apparatus for generating and storing hot water for rinsing a dishwasher.

In a commercial dishwasher, hot water of about 80 ° C. or higher is used when rinsing dishes. This is because the tableware is sterilized with hot water and the tableware is heated to a high temperature to accelerate the drying of the tableware.

Currently, the methods of generating and storing hot water at 80 ° C or higher with a commercial dishwasher are roughly divided into two methods. One is a method of heating by a combustion gas burner via a heat exchanger, and the other is a method of inserting an electric heater into a hot water storage tank and heating it. The former has a sufficient heating capacity by itself, while the latter has an insufficient heating capacity, and in many cases, medium-temperature water is supplementarily supplied from a gas water heater in order to shorten the time.

Patent Document 1 describes a hot water generator of a dishwasher using a heat pump cycle.

Japanese Unexamined Patent Publication No. 10-80391

However, when HFC (hydrofluorocarbon) is used as the refrigerant for the heat pump cycle, the upper limit of heating temperature of hot water is as low as around 65 ° C, and the high temperature of 80 ° C or higher required for hot water for rinsing dishwashers cannot be obtained. was there.

In view of the above problems, the present invention circulates and connects a compressor, a condenser, an expansion valve and an evaporator in a hot water generating and storing device of a dishwasher that generates and stores hot water for rinsing of a dishwasher. A heat pump unit and a hot water storage tank are provided by enclosing carbon dioxide as a refrigerant in the refrigerant pipe so that the refrigerant can flow, and the condenser is configured to be heat exchangeable with the water in the hot water storage tank. The hot water generated in the hot water storage tank is supplied to the dishwasher as hot water for rinsing, and the evaporators are a first evaporator having a stainless steel refrigerant pipe and a second evaporator having a copper refrigerant pipe. The first evaporator is arranged in the dishwasher, the second evaporator is arranged in the atmosphere outside the dishwasher, and the first evaporator and the second evaporator are refrigerants. It is characterized by being connected in series via a pipe.

According to the hot water generation hot water storage device of the dishwasher of the present invention, since carbon dioxide is used as the refrigerant of the heat pump cycle, the water in the hot water storage tank can be efficiently heated, and hot water for rinsing at a maximum of 90 ° C. is generated. And can store hot water. In particular, the present invention is suitable for application to a commercial dishwasher.

It is a block diagram of the hot water generation hot water storage apparatus of the dishwasher by embodiment of this invention. It is a figure which shows the state which the evaporator is arranged in the dishwasher. It is a figure which shows the thing which divided the evaporator into two and arranged one of them in a dishwasher. It is a figure which shows the one which divided the evaporator into two, and arranged one of them in a dishwasher, and was configured to exchange heat with hot water for rinsing.

An embodiment of a hot water generation hot water storage device of the dishwasher of the present invention will be described with reference to the drawings. As shown in FIG. 1, this hot water generation hot water storage device is a device that generates hot water for rinsing of a dishwasher and stores hot water, and includes a heat pump unit 10 and a hot water storage tank 20.

In the heat pump unit 10, a compressor 1 (compressor), a condenser 2 (condenser), an electromagnetic expansion valve 3 and an evaporator 4 (evaporator) are circulated and connected by a refrigerant pipe 5, and carbon dioxide is used as a refrigerant in the refrigerant pipe 5. It is composed by encapsulating carbon (CO ₂ ) so that it can be distributed. The evaporator 4 and the compressor 1 are connected via an accumulator 6 (accumulator).

The condenser 2 is installed in the hot water storage tank 20 and is configured to directly heat the water in the hot water storage tank 20. City water is supplied to the hot water storage tank 20 through a pipe.

The hot water generated by heating in the hot water storage tank 20 is supplied as rinsing hot water to the dishwasher 31 in the dishwasher 30 via the pump 21, and the used rinsing hot water is supplied via the discharge pipe 32. It is designed to be discharged to the outside.

According to the above-mentioned hot water generation hot water storage device, the water stored in the hot water storage tank 20 can be efficiently heated, and hot water for rinsing at a maximum of 90 ° C. can be generated and stored.

Since the condenser 2 comes into direct contact with the water in the hot water storage tank 20, by forming it in a stainless steel fin-and-tube type, it is possible to improve the heating efficiency while ensuring corrosion resistance.

Further, the auxiliary heat exchange section 7 is formed by closely connecting the refrigerant pipe 5 on the outlet side of the evaporator 4 and the refrigerant pipe 5 on the outlet side of the condenser 2 in parallel by brazing or the like to form the evaporator 4. By heating the low-temperature refrigerant that has passed through the above with the high-temperature refrigerant discharged from the condenser 2, the heat utilization efficiency can be improved.

The evaporator 4 may be arranged in the atmosphere and configured as an air refrigerant heat exchanger that absorbs heat in the atmosphere, but as shown in FIG. 2, if it is arranged in the dishwasher, it is discarded in the dishwasher. By recovering the heat, the thermal efficiency of the heat pump cycle can be improved.

In this case, since the evaporator 4 installed in the dishwasher may be corroded by the hot water for rinsing in the dishwasher, a stainless steel heat exchanger having excellent corrosion resistance (for example, the outer circumference of the stainless steel refrigerant pipe) It is appropriate to use a stainless steel fin attached to the tableware).

However, since stainless steel has a lower thermal conductivity than copper and aluminum, the size of the evaporator 4 (heat exchanger) is large in order to obtain the desired heat exchange efficiency, and it should be stored in the dishwasher. May not be possible.

Therefore, as shown in FIG. 3, the evaporator 4 is divided into a first evaporator 4a having a stainless steel refrigerant pipe and a second evaporator 4b having a copper refrigerant pipe, and the first evaporator is used. By arranging the 4a in the dishwasher 30 and the second evaporator 4b in the atmosphere outside the dishwasher 30, the size of the evaporator 4 (heat exchanger) is suppressed and the heat pump cycle is performed. The thermal efficiency can be improved. The first evaporator 4a and the second evaporator 4b are connected in series via a refrigerant pipe.

In this case, the first evaporator 4a is composed of, for example, a heat exchanger in which a plurality of stainless steel fins are attached to the outer periphery of a stainless steel refrigerant pipe, and the second evaporator 4b is, for example, a copper refrigerant. It is preferably composed of a heat exchanger in which a plurality of aluminum fins are attached to the outer periphery of the tube.

Further, as shown in FIG. 4, the first evaporator 4a can be configured as a water-refrigerant heat exchanger that can exchange heat with the hot water for rinsing discharged from the dishwasher 31 in the dishwasher 30.

In this case, the first evaporator 4a is a heat exchanger having a double pipe structure, and used rinsing hot water and carbon dioxide refrigerant are circulated inside and outside the pipe inside the double pipe, respectively, and the heat of both is circulated. It can be configured to perform exchanges. For example, a carbon dioxide refrigerant is circulated in the inner flow path of the double pipe, and used rinsing hot water is circulated in the outer flow path. With this configuration, it is possible to configure the discharge pipe 32 for discharging the hot water for rinsing through the outer flow path of the double pipe.

1 Compressor 2 Condenser 3 Expansion valve 4 Evaporator 4a First evaporator 4b Second evaporator 5 Refrigerant piping 6 Accumulator 7 Auxiliary heat exchange unit 10 Heat pump unit 20 Hot water storage tank 21 Pump 30 Dishwasher 31 Dishwasher 32 discharge pipe

Claims (3)

In the hot water generation hot water storage device of the dishwasher that generates and stores hot water for rinsing the dishwasher
A heat pump unit consisting of a compressor, a condenser, an expansion valve, and an evaporator that are circulated and connected by a refrigerant pipe and carbon dioxide is circulated in the refrigerant pipe as a refrigerant so that it can flow.
Equipped with a hot water storage tank
The condenser is configured to exchange heat with the water in the hot water storage tank, and the hot water generated in the hot water storage tank is supplied to the dishwasher as hot water for rinsing.
The evaporator includes a first evaporator having a stainless steel refrigerant pipe and a second evaporator having a copper refrigerant pipe, and the first evaporator is arranged in a dishwasher and a second evaporator. The vessel is placed in the atmosphere outside the dishwasher, and the first evaporator and the second evaporator are connected in series via a refrigerant pipe, and the hot water generation hot water storage of the dishwasher is characterized. Device. The hot water generation hot water storage device of the dishwasher according to claim 1, wherein the condenser is installed in the hot water storage tank and is configured to directly heat the water in the hot water storage tank. The first evaporator is configured as a heat exchanger having a double-tube structure, and carbon dioxide is circulated in the inner flow path of the double-tube, and is discharged from the dishwasher in the outer flow path of the double-tube. by circulating already hot water for rinsing, it is configured to be used of the hot water for rinsing and heat exchanger, to claim 1 or 2, characterized in that for discharging the hot water rinse used in the outer flow path The hot water generation hot water storage device of the dishwasher described.

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