Outdoor air treatment machine

Abstract

To solve problems that in the case of use in a cold place in winter season, since outside air temperature taken into an outside air treatment device is low, insufficient heating capacity causes supply of low-temperature air to an indoor side, leading to uncomfortable feeling, and due to defrosting caused by frequent frost formation on a heat exchanger, low-temperature air is supplied to an indoor side, leading to uncomfortable feeling and, that in summer season (intermediate season), when outside air is cooled and then reheated, insufficient reheating capacity causes failure to satisfy required temperature and humidity.SOLUTION: An outside air treatment device supplies to an indoor side outside air whose temperature and humidity are controlled. In the outside air treatment device, a heat pump unit for energy saving and a boiler unit circulating heating medium water having a predetermined temperature are integrally packaged, and output of the heat pump unit and output of the boiler unit are simultaneously controlled.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an outside air treatment device for ventilating a room, which is used in conjunction with an air conditioner. [Background technology]

[0002] Traditionally, in air conditioning to maintain the quality of products in large facilities such as hospitals, elderly care facilities, and large buildings, as well as in production processes in factories, if the amount of air exhausted from inside the room for ventilation is greater than the amount of air supplied from outside, the room will become negative pressure and dirty air will enter through gaps, which can cause the indoor air environment to deteriorate. For this reason, in large facilities that require a large amount of ventilation and exhaust, in order to adjust the amount of air supplied to the room and the amount of air exhausted from the room to maintain positive or negative pressure in the room depending on the purpose of the facility, outside air processing machines that process fresh outside air and supply it to the room are used in addition to air conditioners that adjust the temperature and humidity inside the room.

[0003] For example, the outdoor air treatment machine has the role of supplying air at a lower temperature than the outdoor air into the room in summer, and air at a higher temperature than the outdoor air into the room in winter, thereby eliminating the difference in temperature with the conditioned room, and preventing the area around the indoor air intake from becoming uncomfortable, and also has the function of not placing an unnecessary burden on the air conditioner. In recent years, outdoor air treatment machines that use heat pump technology to obtain greater thermal energy than electrical energy have been provided in order to save energy.

[0004] One such outdoor air treatment machine (outdoor air treatment air conditioner) disclosed is an air-cooled heat pump type outdoor air treatment air conditioner that has, within the same casing, an outdoor air intake, an exhaust intake which takes in exhaust air from indoors, an evaporator which exchanges heat with the outdoor air, a condenser which also serves to recover exhaust heat, a compressor, an air supply fan which blows outdoor air indoors via the evaporator, an exhaust fan which blows exhaust air outdoors via the condenser, an outdoor air damper which adjusts the amount of outdoor air flowing from the outdoors to the evaporator, an exhaust damper which adjusts the amount of exhaust air flowing from the indoors to the condenser, and an outdoor air introduction damper which assists in the amount of air flowing to the condenser (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-228187 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the outdoor air processing machine of Patent Document 1 is used in cold regions in winter, the outdoor air taken into the outdoor air processing machine is low (below 0°C), so the heating capacity is insufficient and low-temperature air is supplied to the room, making it cold around the air intake vent inside the room. In addition, the humidification capacity is insufficient and humidity does not increase. Heat pumps used in cold regions require special heat pumps designed for cold regions, which are expensive. Also, when the outdoor air is low, frost forms frequently on the heat exchanger, making defrosting necessary. There are various problems such as the above, and the machine is unable to perform to its full potential, particularly in cold regions in winter. In summer (intermediate season), the outdoor air is cooled, Ta When the refrigerant was later reheated using hot gas, the reheating capacity was insufficient, and the target temperature and humidity could not be achieved.

[0007] One possible solution to the above problems would be to place an electric heater unit or a heating coil unit in front of or behind the outdoor air treatment unit to preheat the outdoor air to be taken into the outdoor air treatment unit. However, this would require extensive installation work, and it may not be possible to achieve optimal control including the added equipment.

[0008] The present invention has been made to solve the above problems, and aims to provide an outdoor air treatment machine that can be used in cold regions in winter by integrating not only heat pump technology into the outdoor air treatment machine but also a boiler unit that circulates hot water or antifreeze liquid (hereinafter referred to as heat transfer water) at a specified temperature and optimally controlling them simultaneously.In addition, it aims to provide an outdoor air treatment machine that is optimal for facilities that require high-temperature and high-humidity air supply in winter for production processes such as hospitals, elderly care facilities, and factories in non-cold regions in order to maintain the quality of products. [Means for solving the problem]

[0009] The present invention is an outdoor air treatment machine that supplies outside air with adjusted temperature and humidity to the room, characterized in that it is an outdoor air treatment machine that integrates a heat pump unit for energy saving and a boiler unit for circulating heat transfer water at a predetermined temperature into a package.

[0010] The present invention is also characterized in that defrosting of the heat exchanger is suppressed by simultaneously controlling the output of the heat pump unit and the output of the boiler unit. Effect of the Invention

[0011] The outdoor air treatment device of the present invention is a package that integrates a heat pump unit for energy saving and a boiler unit that circulates heat transfer water at a specified temperature. Ta As a result, even in cold regions in winter when the temperature of the outside air taken into the outside air processing machine is low, the temperature of the outside air to be supplied indoors can be preheated by the boiler unit, making it possible to supply outside air with a stable temperature and humidity to the room.

[0012] In addition, by simultaneously controlling the output of the heat pump unit and the output of the boiler unit, it is possible to suppress defrosting of the heat exchanger of the outdoor air processing unit. In other words, by integrating the heat pump unit and the boiler unit and optimally controlling them simultaneously in conjunction with each other, it is possible to control frost formation on the evaporator in the outdoor air processing unit, thereby eliminating discomfort such as reduced performance due to defrosting and the feeling of cold air inside the room. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing a configuration of an outside air processing machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a psychrometric chart illustrating changes in temperature of outside air in an outside air processing device in winter according to one embodiment of the present invention. [Diagram 3]5 is a flowchart for explaining an outline of defrost suppression control in the outdoor air processing device in winter according to one embodiment of the present invention. [Figure 4] FIG. 2 is a psychrometric chart for explaining temperature changes of outside air in an outside air processing device in summer (intermediate season) according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention relates to an outdoor air treatment machine that supplies outdoor air with adjusted temperature and humidity to a room, characterized in that it integrates a heat pump unit for energy saving and a boiler unit for circulating heat transfer water at a predetermined temperature into a package.

[0015] Hereinafter, an outdoor air treatment machine according to an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing the configuration of an outdoor air treatment machine according to an embodiment of the present invention. Fig. 2 is a psychrometric chart explaining the temperature change of outdoor air in an outdoor air treatment machine in winter according to an embodiment of the present invention. Fig. 3 is a flow chart explaining an outline of defrost suppression control in an outdoor air treatment machine in winter according to an embodiment of the present invention. Fig. 4 is a psychrometric chart explaining the temperature change of outdoor air in an outdoor air treatment machine in summer (intermediate season) according to an embodiment of the present invention.

[0016] As shown in FIG. 1, the outside air processing device 1 of this embodiment is configured by unitizing various devices in an upper casing KH, a middle casing KM, and a lower casing KL, which are box-shaped and made of metal (e.g., iron or aluminum). The uppermost upper casing KH is configured with left and right openings, and by operating an exhaust fan 30 provided at the top, it draws in outside air OA from the left and right openings and discharges it to the top. Condensers 20 are installed near the left and right openings of the upper casing KH. This condenser 20 is a heat exchanger that cools the high-pressure and high-temperature refrigerant gas inside with the outside air OA during summer operation, and condenses and liquefies it. The condensed and liquefied refrigerant gas is circulated to an evaporator 21 and a reheater 22, which will be described later, via a refrigerant pipe 25.

[0017] The middle casing KM is configured with left and right openings, similar to the upper casing KH. The right opening of the middle casing KM is an intake for outside air OA, which is adjusted in temperature and humidity and supplied to the room as supply air SA from the left opening of the middle casing KM. Heat transfer water coils 13 are installed near the left and right openings of the middle casing KM. The heat transfer water coil 13 is composed of multiple heat transfer water distribution pipes that circulate the heat transfer water circulating through the heat transfer water piping 12 inside, and adjusts the temperature of the outside air OA taken in from the right opening of the middle casing KM (pre-heating in winter).

[0018] An evaporator 21 is disposed to the left of the heat transfer water coil 13 near the right opening of the middle casing KM. The evaporator 21 is a heat exchanger that utilizes the latent heat of evaporation of the condensed and liquefied refrigerant circulating inside the evaporator 21 to exchange heat with the outside air OA flowing outside the container from the right to the left of the middle casing KM. For this reason, the evaporator 21 is connected to the condenser 20 by a refrigerant piping 25, and the condensed and liquefied refrigerant is supplied from the condenser 20.

[0019] A reheater 22 is disposed to the left of the evaporator 21. The reheater 22 warms the outside air OA, whose temperature has been reduced by passing through the evaporator 21. In other words, it is called a "reheater" because it functions as a heat exchanger to reheat the cooled air. This reheater 22 is also connected to the condenser 20 by a refrigerant pipe 25, and condensed and liquefied refrigerant is supplied from the condenser 20. The reheater 22 uses the condensed and liquefied refrigerant hot gas supplied from the condenser 20 as its heat source.

[0020] That is, the heat pump unit in this embodiment is composed of the condenser 20 installed near the left and right openings of the upper casing KH, the evaporator 21 and reheater 22 installed in the middle casing KM, and the refrigerant piping 25 connecting them. The condenser 20 and evaporator 21 constituting the heat pump unit operate with their functions reversed during heating operation in winter and cooling operation in summer. That is, the condenser 20 functions as the evaporator 20 during heating operation in winter, and the evaporator 21 functions as the condenser 21 during heating operation in winter. For this reason, in the following description, the same reference numerals may be used to refer to the condenser 20, the evaporator 20, or the evaporator 21, the condenser 21.

[0021] A humidifier 23 is disposed to the left of the reheater 22. This humidifier 23 imparts a predetermined humidity to the outside air OA flowing from left to right through the upper casing KH. A heat transfer water coil 14 is disposed to the left of the humidifier 23, near the left opening of the middle casing KM. The heat transfer water coil 14 circulates the heat transfer water circulating through the heat transfer water piping 12 inside, thereby performing final temperature adjustment of the outside air OA taken in from the right opening of the middle casing KM, and supplies air at a predetermined temperature from the left opening of the middle casing KM into the room as supply air SA.

[0022] The lower casing KL is configured with various devices installed inside, unlike the upper casing KH and the middle casing KM. A hot water tank 10 and a boiler 11 are installed on the right side of the lower casing KL, and heat transfer water at a constant temperature is always stored in the hot water tank 10. The heat transfer water stored in the hot water tank 10 is circulated between the hot water tank 10 and the heat transfer water coils 13 and 14, which are connected by the heat transfer water pipe 12, by a pump (P in the figure) installed midway in the heat transfer water pipe 12.

[0023] That is, the boiler unit in this embodiment is composed of heat transfer water coils 13 and 14 installed respectively near the left and right openings of the middle casing KM, a hot water tank 10 installed in the lower casing KL, a boiler 11, and heat transfer water piping 12 connecting them.

[0024] According to the outdoor air treatment device 1 having the above-mentioned configuration, in summer, high-temperature outdoor air OA is cooled by the evaporator 21 of the heat pump unit, and if reheating is required, it is reheated by the reheater 22. If the amount of reheat is insufficient, heat transfer water in the hot water tank of the boiler unit is supplied to the heat transfer water coil 14 to supplement the reheating, so that supply air SA of an appropriate temperature and humidity can be provided to the room. Also, in winter, the temperature of low-temperature outdoor air OA is heated by the condenser 21 of the heat pump unit, and if humidification is required, it is humidified by the humidifier 23. If the temperature cooled by evaporation in the humidifier is low, heat transfer water in the hot water tank of the boiler unit is supplied to the heat transfer water coil 14 and heated, so that supply air SA of an appropriate temperature and humidity can be provided to the room.

[0025] Hereinafter, an example of a temperature change of the outdoor air OA in the outdoor air processing machine 1 in winter will be described with reference to Fig. 2. The example shown in Fig. 2 shows a temperature change of the outdoor air OA in the outdoor air processing machine 1 installed in a cold region in winter.

[0026] As shown in Fig. 2, the temperature of the outside air OA taken in from the right opening of the middle casing KM is -15°C (circle 1 in the figure). The temperature of the outside air OA flowing from the right opening to the left opening of the middle casing KM is preheated in the heat transfer water coil 13 that constitutes the boiler unit near the right opening of the middle casing KM and rises to 35°C (circle 2 in the figure). The temperature of the outside air OA rises to 45°C in the condenser 20 of the heat pump unit installed to the left of the heat transfer water coil 13 of the middle casing KM (circle 3 in the figure).

[0027] The temperature of the outside air OA, which has been humidity-adjusted by the humidifier 23, drops to 30.7°C as the moisture evaporates due to humidification (circle 4 in the figure). Finally, the temperature of the outside air OA flowing from the right opening to the left opening of the middle casing KM is heated by the heat transfer water coil 14 that constitutes the boiler unit near the left opening of the middle casing KM, and rises to 40°C (circle 5 in the figure). Then, the outside air OA heated by the heat transfer water coil 14 from the left opening of the middle casing KM is supplied into the room as supply air SA.

[0028] As described above, in this embodiment, the outdoor air treatment machine 1 is configured not only as a heat pump unit, but also as an integrated unit with a boiler unit that circulates heat transfer water at a predetermined temperature, making it possible to provide an outdoor air treatment machine 1 that can be used in cold regions in winter.

[0029] Here, the outdoor air processing machine 1 in this embodiment is configured to control the heat pump unit and boiler unit, which are configured as an integral unit, in conjunction with each other in a control unit (not shown). That is, by simultaneously controlling the condenser 20, evaporator 21, and reheater 22 that configure the heat pump unit and the temperature control by the hot water tank 10, circulation pump P, and boiler 11 that configure the boiler unit, the heat pump unit with the best operating efficiency is operated preferentially, and the boiler unit is operated only when necessary, making it possible to perform optimal control without waste and to conserve energy.

[0030] In addition, in cold regions in winter, the outdoor air OA taken in by the outdoor air processing device 1 is preheated in advance by the heat transfer water coil 13 constituting the boiler unit, and flows through the condenser 21 constituting the heat pump unit, which is a heat exchanger. This prevents the low-temperature (for example, -15°C) outdoor air OA taken in by the outdoor air processing device 1 from flowing through the condenser 21 constituting the heat pump unit, which is a heat exchanger, at a low temperature, and compensates for the lack of heating capacity. In addition, when the evaporation temperature of the evaporator 20 of the heat pump unit drops and reaches the defrost detection temperature, the output of the heat pump unit is reduced to raise the evaporation temperature, and then the output of the boiler unit is increased to compensate for the lack of heating capacity, so that the evaporator 20 is less likely to frost, suppressing defrosting, and allowing the evaporator 20 to demonstrate sufficient capacity even in cold regions in winter.

[0031] An example of a defrost suppression control method controlled by the outdoor air processing machine 1 of this embodiment will be described below with reference to Fig. 3. Note that the following control process will be described as an example of heating operation in winter, which is executed by a control program stored in a control unit (not shown) attached to the outdoor air processing machine 1.

[0032] 3, the defrost setting conditions of the outside air temperature and the evaporation temperature of the evaporator 20 are monitored, and when the conditions are not met, the heat pump unit output is increased or decreased to control toward the supply air set temperature, and when the conditions are met, the heat pump unit output is decreased to raise the evaporation temperature to prevent frost formation on the evaporator 20. At that time, the heat pump unit's heat transfer water coil output is increased or decreased to control toward the supply air set temperature, and defrosting of the heat pump unit is suppressed.

[0033] 3, the control unit determines whether the temperature of the outdoor air OA is equal to or lower than the set supply air temperature (step S1). If the control unit determines that the temperature of the outdoor air OA is not equal to or lower than the set supply air temperature (step S1: No), it reduces the output of the heat pump unit (step S2) and proceeds to step S1. On the other hand, if the control unit determines that the temperature of the outdoor air OA is equal to or lower than the set supply air temperature (step S1: Yes), it proceeds to step S3.

[0034] The control unit determines whether the temperature of the outdoor air OA is A (set value) °C and the evaporation temperature is equal to or lower than X (set value) °C (step S3). If the control unit determines that the temperature of the outdoor air OA is not A (set value) °C and the evaporation temperature is not equal to or lower than X (set value) °C (step S3: No), it increases the output of the heat pump unit (step S4) and moves the process to step S1. On the other hand, if the control unit determines that the temperature of the outdoor air OA is A (set value) °C and the evaporation temperature is equal to or lower than X (set value) °C (step S3: Yes), it decreases the output of the heat pump unit (step S5) and moves the process to step S6.

[0035] The control unit determines whether the temperature of the outdoor air OA is equal to or lower than the set supply air temperature (step S6). If the control unit determines that the temperature of the outdoor air OA is not equal to or lower than the set supply air temperature (step S6: No), the process proceeds to step S1. On the other hand, if the control unit determines that the temperature of the outdoor air OA is equal to or lower than the set supply air temperature (step S6: Yes), the control unit increases the output of the heat transfer water coils 13 and 14 (step S7) and proceeds to step S8.

[0036] The control unit determines whether the temperature of the outdoor air OA is equal to or lower than the set supply air temperature (step S8). If the control unit determines that the temperature of the outdoor air OA is not equal to or lower than the set supply air temperature (step S8: No), it reduces the output of the heat transfer water coils 13 and 14 (step S9) and proceeds to step S8. On the other hand, if the control unit determines that the temperature of the outdoor air OA is equal to or lower than the set supply air temperature (step S8: Yes), it proceeds to step S10.

[0037] The control unit determines whether the temperature of the outdoor air OA is A (set value) °C and the evaporation temperature is equal to or lower than X (set value) °C (step S10). If the control unit determines that the temperature of the outdoor air OA is A (set value) °C and the evaporation temperature is equal to or lower than X (set value) °C (step S10: Yes), it reduces the output of the heat pump unit (step S11) and moves the process to step S10. On the other hand, if the control unit determines that the temperature of the outdoor air OA is not equal to or lower than A (set value) °C and the evaporation temperature is not equal to or lower than X (set value) °C (step S10: No), it increases the output of the heat transfer water coils 13 and 14 (step S12) and moves the process to step S13.

[0038] The control unit determines whether or not to continue the heating operation (step S13). If the control unit determines that the heating operation should be continued (step S13: Yes), the process proceeds to step S1. On the other hand, if the control unit determines that the heating operation should not be continued (step S13: No), the process ends.

[0039] Hereinafter, with reference to FIG. 4, an example of a change in temperature of the outside air OA in the outside air processing unit 1 in summer (intermediate season) will be described.

[0040] As shown in FIG. 4, the temperature of the outside air OA taken in from the right opening of the middle casing KM is 23°C (circle 1 in the figure). The temperature of the outside air OA flowing from the right opening to the left opening of the middle casing KM is cooled to 11.3°C by the evaporator 21 of the heat pump unit (circle 2 in the figure), and heated to 22°C by the reheater 22 (circle 3 in the figure). When the supply air set temperature is 25°C, the reheating capacity is insufficient with the refrigerant hot gas alone, so the outside air is heated to 25°C by the heat transfer water coil 14 constituting the boiler unit (circle 4 in the figure). Then, the outside air OA heated by the heat transfer water coil 14 from the left opening of the middle casing KM is supplied to the room as supply air SA.

[0041] An example of an embodiment of the present invention has been described above, but the specific configuration of the present invention is not limited to the above embodiment, and design changes and the like that do not deviate from the gist of the invention are also included in the present invention. [Explanation of symbols]

[0042] 1. Outdoor air treatment machine 10 Hot water tank 11 Boiler 12 Heat transfer water piping 13 Heat transfer water coil 14 Heat transfer water coil 20 Condenser (evaporator in winter) 21 Evaporator (condenser in winter) 22 Reheater 23 Humidifier 25 Refrigerant piping 30 Exhaust fan KH upper casing KM Middle Casing KL Lower Casing OA Outdoor air SA Air Supply

Claims

1. An outdoor air treatment device that adjusts the temperature and humidity of the outdoor air taken in and supplies it to a room as intake air, The heat pump unit is installed inside the casing and is controlled by a control unit in cooperation with each other to save energy. The boiler unit circulates heat transfer water at a predetermined temperature. The heat pump unit comprises: a first heat exchanger that exchanges heat with the refrigerant circulating inside the casing using outside air flowing inside the casing; a second heat exchanger that exchanges heat with outside air flowing through the casing by using a refrigerant circulating therein; a reheater for reheating the outside air that has been heat exchanged by the second heat exchanger; a refrigerant pipe connecting the first heat exchanger, the second heat exchanger, and the reheater to each other; The boiler unit includes: a heat transfer water coil disposed near each of an opening of the casing for taking in outside air and an opening of the casing for supplying supply air to the room; A hot water storage tank storing heat transfer water that circulates between each of the heat transfer water coils; a boiler connected to the hot water tank; An outdoor air treatment machine characterized by:

2. The outdoor air treatment machine described in Claim 1, characterized in that the control unit, when the outdoor air temperature falls below a set value, suppresses defrosting of the first heat exchanger by controlling the output of the heat pump unit to decrease and the output of the boiler unit to increase.

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