TW201640065A - Method and device for recovering and saving energy through direct expansion - Google Patents

Abstract

The present invention relates to a method and a device for recovering and saving energy through direct expansion, which generally comprise a complete refrigeration cycle including a compression process of a compressor, a condensation process of a condenser, a restrain process of an expansion valve, and an evaporation process of an evaporator and are characterized in that a heat dissipation process of the condensation process of the condenser involves at least two condensers connected in cascade, wherein a required heat dissipation amount of the second condenser is in proportional control of the heat dissipation amount of the first condenser in order to precisely control the required heat dissipation amount of the second condenser; a heat absorption process of the evaporation process of the evaporator involves at least two evaporators connected in cascade, wherein the required heat absorption amount of the second evaporator is in proportional control of the heat absorption amount of the first evaporator in order to precisely control the required heat absorption amount of the second evaporator. The present invention simultaneously achieves functions of cooling, dehumidification, re-heating, and humidification through heat recovery by simply activating the compressor.

Description

Direct expansion heat recovery energy saving method and device

The invention belongs to the technical field of air conditioners, and particularly relates to a direct expansion multiple heat recovery energy-saving method and device, which is particularly suitable for application in a place where temperature and humidity control are required. The invention only needs to start a compressor, and by heat recovery, it can simultaneously With cooling, dehumidification, reheat and humidification.

China is an island-type climate. In most of the year, most of the days are wet weather. Various industries have realized the importance of temperature control and humidity control in order to achieve product quality improvement or develop high-tech technology. . Along with the progress of the times, various industries seek to achieve product quality improvement or develop high-tech technology, and their working environment needs to be in a state of constant temperature and humidity, and many electronic devices installed in the data center are provided with circuit boards. And electronic components, if the surrounding environment of the data center is too dry, the static electricity is easily generated between the circuit board and the electronic components, or the surrounding environment is too humid, and the circuit board and electronic components are prone to rust in the environment for a long time. Therefore, high-efficiency constant temperature and humidity air conditioning equipment must be installed in data centers or other working environments.

Generally, the constant temperature and humidity air conditioning equipment processes the air by passing the indoor air through the cooling and dehumidifying coil, so that the air is simultaneously cooled and dehumidified, until the dew point temperature lower than the indoor air temperature and humidity is reached, and then the air is sent to the room. The indoor air temperature and humidity are simultaneously reduced. However, during operation, the indoor air temperature is easier to reach the set point than the humidity first. In order to maintain the temperature Constant, while the cooling dehumidification coil can continue to dehumidify, so after the air passes through the cooling dehumidification coil, the heater is set to heat the air, so that the indoor air temperature is kept constant until the indoor air humidity reaches the set point, then the cooling and dehumidification coil is controlled to be lowered. The energy, but the use of electric heat as a reheat device, its cost is low, but the running electricity bill is very wasteful. That is to say, the compressor of the conventional direct expansion constant temperature and humidity system has only the cooling and dehumidifying functions, and the reheating and humidifying functions must be replaced by an electric heater and an electric humidifier.

Moreover, the heat dissipation (or heat absorption) of the conventional heat exchanger controls the heat exchange. The flow of refrigerant or air (or water) to achieve the required heat transfer, or temperature and humidity conditions, for example, to control the flow and temperature difference of the primary side fluid (refrigerant) of the heat exchanger to achieve the desired heat Exchange volume (high or low temperature), or control the flow rate and temperature difference of the secondary side fluid (water or air) of the heat exchanger to achieve the required heat exchange rate (high temperature or low temperature). However, because the compressor refrigerant discharges high-pressure gas is high-pressure gas, first, the flow rate is difficult to control, and second, when controlling the refrigerant flow rate and pressure change, it will indirectly affect the operation of the compressor.

Because the refrigerant system is not easy to control, there is a secondary refrigerant system, for example, freezing The brine system, the air conditioning ice water system or the hot water system uses secondary refrigerant as cooling, dehumidification and heating, but the system is more complicated and bulky. That is, the conventional heat exchanger heats (or absorbs heat) to control the temperature difference of the flow of the primary side fluid (secondary refrigerant such as brine, ice water or hot water) to achieve the required heat transfer, or temperature. , humidity conditions, for which it is missing.

In view of the lack of the aforementioned conventional techniques, the inventor of the present case actually worked on the space for many years. After the continuous research and improvement, the professional knowledge of the design and construction of the product has been successfully developed and published in the world.

The main purpose of the present invention is to provide a direct expansion heat recovery energy-saving method. The utility model mainly comprises a compression process of a compressor, a condensation process of the condenser, a throttling process of the expansion valve and a complete refrigeration cycle of the evaporation process of the evaporator, and the heat dissipation process of the condensation process of the condenser of the invention is connected in series by at least two condensers. The amount of heat required for the second condenser is not to control the flow temperature difference of the primary side fluid (refrigerant) of the second condenser, but to proportionally control the amount of heat dissipated by the first condenser to precisely control the required amount of the second condenser. The amount of heat dissipated, the second condenser is used as a heat recovery heater or humidifier, and does not affect the normal operation of the compressor.

The endothermic process of the evaporator evaporation process of the present invention is characterized by at least two evaporator strings Further, the amount of heat absorbed by the second evaporator is not the temperature difference of the flow rate of the primary side fluid (refrigerant) of the second evaporator, but the amount of heat absorbed by the first evaporator is proportionally controlled to precisely control the second evaporator. The heat absorption, the second evaporator is used for cooling and dehumidification purposes. When the capacity is lower than the heat recovery heater, the system has a high temperature heating effect and does not affect the normal operation of the compressor.

Another main object of the present invention is to provide a direct expansion heat recovery energy-saving device, the main A complete refrigeration cycle is constructed by connecting a compressor, a condenser, an expansion valve, and an evaporator, wherein the condenser is composed of a first condenser and a second condenser connected in series.

In the evaporator of the present invention, the first evaporator and the second evaporator are connected in series.

The present invention further includes a third condenser and a fourth condenser connected in series, and the third condenser and the fourth condenser connected in series are connected to the first condenser and the second condenser in series. Parallel, and equipped with a solenoid valve (S) to control the start heat recovery heating or heat recovery humidification function.

The fourth condenser of the present invention is a humidifier.

The humidifier of the present invention comprises an external water source control device for controlling the humidification water level, the high temperature refrigerant pipe connecting the heat recovery high temperature refrigerant, heating the humidified water, generating moisture, and compressing The air line is connected to the air compressor, and the compressed air is used to generate air bubbles to increase the contact area between the air and the water, thereby increasing the amount of humidification.

The present invention further includes a second compressor that is connected to the compressor and connected back to the original refrigeration cycle.

(COM)‧‧‧Compressors

(COM2)‧‧‧Second compressor

(CON)‧‧‧Condenser

(CON1)‧‧‧1st condenser

(CON2)‧‧‧2nd condenser

(CON3)‧‧‧3rd condenser

(CON4) ‧ ‧ 4th condenser

(EXP)‧‧‧Expansion valve

(EVP)‧‧Evaporator

(EVP1)‧‧‧1st evaporator

(EVP2)‧‧‧2nd evaporator

(HC) ‧ ‧ reheat coil

(CC)‧‧‧Cooling coil

(S)‧‧‧ solenoid valve

(HR)‧‧‧Humidifier

(HRA)‧‧‧External water source control unit

(HRB)‧‧‧High temperature refrigerant piping

(HRC)‧‧‧Compressed air lines

(HRD)‧‧ Air compressor

(1) ‧‧‧ body

(10) ‧‧‧Device space

(11) ‧ ‧ constant temperature and humidity space in the cabinet

(2) ‧ ‧ ‧ outside the cabinet constant temperature and humidity space

(SF)‧‧‧Air blower

(SA)‧‧‧Air outlet

(RA) ‧‧‧ return air outlet

1 is a conventional basic refrigeration cycle pressure diagram; FIG. 2 is a refrigeration cycle pressure diagram of the present invention; FIG. 3 is a schematic view of a first embodiment of the present invention; and FIG. 4 is a schematic view of a second embodiment of the present invention. Figure 5 is a schematic view of a device according to a third embodiment of the present invention; Figure 6 is a schematic view of a humidifier of the present invention; Figure 7 is a schematic view of a device of a fourth embodiment of the present invention; and Figure 8 is a schematic view of a device of a fifth embodiment of the present invention. Fig. 9 is a schematic view showing the fifth embodiment of the present invention applied to an industrial space.

The invention relates to a direct expansion heat recovery energy-saving method and device, which only needs to start the compressor, and has the functions of cooling, dehumidification, reheating and humidification by heat recovery.

1. Compression process ab (compressor) W _c = G × ( h _b - h _a )

2. Condensation process bc (condenser) Q _c = G × ( h _b - h _c )

3. Throttling process cd (expansion valve) h _d = h _c

4. Evaporation process da (evaporator) Q _e = G × ( h _a - h _d )

Operating balance of the compressor Q _c = Q _e + W _c

If Qc and Qe are unbalanced, the compressor will trip due to high and low voltage abnormalities.

Formula symbol description: W _c = compressor power KJ / S (KW)

G=refrigerant mass flow rate KG/S

h=refrigerant value KJ/KG

Q _c = heat dissipation per unit time of the condenser KJ/S (KW)

Q _e = heat absorption per unit time of the evaporator KJ/S (KW)

Please refer to the frozen cycle pressure map of the present invention in FIG. 2, which can be seen from the following figures:

1. Compression process ab (compressor) W _c = G × ( h _b - h _a )

2. Condensation process bc (condenser) Q _c = Q _{c 1} + Q _{c 2}

Q _{c 1} =G(h _b -h _X )= G _{f 1} × C _{f 1} ×△ T ₁

Q _{c 2} =Q _c -Q _{c 1} =Q _c - G _{f 1} ×C _{f 1} ×△ T ₁

Note: Qc=constant under fixed conditions, so the value of Qc1 can be precisely controlled by precisely controlling the value of Qc1.

3. Throttling process cd (expansion valve) h _d = h _c

4. Evaporation process da (evaporator) Q _c = Q _{e 1} + Q _{e 2}

Q _{e 1} =G(h _r - h _d )= G _{f 2} ×C _{f 2} ×△ T ₂

Q _{e 2} =Q _e -Q _{e 1} =Q _e - G _{f 2} ×C _{f 2} ×△ T ₂

Qe = constant under fixed conditions, so precise control of the value of Qe1 can accurately control the value of Qe2.

Operating balance of the compressor Q _c = Q _e + W _c

(Q _{c 1} +Q _{c 2} )=( Q _{e 1} + Q _{e 2} )+ W _c

Qc1 and Qc2, Qe1 and Qe2 form a complementary relationship, so the total amount of Qc,

Qe and Wc are easy to balance, and it is not easy to cause high and low pressure abnormalities of the compressor and tripping.

Formula symbol description: W _c = compressor power KJ / S (KW)

G=refrigerant mass flow rate KG/S

h=refrigerant value KJ/KG

Q _c = total heat dissipation per unit time of the condenser KJ/S (KW)

Q _{c 1} = heat dissipation per unit time of the condenser KJ/S (KW)

Q _{c 2} = heat dissipation of the condenser 2 unit time KJ/S (KW)

G _{f 1} = mass flow rate KG/S of the secondary side fluid (water or air) of the condenser 1

C _{f 1} = condenser 1 secondary side fluid (water or air) specific heat KJ / KG ° C

ΔT ₁ = temperature difference of the secondary side fluid (water or air) of the condenser 1 °C

Q _e = total heat absorption per unit time of the evaporator KJ/S (KW)

Q _{e 1} = total heat absorption per unit time of the evaporator 1 KJ/S (KW)

Q _{e 2} = total heat absorption per unit time of evaporator 2 KJ/S (KW)

G _{f 2} = secondary flow (water or air) mass flow rate KG/S of evaporator 1

C _{f 2} = evaporator 1 secondary side fluid (water or air) specific heat KJ / KG ° C

ΔT ₂ = temperature difference of the secondary side fluid (water or air) of the evaporator 1 °C

The heat dissipation process of the present invention is connected in series with at least two condensers (CON1~2) to control the amount of heat dissipation (Qc2) required by the second condenser, instead of controlling the flow temperature difference of the primary side fluid (refrigerant) of the second condenser, It is proportionally controlling the heat dissipation amount (Qc1) of the first condenser, that is, forming the X point on the heat dissipation process line on the second drawing, so that the X point can be moved left and right, thereby achieving the precise heat required for controlling the second condenser. The quantity (Qc2), that is to say the total amount of heat dissipation in the condensation cycle condensation process is limited (under fixed conditions), the total amount of heat dissipation - heat dissipation = the required heat dissipation amount, ie Q _c -Q _{c 1} =Q _{c 2} .

Endothermic process of the present invention at least two evaporators (EVP1 ~ 2) connected in series, the heat absorption (Q _{e 2)} required for the second evaporator, the second evaporator instead of controlling the primary-side fluid (refrigerant) flow temperature, Rather, proportionally control the heat absorption (Q _{e 1} ) of the first evaporator, that is, form a Y point on the endothermic process line on the second drawing, so that the Y point can be moved left and right, thereby achieving precise control of the second evaporator. The required heat absorption (Q _{e 2} ), that is to say the total amount of heat absorption in the freezing cycle evaporation process is limited (under fixed conditions), the total heat absorption - the heat absorption = the required heat absorption, ie Q _e -Q _{e 1} = Q _{e 2} .

It can be seen from the above description that the direct expansion heat recovery energy-saving method of the present invention mainly includes a compression process of a compressor, a condensation process of a condenser, a throttling process of an expansion valve, and steaming of an evaporator. In the process of complete refrigeration cycle, the heat dissipation process of the condenser condensation process of the present invention is performed by connecting at least two condensers in series, and the heat dissipation amount of the second condenser is proportionally controlling the heat dissipation amount of the first condenser to accurately control The amount of heat required by the second condenser, the second condenser is used as a heat recovery heater or humidifier, and does not affect the normal operation of the compressor, and the heat absorption process of the evaporator evaporation process is at least 2 The evaporators are connected in series, and the heat absorption required by the second evaporator is proportionally controlled to absorb the heat absorbed by the first evaporator to precisely control the heat absorption required for the second evaporator, and the second evaporator is used for cooling and dehumidification purposes. When the capacity is lower than the heat recovery heater, the system has a high temperature heating effect and does not affect the normal operation of the compressor.

In order to achieve the technical means for achieving the aforementioned objects of the present invention, the embodiments are enumerated and cooperated. BRIEF DESCRIPTION OF THE DRAWINGS As will be appreciated by the reviewing committee, the structure, features and effects achieved by the present invention will be better understood.

The invention relates to a direct expansion heat recovery energy-saving device, which is to improve the traditional direct expansion thermostat The shortcomings of the constant humidity system, the compressor of the traditional direct expansion constant temperature and humidity system only has the function of cooling and dehumidification, and the electric heating heater and the electric humidifier must be used for the reheating and humidifying functions. The invention only needs to start the compressor, and by heat recovery, it can simultaneously have the functions of cooling, dehumidification, reheating and humidification.

The heat exchanger mentioned in the specification of the present invention mainly refers to a compressor COM (COMPRESSOR) refrigeration cycle refrigerant refrigeration, in the basic refrigeration cycle, only the name of evaporator EVP (EVAPERATOR), condenser CON (CONDENSER), but the present invention puts the evaporator and condenser in different positions , has a different name, but its main function (hot swap) is still the same. For example, the cooling coil CC (COOLING COIL) is also an evaporator (EVP), the reheat coil HC (HEATING COIL) is also a condenser (CON), and the humidifier HR (HUMIDIFIER) is also a condenser (CON).

The heat exchanger described in the specification of the present invention is described in an air-cooled manner, that is, a refrigerant and The air is heat exchanged. However, if the partial or full replacement is water-cooled, that is, the refrigerant exchanges heat with water, all functions and principles are also applicable.

The air-cooled fan described in the specification of the present invention is mostly an axial flow type wind Machine description. However, if partial or full replacement is made with a centrifugal fan, all functions and principles are also applicable.

Please refer to FIG. 3, which shows that the embodiment is mainly composed of a compressor. (COM), condenser (CON), expansion valve (EXP) [expansion valve EXPANSION VALVE] and evaporator (EVP) are connected to form a complete refrigeration cycle, characterized in that the condenser (CON) is composed of a first condenser (CON1) and the second condenser (CON2) are connected in series. The amount of heat required to control the second condenser (CON2) is proportionally controlled to control the amount of heat dissipated by the first condenser (CON1) to accurately control the amount of heat required for the second condenser (CON2), and the second condenser It is used as a heat recovery heater and does not affect the normal operation of the compressor. That is to say, only the compressor needs to be started, and by heat recovery, the cooling, dehumidification and heating functions can be simultaneously performed. It is suitable for industries that require low-humidity constant temperature (low temperature), such as food low-temperature drying processes, warehouses, etc. The second condenser (CON2) of the present invention may be a reheat coil (HC), and the evaporator (EVP) may be a cooling coil (CC).

Referring to Figure 4, the aforementioned evaporator (EVP) is made up of the first evaporator. (EVP1) and the second evaporator (EVP2) are connected in series. In this embodiment, the amount of heat required to control the second condenser (CON2) is proportionally controlled to control the amount of heat dissipated by the first condenser (CON1) to accurately control the amount of heat required for the second condenser (CON2). 2 The condenser is used as a heat recovery heater, and does not affect the normal operation of the compressor. The heat absorption required by the second evaporator proportionally controls the heat absorption of the first evaporator to precisely control the second evaporation. The heat absorption required by the device, the second evaporator is used for cooling and dehumidification purposes, and when the capacity is lower than the heat recovery heater, the system has a high temperature heating effect, and It will not affect the normal operation of the compressor. That is to say, only the compressor needs to be started, and by heat recovery, the cooling, dehumidification and heating functions can be simultaneously performed. It is suitable for industries that require low-humidity temperature (higher temperature), such as food low-temperature drying process. The second evaporator (EVP2) of the present invention is a cooling coil (CC).

Referring to Figure 5, the present invention further includes a third condenser connected in series. (CON3) and a fourth condenser (CON4), the third condenser (CON3) and the fourth condenser (CON4) connected in series are further connected to the first condenser (CON2) and the second condenser (CON2) Two serial circuits are connected in parallel, and a solenoid valve (S) [SOLENOID VALVE] is provided to control the start of heat recovery heating or heat recovery humidification. That is to say, only the compressor needs to be started, and by heat recovery, it can simultaneously have the functions of cooling, dehumidification, heating and humidification. Applicable to the computer room, electronic constant temperature and humidity machine, dewaxing casting shell mold drying process, etc., which requires constant temperature and humidity.

The fourth condenser (CON4) of the present invention is a humidifier (HR), see Fig. 6. As shown, the humidifier (HR) includes an external water source control unit (HRA) to control the humidification water level, a high temperature refrigerant line (HRB) to connect the heat recovery high temperature refrigerant, heat humidification water, generate moisture, and compress air. The pipeline (HRC) is connected to a air compressor (HRD), which uses compressed air to generate air bubbles to increase the contact area between air and water and increase the amount of humidification.

The calculation of the humidification amount of the heat recovery humidifier of the present invention: in an open water tank, the evaporation of water from the water surface depends on the saturation humidity ratio corresponding to the water temperature, the humidity ratio in the air, and the contact area of the air and water ( The water level and the water surface), and the velocity of the air above the surface. The amount of water evaporated can be expressed as: G _h = ( θA ₁ + C ₃ A ₂ ) (X _s - X ) Formula Description: G _h = amount of water evaporated per hour (kg/hr)

θ = (C1 + C2 V) = evaporation coefficient (kg / m ² h)

C1 = constant (no unit) under fixed conditions

C2 = constant (no unit) under fixed conditions

C3 = constant (kg/m ² h) under fixed conditions

V = the speed of the air above the water surface (m / s)

A1=contact area of air and water on the horizontal plane (m ² )

A2 = contact area of microbubble air with water in the horizontal plane (m ² )

X _s = humidity ratio of saturated air water at this water temperature (kg/kg)

X = humidity ratio in air (kg/kg)

note! The units θ, C3 do not match because this is an empirical formula - the result of the experiment.

Referring to Fig. 7, the present invention further includes a second compressor (COM2) connected in parallel with the compressor (COM) and connected back to the original refrigeration cycle. In this embodiment, the water-cooled double-compressor heat recovery device, that is, only needs to start the compressor, and has the functions of cooling, dehumidification, heating and humidification by heat recovery. Applicable to the computer room, electronic constant temperature and humidity machine, dewaxing casting shell mold drying process, etc., which requires constant temperature and humidity.

Referring to Figure 8, the present invention further includes a third condenser connected in series. (CON3) and a fourth condenser (CON4), the third condenser (CON3) and the fourth condenser (CON4) connected in series are further connected to the first condenser (CON2) and the second condenser (CON2) Two serial circuits are connected in parallel, and a solenoid valve (S) [SOLENOID VALVE] is provided to control the start of heat recovery heating or heat recovery humidification. That is to say, only the compressor needs to be started, and by heat recovery, it can simultaneously have the functions of cooling, dehumidification, heating and humidification. Applicable to computer room, electronic constant temperature and humidity machine, sauna oven space, dewaxing casting shell mold drying process, etc. Need constant temperature and humidity industry.

The actual application of the present invention is applied to an industrial space. Taking Figure 9 as an example, the present invention is further packaged. Including the organism (1), the body (1) is separated by a device space (10) and a constant temperature and humidity space (11) in the cabinet to set the foregoing components of the present invention, and further includes a constant temperature and humidity space outside the cabinet (2). The constant temperature and humidity space (11) in the cabinet is provided with a blower fan (SF) to connect the air outlet (SA) of the constant temperature and humidity space outside the cabinet (2), and the constant temperature and humidity space outside the cabinet (2) another return air inlet (RA) link The constant temperature and humidity space (11) in the cabinet is used in various industries.

The invention directly recovers the high temperature of the refrigerant accurately into the temperature and humidity required by the system. Condition, completely replace the electric heater or electric humidifier currently used in the market. There may be other different heat recovery methods on the market (such as heat storage heat pump heat recovery), but the system of the invention is simple, stable and simple to control, and is the best choice for a direct-expanding constant temperature or constant humidity system.

The foregoing embodiments of the present invention are only for convenience of understanding, and the above only describes a single-segment compression list. The most basic circulation system for segment expansion, if applied to multiple compressor parallel systems, multi-stage compressor systems, refrigerant circuit parallel systems, multi-stage expansion systems or multi-element refrigerant systems, the above working principles are also applicable, and will not be repeated here.

In summary, the present invention discloses a "direct expansion heat recovery energy-saving method and equipment It has never been seen in the past, and it has never been seen in public publications at home and abroad. The invention can indeed eliminate the lack of customary technology and achieve the design purpose. It has also fully complied with the patent requirements and submitted an application according to law. I would like to ask your review committee to give a review and give the patent in this case.

However, the above description is only a preferred embodiment of the present invention, and is not To the extent that the scope of the present invention is limited, any alternatives or equivalent structural changes made by the skilled artisan to the invention and the scope of the invention are intended to be included in the scope of the invention.

(COM)‧‧‧Compressors

(CON)‧‧‧Condenser

(CON1)‧‧‧1st condenser

(CON2)‧‧‧2nd condenser

(CON3)‧‧‧3rd condenser

(CON4) ‧ ‧ 4th condenser

(EXP)‧‧‧Expansion valve

(EVP)‧‧Evaporator

(EVP1)‧‧‧1st evaporator

(EVP2)‧‧‧2nd evaporator

(HC) ‧ ‧ reheat coil

(CC)‧‧‧Cooling coil

(S)‧‧‧ solenoid valve

(HR)‧‧‧Humidifier

Claims (10)

The utility model relates to a direct expansion heat recovery energy-saving method, which mainly comprises a compression process of a compressor, a condensation process of a condenser, a throttling process of an expansion valve and a complete refrigeration cycle of an evaporation process of the evaporator, characterized in that: heat dissipation of the condensation process of the condenser The process is connected in series with at least two condensers, and the amount of heat required by the second condenser is proportionally controlled to control the amount of heat dissipated by the first condenser to precisely control the amount of heat required for the second condenser, and the second condenser is configured. It is used for heat recovery heaters or humidifiers and does not affect the normal operation of the compressor. The utility model relates to a direct expansion heat recovery energy-saving method, which mainly comprises a compression process of a compressor, a condensation process of a condenser, a throttling process of an expansion valve and a complete refrigeration cycle of an evaporation process of the evaporator, characterized in that the heat absorption of the evaporator evaporation process The process is connected in series with at least two evaporators, and the heat absorption required by the second evaporator proportionally controls the heat absorption amount of the first evaporator to precisely control the heat absorption amount required for the second evaporator, and the second evaporator performs For cooling and dehumidification purposes, when the capacity is lower than the heat recovery heater, there is a high temperature heating effect, and will not affect the normal operation of the compressor. For example, in the direct expansion heat recovery energy saving method described in claim 1, the endothermic process of the evaporator evaporation process is connected in series by at least two evaporators, and the heat absorption required by the second evaporator is proportionally controlled. The heat absorption of the evaporator to precisely control the heat absorption required by the second evaporator, and the second evaporator is used for cooling and dehumidification purposes, and when the capacity is lower than the heat recovery heater, there is a high temperature heating effect, and It will not affect the normal operation of the compressor. The utility model relates to a direct expansion heat recovery energy-saving device, which is mainly composed of a compressor, a condenser, an expansion valve and an evaporator to form a complete refrigeration cycle, wherein the condenser is composed of a first condenser and a second condenser. The amount of heat required to control the second condenser is proportionally controlled to control the amount of heat dissipated by the first condenser to accurately control the amount of heat required for the second condenser, and the second condenser is used for heat recovery. The heater is used without affecting the normal operation of the compressor. The direct expansion heat recovery energy-saving device according to claim 4, wherein the evaporator is composed of a first evaporator and a second evaporator, and the heat absorption required for the second evaporator is proportionally controlled. The heat absorption of the first evaporator is used to precisely control the heat absorption required by the second evaporator, and the second evaporator is used for cooling and dehumidification purposes. When the capacity is lower than that of the heat recovery heater, there is a high temperature heating effect. And will not affect the normal operation of the compressor. The direct expansion heat recovery energy-saving device according to claim 4, further comprising a third condenser and a fourth condenser connected in series, wherein the third condenser and the fourth condenser in series are connected in series The first condenser and the second condenser are connected in parallel in parallel with each other, and a solenoid valve is provided to control the start heat recovery heating or the heat recovery humidification function. The direct expansion heat recovery energy-saving device according to claim 6, wherein the fourth condenser is a humidifier. The direct expansion heat recovery energy-saving device according to claim 7, wherein the humidifier comprises an external water source control device to control the humidification water level, the high-temperature refrigerant pipeline is connected to the heat recovery high-temperature refrigerant, and the humidification water is heated. The moisture is generated, and the compressed air pipeline is connected to the air compressor, and the compressed air is used to generate air bubbles to increase the contact area between the air and the water, and increase the humidification amount. The direct expansion heat recovery energy-saving device according to claim 6, further comprising a second compressor connected to the compressor and connected to the original refrigeration cycle. The direct expansion heat recovery energy-saving device according to claim 5, further comprising a third condenser and a fourth condenser connected in series, wherein the third condenser and the fourth condenser in series are further The serially connected first condenser and the second condenser are connected in parallel in parallel with each other, and a solenoid valve is provided to control the start heat recovery heating or the heat recovery humidification function.