A six-pipe central fresh air handling unit chilled water supply system

Abstract

The utility model relates to a kind of six-tube centralized fresh air handling unit chilled water supply system, its innovation lies in: including air-cooled water source, water-cooled water source and six-tube centralized fresh air handling unit, six-tube centralized fresh air handling unit includes hot coil and high temperature, low temperature cold water coil, the hot water outlet and hot water return water mouth of air-cooled water source are connected with the hot water inlet and outlet of hot coil respectively, the low temperature cold water outlet and low temperature cold water return water mouth of air-cooled water source are connected with the low temperature cold water inlet and low temperature cold water outlet of low temperature cold water coil respectively, the high temperature cold water outlet and high temperature cold water return water mouth of water-cooled water source are connected with the high temperature cold water inlet and high temperature cold water outlet of high temperature cold water coil respectively, in summer, the air-cooled water source and water-cooled water source work simultaneously, in transition season, the air-cooled water source works.The utility model accesses two different chilled water systems, realizes single chilled water system in transition season, and two different chilled water systems cooperation mode in summer, to achieve the purpose of energy saving and cost reduction.

Description

Technical Field

[0001] This utility model relates to a chilled water supply system, specifically a chilled water supply system for a six-pipe centralized fresh air unit suitable for the operating room. Background Technology

[0002] Currently, the hospital's operating department relies on a four-pipe centralized fresh air handling unit to deeply dehumidify fresh air in summer and preheat it in winter. The main pipeline switching allows for water-cooled cooling in summer and air-cooled cooling in the transitional seasons. An example illustrating the chilled water energy consumption of this type of fresh air handling unit is provided below:

[0003] In summer, fresh air is pre-treated to 10°C. This dry fresh air is then supplied to the recirculation unit, which operates in dry condition (without condensation), handling the entire indoor humidity load. To bring the fresh air to 10°C, the fresh air unit requires two stages of treatment. The first stage involves the chilled water coil reducing the outdoor 34.4°C hot air to 14°C. The second stage uses the refrigerant coil to further reduce the 14°C fresh air to 10°C. For the chilled water coil to complete the first stage of treatment, a 7°C chilled water source is needed, with a 12°C return water source. During this time, the hot water coil is closed.

[0004] During the transitional season, 7°C cold water is supplied by an air-cooled water source, and 12°C return water is supplied. At this time, the outdoor temperature is 12-22°C, and the working conditions are the same as in summer.

[0005] In winter, the fresh air is preheated by the hot water coil before being sent to the circulating unit, while the chilled water coil is in the off state.

[0006] This four-pipe centralized fresh air handling unit water supply mode has the following disadvantages:

[0007] 1. Since many departments in the hospital are ordinary air-conditioned areas, they do not require low-temperature water such as 7℃ supply and 12℃ return. Generally, 12℃ supply and 17℃ return are sufficient for normal use. However, in order to provide low-temperature chilled water to the clean areas, the outlet water temperature has been uniformly lowered, which has correspondingly reduced the energy efficiency ratio. These ordinary air-conditioned areas may account for as much as 70%.

[0008] 2. The main cold and heat source pipelines need to be switched, which requires manual operation by maintenance personnel to achieve different cold source supply. This also adds a fault point and increases the workload for subsequent maintenance.

[0009] 3. The hot air is treated by a four-pipe centralized fresh air unit, that is, the fresh air is treated from the outdoor temperature of 34.4℃ to 14℃, which requires a lot of cooling capacity. All of it uses high-quality low-temperature water, which is somewhat wasteful of energy. Utility Model Content

[0010] The purpose of this utility model is to provide a six-pipe centralized fresh air unit chilled water supply system that connects to two different chilled water systems, enabling a single chilled water system to be used during the transition season and two different chilled water systems to cooperate during the summer, in order to achieve energy saving and cost reduction.

[0011] To achieve the above objectives, the technical solution of this utility model is: a chilled water supply system for a six-pipe centralized fresh air handling unit, the innovation of which lies in: including an air-cooled water source, a water-cooled water source, and a six-pipe centralized fresh air handling unit, wherein the six-pipe centralized fresh air handling unit includes a hot water coil and a chilled water coil located behind the hot water coil.

[0012] The chilled water coil includes high-temperature chilled water coils and low-temperature chilled water coils arranged side by side, with the high-temperature chilled water coils adjacent to the hot water coils.

[0013] The hot water outlet of the air-cooled water source is connected to the hot water inlet of the heating coil via a hot water supply pipe RG, and its hot water return outlet is connected to the outlet of the heating coil via a hot water return pipe RH.

[0014] The low-temperature cold water outlet of the air-cooled water source is connected to the low-temperature cold water inlet of the low-temperature cold water coil via the low-temperature cold water supply pipe LG, and its low-temperature cold water return outlet is connected to the low-temperature cold water outlet of the low-temperature cold water coil via the low-temperature cold water return pipe LH.

[0015] The high-temperature cold water outlet of the water-cooled water source is connected to the high-temperature cold water inlet of the high-temperature cold water coil via a high-temperature cold water supply pipe GLG, and its high-temperature cold water return outlet is connected to the high-temperature cold water outlet of the high-temperature cold water coil via a high-temperature cold water return pipe GLH.

[0016] In summer, the air-cooled water source and the water-cooled water source operate simultaneously, supplying cold water to the low-temperature chilled water coil and the high-temperature chilled water coil respectively, forming a chilled water supply cycle.

[0017] During the transitional season, the air-cooled water source continues to supply cold water to the low-temperature chilled water coil, forming a cold water supply cycle, while the water-cooled water source is in a shut-off state.

[0018] In the above technical solution, a first switch valve is provided on the low-temperature cold water return pipe LH, a second switch valve is provided on the low-temperature cold water supply pipe LG, a third switch valve is provided on the hot water return pipe RH, a fourth switch valve is provided on the hot water supply pipe RG, a fifth switch valve is provided on the high-temperature cold water supply pipe GLG, and a sixth switch valve is provided on the high-temperature cold water return pipe GLH.

[0019] In the above technical solution, the air-cooled water source is a four-pipe air-cooled scroll chiller heat pump unit or a four-pipe air-cooled screw chiller heat pump unit.

[0020] In the above technical solution, the water-cooled water source is a two-pipe water-cooled screw chiller or a two-pipe water-cooled centrifugal chiller.

[0021] In the above technical solution, the six-pipe centralized fresh air unit also includes an air inlet section, a fan section, a flow equalization section, a medium-efficiency section and a sub-high-efficiency section arranged sequentially in front of the heat coil, as well as a humidification section and a refrigerant coil section arranged sequentially behind the low-temperature chilled water coil.

[0022] In the above technical solution, the air inlet of the air inlet section is provided with a filter screen to prevent foreign objects from entering.

[0023] The positive effects of this utility model are as follows: The chilled water supply system for the six-pipe centralized fresh air handling unit of this utility model includes an air-cooled water source, a water-cooled water source, and a six-pipe centralized fresh air handling unit. The six-pipe centralized fresh air handling unit includes a heat exchange coil and a chilled water coil located behind the heat exchange coil.

[0024] The chilled water coil includes high-temperature chilled water coils and low-temperature chilled water coils arranged side by side, with the high-temperature chilled water coils adjacent to the hot water coils.

[0025] The hot water outlet of the air-cooled water source is connected to the hot water inlet of the heating coil via a hot water supply pipe RG, and its hot water return outlet is connected to the outlet of the heating coil via a hot water return pipe RH.

[0026] The low-temperature cold water outlet of the air-cooled water source is connected to the low-temperature cold water inlet of the low-temperature cold water coil via the low-temperature cold water supply pipe LG, and its low-temperature cold water return outlet is connected to the low-temperature cold water outlet of the low-temperature cold water coil via the low-temperature cold water return pipe LH.

[0027] The high-temperature cold water outlet of the water-cooled water source is connected to the high-temperature cold water inlet of the high-temperature cold water coil via a high-temperature cold water supply pipe GLG, and its high-temperature cold water return outlet is connected to the high-temperature cold water outlet of the high-temperature cold water coil via a high-temperature cold water return pipe GLH.

[0028] In summer, the air-cooled water source and the water-cooled water source operate simultaneously, supplying cold water to the low-temperature chilled water coil and the high-temperature chilled water coil respectively, forming a chilled water supply cycle.

[0029] During the transitional season, the air-cooled water source continues to supply chilled water to the low-temperature chilled water coil, forming a chilled water supply cycle. Meanwhile, the water-cooled water source remains in a powered-off state.

[0030] The six-pipe centralized fresh air handling unit of this utility model is equipped with two sets of chilled water coils: one high-temperature chilled water coil and one low-temperature chilled water coil. The high-temperature chilled water coil is connected to a water-cooled source with high-temperature chilled water, responsible for treating the fresh air from 34.4℃ (outdoor temperature) to 22℃ (adjusted as needed). The low-temperature chilled water coil is connected to an air-cooled source with low-temperature chilled water, responsible for treating the fresh air from 22℃ to 14℃. During the transitional season, the air-cooled source provides the chilled water; in summer, a combination of air-cooled and water-cooled sources provides the chilled water.

[0031] The advantages of this utility model compared to the four-pipe centralized fresh air handling unit and cold / heat source configuration scheme are:

[0032] (1) It can reduce the initial equipment cost, reduce the host capacity of the water-cooled cold source, and the reduction value is equal to the total cooling capacity of the air-cooled water source. For example, if the configured air-cooled water source is 1225kw, then the host capacity of the water-cooled water source is reduced by 1225kw.

[0033] (2) It reduces operating costs significantly. If the outlet water temperature of the water-cooled water source increases by 5°C, the energy efficiency ratio increases by 15%, and electricity consumption is reduced by 15%.

[0034] (3) No water pipeline needs to be switched, which makes operation convenient and reduces the workload of subsequent maintenance. Attached Figure Description

[0035] Figure 1 This is a structural schematic diagram of a specific embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the six-pipe centralized fresh air handling unit of this utility model;

[0037] Figure 3 This is a schematic diagram of the enthalpy-humidity diagram processing process of the six-pipe centralized fresh air handling unit of this utility model. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and the given embodiments, but it is not limited thereto.

[0039] like Figure 1 , 2 As shown in Figure 3, a chilled water supply system for a six-pipe centralized fresh air handling unit includes an air-cooled water source 100, a water-cooled water source 200, and a six-pipe centralized fresh air handling unit. The six-pipe centralized fresh air handling unit includes a heat coil 6 and a chilled water coil located behind the heat coil 6.

[0040] The chilled water coil includes a high-temperature chilled water coil 7 and a low-temperature chilled water coil 8 arranged side by side, with the high-temperature chilled water coil 7 adjacent to the hot water coil 6.

[0041] The hot water outlet of the air-cooled water source 100 is connected to the hot water inlet of the heating coil 6 via a hot water supply pipe RG, and its hot water return outlet is connected to the outlet of the heating coil 6 via a hot water return pipe RH.

[0042] The low-temperature cold water outlet of the air-cooled water source 100 is connected to the low-temperature cold water inlet of the low-temperature cold water coil 8 via the low-temperature cold water supply pipe LG, and its low-temperature cold water return port is connected to the low-temperature cold water outlet of the low-temperature cold water coil 8 via the low-temperature cold water return pipe LH.

[0043] The high-temperature cold water outlet of the water-cooled water source 200 is connected to the high-temperature cold water inlet of the high-temperature cold water coil 7 via a high-temperature cold water supply pipe GLG, and its high-temperature cold water return outlet is connected to the high-temperature cold water outlet of the high-temperature cold water coil 7 via a high-temperature cold water return pipe GLH.

[0044] In summer, the air-cooled water source 100 and the water-cooled water source 200 operate simultaneously, supplying cold water to the low-temperature chilled water coil 8 and the high-temperature chilled water coil 7 respectively, forming a chilled water supply cycle.

[0045] During the transitional season, the air-cooled water source 100 continues to supply cold water to the low-temperature cold water coil 8, forming a cold water supply cycle, while the water-cooled water source 200 is in a shut-off state.

[0046] Furthermore, such as Figure 1 As shown, to facilitate the maintenance of different pipelines, the low-temperature cold water return pipe LH is equipped with a first switch valve 300, the low-temperature cold water supply pipe LG is equipped with a second switch valve 400, the hot water return pipe RH is equipped with a third switch valve 500, the hot water supply pipe RG is equipped with a fourth switch valve 600, the high-temperature cold water supply pipe GLG is equipped with a fifth switch valve 700, and the high-temperature cold water return pipe GLH is equipped with a sixth switch valve 800.

[0047] Furthermore, in order to make the structure of this utility model more reasonable, the air-cooled water source 100 is a four-pipe air-cooled scroll chiller heat pump unit or a four-pipe air-cooled screw chiller heat pump unit.

[0048] Furthermore, the water-cooled water source 200 is a two-pipe water-cooled screw chiller or a two-pipe water-cooled centrifugal chiller.

[0049] The air-cooled water source 100 of this invention is installed on the roof, and the water-cooled water source 200 is installed in the basement.

[0050] It should be noted that the standard operating condition energy efficiency ratio (COP) for water-cooled water sources in basements is generally 4.6. Energy efficiency ratio (COP) = cooling capacity / electrical power, therefore electrical power = cooling capacity / COP value.

[0051] When the outlet temperature of the water-cooled source increases, the evaporation temperature in the refrigeration cycle increases accordingly, the pressure difference between the compressor's suction and discharge decreases, and the energy consumption of the compression process decreases. Therefore, the cooling capacity produced per unit of energy consumption increases, and the energy efficiency ratio improves. For every 1°C increase in the outlet temperature of the water-cooled source, the energy efficiency ratio can increase by approximately 3%.

[0052] Furthermore, such as Figure 2 As shown, in order to further improve the rationality of the structure, the six-pipe centralized fresh air unit also includes an air inlet section 1, a fan section 2, a flow equalization section 3, a medium-efficiency section 4 and a sub-high-efficiency section 5 arranged in sequence in front of the hot coil 6, and a humidification section 9 and a refrigerant coil section 10 arranged in sequence behind the low-temperature chilled water coil 8.

[0053] Furthermore, in order to prevent foreign objects from entering through the air inlet and affecting the normal operation of the fresh air unit, a filter screen is provided at the air inlet of the air inlet section 1 to prevent foreign objects from entering.

[0054] This utility model illustrates the energy-saving and cost-reducing operation of a six-pipe centralized fresh air handling unit:

[0055] If the total cooling capacity requirement of a surgical purification air conditioning system is 2100kW, of which the centralized fresh air unit delivers 75200m³ of fresh air... 3 / h, the total required cooling capacity = air volume * enthalpy difference * air density * outdoor temperature fluctuation coefficient = 75200 * (89.6 - 38.2) * 1.2 * 1.2 = 1546kw, and the cooling capacity of other circulating units is 2100 - 1546 = 554kw. The total cooling capacity of the building is 7000kw.

[0056] If a six-pipe centralized fresh air unit is used, considering the outdoor temperature below 22℃ as a transitional season, the cooling capacity required for the high-temperature chilled water coil to lower the outdoor temperature from 34.4℃ to 22℃ is 75200 * (89.6 - 60.4 * 1.2 * 1.2) = 875 kW. The cooling capacity required for the low-temperature chilled water coil to lower the temperature from 22℃ to 14℃ is 1546 - 875 = 671 kW. The cooling capacity of the air-cooled water source is 2100 kW - 875 kW = 1225 kW. The water-cooled water source configuration capacity in the basement only needs to be 7000 kW - 1225 kW = 5775 kW, saving 1225 kW of water-cooled chiller capacity. Calculated at 0.6 yuan per watt, the initial investment saved in equipment costs is 1225 * 1000 * 0.6 = 735,000 yuan = 735,000 yuan.

[0057] The water-cooled source has a cooling capacity of 5775 kW. At an outlet water temperature of 7℃, the hourly power consumption is 5775 / 4.6 = 1255.4 kW. When the outlet water temperature is increased to 12℃, the hourly power saving is 1255.4 * 15% = 188.31 kW. Operating the water-cooled source 24 hours a day during the hot summer months, assuming a three-month hot summer each year, the annual power saving is 188.31 * 24 * 30 * 3 = 406749.6 kW. Based on an electricity price of 1 yuan per kW, this translates to annual operating cost savings of over 400,000 yuan.

[0058] In summary, this utility model effectively reduces initial investment and operating costs.

[0059] Furthermore, the energy consumption comparison between this utility model and a four-pipe centralized fresh air handling unit is as follows:

[0060] (1) A four-pipe centralized fresh air handling unit is adopted:

[0061] If the air-cooled water source chiller has a cooling capacity of 1225kW, it provides chilled water during the transitional season and not during the summer, providing 7℃ supply water and 12℃ return water.

[0062] If the water-cooled water source unit has a cooling capacity of 7000kW, it provides chilled water in summer and provides 7℃ supply water and 12℃ return water when the unit is shut down during the transition season.

[0063] (2) Six-pipe centralized fresh air handling unit is adopted:

[0064] If the air-cooled water source chiller has a cooling capacity of 1225kW, and provides chilled water in summer and transitional seasons, it provides 7℃ supply water and 12℃ return water.

[0065] If the cooling capacity of the water-cooled power unit is 5775kW, it provides chilled water in summer and provides 12℃ supply water and 17℃ return water when the unit is shut down during the transition season.

[0066] Therefore, it can be seen that by adopting a six-pipe centralized fresh air unit, not only can the cooling capacity of the water-cooled main unit be reduced, but the temperature of the high-temperature cooling water can also be provided to achieve the purpose of energy saving and cost reduction.

[0067] In summary, the six-pipe centralized fresh air handling unit of this utility model is equipped with two sets of chilled water coils: one high-temperature chilled water coil and one low-temperature chilled water coil. The high-temperature chilled water coil is connected to a water-cooled source with high-temperature chilled water, responsible for treating the fresh air from 34.4℃ (outdoor temperature) to 22℃ (adjusted as needed). The low-temperature chilled water coil is connected to an air-cooled source with low-temperature chilled water, responsible for treating the fresh air from 22℃ to 14℃, and then the refrigerant coil treats the fresh air from 14℃ to 10℃. During the transitional season, the air-cooled source provides the chilled water; in summer, a combination of air-cooled and water-cooled sources provides the chilled water.

[0068] Furthermore, such as Figure 3As shown in the enthalpy-humidity diagram, the goal of the chilled water is to treat the fresh air from the outdoor temperature to 14°C, after which it is treated by the refrigerant coil. Generally, the water-cooled water supply to the basement is shut off when the outdoor temperature is below 22°C. Therefore, the cooling capacity for the outdoor temperature to 22°C is provided by the water-cooled water source with a supply and return water temperature of 12-17°C, while the cooling capacity for the temperature from 22°C to 14°C is provided by the air-cooled water source with a supply and return water temperature of 7-12°C. The main energy-saving operation range of this invention is within the outdoor temperature range of 22°C. The 12-17°C high-temperature chilled water used in this range has high production efficiency and can effectively treat the fresh air to 22°C.

[0069] The advantages of this utility model compared to the four-pipe centralized fresh air handling unit and cold / heat source configuration scheme are:

[0070] (1) It can reduce the initial equipment cost, reduce the host capacity of the water-cooled cold source, and the reduction value is equal to the total cooling capacity of the air-cooled water source. For example, if the configured air-cooled water source is 1225kw, then the host capacity of the water-cooled water source is reduced by 1225kw.

[0071] (2) It reduces operating costs significantly. If the outlet water temperature of the water-cooled water source increases by 5°C, the energy efficiency ratio increases by 15%, and electricity consumption is reduced by 15%.

[0072] (3) No water pipeline needs to be switched, which makes operation convenient and reduces the workload of subsequent maintenance.

[0073] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A chilled water supply system for a six-pipe centralized fresh air handling unit, characterized in that: It includes an air-cooled water source (100), a water-cooled water source (200), and a six-pipe centralized fresh air handling unit. The six-pipe centralized fresh air handling unit includes a heat coil (6) and a chilled water coil located behind the heat coil (6). The chilled water coil includes a high-temperature chilled water coil (7) and a low-temperature chilled water coil (8) arranged side by side, and the high-temperature chilled water coil (7) is adjacent to the hot water coil (6). The hot water outlet of the air-cooled water source (100) is connected to the hot water inlet of the heat coil (6) through the hot water supply pipe RG, and its hot water return outlet is connected to the outlet of the heat coil (6) through the hot water return pipe RH. The low-temperature cold water outlet of the air-cooled water source (100) is connected to the low-temperature cold water inlet of the low-temperature cold water coil (8) through the low-temperature cold water supply pipe LG, and its low-temperature cold water return outlet is connected to the low-temperature cold water outlet of the low-temperature cold water coil (8) through the low-temperature cold water return pipe LH. The high-temperature cold water outlet of the water-cooled water source (200) is connected to the high-temperature cold water inlet of the high-temperature cold water coil (7) through the high-temperature cold water supply pipe GLG, and its high-temperature cold water return outlet is connected to the high-temperature cold water outlet of the high-temperature cold water coil (7) through the high-temperature cold water return pipe GLH. In summer, the air-cooled water source (100) and the water-cooled water source (200) operate simultaneously, supplying cold water to the low-temperature cold water coil (8) and the high-temperature cold water coil (7) respectively, forming a cold water supply cycle. During the transitional season, the air-cooled water source (100) continues to supply cold water to the low-temperature cold water coil (8) and forms a cold water supply cycle. Meanwhile, the water-cooled water source (200) is in a shutdown state.

2. The chilled water supply system for a six-pipe centralized fresh air handling unit according to claim 1, characterized in that: The low-temperature cold water return pipe LH is equipped with a first switch valve (300), the low-temperature cold water supply pipe LG is equipped with a second switch valve (400), the hot water return pipe RH is equipped with a third switch valve (500), the hot water supply pipe RG is equipped with a fourth switch valve (600), the high-temperature cold water supply pipe GLG is equipped with a fifth switch valve (700), and the high-temperature cold water return pipe GLH is equipped with a sixth switch valve (800).

3. The chilled water supply system for a six-pipe centralized fresh air handling unit according to claim 1, characterized in that: The air-cooled water source (100) is a four-pipe air-cooled scroll chiller heat pump unit or a four-pipe air-cooled screw chiller heat pump unit.

4. The chilled water supply system for a six-pipe centralized fresh air handling unit according to claim 1, characterized in that: The water-cooled water source (200) is a two-pipe water-cooled screw chiller or a two-pipe water-cooled centrifugal chiller.

5. The chilled water supply system for a six-pipe centralized fresh air handling unit according to claim 1, characterized in that: The six-pipe centralized fresh air unit also includes an air inlet section (1), a fan section (2), a flow equalization section (3), a medium-efficiency section (4) and a sub-high-efficiency section (5) arranged in sequence in front of the hot coil (6), and a humidification section (9) and a refrigerant coil section (10) arranged in sequence behind the low-temperature chilled water coil (8).

6. The chilled water supply system for a six-pipe centralized fresh air handling unit according to claim 5, characterized in that: The air inlet of the air inlet section (1) is equipped with a filter screen to prevent foreign objects from entering.

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