Water spraying unit

Abstract

To provide a water spraying unit that prevents the pressure inside a refrigerant circuit from exceeding the design pressure even when a refrigeration and air-conditioning system using a CO2 refrigerator is not in operation.SOLUTION: A water spraying unit 30 includes: a water spraying tank 11 installed at a position higher than a CO2 refrigerator unit 20; and a mechanism that sprays water, supplied from the water spraying tank 11 by elevation difference without the use of power, through a water spraying nozzle 14 installed at the top of a heat exchanger of a gas cooler 4 and / or the top of a liquid receiver 6. When the water spraying unit 30 is used in a refrigerant system comprising the gas cooler 4, the liquid receiver 6, an expansion valve 8, a CO2 cooler 9, and a CO2 compressor 1, the water spraying tank 11 is equipped with a built-in heat exchanger 15 that performs heat exchange between gas and water, allowing the return refrigerant gas to cool the water inside the water spraying tank 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a water sprinkler unit for a CO2 refrigerator. [Background technology]

[0002] Carbon dioxide (CO2) refrigerant is one of the non-freon natural refrigerants, and among natural refrigerants, it has many advantages, such as being odorless, non-toxic as it is approved as a food additive, non-flammable, and highly safe.For this reason, CO2 freezers are used in a wide range of applications, such as in convenience store and supermarket showcases, and even in beverage vending machines.

[0003] Patent document 1 discloses that a refrigeration cycle device having a refrigerant circuit with a compressor, a condenser, an evaporator, and an expansion means is provided with an indoor temperature detection means for detecting the dry-bulb temperature of the indoor air to be cooled, an indoor humidity detection means for detecting the humidity of the indoor air to be cooled, an evaporation temperature detection means for detecting the evaporation temperature of the evaporator, a sprinkling means for sprinkling water onto the condenser, a sprinkling amount calculation means for calculating the amount of water sprinkled onto the condenser, and a sprinkling control means for controlling the amount of water sprinkled by the sprinkling means so that it becomes the amount of water sprinkled by the sprinkling amount calculation means. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4990339 Summary of the Invention [Problem to be solved by the invention]

[0005] In the refrigeration cycle device of Patent Document 1, the necessary amount of water may be sprayed from the sprinkler unit to the condenser according to the outside air temperature, but when the outside air temperature is on an upward or downward trend, adjusting the amount of water sprayed based on the current outside air temperature may cause a time lag in the increase or decrease in the amount of water sprayed, and this time lag may cause the air conditioner to stop due to a high pressure cut. Therefore, it is described that the future value of the outside air temperature is predicted, the necessary amount of water sprayed is determined based on the predicted value, and the time lag is compensated for.

[0006] When a refrigeration and air conditioning system using a CO2 refrigerator is in operation, the pressure in the refrigerant system does not exceed the design pressure, but when it is stopped, it may exceed the design pressure due to the influence of the outside air environment. Therefore, even when the refrigeration and air conditioning are stopped, it is necessary to always operate the refrigerator at minimum capacity so that the pressure in the refrigerant system does not exceed the design pressure. Also, when the refrigerator stops due to a power outage in the summer, the pressure in the refrigerant system may exceed the design pressure due to the influence of the outside air temperature, causing the safety valve to operate.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a sprinkler unit that can prevent the pressure in the refrigerant system from exceeding the design pressure even when a refrigeration and air conditioning system using a CO2 refrigerator is stopped. [Means for solving the problem]

[0008] In order to achieve the above object, the sprinkling unit of the present invention is characterized by having a sprinkling tank installed at a position higher than the CO2 refrigerator unit, and a mechanism for sprinkling water supplied from the sprinkling tank by head difference without using power, with a sprinkling nozzle installed on the upper part of the heat exchanger of the gas cooler and / or on the upper part of the receiver. Other aspects of the present invention will be described in the embodiments described later. Effect of the Invention

[0009] According to the present invention, even when a refrigeration / air-conditioning system using a CO2 refrigerator is stopped, the pressure in the refrigerant system can be prevented from exceeding the design pressure. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing the configuration of a sprinkling unit applied to a CO2 refrigerator according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing the structure of a water control valve of a sprinkler unit. [Diagram 3] FIG. 13 is a diagram showing an example in which a water sprinkling unit is provided in a CO2 refrigerator according to an embodiment. [Figure 4] FIG. 4 is a diagram showing the right side of the CO2 refrigerator in FIG. [Diagram 5] FIG. 13 is a diagram showing the state of water spraying from a spray nozzle disposed on the top of the receiver. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various changes and modifications are possible by those skilled in the art within the scope of the technical ideas disclosed in this specification. In addition, in all the drawings for explaining the present invention, parts having the same functions are given the same reference numerals, and repeated explanations thereof may be omitted.

[0012] Fig. 1 is a diagram showing the configuration of a sprinkler unit 30 applied to a CO2 refrigerator according to an embodiment. First, in Fig. 1, the CO2 refrigerator other than the sprinkler unit 30 will be described. The CO2 refrigerator includes a CO2 compressor 1, a safety valve 2, an oil separator 3, a gas cooler 4 having a condenser 4A therein, a high-pressure control valve 5, a receiver 6, an expansion valve 8, a CO2 cooler 9, and a liquid separator 10, which are connected by refrigerant piping.

[0013] The basic operation of the CO2 refrigerator will be explained. The gaseous refrigerant compressed by the CO2 compressor 1 flows into the condenser 4A via the oil separator 3. The flowing refrigerant releases heat to the outdoor air with the airflow generated by the fan of the gas cooler 4 and undergoes heat exchange, condensing and changing from a gaseous state to a liquid state. The liquid refrigerant flows into the receiver 6 via the high pressure control valve 5. The flowing refrigerant absorbs heat in the CO2 cooler 9 via the expansion valve 8, evaporates, and returns in a gaseous state to the CO2 compressor 1 via the liquid separator 10.

[0014] The sprinkler unit 30 applied to the CO2 refrigerator described above has a sprinkler tank 11 installed at a position higher than the CO2 refrigerator unit 20, and a mechanism for sprinkling water supplied from the sprinkler tank 11 by head difference without using power, with a sprinkler nozzle 14 installed on the top of the heat exchanger (condenser 4A) of the gas cooler 4 and / or on the top of the receiver 6. Note that, for the sake of illustration, FIG. 1 is drawn so that the sprinkler nozzle 14 is not included in the sprinkler unit 30, but in this embodiment, the sprinkler nozzle 14 is also a component of the sprinkler unit 30.

[0015] The sprinkling unit 30 is used to cool CO2 as a refrigerant flowing through a refrigerant system having a gas cooler 4, a receiver 6, an expansion valve 8, a CO2 cooler 9, and a CO2 compressor 1, and the sprinkling tank 11 has a heat exchanger 15 built in that exchanges heat between gas and water. The sprinkling unit 30 can cool the water in the sprinkling tank 11 with the refrigerant return gas (CO2 flowing through the refrigerant system). The temperature of the refrigerant gas in the heat exchanger 15 is, for example, about 2°C, so the water in the sprinkling tank 11 can be cooled.

[0016] More specifically, the sprinkler unit 30 is composed of a sprinkler tank 11 installed at a position higher than the CO2 refrigerator unit 20, a sprinkler valve 12 that supplies water to the unit during a power outage, a water control valve 13 that controls the amount of water sprinkled depending on the refrigerant system pressure in the unit, and a sprinkler nozzle 14 that sprinkles water to the gas cooler 4 and / or the receiver 6. In addition, a heat exchanger 15 is provided in the sprinkler tank 11 that constitutes the sprinkler unit 30, and the water for sprinkling is cooled by passing the CO2 flowing through the refrigerant system through the heat exchanger 15 (in the example of FIG. 1, the entire amount of CO2 flowing through the refrigerant system passes through the heat exchanger 15). This allows the sprinkler unit to cool the refrigerant system so that the refrigerant pressure does not rise to the design pressure of the refrigerant system.

[0017] Water supplied from a ball tap is stored in advance in the watering tank 11. The size of the watering tank 11 is determined based on the amount of water to be stored, which is calculated based on the expected downtime period.

[0018] As described above, the water in the watering tank 11 is cooled by the refrigerant gas returned from the CO2 cooler in the heat exchanger 15 installed in the tank, thereby increasing the cooling effect of the water spray.

[0019] The sprinkler valve 12 is an electromagnetic valve that opens when the refrigerator stops or there is a power outage, and supplies water by using the head difference of the sprinkler tank 11.

[0020] The water control valve 13 is a self-acting valve that controls the amount of water sprayed by the pressure in the refrigerant system, suppressing the consumption of water stored in the spray tank 11. When the water control valve 13 is used to spray water to the gas cooler 4, the pressure in the refrigerant system is the inlet pressure of the gas cooler 4. When the water control valve 13 is used to spray water to the receiver 6, the pressure in the refrigerant system is the pressure in the receiver 6. The structure of the water control valve 13 will be described later with reference to FIG. 2. Incidentally, the critical temperature of CO2 is 31.1°C, and at temperatures above 31.1°C, CO2 becomes a supercritical fluid rather than a liquid (the critical pressure of CO2 is 7.38MPa). The receiver 6 is configured as a container with a pressure-resistant structure that can withstand a specified pressure.

[0021] The water spray nozzle 14 is installed on the top of the heat exchanger (condenser 4A) of the gas cooler 4, on the top of the receiver 6, or on both, and cools the refrigerant in the unit system with sensible heat and latent heat from the water spray, suppressing pressure rise due to the influence of outside air. In the example of Fig. 1, the water spray nozzle 14 is installed on the top of the condenser 4A and on the top of the receiver 6. Incidentally, the water lost by water spraying is captured from the outside in the water spray tank 11 as make-up water, but the water in the water spray tank 11 is cooled by the heat exchanger 15.

[0022] A drain pan 7 is provided at the bottom of the receiver 6 to receive the water sprayed from above and drain it outside the unit.

[0023] During refrigeration / air conditioning operation, cold water cooled in the sprinkler tank 11 may be sprinkled from the sprinkler nozzle 14 onto the gas cooler 4 to cool the gas cooler 4. This can improve the cooling effect of the condenser 4A.

[0024] FIG. 2 is a diagram showing the structure of the water control valve 13 of the water sprinkler unit 30. The water control valve 13 is composed of an adjustment spindle 41, a cover 42, a spring 43, a diaphragm 44, a main body 45, a valve 46, a diaphragm 47, a bellows 48, and a bellows cap 49. The lower end of the water control valve 13 has a gas inlet. When the pressure in the bellows cap 49 increases, the bellows 48 is compressed, and the valve 46 moves upward against the spring 43, and the cooling water in the main body 45 flows in the direction of the arrow. When the pressure decreases, the opposite action occurs and the cooling water stops. That is, the water control valve 13 starts to open at a set value (valve opening pressure), and when the pressure increases, the valve gradually opens and the flow rate increases, so that the amount of water sprinkled can be controlled.

[0025] Fig. 3 is a diagram (rear view) showing an example in which a sprinkling unit 30 is provided in a CO2 refrigerator 20A according to an embodiment. Fig. 4 is a diagram showing the right side of the CO2 refrigerator in Fig. 3. Fig. 3 is a diagram that clearly shows the positions of mainly the sprinkling nozzle 14 and the like, and omits the heat exchanger 15.

[0026] As shown in Fig. 3, the CO2 refrigerator is arranged in a three-layer configuration consisting of an upper stage, a middle stage, and a lower stage, with a condenser 4A and a spray nozzle 14 arranged above it in the upper stage. In the middle stage, a liquid separator 10, a receiver 6, a spray nozzle 14 above the receiver 6, and a drain pan 7 below the receiver 6 are arranged. In the lower stage, an oil separator 3, a high-stage compressor 1A, and a low-stage compressor 1B are arranged. The upper and middle stage spray nozzles 14 each have two systems, as shown in Fig. 4.

[0027] 5 is a diagram showing the state of water spraying from the spray nozzle 14 disposed on the upper part of the receiver 6. The water droplets from the spray nozzle 14 create a water film on the surface of the cylindrical tank of the receiver 6, which has the effect of preventing heat from entering from the outside air.

[0028] As described above, the sprinkler valve 12 is a valve that is opened during a power outage, and the water control valve 13 is an adjustment valve that is opened when the refrigerant pressure rises. Therefore, by using the sprinkler unit 30 of this embodiment, the pressure in the refrigerant system can be prevented from exceeding the design pressure even when the refrigeration and air conditioning system using a CO2 refrigerator is stopped.

[0029] As described above, the water sprinkler unit 30 according to this embodiment has the following features. (1) The sprinkler unit 30 has a sprinkler tank 11 installed at a position higher than the CO2 refrigerator unit 20, and a mechanism for sprinkling water supplied from the sprinkler tank 11 by head difference without using power, with sprinkler nozzles 14 installed on the top of the heat exchanger (condenser 4A) of the gas cooler 4 and / or on the top of the receiver 6. This makes it possible to prevent the pressure in the refrigerant system from exceeding the design pressure even when the refrigeration and air conditioning system using the CO2 refrigerator is stopped.

[0030] (2) When the sprinkling unit 30 described in (1) above is used in a refrigerant system having a gas cooler 4, a receiver 6, an expansion valve 8, a CO2 cooler 9, and a CO2 compressor 1, the sprinkling tank 11 has a built-in heat exchanger 15 that exchanges heat between gas and water, and the water in the sprinkling tank 11 can be cooled by the refrigerant return gas. This allows cold water to be sprayed by the sprinkling nozzles 14 installed on the top of the heat exchanger of the gas cooler 4 and / or on the top of the receiver 6.

[0031] (3) The water sprinkler unit 30 of (1) above is provided with a water control valve 13 that controls the amount of water sprinkled based on the pressure in the refrigerant system having the gas cooler 4, receiver 6, expansion valve 8, CO2 cooler 9, and CO2 compressor 1. The water control valve 13 starts to open at a set value (valve opening pressure), and as the pressure rises, the valve gradually opens and the flow rate increases, so that the amount of water sprinkled can be controlled.

[0032] (4) In the water sprinkler unit 30 of (3) above, when the water control valve 13 is used for sprinkling water to the gas cooler 4, the pressure in the refrigerant system is the inlet pressure of the gas cooler 4.

[0033] (5) In the sprinkling unit 30 of (3) above, when the water control valve 13 is used for sprinkling water to the receiver 6, the pressure in the refrigerant system is the pressure in the receiver 6.

[0034] (6) The sprinkling unit of (2) above, which can cool the gas cooler 4 by sprinkling cold water cooled in the sprinkling tank 11 from the sprinkling nozzles 14 during refrigeration / air conditioning operation. [Explanation of symbols]

[0035] 1 CO2 compressor (compressor) 2. Safety valve 3 Oil separator 4 Gas Cooler 4A Condenser (gas cooler heat exchanger) 5. High Pressure Control Valve 6 Receiver 7 Drain pan 8 Expansion valve 9 CO2 cooler 10 Liquid separator 11 Watering tank 12 Sprinkler valve 13 Water control valve 14 Watering nozzle 15 Heat exchanger 20 CO2 Refrigeration Unit 30 Watering unit

Claims

1. CO ２ A watering tank installed at a higher position than the refrigeration unit, and a mechanism for spraying water supplied from the spray tank by head difference without using power with a spray nozzle installed on the upper part of the heat exchanger of the gas cooler and / or on the upper part of the receiver. A water sprinkler unit characterized by:

2. The water sprinkler unit according to claim 1, The gas cooler, the receiver, the expansion valve, the CO ２ CO as a refrigerant flowing through a refrigerant system having a cooler and a compressor ２ The water sprinkling tank is used to cool the water in the tank. The water sprinkling tank has a built-in heat exchanger that exchanges heat between gas and water, and the refrigerant return gas is used to cool the water in the water sprinkling tank. A water sprinkler unit characterized by:

3. The water sprinkler unit according to claim 1, The gas cooler, the receiver, the expansion valve, the CO ２ A water control valve is provided to control the amount of water sprayed based on the pressure in the refrigerant system that has a cooler and a compressor. A water sprinkler unit characterized by:

4. The water sprinkler unit according to claim 3, When the water control valve is used for spraying water to the gas cooler, The pressure in the refrigerant system is the inlet pressure of the gas cooler. A water sprinkler unit characterized by:

5. The water sprinkler unit according to claim 3, When the water control valve is used for watering the receiver, The pressure in the refrigerant system is the pressure in the receiver. A water sprinkler unit characterized by:

6. The water sprinkler unit according to claim 2, During refrigeration and air conditioning operation, cold water cooled in the sprinkler tank is sprinkled from the sprinkler nozzle onto the gas cooler to cool the gas cooler. A water sprinkler unit characterized by:

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