JPH074812A - Double-pipe type chilled water maker with cyclic circuit - Google Patents

Abstract

PURPOSE:To obtain a chilled water maker which does not need a tank for individually controlling water temperature and the rate of water-flow and is mainly used for processing of foodstuffs. CONSTITUTION:In a chilled water maker, which is directly connected to a service water line, water is cycled repeatedly in double-pipe type heat-exchanger 6 and temperature of the water is lowered to a preset temperature, following which its chilled water is taken out using a thermal control valve and related instruments 7, 10, 11, 12. In order that a refrigerating capacity is controlled corresponding to the amount of discharge, an inverter 14 on the market is incorporated, the heat-exchanger 6 divided is selectively used, the refrigerating capacity is varied in no stage, and a desired rate of water-flow is determined.

Description

Detailed Description of the Invention

[0001]

[Industrial application] This chiller is a one-pass type that uses a double-tube heat exchanger, and can cool tap water as it is to about 2 ° C, making it possible to control the amount and temperature of water. The double-tube heat exchanger (6) used here is of a type in which water is passed through the inner tube and freon gas is passed through the outer tube to cool the water in the inner tube from the outer tube.

This chiller can be used mainly in the field of food processing, and specifically, tofu manufacturing, noodle manufacturing, soft drinks, fresh fish processing, brewing relations, pickling manufacturing, cooling sterilization, freshness maintenance, taste effect. Expect to use.

Other than food, if the material of the liquid collecting member is adapted to the cooling liquid, it can be used for cooling various liquids such as chemicals.

[0004]

2. Description of the Related Art As conventional techniques, there are typically a circulation type and a one-pass type. The circulating water chiller has a water storage tank and circulates water between it and a heat exchanger to store cold water in the tank. As an advantage, the structure is simple and nighttime electricity can be used. In addition, there is a merit that a large amount of water can be used at one time. On the other hand, there are drawbacks such as bacteria that occur in the tank, cleaning is required, installation space is required, and cost is high.

The 1-pass type water cooler is a type that cools from the tap water inlet through the heat exchanger to the outlet in one pass, and does not have a circulation circuit of the proposed bypass (8) and does not have a tank. The disadvantage is the opposite of a circulating water chiller. Although the structure is simple, the heat exchanger is generally large. Further, the temperature flow rate has a constant relationship between the temperature difference between the inlet and the outlet × flow rate = flow rate, and if the outlet water amount is reduced, the temperature will decrease, and if the water amount is increased, the temperature will increase, and there is no function to adjust each independently.

[0006]

[Problems to be Solved by the Invention]

(1) First, we would like to use a one-pass type that can supply sanitary cooling water. (2) We want to make the system as a whole compact and as inexpensive as possible. (3) I want to be able to freely control the temperature and water volume.

[0007]

In order to use the above-described tank-free 1-pass type, the cooling method was considered to be a conventional 1-pass type and a circulation type combined type. That is, consider the pipes and pipelines as water storage tanks,
By circulating the double pipe heat exchanger (6) and the pipe between the pipe and the pipe at the highest speed, the heat exchange rate can be greatly increased and the capacity can be fully brought out. Further, if the pipe line is made as short as possible and the volume is made small, the rise time at the time of starting can be shortened and the same effect as the one-pass type can be obtained.

Also, since this method reduces the temperature difference between the inlet and the outlet in several steps, the heat exchanger can be made much smaller than the conventional one-pass type.

This temperature adjustment method is such that, when the water temperature of the circulation circuit (5, 6, 8, 9) reaches a set temperature, a signal from a temperature detector (7) outputs a temperature adjustment valve (10, 11). Is activated and the two-way valve (12) is opened. If it is discharged excessively, the water temperature rises, so the signal from the temperature detector (7) causes the two-way valve (1
2) reversely operates in the closing direction. By repeating this, the water temperature proportionally approaches the set temperature, and the set temperature is finally kept.

Next, the water quantity is adjusted by using a commercially available inverter (1
Use 4). Since the range of use of the expansion valve in the refrigeration cycle is limited, the double-tube heat exchanger (6) is divided into several parts according to its capacity, and the double-tube heat exchanger desired to be used by the solenoid valve (16). Only the exchanger (6) is selected.

For example, the double tube heat exchanger (6) and the solenoid valve (16) are divided into three parts, number 1, number 2 and number 3, and the manual knob of the inverter is number 1 to 20 to 30 cycles and number 2 to 30. ~ 4
If you work with 5 cycles, 3rd 45-60 cycles,
With respect to the expansion valve (17), the refrigerating capacity continuously increases as the cycle increases within each cycle range, and the amount of treated water increases.

It is important to note that the refrigerator has a built-in general-purpose motor, and there is insufficient torque in the low speed range.
There is a risk of motor burnout during long-time operation in the low speed range. Therefore, in order to avoid this low speed range, when selecting a refrigerator, the lower limit value of the cycle is set so that about 80% of the total motor torque can be secured.

Generally, if the cycle lower limit value is set to about 20 cycles, about 80% of the total torque can be secured,
There is no hindrance.

[0014]

In general, the one-pass type can be achieved by providing a circulation circuit instead of the conventional circulation type tank.

The water temperature of this circuit can be set arbitrarily by the knob of the temperature controller (10), and water can be easily taken out by the proportional opening / closing of the two-way valve (12). Moreover, the same amount of water is automatically supplied as the discharged water.

If only the water temperature is adjusted as described above, the freezing capacity becomes excessive due to the decrease in the water temperature during the winter season, and more water is discharged than necessary. It is not necessary to fully operate the refrigerator to save power. In addition, a commercially available inverter was adopted.

With the above idea, the function required by the cooler can be incorporated. At present, this is the first attempt to divide this with a double-tube heat exchanger (6), lower the water temperature with a circulation circuit, and adjust the refrigeration function with an inverter, which is not available in the conventional technology.

[0018]

[Embodiment] Refrigerator (15) General-purpose 2HP 3,400Kc
An example of using al / h, an evaporation temperature of -5 ° C, and a refrigerant R12 is shown below.

The double-tube heat exchanger (6) has a titanium tube of 15.88φ × 0.5t × 1,100l, an outer tube made of copper and inner grooved tube of 22φ, three pipes are connected to each other. Was directly connected, and the CFC gas of the outer tube was in parallel.

As the initial temperature control valve, an electric rotary two-way valve (12) which is operated by a signal by a liquid temperature detector (7) is used. Since this port has a round shape and is a rotary type, it cannot cope with flow rate changes.

Therefore, although expensive, a temperature measuring resistance type temperature detector (7), a temperature controller (10), an electric actuator (1)
1), changed to a straight open / close type 2-way valve (12). In this system, the valve operation is vertical slide and the port shape is equal percent, and the CV value of the flow rate characteristic changes linearly, and can follow the change of small flow rate-large flow rate.

The inverter (14) is a standard type 1.5K
W200V analog type is adopted. The solenoid valve (16) and the expansion (17) were linked in three cycles of 25 cycles, 45 cycles, and 60 cycles. The change in the flow rate was well linked to the change in the refrigerating capacity.

The pump (5) was located at a position where the water was mixed by the impeller of the pump at the confluence point of the water that had returned to the circulation and the tap water, the water temperature was averaged, and the water was sent to the double pipe heat exchanger (6). .

The temperature detector (7) was the outlet of the double tube heat exchanger (6). In this circuit, the two-way valve (12) was also placed near this at the lowest water temperature so that water at this lowest temperature could be discharged.

Although not shown in FIG. 1, a flow switch for freeze prevention is provided in the circuit of the bypass (8).

Do not attach the tap to the tap water outlet (13). Controlling the amount of water depends on the refrigerating capacity of the double pipe heat exchanger (6). Controlling the amount of water at the faucet causes freezing of the water circuit.

Initially, when only the water that reached the set temperature was discharged from this circuit (5, 6, 8, 9), I was concerned that the same amount of water would be automatically supplied according to the theory. It worked well.

With this test machine, the temperature of tap water in winter was lowered from 12 ° C. to 2 ° C., and during this period, various attempts were made to adjust the amount of water by operating the inverter (14). The results were very satisfactory.

[0029]

[Effect] Can be used by directly connecting to tap water.

There is no need for a tank, no worry of germs, and no need for cleaning. No tank installation space required.

Cold water of about 2 ° C. can be obtained in one pass regardless of the seasons.

The amount of water can be adjusted by adjusting the refrigerating capacity.

The heat exchanger can be downsized, and the piping system is simple and overall compact.

[Brief description of drawings]

[Fig. 1] Piping system diagram and refrigeration cycle system diagram

[Explanation of symbols]

(1) Tap water inlet (11) Electric actuator (2) Pressure reducing valve (12) Two-way valve (3) Throttle valve (13) Tap water outlet (4) Check valve (14) Inverter (5) Pump (15) Refrigerator (6) Double-pipe heat exchanger (16) Solenoid valve (7) Temperature detector (17) Expansion valve (8) Bypass (9) Check valve (10) Temperature controller

Claims (2)

[Claims] 1. The water supplied from tap water (1) is returned to the pump (5) again via a pump (5), a double pipe heat exchanger (6), a bypass (8) and a check valve (9). The water temperature is lowered to the set temperature by repeatedly passing through this circuit. The lowered water is discharged from this circuit while keeping the set water temperature by the temperature detector (7) and the proportional on-off valves (10, 11, 12). The amount of discharged water is automatically supplied to the circuit from the tap water inlet (1).
With this system, you can freely obtain water at the desired temperature. 2. A double tube divided into several parts, combined with a circuit for circulating water (5, 6, 8, 9) to change the amount of treated water, a cycle change of a commercially available inverter (14) and several pieces. Type heat exchanger (6) solenoid valve 6) is interlocked, expansion valve (1
The refrigerating capacity is changed while steplessly adjusting the Freon gas pressure of 7).