Sunil Healthcare Limited, Alwar, Rajasthan

General Information on the company using solar thermal energy

Description of the company

Sunil Healthcare started its operations over three decades ago. It is the second largest manufacturer of Empty Hard Gelatin Capsule (EHGC) in India and enjoys immense credibility in various global markets. Sunloc, a leading brand of Empty Hard Gelatine Capsules, is from Sunil Healthcare Ltd.

Type of Industry

Chemical - Pharmaceutical

Location of the company and the solar plant

The SWHS Plant is installed on the roof tops of the buildings at their plant address below:

M/s. Sunil Healthcare Limited,
Works:17/18,Old Industrial Area
Alwar, Rajasthan -301 001

Contact person: C.Kumar Singh
DGM - Engineering
Contact: +91 9549898630

Heat demanding processes

5000 litres at 75°C and 1500 litres at 60°C.

5000 litres is used for gelatine melting process in three batches of 1300 litre each per day. The remaining 1500 litres is circulated throughout the entire plant at 60°C continuously for various processes.

The plant operates for 24 hours and 7 days a week.

Conventional heat supply

Electrical heater in auxiliary tank and additional tank to help maintain the required temperature. There is also a conventional HSD boiler, but it is rarely used and is kept only when there is no solar output for couple of days in succession.

Conventional fuel used

Electricity from utility grid. At times HSD in boiler.

Motivation to use solar thermal energy

The company aims at reducing carbon dioxide emissions and other greenhouse gases emissions by investing more in renewable energy and energy efficiency measures.

Among others, corporate social responsibility and rising diesel prices were major influencing factors for the company to install solar thermal system for their hot water demand.

Description of the solar thermal system

Type of solar plant

Non-pressurised closed loop FPC having solar tank of 6500 litres capacity. The hot water at 75°C is used for melting gelatin used in manufacturing capsules, while the hot water at 60°C is used for cleaning purposes. The former is supply side integration through additional storage and latter is process side integration through auxiliary storage tank.

Year of installation

The SWHS was commissioned in the year 2012.

Solar collector field

70 FPC collectors are installed on the roof top of the plant building. The aperture collector area is 147 m2. This is equivalent to 103kW capacity.

Water storage

There is one solar system storage tank of 6500 litres. In addition there are two storage tank of 6500 litres and 2000 litres which are connected on the process and supply side respectively.

Hydraulics & Operation of the system

Type

Non-pressurised solar heating system for heating water for gel making process and washing purposes in a chemical company.

Operation

Collector circuit

At the beginning of the operation, cold RO water is pumped into the empty solar hot water tank on the roof of the building every day in the morning. A water level controller placed inside the storage, signals the pump to stop when the tank is filled up. A photo sensor placed near the collector circuit sends a signal to the collector pump when it receives the sun’s irradiation and pump switches on. A temperature sensor placed in the pipes between the collectors measures the temperature of the water and compares it with the temperature of the water at the bottom of the solar hot water tank. When the difference between the temperature in the storage tank and the collectors is greater than 3°C, the pumps on the heat exchanger circuit will be switched on and the water in solar hot water tank will start to heat up. Air vents are installed to the piping near the collectors to let the air out in case of steam build up on days with high solar radiation. A make-up tank is also connected to the collector circuit that will provide water for the collectors in case the mass flow is reduced due to evaporation caused also by stagnation.

Process circuit

On a sunny day, temperatures in the solar hot water tank can reach up to 80°C within the first few hours of the day. When this temperature is reached, the water level in the auxiliary tank is checked. If the water level is below half its capacity (3000 l) then, the water from the hot water tank is drawn to the auxiliary and stored for further use during the day. If all the water from the solar storage could not be drawn to the auxiliary storage then it is taken to the additional 2000 litre tank which provides water to the rest of the processes in the manufacturing unit continuously for 24 hours. The storage tanks are unpressurized and the water from the solar hot water tank is drawn into the auxiliary tank just by gravitational force, and a valve controls the supply of hot water from the solar hot water tank into the auxiliary tank.

There are six heating rods attached at the bottom of the auxiliary tank. A temperature sensor connected to the control panel will sense the temperature at the bottom of the tank and control the switching on/off of the heaters in case the water did not reach 75°C in the auxiliary tank or drops below 60°C in the additional storage tank.

There is a control panel that monitors and controls the collector circuit and a control panel that monitors and controls the pump that is used for filling up the solar hot water tank in the morning with cold water. The solar hot water tanks, piping from the collectors to the solar hot water tank and downward to the auxiliary tank are all insulated with glass wool insulation.

Supplier/ manufacturer of the solar system

Inter Solar Systems (P) Ltd
901 A, Industrial Area, Phase II
Chandigarh-160002.

Data recorded

There is no data logged.

Energy balance

Heat demand

For Gelatine mixing purpose:

The plant hot water demand is 5000 LPD. The hot water is used for cleaning purpose.

It is assumed, that the factory requires 5000 litre per day of 75°C hot water and the cold water temperature is about 22°C.

Then the energy demand per day for hot water heating is: Qdaily = 5 m3/day * (75°C – 22°C) * 1.16 kWh/(m3*K) = 307 kWh/day

The energy demand per year is: Qannually = 365 days * 307 kWh/day = 112,200 kWh/year

For Cleaning purpose:

The plant hot water demand is 2000 LPD. The hot water is used for cleaning purpose. The plant heat requirement is about 100 kWh/day.

It is assumed, that the factory requires 1500 litre per day of 60°C hot water and the cold water temperature is about 22°C.

Then the energy demand per day for hot water heating is: Qdaily = 2 m3/day * (60°C – 22°C) * 1.16 kWh/(m3*K) = 66 kWh/day

The energy demand per year is: Qannually = 365 days * 66 kWh/day = 24,000 kWh/year

Total heat demand is around 373 kWh/day.

(The temperature difference in °C is measured in K (=Kelvin), it is assumed, that the factory is operating 350 days a year)

Solar radiation-on site

The site receives an average annual solar irradiation of 4.91 kWh/(m2*day), this means 1792 kWh/(m2*year) on horizontal surface. On collectors with an inclination of 30° the irradiation is 1.13 * 1792 kWh/(m2*year) = 2025 kWh/(m2*year).

(Longitude: 76.5 & latitude:27.5)

Source: NASA Surface meteorology and Meteonorm

Useful solar energy delivery

The solar radiation on the collector surface is 147 m2 * 2025 kWh/(m2*year) = 297,694 kWh/year.

If a system efficiency of about 20% is assumed, the useful solar energy is about 297,294 kWh/year * 0.2 = 59460 kWh/year.

Useful solar energy per unit sq. meter of the collector area is 1.1 kWh.

Fuel saved by solar energy

Diesel saved by the SWHS System is about 20 litre per day and 7146 litres/year.

(Assumptions: The energy content of diesel is 10.7kWh/litre; plant working for 365 days a year; Boiler efficiency of 80%).

Emissions saved

If diesel replacement is considered then the CO2 emissions saved is around 18.5 tCO2/year.

If electricity replacement is considered then the CO2 emissions saved is around 63 tCO2/year.

Economy

Investment costs

Cost per m2 = INR 18,409

Subsidies

MNRE subsidy of INR 462,000. This is based on subsidy of INR 6600 per collector (100 LPD) for 70 collectors.

Economics of the solar system

Based on the diesel price of INR 52 per litre in 2015, INR 3.7 Lakh is saved per year. Payback period without considering interest on debt is around 6 years.

For the case, electricity is substituted at the cost of INR 6/kWh, INR 6.7 Lakh is saved per year. Payback period without considering interest on debt is around 5 years.