JP4020705B2 - Heat pump and dehumidifying air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat pump and a dehumidifying air conditioner, and more particularly to a heat pump and a dehumidifying air conditioner having a high coefficient of performance (COP) and capable of switching operation modes.
[0002]
[Prior art]
Conventionally, there has been a dehumidifying air conditioner as shown in FIG. In this apparatus, a compressor 260 that compresses the refrigerant C, a condenser 220 that condenses the compressed refrigerant C with the outside air B, and an expansion valve 291 with a bypass having a solenoid valve depressurizes the condensed refrigerant C to an intermediate pressure. The intermediate heat exchanger 300 ″ that repeatedly evaporates and condenses in the above, and the refrigerant C condensed here is decompressed by the expansion valve 292 with a bypass having a solenoid valve, and is evaporated to process air A from the conditioned space 101. And an evaporator 210 for cooling to a dew point temperature.
[0003]
In this apparatus, in the dehumidifying operation mode, the bypass solenoid valve of the expansion valve 292 is closed, and the evaporation and condensation pressure of the intermediate heat exchanger 300 ″ is set to the intermediate pressure between the condensation pressure of the condenser 220 and the evaporation pressure of the evaporator 210. . Further, in the cooling operation mode, the solenoid valve of the expansion valve 292 is opened so that the pressure of the intermediate heat exchanger 300 ″ is equal to the evaporation pressure of the evaporator 210, so that the intermediate heat exchanger 300 ″ is one of the evaporators. Operate as a part.
Therefore, in the dehumidifying operation mode, the intermediate heat exchanger 300 ″ performs heat exchange using the refrigerant as a medium between the processing air before and after being cooled to the dew point temperature by the evaporator 210. In this way, the processing air A cooled to the dew point by the evaporator 210 is reheated by the heat exchanger 300 ″.
[0004]
[Problems to be solved by the invention]
In the conventional dehumidifying air conditioner as described above, the dehumidifying operation mode and the cooling operation mode are possible, but the heating operation mode cannot be directly supported. In particular, there is a demand for a dehumidifying air conditioner for home use to support heating in winter as well as dehumidifying and cooling in summer with a single air conditioner.
[0005]
Then, an object of this invention is to provide the heat pump and dehumidification air conditioner which can switch an operation mode. In particular, it is an object of the present invention to provide a heat pump capable of switching the direction of pumping heat and a dehumidifying air conditioner capable of switching between a dehumidifying / cooling operation mode and a heating operation mode.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a heat pump according to a first aspect of the present invention provides a booster that boosts the refrigerant C by discharging the refrigerant C from the suction side and discharging the refrigerant C from the suction side, for example, as shown in FIGS. A switching mechanism 701 that switches between the first operation mode and the second operation mode by switching between the suction side and the discharge side of the booster 260; and evaporates the refrigerant C in the first operation mode. A first heat exchanger 210 that cools the first fluid A and condenses the refrigerant C in the second operation mode to heat the first fluid A; and the refrigerant C in the first operation mode. A second heat exchanger 220 that condenses and heats the second fluid B, evaporates the refrigerant C and cools the second fluid B in the second operation mode; and a first heat exchanger 210 Refrigerant path 2 connecting the first heat exchanger 220 and the second heat exchanger 220 The refrigerant C is evaporated and condensed at a pressure intermediate between the condensation pressure of the second heat exchanger 220 and the evaporation pressure of the first heat exchanger 210 in the first operation mode. The first fluid A is cooled by the intermediate pressure evaporation, the first fluid A is heated by the intermediate pressure condensation, and is approximately the same pressure as the condensation pressure of the first heat exchanger 210 in the second operation mode. A third heat exchanger 300 that condenses the refrigerant C and heats the first fluid A; and is provided in the refrigerant path 203 between the third heat exchanger 300 and the first heat exchanger 210. A first throttling mechanism 292 whose degree of throttling is switchable; a second throttling mechanism 711 provided in the refrigerant path 202 between the second heat exchanger 220 and the third heat exchanger 300; The first fluid A is in the third heat exchanger 300 in the first mode of operation. Consists of cooling and heating in the cooling and the third heat exchanger 300 in the first heat exchanger 210 so as to receive in this order; third heat exchanger 300, in the first operating mode A first section 310 in which the refrigerant C performs the intermediate pressure evaporation and a second section 320 in which the intermediate pressure condensation is performed are formed, and the refrigerant C meanders in the first section 310 a plurality of times in the first operation mode. And then meandering multiple times in the second compartment 320 and then toward the first heat exchanger 210; the first heat exchanger 210 is between the first compartment 310 and the second compartment 320. Ru is located.
[0007]
The booster typically discharges the refrigerant from the suction side to the suction discharge side, and the switching mechanism typically switches the operation mode by switching between the suction side and the discharge side of the booster.
[0008]
The first operation mode is typically the dehumidification operation mode when the heat pump is used for dehumidification air conditioning. Similarly, the second operation mode is typically the heating operation mode. The first fluid is a low heat source fluid in the first operation mode, the second fluid is a high heat source fluid in the first operation mode, and the first heat exchanger is evaporated in the dehumidification / cooling operation mode. The second heat exchanger is a condenser in the dehumidifying / cooling operation mode, and the third heat exchanger is an intermediate heat exchanger in the dehumidifying operation mode. The change of the aperture degree is typically an increase or decrease in the opening area.
[0009]
If comprised in this way, since the switching mechanism is provided, a 1st operation mode and a 2nd operation mode can be switched.
[0010]
In order to achieve the above object, a dehumidifying air conditioner according to a second aspect of the present invention includes, for example, as shown in FIGS. 1 and 2 , a booster 260 that boosts the refrigerant C; a dehumidifying operation mode and a heating operation mode; A first heat exchange for evaporating the refrigerant C in the dehumidifying operation mode to cool the processing air A to the dew point temperature and condensing the refrigerant C in the heating operation mode to heat the processing air A A second heat exchanger 220 that condenses the refrigerant C in the dehumidifying operation mode to heat the heat source fluid B and evaporates the refrigerant C in the heating operation mode to cool the heat source fluid B; Provided in the refrigerant paths 202 to 203 that connect the second heat exchanger 210 and the second heat exchanger 220, and the condensation pressure of the second heat exchanger 220 and the first heat exchanger 210 in the dehumidifying operation mode. Between the evaporation pressure of The refrigerant C is evaporated and condensed by force, the processing air A is cooled by the intermediate pressure evaporation, the processing air A is heated by the intermediate pressure condensation, and the condensation pressure of the first heat exchanger 210 is heated in the heating operation mode. A third heat exchanger 300 that condenses the refrigerant C and heats the processing air A at substantially the same pressure as in the above; provided in the refrigerant path 203 between the third heat exchanger 300 and the first heat exchanger 210 A first throttling mechanism 292 having a switchable throttling degree; and a second throttling mechanism provided in the refrigerant path 202 between the second heat exchanger 220 and the third heat exchanger 300. 711; the processing air A performs cooling in the third heat exchanger 300, cooling in the first heat exchanger 210, and heating in the third heat exchanger 300 in the dehumidifying operation mode. It is configured to receive in this order; third heat exchanger 300, the removal A first section 310 in which the refrigerant C performs the intermediate pressure evaporation in the operation mode and a second section 320 in which the intermediate pressure condensation is performed are formed, and the refrigerant C flows in the first section 310 a plurality of times in the dehumidifying operation mode. After being meandered, configured to meander multiple times in the second compartment 320 and then toward the first heat exchanger 210; the first heat exchanger 210 is between the first compartment 310 and the second compartment 320 Ru is located between.
[0011]
The booster typically discharges the refrigerant from the suction side to the suction discharge side, and the switching mechanism typically switches the operation mode by switching between the suction side and the discharge side of the booster. A cooling operation mode is an extension of the dehumidifying operation mode.
[0012]
If comprised in this way, since the switching mechanism is provided, switching will be possible between the dehumidifying operation mode and the heating operation mode.
[0013]
Further, as described in claim 3, in the dehumidifying air conditioner described in claim 2, for example, as shown in FIG. 6, the degree of superheat of the refrigerant C exiting the first heat exchanger 210 in the dehumidifying operation mode is detected. First superheat detectors 733T, 733P, 734; and second superheat detectors 732T, 732P, 734 for detecting the superheat of the refrigerant exiting the second heat exchanger 220 in the heating operation mode; The second throttle mechanism 711 increases or decreases the throttle degree based on the detection results of the first superheat degree detectors 733T, 733P, and 734 in the dehumidifying operation mode, and the second superheat degree detector 732T in the heating operation mode. , 732P, 734 may have an expansion valve 731 that increases or decreases the degree of throttling.
[0014]
The superheat detector typically includes, for example, a pressure detector that detects the pressure at that location and a temperature detector that detects the temperature, as shown in FIG. 6, and based on the detection results of both detectors. Is calculated. For example, an electronic expansion valve. Further, for example, as shown in FIG. 1, temperature automatic expansion valves 713 and 712 having pressure equalizing tubes and temperature detectors (temperature sensing cylinders) 722, 722A, 721, and 721A may be used.
[0015]
Further, as shown in claim 4, in the dehumidifying air conditioner according to claim 2 or claim 3, the first throttle mechanism 292 is provided between the first heat exchanger 210 and the third heat exchanger 300. It may be possible to reduce the degree of throttling to substantially zero.
[0016]
When the degree of constriction between the first heat exchanger 210 and the third heat exchanger 300 is reduced to substantially zero, the cooling operation mode is typically set.
Here, when the degree of throttling is substantially zero, it may be said that the throttling action is substantially zero. When the throttling is, for example, a control valve that increases or decreases the opening area, the opening area is sufficiently large. This is true.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In addition, in each figure, the same code | symbol or a similar code | symbol is attached | subjected to the mutually same or equivalent member, and the overlapping description is abbreviate | omitted.
[0018]
FIG. 1 is a flow diagram of a heat pump HP1 according to a first embodiment of the present invention and a dehumidifying air conditioner 21 that is an example of the dehumidifying air conditioner according to the present invention. The dehumidifying air conditioner 21 can perform a dehumidifying operation in which the processing air A is cooled to its dew point temperature to remove moisture and then reheated to dehumidify, and a cooling operation mainly depriving sensible heat, and further heating to raise the temperature of the processing air A The dehumidifying air conditioner 21 is operable. Here, when "processing air A is cooled to its dew point temperature and dehumidified", the processing air A may be somewhat supercooled, but in this case, it is "cooled below dew point temperature and dehumidified" This concept is also included. In addition, air that has been cooled to the dew point temperature and dehydrated has a lower dew point temperature than the original air, so if you use the original dew point temperature as a reference, it will be `` cooled below the dew point temperature and dehumidified. '' Including.
[0019]
With reference to FIG. 1, the structure of heat pump HP1 which is 1st Embodiment, and the dehumidification air conditioner 21 provided with the same is demonstrated. This dehumidifying air conditioner 21 is processed air A as a first fluid by a first heat exchanger (acting as an evaporator) 210 in a dehumidifying operation mode as a first operation mode and a cooling operation mode on its extension. In the heating operation mode as the second operation mode, the temperature of the processing air A as the first fluid is increased by the first heat exchanger (acting as a condenser) 210 in the heating operation mode as the second operation mode. The air-conditioned space 101 supplied with the processing air A is maintained in a comfortable environment.
[0020]
FIG. 1 shows the case of dehumidifying operation. In the figure, the black valve is closed. If the valve 253 is white, the cooling operation is performed. Here, for the sake of convenience, the configuration will be described with the function of the dehumidifying operation.
A device configuration related to the processing air will be described along the path of the processing air A from the air-conditioned space 101. First, the path 107 connected to the air-conditioned space 101, the first section 310 as the intermediate evaporator of the heat exchanger 300 as the third heat exchanger, the path 108, and evaporation for cooling the processing air A to its dew point temperature. The second section 320 as an intermediate condenser of the heat exchanger 300, the path 109, the path 110, the blower 102 for circulating the processing air A connected to the path 110, and the path 111 are arranged in this order. And, it is configured to return to the air-conditioned space 101. In the figure, the air supplied from the dehumidifying air conditioner 21 to the air conditioned space 101 is indicated as SA, and the air returning from the air conditioned space 101 to the dehumidifying air conditioner is indicated as RA.
[0021]
Further, along the path of cooling air (outside air) B as the second fluid from the outdoor OA, the path 124, the condenser 220 for cooling and condensing the refrigerant C, the path 125, and the blower for blowing the cooling air B 140 and the path 126 are arranged in this order, and are configured to exhaust EX to the outdoor OA.
[0022]
Next, the device configuration of the heat pump HP1 will be described along the path from the evaporator 210 to the refrigerant C. In the figure, evaporator 210, path 204, four-way valve 701 (port 701A to port 701B), path 204-1 and compression as a booster that compresses (increases) the refrigerant C that has become gas by evaporation in evaporator 210. Machine 260, path 201-1, four-way valve 701 (port 701C to port 701D), path 201, condenser 220, path 202, expansion valve mechanism 711 as a second throttle mechanism inserted in path 202, heat An evaporating section 251 that cools the processing air A that flows through the first section 310 of the exchanger 300, a refrigerant path 202B, and a condensing section 252 that heats (reheats) the processing air A that flows through the second section 320 of the heat exchanger 300. The heat pump HP1 is configured such that the path 203 and the diaphragm 250 are arranged in this order and return to the evaporator 210 again. .
[0023]
Here, the configuration of the four-way valve 711 as a switching mechanism for switching between the first operation mode and the second operation mode will be described. The four-way valve 701 has four ports as ports. That is, the port 701A, the port 701B, the port 701C, and the port 701D. In the first operation mode and the cooling operation mode that is an extension of the first operation mode, the port 701A and the port 701B communicate with each other, and the port 701C and the port 701D communicate with each other. In the second operation mode, port 701A and port 701D communicate with each other, and port 701B and port 701C communicate with each other. The switching mechanism is not limited to a four-way valve, and may be a combination of four two-way valves or a combination of two three-way valves.
[0024]
Note that the evaporation section 251 is formed by a tube meandering in the first section 310, and the condensation section 252 is formed by a tube meandering in the second section 320. In the present embodiment, the evaporation section 251 meanders the first section 310 a plurality of times and is then connected to the condensation section 252 via the path 202B. The condensing section 252 is connected to the path 203 after meandering the second compartment 320 multiple times. In the drawing, each section is shown to meander in a plane along the flow of the processing air A, but in reality, it is preferable to meander in a plane perpendicular to the flow of the processing air A (see FIG. 2). ). However, a plurality of meandering layers may be provided by providing a plurality of orthogonal surfaces.
[0025]
In this way, the evaporation section 251 and the condensation section 252 are formed by continuous heat transfer tubes, and the evaporation section 251 is sufficiently meandered in the first section 310 a plurality of times, that is, the refrigerant flowing inside is evaporated. Later, if the condensing section 252 is configured to meander multiple times in the second compartment, the number of pipes connecting the evaporating section 251 and the condensing section 252 may be one or a minimum (2 to 4). The first section 310 and the second section 320 can be easily set apart (see FIGS. 2B and 2C).
[0026]
In addition, although the expansion valve mechanism 711 is arrange | positioned in the path | route 202 of the refrigerant | coolant C, the expansion valve mechanism 711 has arrange | positioned the expansion valve 712 and the expansion valve 713 in series from the upstream of a refrigerant | coolant. A bypass path 202A that bypasses the expansion valve 712 is provided, and a check valve 714 is inserted into the bypass path 202A. The flow direction of the check valve (check valve) 714 is a direction from the condenser 220 toward the expansion valve 713.
Similarly, a bypass path 202B that bypasses the expansion valve 713 is provided, and a check valve 715 is inserted into the bypass path 202B. The flow direction of the check valve 715 is a direction from the heat exchanger 300 toward the expansion valve 712. A path 203A that bypasses the throttle 250 is provided in the path 203 of the refrigerant C, and a solenoid valve 253 is provided in the path 203A.
[0027]
An expansion valve mechanism 711 as a second throttle mechanism is configured including the expansion valve 712, the expansion valve 713, the bypass path 202A (including the check valve 714), and the bypass path 202B (including the check valve 715). A first throttle mechanism 292 is configured including the solenoid valve 253.
[0028]
When the solenoid valve 253 is opened, the opening area is formed to be substantially equal to the cross-sectional area of the path 203. In other words, when the solenoid valve 253 is opened, the aperture of the first aperture mechanism 292 is reduced (the aperture area is increased), and the aperture is large enough not to act as an aperture. (The aperture value is substantially zero).
[0029]
In other words, when the solenoid valve 253 is opened, the opening area of the first throttle mechanism 292 is increased and the first throttle mechanism 292 is set so as not to substantially form a throttle. The case where the solenoid valve 253 is closed is the case where the opening area of the first diaphragm mechanism 292 is reduced and the first diaphragm mechanism 292 is set to form a diaphragm.
[0030]
The path 201 is provided with a temperature sensing cylinder 721 as a temperature detector for detecting the temperature of the refrigerant flowing therethrough, and a temperature detection signal is sent to the expansion valve 712. A pressure equalizing pipe 721A is provided between the expansion valve 712 and the path 201.
Similarly, the path 204 is provided with a temperature sensing cylinder 722 as a temperature detector for detecting the temperature of the refrigerant flowing therethrough, and a temperature detection signal is sent to the expansion valve 713. A pressure equalizing pipe 722 </ b> A is provided between the expansion valve 713 and the path 204.
[0031]
Since it is comprised in this way, the direction which acts as an expansion valve among expansion valves 712 and 713 is decided by the level of pressure before and after expansion valve mechanism 711.
In the case of the dehumidifying operation mode and the cooling operation mode as the first operation mode, the path 201 is connected to the discharge side of the compressor 260, and the second heat exchanger 220 side has a higher pressure than the heat exchanger 300 side. is there. Therefore, the check valve 715 is closed as shown in black, and the check valve 714 is open, so that the expansion valve 713 functions as an expansion valve.
[0032]
Next, the configuration of the heat exchanger 300 will be described. The heat exchanger 300 is a heat exchanger that indirectly exchanges heat between the processing airs A before and after flowing into the evaporator 210 via the refrigerant C.
[0033]
In this heat exchanger 300, a first section 310 for flowing the processing air A before passing through the evaporator 210 and a second section 320 for flowing the processing air A after passing through the evaporator 210 are separated. A rectangular parallelepiped space is formed. Both compartments are provided with partition walls 301 and 302 so that the processing air flowing through both sections is not mixed, and the pipe 202B connecting the evaporation section 251 and the condensation section 252 which are heat exchange tubes has the partition walls of these two sections. It penetrates.
[0034]
In the figure, the processing air A before being introduced into the evaporator 210 is supplied to the first section 310 from the right through the path 107 and exits through the path 108 from the left. Further, the processing air A cooled to the dew point temperature (below) through the evaporator 210 and having a reduced absolute humidity is supplied to the second section 320 from the left side through the path 109 and exits from the right side through the path 110. .
[0035]
Here, the concept of the circuit of the evaporator 210 in the case shown in FIG. 1 will be described (see FIG. 2B as appropriate). The number of circuits in the heat exchanger that exchanges heat between the refrigerant flowing in the heat transfer tube and heat exchange between the fluid flowing outside the heat transfer tube and the refrigerant is the number of flow paths through which the refrigerant flows in parallel. In the figure, the refrigerant path 203 is connected to a distributor 601 provided after exiting the throttle 250 and immediately before entering the heat transfer tubes 210A and 210B of the evaporator 210. From the distributor 601, the refrigerant path 621 and the refrigerant path 622 are branched to introduce the refrigerant into the heat transfer tubes 210A and 210B, respectively.
[0036]
The heat transfer tubes 210 </ b> A and 210 </ b> B are arranged so that the refrigerant flows in parallel in the evaporator 210. Further, the flow direction of the refrigerant is opposite to the flow direction of the processing air A. As will be described later with reference to FIG. 3, this is also a thermal counter flow.
[0037]
In this embodiment, the number of circuits of the evaporator 210 is two. On the other hand, in the heat exchanger 300, one heat transfer tube meanders and the number of circuits is one. That is, since the number of circuits in the first section 310 that is the intermediate evaporator portion of the heat exchanger 300 is 1, it is less than the number 2 of circuits in the evaporator 210.
[0038]
Although not shown, the number of circuits in the first section and the second section may be two, and the two sections may be merged when exiting the second section and guided to the first throttling mechanism 292. At this time, the number of circuits of the evaporator 210 is preferably 3 or more.
[0039]
In the figure, in the dehumidifying operation mode, the solenoid valve 253 is closed as shown in black. The refrigerant piping between the heat exchanger 300 and the evaporator 210 is connected via the restriction 250, and the evaporation pressure and the condensation pressure in the heat exchanger 300 are the evaporation pressure of the evaporator 210 and the condenser 220. The pressure is intermediate to the condensation pressure.
[0040]
When the temperature (air temperature) is relatively high, the cooling operation mode is selected and the solenoid valve 253 is opened. At this time, the expansion valve 713 acts. Especially in the Japanese climate, when the temperature is high, the absolute humidity is usually high. At this time, it is preferable to select the cooling operation mode and actively take away both sensible heat and latent heat.
[0041]
When the solenoid valve 253 is opened, the refrigerant pipe between the heat exchanger 300 and the evaporator 210 is connected without substantial restriction, and the pressure in the heat transfer tube in the heat exchanger 300 is Both the evaporation section 251 and the condensation section 252 are substantially equal to the evaporation pressure of the evaporator 210, and the heat exchanger 300 also acts as an evaporator together with the evaporator 210.
[0042]
The selection of the dehumidifying operation mode and the cooling operation mode may be performed automatically by detecting temperature and humidity, or may be performed manually. High and low humidity also has personal preference. In addition, there are cases where it is desired to forcibly lower the temperature regardless of humidity or temperature, or cases where it is desired to lower the humidity anyway to forcibly dry the room.
[0043]
Next, a configuration example of the evaporator 210 and the heat exchanger 300 will be specifically described with reference to a schematic side view showing the installation state of the dehumidifying air conditioner in FIG. 2 and a perspective view of the heat exchanger. (B) As shown in (c), the evaporating section 251 formed of a heat transfer tube (narrow tube) is disposed through a large number of plate fins. And it is mutually connected by the U tube (you tube) outside the outermost fin. In this way, the heat transfer tube penetrates the first section 310 multiple times while meandering.
[0044]
The first section 310 is a rectangular parallelepiped space formed by arranging a large number of rectangular plate fins in parallel. Further, the outer surface of the rectangular parallelepiped space for housing the plate fins and the thin tube group may be surrounded by a plate housing. However, two opposing surfaces of the housing are open, and the processing air passes through the openings.
[0045]
Similarly, the condensing section 252 which is a heat transfer tube penetrates the second section 320 a plurality of times while meandering. The second section 320 is also a rectangular parallelepiped space having a structure similar to that of the first section 310.
[0046]
The end of the evaporation section 251 and the end of the condensing section 252 are connected by a pipe 202B. In the present embodiment, the pipe 202B is configured as a part of a continuous tube constituting the evaporation section 251 and the condensation section 252.
[0047]
As described above, the evaporating section 251 and the condensing section 252 that are refrigerant flow paths constitute meandering thin tube groups. In this way, the refrigerant C flowing in one direction from the evaporation section 251 to the condensation section 252 as a whole flows in a meandering manner in the narrow tube group, while evaporating in the evaporation section 251 and condensing in the condensation section 252. Heat from the high-temperature processing air A flowing through the first section 310 is transferred to the low-temperature processing air A flowing through the second section 320.
[0048]
Similarly, the evaporator 210 is configured such that the heat transfer tube passes through a large number of rectangular plate fins. The configuration is configured as a rectangular parallelepiped space like the first section 310 and the second section 320. And it is connected by the U tube (you tube) outside the outermost fin. In this way, the heat transfer tube penetrates the fin a plurality of times while meandering.
[0049]
In the present embodiment, the evaporating section 251 and the condensing section 252 are each configured as a single layer of thin tubes arranged in a meandering manner in one plane orthogonal to the flow of the processing air A. The evaporator 210 is configured as a two-layered thin tube group arranged meandering in two planes orthogonal to the flow of the processing air A.
[0050]
In this embodiment, the thin tube (heat transfer tube) group of the evaporator 210 is divided into two groups, an upper half and a lower half in the figure. The upper half heat transfer tube 210 </ b> A and the lower half heat transfer tube 210 </ b> B are arranged in parallel and in a direction opposite to the flow of the processing air in parallel while meandering.
[0051]
The number of layers of the heat transfer tube of the evaporator 210 may be determined according to the amount of heat transfer. Further, the distribution of the heat transfer area of the thin tube group in the heat exchanger 300 and the evaporator 210 may be determined according to the ratio of the latent heat load and the sensible heat load as will be described later.
[0052]
The evaporator 210 is disposed between the first compartment 310 and the second compartment 320. When arranged in this way, one rectangular parallelepiped space can be divided into three, and each can be configured as a first compartment 310, an evaporator 210, and a second compartment 320, and the structure is simplified. Between each compartment 310, 320 and evaporator 210, the fins are preferably scored to be discontinuous as shown. This is because the temperatures of adjacent parts are different.
[0053]
In this configuration, a thin tube group consisting of heat transfer tubes of the same size (especially the same diameter) penetrates the fins at equal intervals and is expanded and fixed to the fins, and the thin tubes are connected by simple U tubes, Since the sections 310 and 320 and the evaporator 210 may be connected by one or a small number of pipes (or a part of a narrow pipe), the configuration is simple and the manufacture is easy.
[0054]
Next, an example in which the dehumidifying air conditioner described above is applied as an air conditioner in the air-conditioned space 101 will be described with reference to a schematic cross-sectional view of FIG. In the indoor unit installed in the air-conditioned space 101, that is, indoors, a heat exchanger assembly in which the first section 310, the evaporator 210, and the second section 320 are integrally formed, the return air RA, and the supply air SA. A blower 102 that circulates is stored. If a cross flow fan is used as the blower 102, the indoor unit can be compactly assembled. A dust filter is provided on the upstream side of the flow of the return air RA in the first section 310.
A drain pan 450 is provided below the heat exchanger 300 and the evaporator 210, and a drain pipe is led to the outdoors from the drain pan 450.
[0055]
The return air RA is removed through a filter, precooled in the first section 310, further cooled by the evaporator 210, dehumidified, and becomes saturated air. The saturated air is reheated in the second section 320 and is supplied to the conditioned space 101 by the blower 102 as supply air SA having an appropriate absolute humidity and an appropriate temperature, that is, an appropriate relative humidity. That is, the process air is pre-cooled while passing in one direction through a group of plate fins and tubules (although there is a break between each compartment and the evaporator) at first glance, which looks like a normal cooling fin tube heat exchanger. The three processes of water removal and reheating are performed all at once, so that the supply air SA having an appropriate humidity and temperature is obtained.
[0056]
In an outdoor unit installed outside the air-conditioned space 101, a condenser 220, a compressor 260, and a blower 140 are housed. The condenser 220 and the evaporation section 251 of the first section 310 are connected by a pipe 202, and the evaporator 210 and the compressor 260 are connected by a pipe 203. That is, the indoor unit and the outdoor unit are connected by only two pipes 202 and 203. In this figure, the aperture mechanism 711 is not shown.
[0057]
Next, the flow of the refrigerant C between the devices in the cooling / dehumidifying operation mode will be described with reference to the flow chart of FIG. 1, followed by dehumidification as the first operation mode of the heat pump HP1 shown in FIG. The operation of the heat pump HP1 will be described with reference to the refrigerant Mollier diagram in the operation mode.
[0058]
In FIG. 1, first, the case of the dehumidifying operation mode as the first operation mode will be described. At this time, by switching the four-way valve 701, the path 204 is connected to the suction side of the compressor 260 and the path 201 is connected to the discharge side thereof. The solenoid valve 253 is closed. The refrigerant gas C compressed by the compressor 260 is guided to the condenser 220 via the refrigerant gas pipe 201-1 connected to the discharge port of the compressor 260, the four-way valve 701, and the path 201. The refrigerant gas C compressed by the compressor 260 is cooled and condensed by the outside air B as cooling air.
[0059]
The condensed refrigerant passes through the check valve 714 of the expansion valve mechanism 711 provided at the refrigerant outlet of the condenser 220 and is throttled by the expansion valve 713. Since the check valve 714 flows the refrigerant almost without resistance, the expansion valve 712 does not act as an expansion valve. The check valve 715 does not flow the refrigerant due to the check action.
[0060]
The expansion valve 713 receives a signal (pressure) corresponding to the temperature of the refrigerant in the path 204 from the temperature sensing cylinder 722 and the pressure of the refrigerant in the path 204 through the pressure equalizing pipe 722A.
Since the degree of superheat of the refrigerant in the path 204 is a function of its pressure and temperature, the expansion valve 713 can open and close according to the degree of superheat of the refrigerant by receiving both. That is, when the superheat degree of the refrigerant in the path 204 (refrigerant evaporated by the evaporator 210) is high, the refrigerant flow rate is increased as an open direction, and when the superheat degree is low (including when the refrigerant is wet), the close direction is set. Reduce the refrigerant flow rate.
This is the same in both the dehumidifying operation mode and the cooling operation mode.
[0061]
The expansion valve mechanism 711 is connected to the inlet of the evaporation section 251 of the heat exchanger 300 by the refrigerant path 202.
[0062]
The liquid refrigerant C exiting the condenser 220 is decompressed by the expansion valve mechanism 711, expands, and part of the refrigerant C evaporates (flashes). The refrigerant C mixed with the liquid and gas reaches the evaporation section 251, where the liquid refrigerant C repeatedly flows and evaporates so as to wet the inner wall of the tube of the evaporation section 251 that passes through the plate fins. The processing air A flowing through the first section 310 and before flowing into the evaporator 210 is cooled (precooled).
[0063]
The refrigerant that has evaporated to some extent in the evaporation section 251 and becomes a mixture of gas and liquid is guided to the pipe 202B and flows into the condensation section 252. The processing air A flowing through the second section 320, that is, the processing air A that has been pre-cooled in the first section 310 and then cooled and dehumidified in the evaporator 210 and cooled to a temperature lower than that before flowing into the evaporator 210 is heated (recycled). The refrigerant itself is deprived of heat and condenses. In the present embodiment, the evaporation section 251 and the condensation section 252 are formed of a series of tubes (including U tubes). That is, since it is configured as an integral flow path, the refrigerant gas C (and the refrigerant liquid C that has not evaporated) evaporated in the evaporation section 251 flows into the condensation section 252 and condenses, so that heat is transferred simultaneously with mass transfer. Move.
[0064]
The outlet side of the final condensing section 252 of the heat exchanger 300 is connected to the evaporator 210 by a refrigerant liquid pipe 203, and a throttle valve 250 and a solenoid valve 253 that bypasses the throttle 250 are installed in the refrigerant pipe 203. .
[0065]
The refrigerant liquid C condensed in the condensing section is depressurized by the restriction 250 and expanded to lower the temperature, branch to the pipes 621 and 622 through the distributor 601, and enter the heat transfer tubes 210A and 210B of the evaporator 210, respectively. It evaporates and the process air A is cooled with the heat of evaporation. As the throttles 330 and 250, for example, an orifice, a capillary tube, an expansion valve or the like is used. Since the solenoid valve 253 is closed, the refrigerant liquid C does not pass through the solenoid valve 253.
[0066]
Here, the pressure of the refrigerant is reduced before and after the restriction 292. Therefore, the volume flow rate of the refrigerant in the heat transfer tube in the heat exchanger 300, for example, the heat transfer tube 251, is smaller than that in the heat transfer tubes 210A and 210B in the evaporator 210. While the refrigerant is almost gasified at the outlet of the heat transfer tube of the evaporator 210, the refrigerant usually has a two-phase flow in the heat transfer tube of the heat exchanger 300, so that there is a tendency for further difference.
[0067]
However, according to this embodiment, since the number of circuits of the heat exchanger 300 is 1 and the number of circuits of the evaporator 210 is 2, even if the size of the heat transfer tubes constituting both is the same, The difference in the flow rate of the flowing refrigerant can be reduced. Therefore, for example, when the size of the heat transfer tube is selected so that the refrigerant flow rate in the evaporator 210 is an appropriate value, the refrigerant flow rate of the heat exchanger 300 using the heat transfer tube of the same size is also set to an appropriate value. Can do.
[0068]
Refrigerant C evaporated and gasified in the evaporator 210 joins again, passes through the path 204, passes through the ports 701 </ b> A and 701 </ b> B of the four-way valve 711, and is guided to the suction side of the compressor 260 through the path 204-1. Repeat the above cycle.
[0069]
In the figure, the behavior of the refrigerant C in the evaporation section 251 and the condensation section 252 of the heat exchanger 300 will be described. First, liquid phase and gas phase refrigerant C flows into the evaporation section 251. It may be a refrigerant liquid C that is partially vaporized and contains a slight gas phase. While the refrigerant C flows through the evaporation section 251, the processing air A is pre-cooled and is heated to flow into the condensing section 252 while increasing the gas phase. In the condensing section 252, the processing air A having a temperature lower than that of the processing air A in the evaporation section 251 is heated by being cooled and dehumidified, and the heat is taken away to condense the gas-phase refrigerant C. Thus, the refrigerant C flows through the refrigerant flow path while changing the phase between the gas phase and the liquid phase, and the processing air A before being cooled by the evaporator 210 and the evaporator 210 are cooled to lower the absolute humidity. Heat exchange with the processing air A is performed.
[0070]
In the case of the cooling operation that is an extension of the first operation mode, the solenoid valve 253 is closed to open so that the refrigerant C does not drop in pressure before and after the throttle 250, and the dehumidification operation as the first operation mode is performed. Switch operation mode to cooling operation. Also at this time, the expansion valve 713 acts, and the refrigerant flow rate is adjusted so that the superheat degree of the refrigerant evaporated in the evaporator 210 becomes an appropriate value.
[0071]
By doing so, the pressure drop of the refrigerant C before and after the throttle 250 can be made almost zero, and the pressure drop of the refrigerant C excluding the pipe pressure loss can be generated by the expansion valve mechanism 711, and the condensation section 252 of the heat exchanger 300 The pressure of the refrigerant C in the evaporation section 251 becomes substantially equal to the pressure of the refrigerant C in the evaporator 210, and the refrigerant C is evaporated in the condensation section 252 and the evaporation section 251 in addition to the evaporator 210. Therefore, since the heat transfer area of evaporation increases, the cooling capacity, that is, the sensible heat treatment capacity can be increased.
[0072]
In the dehumidifying operation mode, by using the heat exchanger 300 as a reheat heat exchanger for the processing air A before and after passing through the evaporator 210, the amount of condensed moisture due to cooling is increased compared to that in the cooling operation mode, and in the cooling operation mode. It is possible to increase the dehumidifying ability, that is, the latent heat treatment ability. Thus, in the dehumidifying operation mode, the humidity can be lowered more quickly than in the cooling operation mode, and it is possible to cope with a so-called low sensible heat ratio and high humidity indoor air conditioning load.
Furthermore, in the dehumidifying operation mode, the amount of condensed water may be increased from that in the cooling operation mode by reducing the amount of air blown by the blower 102 compared to that in the cooling operation mode. For this purpose, the blower 102 may be driven by a variable speed motor (not shown) so that the increase / decrease control of the rotational speed can be performed.
[0073]
When the dehumidifying air conditioner of the first embodiment is applied to a domestic air conditioner, a dehumidifying operation is performed so that the room is not too cold during the rainy season or at night during the summer, and the environment is comfortable with low humidity. Can be made.
[0074]
As described above, the dehumidifying air conditioner according to the present embodiment has a variable sensible heat ratio of the air conditioning load, and can perform an energy saving operation in any of the dehumidifying operation and cooling operation modes.
[0075]
Next, the operation of the heat pump HP1 in the dehumidifying operation mode will be described with reference to the Mollier diagram of FIG. Note that FIG. 1 is referred to as appropriate for devices and the like. FIG. 3 is a Mollier diagram when the mixed refrigerant HFC407C is used. In this diagram, the horizontal axis is enthalpy and the vertical axis is pressure.
[0076]
In the figure, point a is the state of the refrigerant outlet of the evaporator 210, and the refrigerant C is in a saturated gas state. The pressure is 0.67 MPa, the temperature is 11.2 ° C., and the enthalpy is 414.0 kJ / kg. A state where the gas is sucked and compressed by the compressor 260 and a state at the discharge port of the compressor 260 are indicated by a point b. In this state, the pressure is 1.66 MPa and the state is superheated gas.
[0077]
The refrigerant gas C is cooled in the condenser 220 and reaches a point c on the Mollier diagram. This point is a state of saturated gas, the pressure is 1.66 MPa, and the temperature is 42.9 ° C. Under this pressure, it is further cooled and condensed and reaches point d. This point is a saturated liquid state, the pressure is the same as the point c, the temperature is 38 ° C., and the enthalpy is 256.9 kJ / kg. Since the refrigerant used is a mixed refrigerant, the temperature on the saturated gas line differs from the temperature on the saturated liquid line even when condensing at the same pressure.
[0078]
The refrigerant liquid C is decompressed by the expansion valve mechanism 711 and flows into the evaporation section 251 of the heat exchanger 300. On the Mollier diagram, it is indicated by a point e. The pressure is an intermediate pressure according to the present invention, and in this embodiment, the pressure is an intermediate value between 0.67 MPa and 1.66 MPa. Here, a part of the liquid is evaporated and the liquid and the gas are mixed.
[0079]
In the evaporating section 251, the refrigerant liquid C evaporates under the intermediate pressure, and reaches the intermediate point f between the saturated liquid line and the saturated gas line at the same pressure. Here, a part of the liquid is evaporated, but the refrigerant liquid C remains to some extent.
[0080]
The refrigerant C in the state indicated by the point f flows into the condensation section 252. In the condensing section 252, the refrigerant C is deprived of heat by the low-temperature processing air A flowing through the second section 320 and reaches the point g.
[0081]
The point g is on the saturated liquid line in the Mollier diagram. The temperature is 18 ° C. and the enthalpy is 226.1 kJ / kg.
[0082]
The refrigerant liquid C at point g is depressurized to 0.67 MPa, which is a saturation pressure at a temperature of 5.2 ° C., by the restriction 250 and reaches point j. The refrigerant C at this point j reaches the evaporator 210 as a mixture of the refrigerant liquid C and the refrigerant gas C at 5.2 ° C., where heat is taken from the processing air A and evaporated to a point a on the Mollier diagram. The saturated gas in this state is obtained, and is again sucked into the compressor 260, and the above cycle is repeated. Since the mixed refrigerant is used as in the condenser, the temperature on the saturated gas line is different from the temperature on the saturated liquid line even when evaporation is performed at the same pressure.
[0083]
Therefore, as described with reference to the flow chart of FIG. 1, when the flow of the refrigerant and the processing air is set as a counter flow, the flow of both becomes a counter flow in terms of temperature. That is, the refrigerant temperature when it flows into the evaporator 210 is 5.2 ° C., which is lower than the outflow refrigerant temperature 11.2 ° C. This low temperature refrigerant comes into contact with the process air that is about to exit the evaporator 210. Therefore, the heat exchange efficiency of the evaporator 210 can be increased.
Although the specific temperature is omitted for the heat exchanger 300, the same effect can be obtained by making the flow of the refrigerant and the processing air counterflow (see FIG. 1).
[0084]
As described above, in the heat exchanger 300, the refrigerant C changes in the evaporation state from the point e to the point f in the evaporation section 251, and changes in the condensation state from the point f to the point g1 in the condensation section 252. The heat transfer rate is very high and the heat exchange efficiency is high.
[0085]
Further, as the compression heat pump HP1 including the compressor 260, the condenser 220, the expansion valve mechanism 711, the throttle 250, and the evaporator 210, the refrigerant C in the state of the point d in the condenser 220 when the heat exchanger 300 is not provided. Is returned to the evaporator 210 through the restriction, the difference in enthalpy available in the evaporator 210 is only 414.0-256.9 = 157.1 kJ / kg, whereas the book provided with the heat exchanger 300 In the case of the heat pump HP1 used in the embodiment, 414.0-226.1 = 187.9 kJ / kg, and the amount of gas circulated to the compressor 260 with respect to the same cooling load, and thus the required power as much as 16%. Can be small. That is, it is possible to have the same effect as the subcool cycle.
[0086]
Next, the operation of the heat pump HP1 during the cooling operation mode will be described. Since the process up to point d in the figure is the same as in the dehumidifying operation mode, the description up to point d is omitted. The refrigerant C that has left the condenser 220 passes through the expansion valve mechanism 711. When passing through this restriction, the pressure decreases from 1.66 MPa to 0.67 MPa, and shifts from point d to point j ′ in the figure. The enthalpy at this point j ′ is 256.9 kJ / kg. The refrigerant evaporates in the heat exchanger 300 and the evaporator 210 and reaches the point a.
[0087]
In general, especially in temperate and subtropical climates such as Japan, the maximum value of the dehumidification load (latent heat load) of the air conditioning load is not so different in the midsummer and rainy seasons. On the other hand, the sensible heat load increases remarkably at the time of midsummer such as August. For this reason, as the maximum design load of an air conditioner that combines cooling and dehumidification, the load during midsummer must be adopted.
[0088]
On the other hand, the maximum load in the dehumidifying operation mode is not more than half of the maximum load in the cooling operation mode. For example, if the total load in midsummer is 100, the latent heat load is 30, the total load in the rainy season such as the rainy season is 40, and the latent heat load is 25.
Therefore, the amount of heat to be taken away by the evaporator is much larger in the cooling operation mode than in the dehumidification operation mode. This is because the amount of sensible heat load increases. However, the latent heat load does not change much between the rainy season and the midsummer.
[0089]
According to the embodiment of the present invention, the heat transfer area that can be used as an evaporator in the cooling operation mode is added to the evaporator 210 in addition to the heat exchanger 300, so that sufficient heat transfer can be ensured. Further, in the dehumidifying operation mode, the heat transfer area that can be used as the evaporator is the amount of the evaporator 210 and can be a heat transfer area suitable for the dehumidifying load. The heat exchanger 300 can be used to reheat the so-cooled process air after dehumidification, and at the same time can be used to pre-cool the process air.
[0090]
When viewed from another direction, the heat transfer area of an evaporator having a heat transfer area necessary and sufficient for an air conditioner dedicated to cooling may be divided into three parts, ie, an evaporator 210, an evaporation section 251 and a condensation section 252. That is, a compact and efficient air conditioner for both cooling and dehumidification can be configured by adjusting the refrigerant pipe with the size of the evaporator of the air conditioner dedicated for cooling as it is.
[0091]
For the load ratio as in the Japanese climate, about 40-60% of the heat transfer area of the entire heat exchanger is allocated to the evaporator 210, and the remaining 60-40% of the heat transfer area is condensed with the evaporation section 251. What is necessary is just to distribute to the section 252 according to the amount of heat transfer.
[0092]
In addition, the refrigerant volume flow rate in the heat exchanger 300 is smaller than the refrigerant volume flow rate in the evaporator 210 in both the dehumidifying operation and the cooling operation. According to the present embodiment, the number of circuits of the heat exchanger 300 is 1, which is smaller than the number of circuits 2 of the evaporator. Therefore, the heat exchanger 300 and the evaporator 210 are used during the dehumidifying operation and the cooling operation. The refrigerant flow rates can be set to the same value, and a decrease in heat transfer coefficient can be prevented.
[0093]
Referring to the humid air diagram in the dehumidifying operation mode of the dehumidifying air conditioner 21 shown in FIG. 4 and referring to FIG. 1 as appropriate for the configuration, the dehumidifying air conditioner 21 having the heat pump HP1 is in the dehumidifying operation mode. The operation will be described. In FIG. 4, the state of the air in each part is shown by alphabet symbols K, X, L, and M. This symbol corresponds to the alphabet circled in the flow diagram of FIG.
[0094]
In the figure, the processing air A (state K) from the conditioned space 101 is sent to the first section 310 of the heat exchanger 300 through the processing air path 107, and to some extent by the refrigerant C evaporated in the evaporation section 251 here. To be cooled. This is pre-cooling before being cooled to the dew point temperature (below) by the evaporator 210 and can be called pre-cooling. During this time, while being precooled in the evaporating section 251, water is removed to some extent, and the point X is reached while slightly reducing the absolute humidity. Point X is on the saturation line. Or you may cool to the intermediate point of the point K and the point X in a pre-cooling step. Alternatively, it may be cooled to a point where the point X is slightly shifted to the low humidity side on the saturation line.
[0095]
The precooled process air A is introduced into the evaporator 210 through the path 108. Here, the processing air A is cooled to its dew point temperature (below) by the refrigerant C decompressed by the diaphragm 250 and evaporated at a low temperature, and the dry bulb temperature is lowered while lowering the absolute humidity while depriving moisture. Point L is reached. The thick line indicating the change from the point X to the point L is drawn out of the saturation line for convenience, but actually overlaps the saturation line.
[0096]
The processing air A in the state of the point L flows into the second section 320 of the heat exchanger 300 through the path 109. Here, the refrigerant C condensed in the condensing section 252 is heated to a point M while being kept at a constant absolute humidity. The point M is sucked by the blower 102 and returned to the conditioned space 101 as air having an appropriate relative humidity whose absolute humidity is sufficiently lower than that of the point K and whose dry bulb temperature is not too low.
[0097]
In the heat exchanger 300, the processing air A is pre-cooled by evaporation of the refrigerant C in the evaporation section 251, and the processing air A is reheated by condensation of the refrigerant C in the condensation section 252. The refrigerant C evaporated in the evaporation section 251 is condensed in the condensation section 252. Thus, heat exchange between the processing airs A before and after being cooled by the evaporator 210 is indirectly performed by the evaporation and condensation action of the same refrigerant C.
[0098]
Outside air B is introduced into the condenser 220 through the path 124. The outside air B takes heat from the condensing refrigerant C, and the heated outside air B is sucked into the blower 140 via the path 125 and discharged to the outdoors via the path 126 (EX).
[0099]
Here, in the cycle on the air side shown in the wet air diagram of FIG. 4, the amount of heat that pre-cools the processing air A in the first section 310, that is, the amount of heat ΔH that reheats the processing air A in the second section 320 is the heat. ΔQ is the amount of heat that is recovered and the processing air A is cooled by the evaporator 210. The cooling effect for cooling the air-conditioned space 101 is Δi.
[0100]
The dehumidifying air conditioner 21 according to the first embodiment uses the heat exchanger 300 as an air / air heat exchanger as an evaporator in the cooling operation mode, thereby increasing the heat transfer area of the evaporator and evaporating temperature. To increase the cooling capacity, that is, the sensible heat treatment capacity. As a result, the room temperature can be quickly lowered, and it is possible to cope with a so-called high sensible heat ratio, a dry and high temperature indoor air conditioning load.
[0101]
That is, in the cooling operation mode, in the wet air diagram of FIG. 4, the process air A exiting the conditioned space 101 (FIG. 1) (state K) is the first section 310 (FIG. 1) of the heat exchanger, The process air A cooled in the evaporator 210 (FIG. 1) and the second section 320 (FIG. 1) of the heat exchanger and exiting the second section 320 of the heat exchanger is a point in the vicinity of the point X in the figure. It is in the state represented by. In the cooling operation mode, it is preferable that the amount of air blown from the blower 102 is larger than that in the dehumidifying operation mode. This is because a large amount of sensible heat is easily obtained.
[0102]
The dehumidifying air conditioner 21 of the present embodiment uses the heat exchanger 300 as a reheat heat exchanger for the processing air A before and after passing through the evaporator 210 in the dehumidifying operation mode, thereby reducing the amount of condensed moisture due to cooling to the cooling operation mode. It is possible to increase the dehumidification capacity, that is, the latent heat treatment capacity, from the time. Accordingly, in the dehumidifying operation mode, the humidity can be quickly reduced, and it is possible to cope with a high indoor air conditioning load with a so-called low sensible heat ratio.
[0103]
The dehumidifying air conditioner 21 has a variable sensible heat ratio of the air conditioning load, and can perform an energy saving operation in any of the dehumidifying operation and cooling operation modes.
[0104]
Next, the case where the dehumidifying air conditioner of FIG. 1 is operated in the heating operation mode will be described with reference to the flowchart of FIG. Here, only the devices that are switched in the heating operation mode and the peripheral devices are given the reference numerals, and the other reference numerals are omitted.
[0105]
First, the suction side and the discharge side of the compressor 260 are switched by switching the four-way valve 701. That is, the port 701A of the four-way valve 701 communicates with 701D, and the port 701B communicates with 701C. As a result, the route 204 communicates with the route 201-1 and the route 201 communicates with the route 204-1.
[0106]
Further, the solenoid valve 253 is opened, and the throttle mechanism 292 makes the throttle action substantially zero. Therefore, the first heat exchanger 210 and the third heat exchanger 300 have substantially the same pressure, receive the discharge pressure of the compressor 260, and act as a condenser.
[0107]
The second heat exchanger 220 functions as an evaporator as a result of being connected to the suction side of the compressor 260 via the four-way valve 701.
[0108]
As described above, since the pressure on the third heat exchanger 300 side is higher than that on the second heat exchanger 220 side before and after the expansion valve mechanism 711 as the second throttling mechanism, the check valve 714 is not checked. Does not flow refrigerant. Therefore, the refrigerant condensed in the first heat exchanger 210 and the heat exchanger 300 passes through the check valve 715 of the expansion valve mechanism 711 and is throttled by the expansion valve 712. Since the check valve 715 flows the refrigerant almost without resistance, the expansion valve 713 does not act as an expansion valve.
[0109]
The expansion valve 712 receives a signal (pressure) corresponding to the temperature of the refrigerant in the path 201 from the temperature sensing cylinder 721 and the pressure of the refrigerant in the path 201 through the pressure equalizing pipe 721A.
Since the degree of superheat of the refrigerant in the path 201 is a function of its pressure and temperature, the expansion valve 712 can open and close according to the degree of superheat of the refrigerant by receiving both. That is, when the superheat degree of the refrigerant in the path 201 (refrigerant evaporated by the heat exchanger 220 acting as an evaporator) is high, the refrigerant flow rate is increased in the opening direction, and when the superheat degree is low (the refrigerant is wet). In some cases, the refrigerant flow rate is reduced in the closing direction.
[0110]
In this way, the heat exchanger 220 acts as an evaporator to pump heat from the outside air, and the heat exchanger 210 and the heat exchanger 300 act as a condenser to heat the processing air flowing through the paths 107 to 111. The dehumidifying air conditioner 21 can be used as a heating device for heating the air-conditioned space 101.
The cycle of the refrigerant is the same as the cycle of points a, b, d, j ′, a in FIG. Although the temperature, pressure, and enthalpy are different from those shown in the figure because the outside air temperature is generally lower than that shown in the winter, the operation is the same, and redundant description is omitted.
[0111]
With reference to the flowchart of FIG. 6, the dehumidification air-conditioning apparatus 22 of 2nd Embodiment is demonstrated. The difference from the first embodiment is the configuration of the second aperture mechanism. Here again, the case of dehumidifying operation will be described first.
In the path 201, a pressure detector 732P and a temperature detector 732T constituting the superheat degree detector 732 are provided. This works in heating mode. The path 204 is provided with a pressure detector 733P and a temperature detector 733T constituting the superheat degree detector 733. This operates in a dehumidifying operation mode and a cooling operation mode.
[0112]
An electronic expansion valve 731 is provided in the path 202. The dehumidifying air conditioner 22 includes an expansion valve controller 734. The expansion valve controller 734 is typically a digital controller. It may be a microcomputer or a personal computer installed with control software.
[0113]
The electronic expansion valve 731 is a needle valve provided with a needle driven by, for example, a step motor. The needle is provided at the tip of the screw, and the opening degree can be adjusted by moving the valve seat portion in and out according to the rotation of the stepping motor.
[0114]
The expansion valve controller 734 receives the pressure detected by the pressure detector 732P and the temperature detected by the temperature detector 732T, or the pressure detected by the pressure detector 733P and the temperature detected by the temperature detector 733T. And calculate the degree of superheat, and adjust the electronic expansion valve so that the calculated degree of superheat will be an appropriate value (so that it will be on the saturated gas line on the Mollier diagram, or at least dry) Adjust.
[0115]
In the dehumidifying operation mode and the cooling operation mode, the pressure is detected by the pressure detector 732P based on the pressure detected by the pressure detector 733P and the temperature detected by the temperature detector 733T, and in the heating operation mode. The electronic expansion valve is adjusted based on the detected pressure and the temperature detected by the temperature detector 732T.
Other configurations and operations are the same as those of the first embodiment, and thus redundant description is omitted.
[0116]
In the above embodiment, the return air from the conditioned space 101 is introduced into the first section 310, but outside air may be introduced without introducing the return air from the conditioned space 101. . The outside air having high humidity and temperature is preferably pre-cooled before being cooled by the evaporator 210. With this configuration, air conditioning in hospitals and restaurants that require the entire amount of outside air can be performed with a high COP.
[0117]
In the above embodiment, the dehumidifying air-conditioning apparatus that air-conditions the air-conditioned space has been described. The dehumidifying air conditioner of the present invention includes such a case.
[0118]
【The invention's effect】
As described above, according to the present invention, since the switching mechanism is provided, it is possible to provide a heat pump capable of switching between the first operation mode and the second operation mode.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a flow of a dehumidifying operation mode of a dehumidifying air conditioner according to a first embodiment of the present invention.
FIG. 2 is a schematic side view showing the installation state of the dehumidifying air conditioner shown in FIG. 1 and a perspective view of the heat exchanger.
FIG. 3 is a Mollier diagram of a heat pump of the dehumidifying air conditioner shown in FIG. 1;
4 is a moist air diagram illustrating the operation of the dehumidifying air conditioner of FIG. 1 in the dehumidifying operation mode.
FIG. 5 is a flowchart showing a flow of a heating operation mode of the dehumidifying air conditioner according to the first embodiment of the present invention.
FIG. 6 is a flowchart showing a flow of a dehumidifying operation mode of the dehumidifying air conditioner according to the second embodiment of the present invention.
FIG. 7 is a flowchart of a conventional dehumidifying air conditioner.
[Explanation of symbols]
21 and 22 Dehumidifying air-conditioning apparatus 101 Air-conditioned space 102 and 140 Blower 210 Evaporator 220 Condenser 251 Evaporating section 252 Condensing section 250 Constriction 253 Solenoid valve 260 Compressor 711 Second throttling mechanism 292 First throttling mechanism 300 Heat exchanger 310 First compartment 320 Second compartment 701 Four-way valve 711 Expansion valve mechanism 712, 713 Expansion valve 714, 715 Check valve 721, 722 Temperature sensing cylinder 731 Electronic expansion valve 732T, 733T Temperature detector 732P, 733P Pressure detector HP1 Heat pump

Claims (4)

A booster for boosting the refrigerant;
A switching mechanism for switching between the first operation mode and the second operation mode;
A first heat exchanger that evaporates the refrigerant in the first operation mode to cool the first fluid and condenses the refrigerant in the second operation mode to heat the first fluid;
A second heat exchanger for condensing the refrigerant in the first operation mode to heat the second fluid and evaporating the refrigerant in the second operation mode to cool the second fluid;
Provided in a refrigerant path connecting the first heat exchanger and the second heat exchanger, and in the first operation mode, the condensation pressure of the second heat exchanger and the first heat exchange. Evaporating and condensing the refrigerant at a pressure intermediate to the evaporation pressure of the vessel, cooling the first fluid by the intermediate pressure evaporation, heating the first fluid by the intermediate pressure condensation, and the second A third heat exchanger that condenses the refrigerant and heats the first fluid at a pressure substantially equal to the condensation pressure of the first heat exchanger in an operation mode;
A first throttling mechanism provided in the refrigerant path between the third heat exchanger and the first heat exchanger, the throttling degree being switchable;
A second throttle mechanism provided in the refrigerant path between the second heat exchanger and the third heat exchanger;
In the first operation mode, the first fluid performs cooling in the third heat exchanger, cooling in the first heat exchanger, and heating in the third heat exchanger. Configured to receive in order ;
The third heat exchanger includes a first section in which the refrigerant performs the intermediate pressure evaporation and a second section in which the intermediate pressure condensation is performed in the first operation mode. In the mode, the refrigerant meanders a plurality of times in the first compartment and then meanders a plurality of times in the second compartment before going to the first heat exchanger;
The first heat exchanger is disposed between the first compartment and the second compartment;
heat pump. A booster for boosting the refrigerant;
A switching mechanism for switching between the dehumidifying operation mode and the heating operation mode;
A first heat exchanger that evaporates the refrigerant in the dehumidifying operation mode to cool the processing air to a dew point temperature and condenses the refrigerant in the heating operation mode to heat the processing air;
A second heat exchanger for condensing the refrigerant in the dehumidifying operation mode to heat the heat source fluid and evaporating the refrigerant in the heating operation mode to cool the heat source fluid;
Provided in a refrigerant path connecting the first heat exchanger and the second heat exchanger, and in the dehumidifying operation mode, the condensation pressure of the second heat exchanger and the first heat exchanger The refrigerant is evaporated and condensed at a pressure intermediate to the evaporation pressure, the processing air is cooled by the intermediate pressure evaporation, the processing air is heated by the intermediate pressure condensation, and the first heat is heated in the heating operation mode. A third heat exchanger that condenses the refrigerant and heats the process air at approximately the same pressure as the condensation pressure of the exchanger;
A first throttling mechanism provided in the refrigerant path between the third heat exchanger and the first heat exchanger, the throttling degree being switchable;
A second throttle mechanism provided in the refrigerant path between the second heat exchanger and the third heat exchanger;
In the dehumidifying operation mode, the processing air is subjected to cooling in the third heat exchanger, cooling in the first heat exchanger, and heating in the third heat exchanger in this order. Composed of ;
In the dehumidifying operation mode, the third heat exchanger includes a first section in which the refrigerant performs the intermediate pressure evaporation and a second section in which the intermediate pressure condensation is performed. Is configured to meander multiple times in the first compartment and then meander multiple times in the second compartment before heading to the first heat exchanger;
The first heat exchanger is disposed between the first compartment and the second compartment;
Dehumidifying air conditioner. A first superheat detector for detecting the superheat of the refrigerant exiting the first heat exchanger in the dehumidifying operation mode;
A second superheat degree detector for detecting the superheat degree of the refrigerant exiting the second heat exchanger in the heating operation mode;
The second throttle mechanism increases or decreases the throttle degree based on the detection result of the first superheat degree detector in the dehumidifying operation mode, and the detection result of the second superheat degree detector in the heating operation mode. Having an expansion valve to increase or decrease the degree of throttling based on;
The dehumidifying air conditioner according to claim 2.   The first throttle mechanism can reduce a throttle degree between the first heat exchanger and the third heat exchanger to substantially zero, according to claim 2 or claim 3. Dehumidification air conditioner of description.

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