JPH076727B2 - Thaw and cold storage using heat pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to thawing and cooling of frozen products, thawing and cooling for performing aging if necessary, and more particularly to thawing and cooling using a heat pump. Is.

(Prior Art) Generally, the defrosting apparatus for factories is classified into an air defrosting apparatus, a water defrosting apparatus, a contact defrosting apparatus, an electric defrosting apparatus, a combination defrosting apparatus using these in combination depending on its heat source, but other than the air defrosting apparatus. The defrosting device has a problem in practicality in terms of energy saving, cost and pollution, and it is possible to reduce the cost as much as possible, reflecting the energy saving era, the running cost is low, and the air defrosting device with high safety, especially An air blast type that uses a heat pump is drawing attention.

(Problems to be Solved by the Invention) However, when a heat pump is used, one unit must heat and cool the inside of the refrigerator throughout the year. However, there is a large difference in outside air temperature between summer and winter, and for units using air cooling, the outside air is used as the heat source of the heat exchanger, so this temperature also changes the pressure during operation of the compressor significantly. . Therefore, there are various problems in the normal driver's seat.

First, when it is used for multiple purposes such as thawing, cooling, or aging, it cannot cope with load fluctuations and stable operation cannot be expected. this is,
This is because, for example, if the load during operation is 100% during thawing, it will be about 30% during cold storage or aging, and the heating and cooling capacities will be excessive except during thawing.

Further, even when the outside air temperature in summer is high, when the heating operation (thawing) is performed using the same outside air heat exchanger as in winter, an overload occurs due to the characteristics of the heat pump, and stable operation is difficult from this point as well.

Further, at the beginning of thawing, as a result of the low-temperature object being stored in the refrigerator, the temperature inside the refrigerator decreases and the blast temperature does not rise, and the thawing efficiency tends to decrease significantly, but the blast temperature is secured. I can't expect a feature.

(Object of the Invention) The present invention is provided with a function of coping with load fluctuations under various operating conditions during multipurpose operation and a function of coping with outside air temperature changes throughout the year to ensure stable operation, and at the same time, the inside of the defrosting chamber It is an object of the present invention to provide, at low cost, a thawing / cooling device that uses a heat pump that can secure the temperature of air blown to the chamber and can increase the humidification efficiency in the refrigerator.

(Means for Solving the Problems) A thawing and cooling device using the heat pump of the present invention cools a compressor, two kinds of heat exchangers, a liquid receiver, two expansion valves and a four-way switching solenoid valve. One heat exchanger of a heat pump connected so that it can be switched between a cycle and a heating cycle is arranged in a defroster having a humidifying means,
In the piping path that forms the cooling cycle and the heating cycle,
The control valve is connected by piping, and more specifically,
While connecting the second expansion valve and the second heat exchanger in series to the compressor via the first heat exchanger and the check valve and the liquid receiver, the outlet side of the liquid receiver and the first heat exchanger At the time of heating, the outlet side is connected by a bypass pipe having a first expansion valve, and a check valve having a check valve forming a passage in a direction opposite to the passage of the valve is provided in parallel in the second expansion valve portion, and The outlet side and the inflow side of the liquid receiver are connected via check valves each having a passage formed in the inflow direction,
Furthermore, in a heat pump with a four-way switching solenoid valve interposed between the high pressure side and low pressure side of the compressor, a suction pressure adjusting valve is installed on the low pressure side of the compressor, and the high pressure side of the compressor and the suction pressure adjusting The outlet side of the valve is connected by a pipe line with a capacity adjusting valve interposed, and a condensing pressure adjusting valve is connected between the first heat exchanger and the liquid receiver to increase the temperature, and the first heat exchange is performed. Defrosting using a heat pump, characterized in that the vessel is placed in a defroster equipped with a circulating means for thawing the air humidified by the humidifying means to accommodate the object to be treated, and a cold storage, It is a summary.

(Operation of the Invention) As described above, by connecting the suction pressure adjusting valve to the low pressure side of the compressor, the suction pressure is automatically adjusted, and the overload operation that occurs when the outside air temperature is high is eliminated. Also, by connecting the high pressure side of the compressor and the outlet side of the suction pressure adjusting valve with a pipe line with a capacity adjusting valve interposed, the compressor operates in response to pressure and has heating and cooling capabilities other than when thawing. It is now possible to prevent overheating and ensure stable operation, and by connecting a condensing pressure adjusting valve between the first heat exchanger and the liquid receiver, the first heating The relationship between the heat exchanger pressure P1 and the second heat exchanger pressure P2 becomes P1 <P2 becomes P1> P2, and these cooperation will ensure stable operation throughout the year.

Moreover, since the first heat exchanger is arranged in the defroster equipped with the circulation means for circulating the air humidified by the humidification means into the defrosting and cold storage housing the object to be treated, a highly humidified air can be efficiently covered. It thaws the processed product and circulates it in the cold storage to work so that excellent thawing and cooling effects can be achieved.

(Example) Next, an example of a thawing and cooling device using the heat pump of the present invention will be described with reference to the drawings.

FIG. 1 is a piping diagram showing a structure of an embodiment of a thawing / cooling device according to the present invention, FIG. 2 is an explanatory diagram of gas flow during thawing, and FIG. 3 is an explanatory diagram of gas flow during cooling. FIG. 4 is an illustration of gas movement during aging.

First, the thawing / cooling device of the present invention comprises a thawing / cooling cabinet 1, a thawing machine 2 and a heat pump 3 adjacent to the thawing / cooling cabinet 1.

The heat pump 3 connects the compressor 4 with the second expansion valve 8 and the second heat exchanger 9 in series via the first heat exchanger 5, the check valve 6a and the liquid receiver 7, The liquid outlet side of the container 7 and the heating outlet side of the first heat exchanger 5 are connected by a bypass pipe 11 having a first expansion valve 10, and the second expansion valve 8 is connected in a direction opposite to the passage of the valve. The backflow pipes 13 each having a check valve 12a forming a passage are connected in parallel, and the liquid outlet side and the inflow side of the liquid receiver 7 are connected to each other via a check valve 14a having a passage formed in the inflow direction. A four-way switching solenoid valve 15 for forming a heating cycle, a cooling cycle and a maturing cycle is interposed on the high pressure side and the low pressure side of the compressor 4, and a suction pressure adjusting valve 16 is piped on the low pressure side of the compressor 4. Furthermore, the compressor 4
Of the suction pressure adjusting valve 16 and the outlet side of the suction pressure adjusting valve 16 are connected by a pipe line with a capacity adjusting valve 17 interposed between the first heat exchanger 5 and the liquid receiver 7. 18 is connected.

In addition, the thawing machine 2 is adjacent to the thawing and cooling box 1,
Above and below the inner boundary wall 19, air circulation passages 20a, 20b communicating with the thawing and cooling box 1 are opened. A first heat exchanger 5 of the heat pump 3 is horizontally installed at an intermediate position between the air circulation passages 20a and 20b, and a circulation fan 21 is provided above the first heat exchanger 5 to defrost the air and blow the air into the cool box 1. The air that is provided and contacts the first heat exchanger 5 through the lower air circulation passage 20b and rises is forcedly circulated in the cool box 1 and the defroster 2. A water tank 23, which is designed to be heated by a heater 22, is disposed in the lower part of the thawing machine 2. The water in the water tank is pumped up by a pump 24 and a first heat exchange is performed from a spray nozzle 25 at a position below the circulation fan 21. Bowl 5
The water is sprinkled on the overheated portion 5a of the water tank, and is received by the water tank 23 to generate water vapor, and the humidified air having high humidity is circulated.

Further, although not shown, the thawing / cooling box 1 is divided so that the circulating air from the thawing machine 2 circulates efficiently, and a single or a plurality of shelves on which the objects to be processed are placed are arranged in a row. It is a thing.

The thawing and cooling device using the heat pump configured as described above operates as follows to achieve the respective objects.

First, at the time of thawing, as shown in FIG. 2, the superheated gas that has been made to have a high pressure in the compressor 4 is condensed in the first heat exchanger 5 from the four-way switching solenoid valve 15, and the condensing pressure control valve 18 that is a three-way valve is formed. Through the check valve 6a and liquefies and flows into the liquid receiver 7, which is vaporized into gas in the second heat exchanger 9 from the second expansion valve 8 and then passes through the four-way switching solenoid valve 15 and the suction pressure adjusting valve 16. It circulates so as to return to the compressor 4, but by interposing the condensing pressure adjusting valve 18, this adjusts and opens / closes according to the pressure, and the pressure (temperature) of the first heat exchanger 5
Is guaranteed above a certain level, and the temperature of the blown air can be raised to the temperature required for thawing as quickly as possible. This is because in the initial stage of thawing, as a result of a low-temperature frozen product (object to be processed) entering the refrigerator, the temperature inside the refrigerator lowers, which lowers the inlet air temperature of the first heat exchanger 5 of the thawing machine 2. Then
As a result, the pressure (temperature) in the first heat exchanger 5 decreases,
It prevents the temperature of the blown air from becoming low and guarantees the pressure balance.

Further, since the condensing pressure adjusting valve 18 is provided, the pressure balance between the first heat exchanger 5 and the second heat exchanger 9 can be secured at the initial stage of thawing in summer, during aging, at low temperature in the refrigerator, and at high temperature in the outside air. The internal pressure P1 of the first heat exchanger 5 is maintained higher than the internal pressure P2 of the second heat exchanger 9, and stable operation can be performed.

The intake pressure control valve 16 is fully opened in the winter season and changes to the half-open state in the summer in response to the pressure due to the relationship with the outdoor temperature, and the capacity control valve 17 is closed during the thawing in both summer and winter seasons. It is in a broken state.

Next, the case of cold storage will be described. As shown in FIG. 3, after the gas having a high pressure in the compressor 4 is switched by the four-way switching solenoid valve 15 and condensed in the second heat exchanger 9, it is liquefied. , From the backflow pipe 13 with the check valve 12a to the liquid receiver 7 through the check valve 14a, to the evaporative gasification in the first heat exchanger 5 through the first expansion valve 10 of the bypass pipe 11, It circulates so as to return to the compressor 4 via the switching electromagnetic valve 15 and the suction pressure adjusting valve 16, and the inside of the first heat exchanger 5 becomes a low pressure (low temperature). In this case, the suction pressure adjusting valve 16 is
It is open in both winter and summer, and the capacity adjustment valve 17
Is in a state where it changes in a half-open state in response to pressure in both summer and winter, and the gas from the compressor 4 is bypassed to the suction side to reduce the overall capacity. The pressure control valve 18 is in the open state.

In the above embodiment, the case of thawing and keeping cold has been described, but as shown in FIG. 4, a cooling cycle (dotted line arrow) and a heating cycle (solid line) are provided by a temperature detector (not shown) provided in the refrigerator. The arrows) can be automatically switched alternately, and a humidity detector (not shown) can be provided with a constant temperature and constant humidity aging function so that the object to be processed can be aged.

In addition, it may happen that the internal temperature rises above the limit during the thawing operation of less than the installed capacity due to the mechanical capacity, which adversely affects the thawing. There may be a case where a temperature controller is provided to perform heating and cooling operations.

(Effects of the Invention) As described above, in the defrosting / cooling apparatus using the heat pump of the present invention, the suction pressure is automatically adjusted by connecting the suction pressure adjusting valve 16 to the low pressure side of the compressor 4. Therefore, the overload operation that occurs when the outside air temperature is high is eliminated, and the high pressure side of the compressor 4 and the outlet side of the suction pressure adjusting valve 16 are connected by a pipe line with the capacity adjusting valve 17 interposed. , It operates according to the pressure, prevents the heating and cooling capacities from becoming excessive except when thawing, and ensures stable operation.

Further, by connecting the condensing pressure adjusting valve 18 between the first heat exchanger 5 and the liquid receiver 7, during the summer heating operation, the first heat exchanger pressure P1 and the second heat exchanger pressure P2 are Relationship P1 <P2 is P1
> P2, and through these collaborations, stable operation will be secured throughout the year.

Moreover, since the first heat exchanger is arranged in the defroster equipped with the circulation means for circulating the air humidified by the humidification means into the defrosting and cold storage housing the object to be treated, a highly humidified air can be efficiently covered. It is possible to achieve excellent thawing and cooling effects by thawing the processed product and circulating it in the cold storage.

Further, the heat pump, the suction pressure adjusting valve, the capacity adjusting valve, and the condensing pressure adjusting valve need not be special ones but are commercially available ones, so that the apparatus cost becomes very low.

As described above, according to the present invention, a stable operation is ensured by providing a function for coping with load fluctuations under various operating conditions during multipurpose operation and a function for coping with changes in outside air temperature throughout the year, and at the same time, the storage at the initial stage of thawing It is possible to use a heat pump which is excellent in thermo-economics and which can secure the temperature of the air blown into the inside and can increase the humidification efficiency in the refrigerator, and to provide the thawing and cooling device at low cost.

[Brief description of drawings]

FIG. 1 is a piping diagram showing a structure of an embodiment of a defrosting / cooling device using a heat pump according to the present invention, FIG. 2 is an explanatory view of gas flow during heating, and FIG. 3 is a gas flow during cooling. Explanatory drawing, FIG. 4 is explanatory drawing of the flow of gas at the time of aging. 1 ... Thaw, cool box, 2 ... Thaw, 3 ... Heat pump, 4 ... Compressor, 5 ... First heat exchanger, 7 ... Liquid receiver, 8 ... Second expansion valve, 9 ... Two heat exchangers 10 …… First expansion valve, 15 …… Four-way switching solenoid valve 16 …… Suction pressure adjusting valve, 17 …… Volume adjusting valve 18 …… Condensing pressure adjusting valve, 21 …… Circulating fan 23 …… Water tank , 24 …… pump 25 …… spray nozzle, 26 …… fan

Claims (4)

[Claims] 1. A heat pump in which a compressor, two types of heat exchangers, a liquid receiver, two expansion valves and a four-way switching solenoid valve are connected by pipes so that they can be switched between a cooling cycle and a heating cycle. The suction pressure adjusting valve is connected to the low pressure side of the compressor, and the high pressure side of the compressor and the outlet side of the suction pressure adjusting valve are connected by a pipe line with a capacity adjusting valve interposed between them. A condensing pressure adjusting valve is connected between the defroster and the first heat exchanger, and the first heat exchanger is thawed by thawing the air humidified by the humidifying means to circulate the air in a cool box. A thawing and cooling device using a heat pump, which is characterized by being installed inside the machine. 2. A humidifying means in the thawing machine pumps up water in a water tank provided at the bottom of the thawing machine, sprays it onto a part of the first heat exchanger with a spray nozzle, and drops it in the water tank. A thawing and cooling device using the heat pump according to claim 1. 3. The circulating means for the humidified air is a circulating means for thawing the humidified air by means of a blower fan above the thawing machine, passing it through the cold storage box and returning it to the thawing machine, and bringing it into contact with the first heat exchanger. A thawing and cooling device using the heat pump according to claim 1. 4. A heat pump in which a compressor, two types of heat exchangers, a liquid receiver, two expansion valves and a four-way switching solenoid valve are connected by pipes so that they can be switched between a cooling cycle and a heating cycle. The suction pressure adjusting valve is connected to the low pressure side of the compressor, and the high pressure side of the compressor and the outlet side of the suction pressure adjusting valve are connected by a pipe line with a capacity adjusting valve interposed between them. A condensing pressure adjusting valve is connected between the defroster and the first heat exchanger, and the first heat exchanger is thawed by thawing the air humidified by the humidifying means to circulate the air in a cool box. A heat pump that is equipped with an aging function of automatically switching between a cooling cycle and a heating cycle by a temperature detector installed in the machine, thawing, and installed in a cool box, and adjusting humidity by a humidity detector. Thaw and store using Apparatus.