JP2022029265A - Distillation device - Google Patents

Abstract

To provide a distillation device that can stably operate with a heat pump alone without using a heat source such as a heater.SOLUTION: A distillation device comprises: a hot water circulation line for circulating and passing hot water from a hot water tank 30 through a heat exchanger 4; a cold water circulation line for circulating and passing cold water from a cold water tank 40 through a heat exchanger 7; and a heat pump 20 for transferring heat of low-temperature fluid to high-temperature fluid, where the low-temperature fluid is the cold water in the cold water tank 40 and the high-temperature fluid is the hot water in the hot water tank 30. A portion of the high-temperature water being supplied from the heat pump 20 to the hot water tank 30 is introduced into the cold water tank 40. The distillation device comprises pipes 50 and 52, a valve 51, and a controller 54 for opening the valve 51 when a water temperature detected by a temperature sensor 53 is a predetermined temperature or lower.SELECTED DRAWING: Figure 1

Description

The present invention relates to a distillation apparatus, and more particularly to a distillation apparatus using a heat pump.

FIG. 2 shows an example of a distillation apparatus using a heat pump.

The raw material water introduced into the distiller 1 via the supply line (not shown) is sent from the distiller 1 to the heat exchanger 4 via the pump 2 and the pipe 3, and is heated by the heat exchanger 4. After that, it is returned to the top of the distiller 1 via the pipe 5, and steam is generated. The upper part in the distiller 1 is sucked by the suction machine 11, and the steam in the distiller 1 is introduced into the heat exchanger 7 through the pipe 6, cooled, and then condensed water through the pipe 8. It is introduced into the tank 9 and separated into air and water. The condensed water collects in the condensed water tank 9 and is taken out from the lower part of the condensed water tank 9 via an extraction line (not shown). The upper part of the condensed water tank 9 is connected to the suction machine 11 via the pipe 10.

High-temperature water from the heat pump system 12 is passed through the heat source fluid flow path 4a of the heat exchanger 4, and low-temperature water from the heat pump system 12 is passed through the heat source fluid flow path 7a of the heat exchanger 7.

The heat pump 20 of the heat pump system 12 has a well-known configuration, and a heat medium such as an alternative fron from the evaporator 21 is introduced into the condenser 23 as a high temperature by adiabatic compression by the compressor 22, and the heat medium from the condenser 23 is introduced. Is introduced into the evaporator 21 via the expansion valve 24, and is configured to adiabatically expand and lower the temperature.

The water in the hot water tank 30 is passed through the heat transfer tube 23a provided in the condenser 23 via the pump 31 and the pipe 32, and is heated by exchanging heat with the high temperature heat medium. The water that has been heated to become high temperature water is returned to the hot water tank 30 via the pipe 33.

The high-temperature water in the hot water tank 30 is passed through the heat source fluid flow path 4a of the heat exchanger 4 via the pump 34 and the pipe 35, and heats and exchanges with the raw material water to heat it. The water whose temperature has dropped due to heat exchange with the raw material water is returned to the hot water tank 30 via the pipe 36.

The water in the cold water tank 40 is passed through the heat transfer tube 21a provided in the evaporator 21 via the pump 41 and the pipe 42, and is cooled by exchanging heat with the low temperature heat medium. The water that has been cooled to become low temperature water is returned to the cold water tank 40 via the pipe 43.

The low-temperature water in the tank 40 is passed through the heat source fluid flow path 7a of the heat exchanger 7 via the pump 44 and the pipe 45, and heat exchanges with the steam to cool the water. The water whose temperature has risen due to heat exchange with steam is returned to the cold water tank 40 via the pipe 46. The cold water tank 40 is provided with a heater 47.

Japanese Unexamined Patent Publication No. 3-52227 Japanese Unexamined Patent Publication No. 2019-158173

In a distillation apparatus that uses a heat pump for the distillation operation as shown in FIG. 2, the heat energy of the steam recovered by the heat exchanger 7 is used for heating the raw material water by the heat pump 20, so that the thermal efficiency is high. Is good.

However, when the device is started in which steam cannot be obtained from the distiller 1, or when the amount of steam is insufficient, the water in the cold water tank 40 is unilaterally deprived of heat and eventually becomes supercooled. The heat pump system 12 is stopped.

In order to prevent such supercooling, it is common to install a heating device such as a heater 47 in the cold water tank 40.

An object of the present invention is to provide a distillation apparatus capable of stably operating a heat pump alone without using a heat source such as a heater.

The gist of the present invention is as follows.

[1] A raw material water circulation line for circulating the raw material water in the distiller, a first heat exchanger for heating the raw material water provided in the raw material water circulation line, and a suction line for sucking steam from the distiller. A hot water circulation line provided in the suction line, which has a second heat exchanger for cooling steam and a hot water tank, and circulates hot water in the hot water tank to the first heat exchanger. A cold water circulation line having a cold water tank and circulating cold water in the cold water tank to the second heat exchanger, cold water in the cold water tank as a low temperature fluid, and hot water in the hot water tank at a high temperature. In a distillation apparatus having a fluid and a heat pump for transferring the heat of the low temperature fluid to the high temperature fluid, an introduction line for introducing a part of high temperature water sent from the heat pump to the hot water tank into the cold water tank and the introduction line. A distillation apparatus including a return line for flowing cold water in a cold water tank into the hot water tank.

[2] The return line is a distillation apparatus according to [1], wherein when hot water flows into a cold water tank from the introduction line, overflow water overflowing from the cold water tank flows into the hot water tank.

[3] The distillation apparatus according to [1] or [2], which is provided with a valve on the introduction line.

[4] The present invention is characterized by comprising a temperature sensor for detecting the temperature of the cold water tank and a controller for opening the valve when the detected temperature of the temperature sensor is lower than the set temperature [3]. Distiller.

[5] A pump and an outward pipe for sending the high temperature water in the hot water tank to the inflow portion of the condenser of the heat pump, and a return pipe for returning the high temperature water flowing out from the outflow portion of the condenser to the hot water tank are provided. The introduction line is an introduction pipe branching from the return pipe, and the distillation apparatus according to [3] or [4], wherein the introduction pipe is provided with the valve.

In general, heat pumps have a gap between cooling capacity and heating capacity, and the heating capacity is larger. In the present invention, this gap is utilized so that the distillation apparatus can be stably operated by the heat pump alone without using a heat source such as a heater.

The distillation apparatus of one aspect of the present invention has a means for mixing hot water and cold water, and by controlling the mixing by the temperature of the cold water, the heat pump can be stably operated without using a heat source such as a heater. It will be possible.

It is a block diagram of the distillation apparatus which concerns on embodiment. It is a block diagram of the distillation apparatus which concerns on a conventional example. It is a graph which shows the result of the comparative example. It is a graph which shows the result of the comparative example. It is a graph which shows the result of the comparative example. It is a graph which shows the result of an Example.

Hereinafter, embodiments will be described with reference to FIG.

In this embodiment, the pipe 50 is branched from the pipe 33. A part of the high temperature water in the pipe 33 can be sent to the cold water tank 40 via the pipe 50, the valve 51 and the pipe 52.

Further, a temperature sensor 53 is provided in the cold water tank 40, and the detected temperature signal is input to the controller 54. The controller 54 controls the opening / closing or opening degree of the valve 51.

Further, a pipe 55 is provided so as to guide the overflow water of the cold water tank 40 to the hot water tank 30.

Other configurations of the distillation apparatus of FIG. 1 are the same as those of FIG. 2, and the same reference numerals indicate the same parts.

In this distillation apparatus, when the temperature of the water in the cold water tank 40 detected by the temperature sensor 53 is higher than the predetermined temperature T1, the valve 51 is closed, and the operation of the distillation apparatus in this state is shown in FIG. It is the same as the case of.

When the temperature of the water in the cold water tank 40 detected by the temperature sensor 53 is equal to or lower than the predetermined temperature T1 (for example, 30 ° C.), the valve 51 is opened.

As a result, a part of the high temperature water heated by the heat pump 20 is diverted from the pipe 33 and flows into the cold water tank 40 through the pipes 50 and 52. A part of the water in the cold water tank 40 overflows into the pipe 55 with the inflow of the high temperature water, and flows into the tank 30 through the pipe 55.

In this way, a part of the high temperature water from the heat pump 20 flows into the cold water tank 40 and raises the water temperature in the cold water tank 40, so that supercooling is prevented.

The controller 54 closes the valve 41 when the detected temperature of the temperature sensor 53 becomes a predetermined temperature T2 (for example, 40 ° C.) or higher.

As a result, the inflow of hot water from the hot water tank 30 into the cold water tank 40 is stopped. After that, since the entire amount of the hot water from the heat pump 20 flows into the hot water tank 30, the rate of increase in the water temperature of the hot water tank 30 increases.

When the temperature of the water in the tank 30 reaches the target temperature T3 (for example, 80 ° C.), the distiller 1 can generate steam, so that the steady operation is started.

In the state where the valve 51 is open, a part of the heat energy given to the water in the condenser 23 is given to the water in the tank 40 in the form of high temperature water, but even in this case, the water temperature in the tank 30 is also given. Does not decrease. That is, in a heat pump, since the heating capacity is generally larger than the cooling capacity, a part of the high temperature water is sent from the pipes 50 and 52 to the cold water tank 40, and the same amount of low temperature water is sent from the cold water tank 40 to the hot water tank. Even in the state of flowing into 30, the water temperature in the hot water tank 30 does not decrease, but gradually increases.

Hereinafter, an operation example of the heat pump system 12 (composed of a heat pump 20, a hot water tank 30, a cold water tank 40, pipes 50, 52, and a valve 51) used in the distillation apparatus of FIG. 1 will be described.

<Heat pump>
Heating capacity: 32.3kW
Cooling capacity: 19.8kW
Power consumption: 10kW
When the temperature of the cold water tank becomes 5 ° C or less, it stops to prevent supercooling.

The target temperature of the hot water tank is 80 ° C.

<Tank capacity>
Both hot water tank and cold water tank are 100L.

[Comparative Example 1] (Valve 51 closed)
The valve 51 was closed, and the operation of the heat pump system 12 was started at the initial temperature of hot water of 10 ° C. and the initial temperature of cold water of 10 ° C.

The time course of the water temperature of hot water and cold water is shown in FIG. This test assumes that the city water in winter is circulating water. As shown in FIG. 3, the temperature of the cold water tank reached 5 ° C. in about 1.7 minutes, and the heat pump stopped. At that time, the temperature reached by the hot water tank was about 18 ° C, which did not reach the target. From this test, it was confirmed that when the initial temperature is 10 ° C, heating from an external heat source such as a heater is necessary.

[Comparative Example 2]
The test was conducted under the same conditions as in Comparative Example 1 except that the initial temperature of hot water was 30 ° C and the initial temperature of cold water was 30 ° C.

The time course of the water temperature of hot water and cold water is shown in FIG. This test assumes that summer city water is circulating water. As shown in FIG. 4, the temperature of the cold water tank reached 5 ° C. in about 9 minutes, and the heat pump stopped. At that time, the temperature reached by the hot water tank was about 70 ° C, which did not reach the target. From this test, it was confirmed that heating from an external heat source such as a heater is necessary even when the initial temperature is 30 ° C.

[Comparative Example 3]
In Comparative Example 1, the test was conducted under the same conditions except that a 20 kW electric heater was installed in a cold water tank and operated.

The time course of the water temperature of hot water and cold water is shown in FIG. In this test, since a heater having a cooling capacity similar to that of the heater was used, the temperature of the cold water was constant at 10 ° C. The hot water reached 80 ° C. in about 15 minutes because the device did not stop due to supercooling. The total power consumption at this time was 7.6 kW.

[Example 1]
The operation of the heat pump system 12 was started at the initial temperature of hot water of 10 ° C. and the initial temperature of cold water of 10 ° C.

The valve 51 was opened for 30 minutes from the start of operation, and the valve 51 was closed after 30 minutes.

The time course of the water temperature of hot water and cold water is shown in FIG. Since the valve 51 is open for 30 minutes after the start of the test, cold water and hot water are mixed and the temperature is raised. After that, since the valve 51 is closed and the hot water and the cold water are not mixed, the hot water is heated and the cold water is cooled. Nine minutes after closing the valve 51, the hot water tank reached the target temperature of 80 ° C., and the cold water was cooled to the initial temperature of 10 ° C.

From the above, it was confirmed that by applying the present invention, the heat pump can be started without using a heat source such as a heater.

The power consumption at this time is 6.6 kW. Compared with the case where the heater of Comparative Example 3 is used, the power consumption is about 13% smaller. Therefore, it has been found that the power consumption can be reduced by using the present invention.

1 Distiller 4, 7 Heat exchanger 12 Heat pump system 20 Heat pump 21 Evaporator 22 Compressor 23 Condensator 24 Expansion valve 30 Hot water tank 40 Cold water tank 47 Heater 51 Valve 53 Temperature sensor 54 Controller

Claims (5)

A raw material water circulation line that circulates the raw material water in the distiller,
A first heat exchanger for heating the raw material water provided in the raw material water circulation line, and
A suction line that sucks steam from the distiller,
A second heat exchanger for cooling the steam provided in the suction line,
A hot water circulation line having a hot water tank and circulating hot water in the hot water tank to the first heat exchanger.
A cold water circulation line having a cold water tank and circulating cold water in the cold water tank to the second heat exchanger.
In a distillation apparatus having a cold water in the cold water tank as a low temperature fluid, hot water in the hot water tank as a high temperature fluid, and a heat pump for transferring the heat of the low temperature fluid to the high temperature fluid.
An introduction line that introduces a part of the hot water sent from the heat pump to the hot water tank into the cold water tank, and
A distillation apparatus including a return line for flowing cold water in the cold water tank into the hot water tank. The distillation apparatus according to claim 1, wherein the return line causes overflow water overflowing from the cold water tank to flow into the hot water tank when hot water flows into the cold water tank from the introduction line. The distillation apparatus according to claim 1 or 2, wherein a valve is provided in the introduction line. A temperature sensor that detects the temperature of the cold water tank and
The distillation apparatus according to claim 3, further comprising a controller for opening the valve when the detection temperature of the temperature sensor is lower than the set temperature. A pump and an outgoing pipe that send high-temperature water in the hot water tank to the inflow portion of the condenser of the heat pump.
It is provided with a return pipe for returning the high-temperature water flowing out from the outflow portion of the condenser to the hot water tank.
The introduction line is an introduction pipe that branches from the return pipe.
The distillation apparatus according to claim 3 or 4, wherein the valve is provided in the introduction pipe.

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